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Wiesner E, Binz-Lotter J, Hackl A, Unnersjö-Jess D, Rutkowski N, Benzing T, Hackl MJ. Correlative multiphoton-STED microscopy of podocyte calcium levels and slit diaphragm ultrastructure in the renal glomerulus. Sci Rep 2024; 14:13019. [PMID: 38844492 PMCID: PMC11156906 DOI: 10.1038/s41598-024-63507-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/29/2024] [Indexed: 06/09/2024] Open
Abstract
In recent years functional multiphoton (MP) imaging of vital mouse tissues and stimulation emission depletion (STED) imaging of optically cleared tissues allowed new insights into kidney biology. Here, we present a novel workflow where MP imaging of calcium signals can be combined with super-resolved STED imaging for morphological analysis of the slit diaphragm (SD) within the same glomerulus. Mice expressing the calcium indicator GCaMP3 in podocytes served as healthy controls or were challenged with two different doses of nephrotoxic serum (NTS). NTS induced glomerular damage in a dose dependent manner measured by shortening of SD length. In acute kidney slices (AKS) intracellular calcium levels increased upon disease but showed a high variation between glomeruli. We could not find a clear correlation between intracellular calcium levels and SD length in the same glomerulus. Remarkably, analysis of the SD morphology of glomeruli selected during MP calcium imaging revealed a higher percentage of completely disrupted SD architecture than estimated by STED imaging alone. Our novel co-imaging protocol is applicable to a broad range of research questions. It can be used with different tissues and is compatible with diverse reporters and target proteins.
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Affiliation(s)
- Eva Wiesner
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Julia Binz-Lotter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Agnes Hackl
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Department of Pediatrics, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - David Unnersjö-Jess
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Nelli Rutkowski
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Matthias J Hackl
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
- Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
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Haydak J, Azeloglu EU. Role of biophysics and mechanobiology in podocyte physiology. Nat Rev Nephrol 2024; 20:371-385. [PMID: 38443711 DOI: 10.1038/s41581-024-00815-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 03/07/2024]
Abstract
Podocytes form the backbone of the glomerular filtration barrier and are exposed to various mechanical forces throughout the lifetime of an individual. The highly dynamic biomechanical environment of the glomerular capillaries greatly influences the cell biology of podocytes and their pathophysiology. Throughout the past two decades, a holistic picture of podocyte cell biology has emerged, highlighting mechanobiological signalling pathways, cytoskeletal dynamics and cellular adhesion as key determinants of biomechanical resilience in podocytes. This biomechanical resilience is essential for the physiological function of podocytes, including the formation and maintenance of the glomerular filtration barrier. Podocytes integrate diverse biomechanical stimuli from their environment and adapt their biophysical properties accordingly. However, perturbations in biomechanical cues or the underlying podocyte mechanobiology can lead to glomerular dysfunction with severe clinical consequences, including proteinuria and glomerulosclerosis. As our mechanistic understanding of podocyte mechanobiology and its role in the pathogenesis of glomerular disease increases, new targets for podocyte-specific therapeutics will emerge. Treating glomerular diseases by targeting podocyte mechanobiology might improve therapeutic precision and efficacy, with potential to reduce the burden of chronic kidney disease on individuals and health-care systems alike.
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Affiliation(s)
- Jonathan Haydak
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Evren U Azeloglu
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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3
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Wang D, Ferrell N. Transglutaminase-mediated stiffening of the glomerular basement membrane mitigates pressure-induced reductions in molecular sieving coefficient by reducing compression. Matrix Biol 2024; 130:47-55. [PMID: 38723871 DOI: 10.1016/j.matbio.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/30/2024] [Accepted: 05/06/2024] [Indexed: 06/03/2024]
Abstract
Proteinuria, the presence of high molecular weight proteins in the urine, is a primary indicator of chronic kidney disease. Proteinuria results from increased molecular permeability of the glomerular filtration barrier combined with saturation or defects in tubular protein reabsorption. Any solute that passes into the glomerular filtrate traverses the glomerular endothelium, the glomerular basement membrane, and the podocyte slit diaphragm. Damage to any layer of the filter has reciprocal effects on other layers to increase glomerular permeability. The GBM is thought to act as a compressible ultrafilter that has increased molecular selectivity with increased pressure due to compression that reduced the porosity of the GBM with increased pressure. In multiple forms of chronic kidney disease, crosslinking enzymes are upregulated and may act to increase GBM stiffness. Here we show that enzymatically crosslinking porcine GBM with transglutaminase increases the stiffness of the GBM and mitigates pressure-dependent reductions in molecular sieving coefficient. This was modeled mathematically using a modified membrane transport model accounting for GBM compression. Changes in the mechanical properties of the GBM may contribute to proteinuria through pressure-dependent effects on GBM porosity.
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Affiliation(s)
- Dan Wang
- Department of Internal Medicine, Division of Nephrology, The Ohio State University Wexner Medical Center, 1664 Neil Ave. 4th Floor, Suite 4100, Columbus, OH 43201, United States
| | - Nicholas Ferrell
- Department of Internal Medicine, Division of Nephrology, The Ohio State University Wexner Medical Center, 1664 Neil Ave. 4th Floor, Suite 4100, Columbus, OH 43201, United States.
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4
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Finn LS. Nephrotic Syndrome Throughout Childhood: Diagnosing Podocytopathies From the Womb to the Dorm. Pediatr Dev Pathol 2024:10935266241242669. [PMID: 38745407 DOI: 10.1177/10935266241242669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The etiologies of podocyte dysfunction that lead to pediatric nephrotic syndrome (NS) are vast and vary with age at presentation. The discovery of numerous novel genetic podocytopathies and the evolution of diagnostic technologies has transformed the investigation of steroid-resistant NS while simultaneously promoting the replacement of traditional morphology-based disease classifications with a mechanistic approach. Podocytopathies associated with primary and secondary steroid-resistant NS manifest as diffuse mesangial sclerosis, minimal change disease, focal segmental glomerulosclerosis, and collapsing glomerulopathy. Molecular testing, once an ancillary option, has become a vital component of the clinical investigation and when paired with kidney biopsy findings, provides data that can optimize treatment and prognosis. This review focuses on the causes including selected monogenic defects, clinical phenotypes, histopathologic findings, and age-appropriate differential diagnoses of nephrotic syndrome in the pediatric population with an emphasis on podocytopathies.
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Affiliation(s)
- Laura S Finn
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at The University of Pennsylvania, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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5
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Gajewska A, Wasiak J, Sapeda N, Młynarska E, Rysz J, Franczyk B. SGLT2 Inhibitors in Kidney Diseases-A Narrative Review. Int J Mol Sci 2024; 25:4959. [PMID: 38732178 PMCID: PMC11084583 DOI: 10.3390/ijms25094959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/27/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
Some of the most common conditions affecting people are kidney diseases. Among them, we distinguish chronic kidney disease and acute kidney injury. Both entities pose serious health risks, so new drugs are still being sought to treat and prevent them. In recent years, such a role has begun to be assigned to sodium-glucose cotransporter-2 (SGLT2) inhibitors. They increase the amount of glucose excreted in the urine. For this reason, they are currently used as a first-line drug in type 2 diabetes mellitus. Due to their demonstrated cardioprotective effect, they are also used in heart failure treatment. As for the renal effects of SGLT2 inhibitors, they reduce intraglomerular pressure and decrease albuminuria. This results in a slower decline in glomelular filtration rate (GFR) in patients with kidney disease. In addition, these drugs have anti-inflammatory and antifibrotic effects. In the following article, we review the evidence for the effectiveness of this group of drugs in kidney disease and their nephroprotective effect. Further research is still needed, but meta-analyses indicate SGLT2 inhibitors' efficacy in kidney disease, especially the one caused by diabetes. Development of new drugs and clinical trials on specific patient subgroups will further refine their nephroprotective effects.
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Affiliation(s)
- Agata Gajewska
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland; (A.G.); (J.W.); (N.S.)
| | - Jakub Wasiak
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland; (A.G.); (J.W.); (N.S.)
| | - Natalia Sapeda
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland; (A.G.); (J.W.); (N.S.)
| | - Ewelina Młynarska
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland; (A.G.); (J.W.); (N.S.)
| | - Jacek Rysz
- Department of Nephrology, Hypertension and Family Medicine, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland
| | - Beata Franczyk
- Department of Nephrocardiology, Medical University of Lodz, ul. Zeromskiego 113, 90-549 Lodz, Poland; (A.G.); (J.W.); (N.S.)
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6
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Clair G, Soloyan H, Cravedi P, Angeletti A, Salem F, Al-Rabadi L, De Filippo RE, Da Sacco S, Lemley KV, Sedrakyan S, Perin L. The spatially resolved transcriptome signatures of glomeruli in chronic kidney disease. JCI Insight 2024; 9:e165515. [PMID: 38516889 PMCID: PMC11063942 DOI: 10.1172/jci.insight.165515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 02/14/2024] [Indexed: 03/23/2024] Open
Abstract
Here, we used digital spatial profiling (DSP) to describe the glomerular transcriptomic signatures that may characterize the complex molecular mechanisms underlying progressive kidney disease in Alport syndrome, focal segmental glomerulosclerosis, and membranous nephropathy. Our results revealed significant transcriptional heterogeneity among diseased glomeruli, and this analysis showed that histologically similar glomeruli manifested different transcriptional profiles. Using glomerular pathology scores to establish an axis of progression, we identified molecular pathways with progressively decreased expression in response to increasing pathology scores, including signal recognition particle-dependent cotranslational protein targeting to membrane and selenocysteine synthesis pathways. We also identified a distinct signature of upregulated and downregulated genes common to all the diseases investigated when compared with nondiseased tissue from nephrectomies. These analyses using DSP at the single-glomerulus level could help to increase insight into the pathophysiology of kidney disease and possibly the identification of biomarkers of disease progression in glomerulopathies.
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Affiliation(s)
- Geremy Clair
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Hasmik Soloyan
- The GOFARR Laboratory, The Saban Research Institute, Division of Urology, Children’s Hospital Los Angeles, Los Angeles, California, USA
| | - Paolo Cravedi
- Department of Medicine, Translational Transplant Research Center, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Andrea Angeletti
- Nephrology Dialysis and Renal Transplantation, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Fadi Salem
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Jacksonville, Florida, USA
| | - Laith Al-Rabadi
- Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah Health, Salt Lake City, Utah, USA
| | - Roger E. De Filippo
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
- Department of Urology, Keck School of Medicine, and
| | - Stefano Da Sacco
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
- Department of Urology, Keck School of Medicine, and
| | - Kevin V. Lemley
- Division of Nephrology, Department of Pediatrics, University of Southern California, Los Angeles, California, USA
| | - Sargis Sedrakyan
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
- Department of Urology, Keck School of Medicine, and
| | - Laura Perin
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
- Department of Urology, Keck School of Medicine, and
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7
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Boruah D, Kashif AW, Chakrabarty BK, Harikrishnan S, Sen A. Correlation of light and electron microscopic morphometric parameters of glomerular capillaries with serum creatinine and proteinuria. J Histotechnol 2024:1-12. [PMID: 38465441 DOI: 10.1080/01478885.2024.2326274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 02/27/2024] [Indexed: 03/12/2024]
Abstract
Waste products in the bloodstream are filtered by the glomerular capillaries in the kidneys and excreted into the urine. When making a differential diagnosis of kidney diseases, structural assessment of glomeruli using histological, ultrastructural, and immunological studies is crucial. This study assessed the microscopic and ultrastructural morphometric parameters of glomerular capillaries and examined their correlation with serum creatinine and proteinuria. A total of 60 kidney biopsy cases received by the transmission electron microscope (TEM) laboratory for diagnosis were included in the study. Toluidine blue stained 300 nm thick sections of TEM tissue blocks were scanned for glomerular morphometry by a whole slide imaging system, and the estimation of Bowman's capsule (BC) area, glomerular capillary lumen diameter (GCLD), glomerular capillary density (GCD), glomerular capillary surface area density (GCSA), and percentage of glomerular capillary lumen space (%GCLS) was performed with QuPath software. TEM images of 70 nm thick sections were used for the evaluation of endothelial fenestration diameter (EFD), glomerular basement membrane (GBM) thickness, and podocyte foot process (PFP) effacement. Proteinuria and serum creatinine showed positive correlations with GBM thickness and PFP effacement. Negative correlations of serum creatinine were observed with EFD, %GCLS, and GCSA. Hence, glomerular filtration is greatly affected by the total area of the glomerular capillary surface and structural changes of GBM. Reduction of glomerulus filtration due to foot process effacement and thickening of GBM results in damage to the filtration barrier leading to the leakage of plasma protein into urine.
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Affiliation(s)
| | - A W Kashif
- Department of Pathology, Armed Forces Medical College, Pune, India
| | | | | | - Arijit Sen
- Department of Pathology, Armed Forces Medical College, Pune, India
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8
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Waller AP, Wolfgang KJ, Pruner I, Stevenson ZS, Abdelghani E, Muralidharan K, Wilkie TK, Blissett AR, Calomeni EP, Vetter TA, Brodsky SV, Smoyer WE, Nieman MT, Kerlin BA. Prothrombin Knockdown Protects Podocytes and Reduces Proteinuria in Glomerular Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.20.544360. [PMID: 38464017 PMCID: PMC10925217 DOI: 10.1101/2023.06.20.544360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Chronic kidney disease (CKD) is a leading cause of death, and its progression is driven by glomerular podocyte injury and loss, manifesting as proteinuria. Proteinuria includes urinary loss of coagulation zymogens, cofactors, and inhibitors. Importantly, both CKD and proteinuria significantly increase the risk of thromboembolic disease. Prior studies demonstrated that anticoagulants reduced proteinuria in rats and that thrombin injured cultured podocytes. Herein we aimed to directly determine the influence of circulating prothrombin on glomerular pathobiology. We hypothesized that (pro)thrombin drives podocytopathy, podocytopenia, and proteinuria. Glomerular proteinuria was induced with puromycin aminonucleoside (PAN) in Wistar rats. Circulating prothrombin was either knocked down using a rat-specific antisense oligonucleotide or elevated by serial intravenous infusions of prothrombin protein, which are previously established methods to model hypo- (LoPT) and hyper-prothrombinemia (HiPT), respectively. After 10 days (peak proteinuria in this model) plasma prothrombin levels were determined, kidneys were examined for (pro)thrombin co-localization to podocytes, histology, and electron microscopy. Podocytopathy and podocytopenia were determined and proteinuria, and plasma albumin were measured. LoPT significantly reduced prothrombin colocalization to podocytes, podocytopathy, and proteinuria with improved plasma albumin. In contrast, HiPT significantly increased podocytopathy and proteinuria. Podocytopenia was significantly reduced in LoPT vs. HiPT rats. In summary, prothrombin knockdown ameliorated PAN-induced glomerular disease whereas hyper-prothrombinemia exacerbated disease. Thus, (pro)thrombin antagonism may be a viable strategy to simultaneously provide thromboprophylaxis and prevent podocytopathy-mediated CKD progression.
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Sachs W, Blume L, Loreth D, Schebsdat L, Hatje F, Koehler S, Wedekind U, Sachs M, Zieliniski S, Brand J, Conze C, Florea BI, Heppner F, Krüger E, Rinschen MM, Kretz O, Thünauer R, Meyer-Schwesinger C. The proteasome modulates endocytosis specifically in glomerular cells to promote kidney filtration. Nat Commun 2024; 15:1897. [PMID: 38429282 PMCID: PMC10907641 DOI: 10.1038/s41467-024-46273-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 02/16/2024] [Indexed: 03/03/2024] Open
Abstract
Kidney filtration is ensured by the interaction of podocytes, endothelial and mesangial cells. Immunoglobulin accumulation at the filtration barrier is pathognomonic for glomerular injury. The mechanisms that regulate filter permeability are unknown. Here, we identify a pivotal role for the proteasome in a specific cell type. Combining genetic and inhibitor-based human, pig, mouse, and Drosophila models we demonstrate that the proteasome maintains filtration barrier integrity, with podocytes requiring the constitutive and glomerular endothelial cells the immunoproteasomal activity. Endothelial immunoproteasome deficiency as well as proteasome inhibition disrupt the filtration barrier in mice, resulting in pathologic immunoglobulin deposition. Mechanistically, we observe reduced endocytic activity, which leads to altered membrane recycling and endocytic receptor turnover. This work expands the concept of the (immuno)proteasome as a control protease orchestrating protein degradation and antigen presentation and endocytosis, providing new therapeutic targets to treat disease-associated glomerular protein accumulations.
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Affiliation(s)
- Wiebke Sachs
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Lukas Blume
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Desiree Loreth
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Lisa Schebsdat
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Favian Hatje
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Sybille Koehler
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Uta Wedekind
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Marlies Sachs
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Stephanie Zieliniski
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | - Johannes Brand
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center of Kidney Health, Hamburg, Germany
| | | | - Bogdan I Florea
- Bio-Organic Synthesis Group, Leiden University, Leiden, The Netherlands
| | - Frank Heppner
- Institute of Neuropathology, Charité, Berlin, Germany
| | - Elke Krüger
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, Greifswald, Germany
| | - Markus M Rinschen
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kretz
- Hamburg Center of Kidney Health, Hamburg, Germany
- Nephrology, III Medical Clinic, Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Roland Thünauer
- Leibniz Institute of Virology, Hamburg, Germany
- Technology Platform Light Microscopy (TPLM), University Hamburg, Hamburg, Germany
- Advanced Light and Fluorescence Microscopy (ALFM) Facility at the Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Hamburg Center of Kidney Health, Hamburg, Germany.
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10
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Nell D, Wolf R, Podgorny PM, Kuschnereit T, Kuschnereit R, Dabers T, Stracke S, Schmidt T. Complement Activation in Nephrotic Glomerular Diseases. Biomedicines 2024; 12:455. [PMID: 38398059 PMCID: PMC10886869 DOI: 10.3390/biomedicines12020455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/23/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
The nephrotic syndrome holds significant clinical importance and is characterized by a substantial protein loss in the urine. Damage to the glomerular basement membrane or podocytes frequently underlies renal protein loss. There is an increasing belief in the involvement of the complement system, a part of the innate immune system, in these conditions. Understanding the interactions between the complement system and glomerular structures continually evolves, challenging the traditional view of the blood-urine barrier as a passive filter. Clinical studies suggest that a precise inhibition of the complement system at various points may soon become feasible. However, a thorough understanding of current knowledge is imperative for planning future therapies in nephrotic glomerular diseases such as membranous glomerulopathy, membranoproliferative glomerulonephritis, lupus nephritis, focal segmental glomerulosclerosis, and minimal change disease. This review provides an overview of the complement system, its interactions with glomerular structures, and insights into specific glomerular diseases exhibiting a nephrotic course. Additionally, we explore new diagnostic tools and future therapeutic approaches.
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11
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Chang TH, Chen YD, Lu HHS, Wu JL, Mak K, Yu CS. Specific patterns and potential risk factors to predict 3-year risk of death among non-cancer patients with advanced chronic kidney disease by machine learning. Medicine (Baltimore) 2024; 103:e37112. [PMID: 38363886 PMCID: PMC10869094 DOI: 10.1097/md.0000000000037112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 01/09/2024] [Indexed: 02/18/2024] Open
Abstract
Chronic kidney disease (CKD) is a major public health concern. But there are limited machine learning studies on non-cancer patients with advanced CKD, and the results of machine learning studies on cancer patients with CKD may not apply directly on non-cancer patients. We aimed to conduct a comprehensive investigation of risk factors for a 3-year risk of death among non-cancer advanced CKD patients with an estimated glomerular filtration rate < 60.0 mL/min/1.73m2 by several machine learning algorithms. In this retrospective cohort study, we collected data from in-hospital and emergency care patients from 2 hospitals in Taiwan from 2009 to 2019, including their international classification of disease at admission and laboratory data from the hospital's electronic medical records (EMRs). Several machine learning algorithms were used to analyze the potential impact and degree of influence of each factor on mortality and survival. Data from 2 hospitals in northern Taiwan were collected with 6565 enrolled patients. After data cleaning, 26 risk factors and approximately 3887 advanced CKD patients from Shuang Ho Hospital were used as the training set. The validation set contained 2299 patients from Taipei Medical University Hospital. Predictive variables, such as albumin, PT-INR, and age, were the top 3 significant risk factors with paramount influence on mortality prediction. In the receiver operating characteristic curve, the random forest had the highest values for accuracy above 0.80. MLP, and Adaboost had better performance on sensitivity and F1-score compared to other methods. Additionally, SVM with linear kernel function had the highest specificity of 0.9983, while its sensitivity and F1-score were poor. Logistic regression had the best performance, with an area under the curve of 0.8527. Evaluating Taiwanese advanced CKD patients' EMRs could provide physicians with a good approximation of the patients' 3-year risk of death by machine learning algorithms.
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Affiliation(s)
- Tzu-Hao Chang
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Clinical Big Data Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Yu-Da Chen
- Department of Family Medicine, Taipei Medical University Hospital, Taipei, Taiwan
- School of Health Care Administration, College of Management, Taipei Medical University, Taipei, Taiwan
- Department of Family Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Henry Horng-Shing Lu
- Institute of Statistics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
- Institute of Data Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Jenny L. Wu
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | | | - Cheng-Sheng Yu
- Graduate Institute of Data Science, College of Management, Taipei Medical University, Taipei, Taiwan
- Clinical Data Center, Office of Data Science, Taipei Medical University, Taipei, Taiwan
- Fintech RD Center, Nan Shan Life Insurance Co., Ltd
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12
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Seegmiller JC, Bachmann LM. Urine Albumin Measurements in Clinical Diagnostics. Clin Chem 2024; 70:382-391. [PMID: 38321881 DOI: 10.1093/clinchem/hvad174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/11/2023] [Indexed: 02/08/2024]
Abstract
BACKGROUND Measurement of urine albumin is critical for diagnosis, risk classification, and monitoring of chronic kidney disease (CKD). Guidelines recommend clinical decision cutoffs for the urine albumin-to-creatinine ratio (ACR) of 30 and 300 mg/g (3 and 30 mg/mmol). However, differences among manufacturers' routine urine albumin measurement procedures have been found to exceed 40%, suggesting CKD diagnosis and risk classification may vary depending upon the specific measurement procedure implemented in the laboratory. CONTENT This review discusses urine albumin pathophysiology and clinical practice guideline recommendations for CKD. The review also provides recommendations for urine specimen collection and storage, and results reporting for the ACR. Recent advances in measurement techniques and development of reference systems intended to facilitate standardization of urine albumin measurements are reviewed. SUMMARY Urine albumin is an important measurement procedure used for diagnosis, risk classification, and management of CKD. Urine albumin results should be reported as the ACR using quantitative measurement procedures. Random urine collections used for albuminuria screening should be followed by confirmation with first morning void collections to reduce variation and increase diagnostic accuracy for urine albumin measurement. Most measurement procedures utilize immunoturbidimetric or immunonephelometric techniques. However, results vary significantly among measurement procedures, potentially resulting in differences in classification or risk assessment for CKD. The National Institute for Standards and Technology (NIST) and other laboratories are developing reference systems, including liquid chromatography-tandem mass spectrometry candidate reference measurement procedures and reference materials, to enable standardization of routine measurement procedures.
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Affiliation(s)
- Jesse C Seegmiller
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, United States
| | - Lorin M Bachmann
- Department of Pathology, Virginia Commonwealth University, Richmond, VA, United States
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13
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Tuttle KR, Hauske SJ, Canziani ME, Caramori ML, Cherney D, Cronin L, Heerspink HJL, Hugo C, Nangaku M, Rotter RC, Silva A, Shah SV, Sun Z, Urbach D, de Zeeuw D, Rossing P. Efficacy and safety of aldosterone synthase inhibition with and without empagliflozin for chronic kidney disease: a randomised, controlled, phase 2 trial. Lancet 2024; 403:379-390. [PMID: 38109916 DOI: 10.1016/s0140-6736(23)02408-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/20/2023] [Accepted: 10/24/2023] [Indexed: 12/20/2023]
Abstract
BACKGROUND Excess aldosterone accelerates chronic kidney disease progression. This phase 2 clinical trial assessed BI 690517, an aldosterone synthase inhibitor, for efficacy, safety, and dose selection. METHODS This was a multinational, randomised, controlled, phase 2 trial. People aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 30 to less than 90 mL/min/1·73 m2, a urine albumin to creatinine ratio (UACR) of 200 to less than 5000 mg/g, and serum potassium of 4·8 mmol/L or less, taking an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, were enrolled. Participants were randomly assigned (1:1) to 8 weeks of empagliflozin or placebo run-in, followed by a second randomisation (1:1:1:1) to 14 weeks of treatment with once per day BI 690517 at doses of 3 mg, 10 mg, or 20 mg, or placebo. Study participants, research coordinators, investigators, and the data coordinating centre were masked to treatment assignment. The primary endpoint was the change in UACR measured in first morning void urine from baseline (second randomisation) to the end of treatment. This study is registered with ClinicalTrials.gov (NCT05182840) and is completed. FINDINGS Between Feb 18 and Dec 30, 2022, of the 714 run-in participants, 586 were randomly assigned to receive BI 690517 or placebo. At baseline, 33% (n=196) were women, 67% (n=390) were men, 42% (n=244) had a racial identity other than White, and mean participant age was 63·8 years (SD 11·3). Mean baseline eGFR was 51·9 mL/min/1·73 m2 (17·7) and median UACR was 426 mg/g (IQR 205 to 889). Percentage change in first morning void UACR from baseline to the end of treatment at week 14 was -3% (95% CI -19 to 17) with placebo, -22% (-36 to -7) with BI 690517 3 mg, -39% (-50 to -26) with BI 690517 10 mg, and -37% (-49 to -22) with BI 690517 20 mg monotherapy. BI 690517 produced similar UACR reductions when added to empagliflozin. Investigator-reported hyperkalaemia occurred in 10% (14/146) of those in the BI 690517 3 mg group, 15% (22/144) in the BI 690517 10 mg group, and 18% (26/146) in the BI 690517 20 mg group, and in 6% (nine of 147) of those receiving placebo, with or without empagliflozin. Most participants with hyperkalaemia did not require intervention (86% [72/84]). Adrenal insufficiency was an adverse event of special interest reported in seven of 436 study participants (2%) receiving BI 690517 and one of 147 participants (1%) receiving matched placebo. No treatment-related deaths occurred during the study. INTERPRETATION BI 690517 dose-dependently reduced albuminuria with concurrent renin-angiotensin system inhibition and empagliflozin, suggesting an additive efficacy for chronic kidney disease treatment without unexpected safety signals. FUNDING Boehringer Ingelheim.
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Affiliation(s)
- Katherine R Tuttle
- University of Washington, Seattle, WA, USA; Providence Inland Northwest Health, Spokane, WA, USA.
| | - Sibylle J Hauske
- Boehringer Ingelheim International, Ingelheim am Rhein, Rheinland-Pfalz, Germany; Vth Department of Medicine, University Medical Centre Mannheim, Heidelberg University, Heidelberg, Germany
| | | | - Maria Luiza Caramori
- Cleveland Clinic Foundation, Cleveland, OH, USA; University of Minnesota, Minneapolis, MN, USA
| | | | - Lisa Cronin
- Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, USA
| | - Hiddo J L Heerspink
- University Medical Centre Groningen, Groningen, Netherlands; The George Institute for Global Health, Sydney, NSW, Australia
| | - Christian Hugo
- Universitätsklinikum Carl Gustav Carus Dresden, Medizinische Klinik und Poliklinik III, Dresden, Germany
| | | | - Ricardo Correa Rotter
- Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
| | - Arnold Silva
- Boise Kidney and Hypertension, Suite, Nampa, ID, USA
| | - Shimoli V Shah
- Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, USA
| | - Zhichao Sun
- Boehringer Ingelheim Pharmaceuticals, Ridgefield, CT, USA
| | - Dorothea Urbach
- Synexus Helderberg Clinical Research Centre, Cape Town, South Africa
| | - Dick de Zeeuw
- University Medical Centre Groningen, Groningen, Netherlands
| | - Peter Rossing
- Steno Diabetes Centre Copenhagen, Herlev, Denmark; Department of Clinical Medicine University of Copenhagen, Copenhagen, Denmark
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14
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Schömig T, Diefenhardt P, Plagmann I, Trinsch B, Merz T, Crispatzu G, Unnersjö-Jess D, Nies J, Pütz D, Sierra Gonzalez C, Schermer B, Benzing T, Brinkkoetter PT, Brähler S. The podocytes' inflammatory responses in experimental GN are independent of canonical MYD88-dependent toll-like receptor signaling. Sci Rep 2024; 14:2292. [PMID: 38280906 PMCID: PMC10821883 DOI: 10.1038/s41598-024-52565-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/20/2024] [Indexed: 01/29/2024] Open
Abstract
Podocytes form the kidney filtration barrier and continuously adjust to external stimuli to preserve their integrity even in the presence of inflammation. It was suggested that canonical toll-like receptor signaling, mediated by the adaptor protein MYD88, plays a crucial role in initiating inflammatory responses in glomerulonephritis (GN). We explored the influence of podocyte-intrinsic MYD88 by challenging wild-type (WT) and podocyte-specific Myd88 knockout (MyD88pko) mice, with a model of experimental GN (nephrotoxic nephritis, NTN). Next-generation sequencing revealed a robust upregulation of inflammatory pathways and changes in cytoskeletal and cell adhesion proteins in sorted podocytes from WT mice during disease. Unchallenged MyD88pko mice were healthy and showed no proteinuria, normal kidney function and lacked morphological changes. During NTN, MyD88pko exhibited a transient increase in proteinuria in comparison to littermates, while histological damage, podocyte ultrastructure in STED imaging and frequencies of infiltrating immune cells by flow cytometry were unchanged. MYD88-deficiency led to subtle changes in the podocyte transcriptome, without a significant impact on the overall podocyte response to inflammation, presumably through MYD88-independent signaling pathways. In conclusion, our study reveals a comprehensive analysis of podocyte adaptation to an inflammatory environment on the transcriptome level, while MYD88-deficiency had only limited impact on the course of GN suggesting additional signaling through MYD88-independent signaling.
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Affiliation(s)
- Thomas Schömig
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Paul Diefenhardt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Ingo Plagmann
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Bastian Trinsch
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Tim Merz
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Giuliano Crispatzu
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Response in Aging-associated Diseases (CECAD), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Unnersjö-Jess
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Jasper Nies
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - David Pütz
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Claudio Sierra Gonzalez
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Response in Aging-associated Diseases (CECAD), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany
- Cluster of Excellence Cellular Stress Response in Aging-associated Diseases (CECAD), Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Paul Thomas Brinkkoetter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany.
| | - Sebastian Brähler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne and University Hospital Cologne, Cologne, Germany.
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15
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Ma S, Qiu Y, Zhang C. Cytoskeleton Rearrangement in Podocytopathies: An Update. Int J Mol Sci 2024; 25:647. [PMID: 38203817 PMCID: PMC10779434 DOI: 10.3390/ijms25010647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/14/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
Podocyte injury can disrupt the glomerular filtration barrier (GFB), leading to podocytopathies that emphasize podocytes as the glomerulus's key organizer. The coordinated cytoskeleton is essential for supporting the elegant structure and complete functions of podocytes. Therefore, cytoskeleton rearrangement is closely related to the pathogenesis of podocytopathies. In podocytopathies, the rearrangement of the cytoskeleton refers to significant alterations in a string of slit diaphragm (SD) and focal adhesion proteins such as the signaling node nephrin, calcium influx via transient receptor potential channel 6 (TRPC6), and regulation of the Rho family, eventually leading to the disorganization of the original cytoskeletal architecture. Thus, it is imperative to focus on these proteins and signaling pathways to probe the cytoskeleton rearrangement in podocytopathies. In this review, we describe podocytopathies and the podocyte cytoskeleton, then discuss the molecular mechanisms involved in cytoskeleton rearrangement in podocytopathies and summarize the effects of currently existing drugs on regulating the podocyte cytoskeleton.
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Affiliation(s)
| | | | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (S.M.); (Y.Q.)
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16
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Zhou W, Zhao Y, Jin J, Cheng M, Bai Y, Xu J. The association of hemoglobin ethylene oxide levels with albuminuria in US adults: analysis of NHANES 2013-2016. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:4130-4139. [PMID: 38100021 DOI: 10.1007/s11356-023-31083-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/13/2023] [Indexed: 01/19/2024]
Abstract
Ethylene oxide (EO) is a common chemical contaminant in the environment and associated with the occurrence of multiple clinical diseases. This study aimed to explore the association of hemoglobin ethylene oxide (HbEO) levels with the risk of albuminuria in a representative sample of US adults. In total, 3523 participants from National Health and Nutrition Examination Survey (NHANES) 2013-2016 were enrolled and classified into four groups based on HbEO. Restricted cubic spline plots and multiple logistic regression were performed to investigate the connection between HbEO levels and albuminuria, and mediation analysis was applied to elucidate the potential mechanism for the effect of HbEO concentrations on albuminuria. In the results, compared with the extreme quartile of HbEO levels, the weighted prevalence of albuminuria was significantly increased in participants with highest quartile (Q4 vs Q1, 11.2% vs 8.1%). Restricted cubic spline plots revealed that the risk of albuminuria raised non-linearly and positively with elevated HbEO level. After adjusting for confounders, the logistic regression suggested that the risk of albuminuria was enhanced by 12% for each one-unit increase in log-2-transformed HbEO (OR = 1.12, 95% CI, 1.03-1.22, P = 0.007). Moreover, the multivariate ORs (95% CIs) on albuminuria was increased across the increasing HbEO quartiles (Q4 vs Q1, OR = 1.54, 95% CI, 1.09-2.17; P for trend = 0.029). Furthermore, the impact of high HbEO level on albuminuria was partially related to inflammation markers, including white blood cells (17.2%), neutrophils (22.1%), and lymphocytes (19.5%). To sum up, our study identified that high HbEO levels increased the risk of albuminuria in representative population of US adults, and several inflammatory mediators might be potentially involved in EO-associated albuminuria.
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Affiliation(s)
- Wei Zhou
- Department of Nephrology, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Hebei Clinical Research Center for Chronic Kidney Disease, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, China
| | - Yunfeng Zhao
- Department of Nephrology, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Hebei Clinical Research Center for Chronic Kidney Disease, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, China
| | - JingJing Jin
- Department of Nephrology, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Hebei Clinical Research Center for Chronic Kidney Disease, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, China
| | - Meijuan Cheng
- Department of Nephrology, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Hebei Clinical Research Center for Chronic Kidney Disease, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, China
| | - Yaling Bai
- Department of Nephrology, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Hebei Clinical Research Center for Chronic Kidney Disease, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, China
| | - Jinsheng Xu
- Department of Nephrology, Hebei Key Laboratory of Vascular Calcification in Kidney Disease, Hebei Clinical Research Center for Chronic Kidney Disease, The Fourth Hospital of Hebei Medical University, 12 Jiankang Road, Shijiazhuang, 050011, China.
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17
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Butt L, Unnersjö-Jess D, Reilly D, Hahnfeldt R, Rinschen MM, Bozek K, Schermer B, Benzing T, Höhne M. In vivo characterization of a podocyte-expressed short podocin isoform. BMC Nephrol 2023; 24:378. [PMID: 38114895 PMCID: PMC10731740 DOI: 10.1186/s12882-023-03420-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 12/01/2023] [Indexed: 12/21/2023] Open
Abstract
The most common genetic causes of steroid-resistant nephrotic syndrome (SRNS) are mutations in the NPHS2 gene, which encodes the cholesterol-binding, lipid-raft associated protein podocin. Mass spectrometry and cDNA sequencing revealed the existence of a second shorter isoform in the human kidney in addition to the well-studied canonical full-length protein. Distinct subcellular localization of the shorter isoform that lacks part of the conserved PHB domain suggested a physiological role. Here, we analyzed whether this protein can substitute for the canonical full-length protein. The short isoform of podocin is not found in other organisms except humans. We therefore analysed a mouse line expressing the equivalent podocin isoform (podocinΔexon5) by CRISPR/Cas-mediated genome editing. We characterized the phenotype of these mice expressing podocinΔexon5 and used targeted mass spectrometry and qPCR to compare protein and mRNA levels of podocinwildtype and podocinΔexon5. After immunolabeling slit diaphragm components, STED microscopy was applied to visualize alterations of the podocytes' foot process morphology.Mice homozygous for podocinΔexon5 were born heavily albuminuric and did not survive past the first 24 h after birth. Targeted mass spectrometry revealed massively decreased protein levels of podocinΔexon5, whereas mRNA abundance was not different from the canonical form of podocin. STED microscopy revealed the complete absence of podocin at the podocytes' slit diaphragm and severe morphological alterations of podocyte foot processes. Mice heterozygous for podocinΔexon5 were phenotypically and morphologically unaffected despite decreased podocin and nephrin protein levels.The murine equivalent to the human short isoform of podocin cannot stabilize the lipid-protein complex at the podocyte slit diaphragm. Reduction of podocin levels at the site of the slit diaphragm complex has a detrimental effect on podocyte function and morphology. It is associated with decreased protein abundance of nephrin, the central component of the filtration-slit forming slit diaphragm protein complex.
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Grants
- KFO 329, BR4917/3, INST 1856/71-1 FUGG Deutsche Forschungsgemeinschaft
- KFO 329, BR4917/3, INST 1856/71-1 FUGG Deutsche Forschungsgemeinschaft
- KFO 329, BR4917/3, INST 1856/71-1 FUGG Deutsche Forschungsgemeinschaft
- KFO 329, BR4917/3, INST 1856/71-1 FUGG Deutsche Forschungsgemeinschaft
- KFO 329, BR4917/3, INST 1856/71-1 FUGG Deutsche Forschungsgemeinschaft
- Project No: 2019_KollegSE.04 Else Kröner-Fresenius-Stiftung,Germany
- Project No: 2019_KollegSE.04 Eva Luise und Horst Köhler Stiftung
- NNF19OC0056043 Novo Nordisk Fonden
- Young Researcher Fellowship Carlsbergfondet
- 311-8.03.03.02-147635 North Rhine-Westphalia return program
- 01ZX1917B Bundesministerium für Bildung und Forschung
- BMBF 01-GM1901E Bundesministerium für Bildung und Forschung
- Universitätsklinikum Köln (8977)
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Affiliation(s)
- Linus Butt
- Department II of Internal Medicine, University Hospital Cologne CECAD building Joseph-Stelzmann-Str. 62, Cologne, 50931, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University of Cologne, University Hospital Cologne, CECAD Building, Joseph-Stelzmann-Str. 62, 50931, Cologne, Germany
- Cologne Excellence Cluster On Cellular Stress Responses in Aging-Associated Diseases (CECAD), Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - David Unnersjö-Jess
- Department II of Internal Medicine, University Hospital Cologne CECAD building Joseph-Stelzmann-Str. 62, Cologne, 50931, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University of Cologne, University Hospital Cologne, CECAD Building, Joseph-Stelzmann-Str. 62, 50931, Cologne, Germany
- MedTechLabs, Karolinska University Hospital, Solna, Sweden
| | - Dervla Reilly
- Department II of Internal Medicine, University Hospital Cologne CECAD building Joseph-Stelzmann-Str. 62, Cologne, 50931, Germany
| | - Robert Hahnfeldt
- Department II of Internal Medicine, University Hospital Cologne CECAD building Joseph-Stelzmann-Str. 62, Cologne, 50931, Germany
| | - Markus M Rinschen
- Department of Biomedicine and Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus, Denmark
- Department of Medicine III, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Katarzyna Bozek
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University of Cologne, University Hospital Cologne, CECAD Building, Joseph-Stelzmann-Str. 62, 50931, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, University Hospital Cologne CECAD building Joseph-Stelzmann-Str. 62, Cologne, 50931, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University of Cologne, University Hospital Cologne, CECAD Building, Joseph-Stelzmann-Str. 62, 50931, Cologne, Germany
- Cologne Excellence Cluster On Cellular Stress Responses in Aging-Associated Diseases (CECAD), Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University Hospital Cologne CECAD building Joseph-Stelzmann-Str. 62, Cologne, 50931, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University of Cologne, University Hospital Cologne, CECAD Building, Joseph-Stelzmann-Str. 62, 50931, Cologne, Germany
- Cologne Excellence Cluster On Cellular Stress Responses in Aging-Associated Diseases (CECAD), Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine, University Hospital Cologne CECAD building Joseph-Stelzmann-Str. 62, Cologne, 50931, Germany.
- Cologne Excellence Cluster On Cellular Stress Responses in Aging-Associated Diseases (CECAD), Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany.
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18
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Yoon Y, Kim YM, Lee S, Shin BC, Kim HL, Chung JH, Son M. Association between Neck Circumference and Chronic Kidney Disease in Korean Adults in the 2019-2021 Korea National Health and Nutrition Examination Survey. Nutrients 2023; 15:5039. [PMID: 38140298 PMCID: PMC10745966 DOI: 10.3390/nu15245039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Chronic kidney disease (CKD) is a major public health problem and a leading cause of cardiovascular disease and death. Early recognition and management of CKD risk factors are necessary to prevent its onset and progression. Neck circumference (NC) is a non-invasive and easily accessible anthropometric measure associated with central obesity and subcutaneous fat accumulation in the upper body. Our study aimed to explore the relationship between NC and the prevalence of CKD using data from the nationally representative Korea National Health and Nutrition Examination Survey (2019-2021). We analyzed data from 10,219 subjects (age > 19 years, no missing values). CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Logistic regression analysis was performed, which revealed a significant association between NC and CKD prevalence even after adjusting for confounding factors, both when NC was considered a continuous variable (OR [95% CI], 1.11 [1.03-1.19]) and in quartiles (Q1 as reference; Q2 OR [95% CI], 1.23 [0.91-1.67]; Q3 OR [95% CI], 1.59 [1.16-2.18]; Q4 OR [95% CI], 1.70 [1.16-2.50]). Our findings suggest that NC could be a simple and effective anthropometric measurement for identifying individuals at risk for CKD.
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Affiliation(s)
- Youngmin Yoon
- Division of Nephrology, Department of Medicine, Chosun University Hospital, Chosun University School of Medicine, Gwangju 61453, Republic of Korea; (Y.Y.); (S.L.); (B.-C.S.); (H.-L.K.); (J.-H.C.)
| | - Yoo-min Kim
- Department of Obstetrics and Gynecology, Chung-Ang University Gwang-myung Hospital, Chung-Ang University College of Medicine, Gwangmyeong-si 14353, Republic of Korea;
| | - Somin Lee
- Division of Nephrology, Department of Medicine, Chosun University Hospital, Chosun University School of Medicine, Gwangju 61453, Republic of Korea; (Y.Y.); (S.L.); (B.-C.S.); (H.-L.K.); (J.-H.C.)
| | - Byung-Chul Shin
- Division of Nephrology, Department of Medicine, Chosun University Hospital, Chosun University School of Medicine, Gwangju 61453, Republic of Korea; (Y.Y.); (S.L.); (B.-C.S.); (H.-L.K.); (J.-H.C.)
| | - Hyun-Lee Kim
- Division of Nephrology, Department of Medicine, Chosun University Hospital, Chosun University School of Medicine, Gwangju 61453, Republic of Korea; (Y.Y.); (S.L.); (B.-C.S.); (H.-L.K.); (J.-H.C.)
| | - Jong-Hoon Chung
- Division of Nephrology, Department of Medicine, Chosun University Hospital, Chosun University School of Medicine, Gwangju 61453, Republic of Korea; (Y.Y.); (S.L.); (B.-C.S.); (H.-L.K.); (J.-H.C.)
| | - Minkook Son
- Department of Physiology, Dong-A University College of Medicine, Busan 49201, Republic of Korea
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19
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Pokidysheva EN, Redhair N, Ailsworth O, Page-McCaw P, Rollins-Smith L, Jamwal VS, Ohta Y, Bächinger HP, Murawala P, Flajnik M, Fogo AB, Abrahamson D, Hudson JK, Boudko SP, Hudson BG. Collagen IV of basement membranes: II. Emergence of collagen IV α345 enabled the assembly of a compact GBM as an ultrafilter in mammalian kidneys. J Biol Chem 2023; 299:105459. [PMID: 37977222 PMCID: PMC10746531 DOI: 10.1016/j.jbc.2023.105459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/28/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023] Open
Abstract
The collagen IVα345 (Col-IVα345) scaffold, the major constituent of the glomerular basement membrane (GBM), is a critical component of the kidney glomerular filtration barrier. In Alport syndrome, affecting millions of people worldwide, over two thousand genetic variants occur in the COL4A3, COL4A4, and COL4A5 genes that encode the Col-IVα345 scaffold. Variants cause loss of scaffold, a suprastructure that tethers macromolecules, from the GBM or assembly of a defective scaffold, causing hematuria in nearly all cases, proteinuria, and often progressive kidney failure. How these variants cause proteinuria remains an enigma. In a companion paper, we found that the evolutionary emergence of the COL4A3, COL4A4, COL4A5, and COL4A6 genes coincided with kidney emergence in hagfish and shark and that the COL4A3 and COL4A4 were lost in amphibians. These findings opened an experimental window to gain insights into functionality of the Col-IVα345 scaffold. Here, using tissue staining, biochemical analysis and TEM, we characterized the scaffold chain arrangements and the morphology of the GBM of hagfish, shark, frog, and salamander. We found that α4 and α5 chains in shark GBM and α1 and α5 chains in amphibian GBM are spatially separated. Scaffolds are distinct from one another and from the mammalian Col-IVα345 scaffold, and the GBM morphologies are distinct. Our findings revealed that the evolutionary emergence of the Col-IVα345 scaffold enabled the genesis of a compact GBM that functions as an ultrafilter. Findings shed light on the conundrum, defined decades ago, whether the GBM or slit diaphragm is the primary filter.
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Affiliation(s)
- Elena N Pokidysheva
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Aspirnaut, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
| | - Neve Redhair
- Aspirnaut, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Octavia Ailsworth
- Aspirnaut, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Patrick Page-McCaw
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Louise Rollins-Smith
- Department of Pathology Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | | | - Yuko Ohta
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | | | - Prayag Murawala
- Mount Desert Island Biological Laboratory, Bar Harbor, Maine, USA; Clinic for Kidney and Hypertension Diseases, Hannover Medical School, Hannover, Germany
| | - Martin Flajnik
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Agnes B Fogo
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Dale Abrahamson
- Department of Cell Biology and Physiology, The Jared Grantham Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Julie K Hudson
- Aspirnaut, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Sergei P Boudko
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Billy G Hudson
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Aspirnaut, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Center for Matrix Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
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20
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Unnersjö-Jess D, Ramdedovic A, Butt L, Plagmann I, Höhne M, Hackl A, Brismar H, Blom H, Schermer B, Benzing T. Advanced optical imaging reveals preferred spatial orientation of podocyte processes along the axis of glomerular capillaries. Kidney Int 2023; 104:1164-1169. [PMID: 37774923 DOI: 10.1016/j.kint.2023.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/21/2023] [Accepted: 08/17/2023] [Indexed: 10/01/2023]
Abstract
Mammalian kidneys filter enormous volumes of water and small solutes, a filtration driven by the hydrostatic pressure in glomerular capillaries, which is considerably higher than in most other tissues. Interdigitating cellular processes of podocytes form the slits for fluid filtration connected by the membrane-like slit diaphragm cell junction containing a mechanosensitive ion channel complex and allow filtration while counteracting hydrostatic pressure. Several previous publications speculated that podocyte processes may display a preferable orientation on glomerular capillaries instead of a random distribution. However, for decades, the controversy over spatially oriented filtration slits could not be resolved due to technical limitations of imaging technologies. Here, we used advanced high-resolution, three-dimensional microscopy with high data throughput to assess spatial orientation of podocyte processes and filtration slits quantitatively. Filtration-slit-generating secondary processes preferentially align along the capillaries' longitudinal axis while primary processes are preferably perpendicular to the longitudinal direction. This preferential orientation required maturation in development of the mice but was lost in mice with kidney disease due to treatment with nephrotoxic serum or with underlying heterologous mutations in the podocyte foot process protein podocin. Thus, the observation that podocytes maintain a preferred spatial orientation of their processes on glomerular capillaries goes well in line with the role of podocyte foot processes as mechanical buttresses to counteract mechanical forces resulting from pressurized capillaries. Future studies are needed to establish how podocytes establish and maintain their orientation and why orientation is lost under pathological conditions.
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Affiliation(s)
- David Unnersjö-Jess
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany; MedTechLabs, BioClinicum, Karolinska University Hospital, Solna, Sweden; Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden; Division of Renal Medicine, Department of Clinical Sciences, Intervention and Technology (CLINTEC), Karolinska Institute, Stockholm, Sweden.
| | - Amer Ramdedovic
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Linus Butt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Ingo Plagmann
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Agnes Hackl
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Hjalmar Brismar
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden; Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
| | - Hans Blom
- MedTechLabs, BioClinicum, Karolinska University Hospital, Solna, Sweden; Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany.
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21
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Ahmad A, Shi J, Ansari S, Merscher S, Pollack A, Zeidan Y, Fornoni A, Marples B. Radiation nephropathy: Mechanisms of injury and recovery in a murine model. Radiother Oncol 2023; 187:109813. [PMID: 37468066 DOI: 10.1016/j.radonc.2023.109813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 07/21/2023]
Abstract
BACKGROUND Radiation nephropathy (RN) can be a severe late complication for patients treated with radiotherapy (RT) targeting abdominal and paraspinal tumors. Recent studies investigating the mechanisms of RT-mediated injury in the kidney have demonstrated that RT disrupts the cellular integrity of renal podocytes leading to cell death and loss of renal function. AIM To determine if RT-induced renal dysfunction is associated with alterations in podocyte and glomerular function, and whether RT-induced podocyte alterations were associated with changes in the glomerular basement membrane (GBM). METHODS C57BL/6 mice were treated with focal bilateral X-irradiation using a single dose (SD) of 4 Gy, 10 Gy, or 14 Gy or fractionated dosing (FD) of 5x6Gy or 24x2Gy. Then, 10-40 weeks after RT parameters of renal function were measured, along with glomerular filtration rate (GFR) and glomerular histology, as well as ultrastructural changes in GBM by transmission electron microscopy. RESULTS RT treatment resulted in persistent changes in renal function beginning at 10 weeks with little recovery up to 40 weeks post RT. Dose dependent changes were seen with increasing SD but no functional sparing was evident after FD. RT-induced loss of renal function was associated with expansion of the GBM and significant increases in foot process width, and associated with significant reduction in GFR, podocyte loss, and renal fibrosis. CONCLUSION For the first time, these data show that expansion of the GBM is one consequence of radiation injury, and disarrangement of the GBM might be associated with the death of podocytes. These data shed new light on the role podocyte injury and GBM in RT-induced renal dysfunction.
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Affiliation(s)
- Anis Ahmad
- Department of Radiation Oncology, Sylvester Comprehensive Cancer Center/Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Junwei Shi
- Department of Radiation Oncology, Sylvester Comprehensive Cancer Center/Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Saba Ansari
- Department of Radiation Oncology, Sylvester Comprehensive Cancer Center/Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Sandra Merscher
- Peggy and Harold Katz Family Drug Discovery Center and Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miami, FL, USA
| | - Alan Pollack
- Department of Radiation Oncology, Sylvester Comprehensive Cancer Center/Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Youssef Zeidan
- Department of Radiation Oncology, Anatomy, Cell Biology, and Physiology, American University of Beirut (AUB) School of Medicine, Beirut, Lebanon
| | - Alessia Fornoni
- Peggy and Harold Katz Family Drug Discovery Center and Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miami, FL, USA
| | - Brian Marples
- Department of Radiation Oncology, Sylvester Comprehensive Cancer Center/Miller School of Medicine, University of Miami, Miami, FL, USA; Peggy and Harold Katz Family Drug Discovery Center and Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami, Miami, FL, USA; Department of Radiation Oncology, University of Rochester, 601 Elmwood Ave. Box 647 Rochester, NY, USA.
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22
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Hayashi K. Targeting DNA Methylation in Podocytes to Overcome Chronic Kidney Disease. Keio J Med 2023; 72:67-76. [PMID: 37271519 DOI: 10.2302/kjm.2022-0017-ir] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The number of patients with chronic kidney disease (CKD) is on the rise worldwide, and there is urgent need for the development of effective plans against the increasing incidence of CKD. Podocytes, glomerular epithelial cells, are an integral part of the primary filtration unit of the kidney and form a slit membrane as a barrier to prevent proteinuria. The role of podocytes in the pathogenesis and progression of CKD is now recognized. Podocyte function depends on a specialized morphology with the arranged foot processes, which is directly related to their function. Epigenetic changes responsible for the regulation of gene expression related to podocyte morphology have been shown to be important in the pathogenesis of CKD. Although epigenetic mechanisms include DNA methylation, histone modifications, and RNA-based regulation, we have focused on DNA methylation changes because they are more stable than other epigenetic modifications. This review summarizes recent literature about the role of altered DNA methylation in the kidney, especially in glomerular podocytes, focusing on transcription factors and DNA damage responses that are closely associated with the formation of DNA methylation changes.
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Affiliation(s)
- Kaori Hayashi
- Division of Nephrology, Endocrinology and Metabolism, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan
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23
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Haeri H, Eisermann J, Schimm H, Büscher A, Hoyer P, Hinderberger D. Profound Changes in Functional Structure and Dynamics of Serum Albumin in Children with Nephrotic Syndrome: An Exploratory Research Study. J Med Chem 2023; 66:12115-12129. [PMID: 37648246 PMCID: PMC10510392 DOI: 10.1021/acs.jmedchem.3c00680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Indexed: 09/01/2023]
Abstract
Patients with nephrotic syndrome (NS) suffer from urinary loss of albumin. As a cause, previous studies focused on the glomerular filter rather than analyzing the molecular properties of albumin itself. Later one was initiated by clinical observations indicating unexplained molecular alterations of human serum albumin (HSA) in an NS pediatric patient. Therefore, we examined serum from eight pediatric patients with steroid-sensitive and -resistant NS and compared it with serum from healthy subjects as well as commercial HSA. We used dynamic and electrophoretic light scattering to characterize the protein size and effective surface charge and electron paramagnetic resonance spectroscopy to measure the local environment and binding dynamics of up to seven fatty acids associated with HSA. Our findings suggest that pronounced differences in binding behavior and surface charge of HSA could enhance their filtration through the GBM, leading to direct toxicity of HSA to podocytes.
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Affiliation(s)
- Haleh
H. Haeri
- Physical
Chemistry, Complex Self-Organizing Systems, Martin Luther University
Halle-Wittenberg, Institute of Chemistry, Von Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| | - Jana Eisermann
- Department
of Chemistry, Molecular Sciences Research Hub, Imperial College London, 82 Wood Ln, W12 0BZ London, U.K.
| | - Heike Schimm
- Physical
Chemistry, Complex Self-Organizing Systems, Martin Luther University
Halle-Wittenberg, Institute of Chemistry, Von Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| | - Anja Büscher
- Universitätsklinikum
Essen (AöR), Klinik für Kinderheilkunde II, Zentrum
für Kinder- und Jugendmedizin, Hufelandstraße 55, D-45147 Essen, Germany
| | - Peter Hoyer
- Universitätsklinikum
Essen (AöR), Klinik für Kinderheilkunde II, Zentrum
für Kinder- und Jugendmedizin, Hufelandstraße 55, D-45147 Essen, Germany
| | - Dariush Hinderberger
- Physical
Chemistry, Complex Self-Organizing Systems, Martin Luther University
Halle-Wittenberg, Institute of Chemistry, Von Danckelmann-Platz 4, 06120 Halle (Saale), Germany
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24
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Denic A, Gaddam M, Moustafa A, Mullan AF, Luehrs AC, Sharma V, Thompson RH, Smith ML, Alexander MP, Lerman LO, Barisoni L, Rule AD. Tubular and Glomerular Size by Cortex Depth as Predictor of Progressive CKD after Radical Nephrectomy for Tumor. J Am Soc Nephrol 2023; 34:1535-1545. [PMID: 37430426 PMCID: PMC10482069 DOI: 10.1681/asn.0000000000000180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/08/2023] [Indexed: 07/12/2023] Open
Abstract
SIGNIFICANCE STATEMENT Glomerular size differs by cortex depth. Larger nephrons are prognostic of progressive kidney disease, but it is unknown whether this risk differs by cortex depth or by glomeruli versus proximal or distal tubule size. We studied the average minor axis diameter in oval proximal and distal tubules separately and by cortex depth in patients who had radical nephrectomy to remove a tumor from 2019 to 2020. In adjusted analyses, larger glomerular volume in the middle and deep cortex predicted progressive kidney disease. Wider proximal tubular diameter did not predict progressive kidney disease independent of glomerular volume. Wider distal tubular diameter showed a gradient of strength of prediction of progressive kidney disease in the more superficial cortex than in the deep cortex. BACKGROUND Larger nephrons are prognostic of progressive kidney disease, but whether this risk differs by nephron segments or by depth in the cortex is unclear. METHODS We studied patients who underwent radical nephrectomy for a tumor between 2000 and 2019. Large wedge kidney sections were scanned into digital images. We estimated the diameters of proximal and distal tubules by the minor axis of oval tubular profiles and estimated glomerular volume with the Weibel-Gomez stereological model. Analyses were performed separately in the superficial, middle, and deep cortex. Cox proportional hazard models assessed the risk of progressive CKD (dialysis, kidney transplantation, sustained eGFR <10 ml/min per 1.73 m 2 , or a sustained 40% decline from the postnephrectomy baseline eGFR) with glomerular volume or tubule diameters. At each cortical depth, models were unadjusted, adjusted for glomerular volume or tubular diameter, and further adjusted for clinical characteristics (age, sex, body mass index, hypertension, diabetes, postnephrectomy baseline eGFR, and proteinuria). RESULTS Among 1367 patients were 62 progressive CKD events during a median follow-up of 4.5 years. Glomerular volume predicted CKD outcomes at all depths, but only in the middle and deep cortex after adjusted analyses. Proximal tubular diameter also predicted progressive CKD at any depth but not after adjusted analyses. Distal tubular diameter showed a gradient of more strongly predicting progressive CKD in the superficial than deep cortex, even in adjusted analysis. CONCLUSIONS Larger glomeruli are independent predictors of progressive CKD in the deeper cortex, whereas in the superficial cortex, wider distal tubular diameters are an independent predictor of progressive CKD.
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Affiliation(s)
- Aleksandar Denic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Mrunanjali Gaddam
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Amr Moustafa
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Aidan F. Mullan
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Anthony C. Luehrs
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
| | - Vidit Sharma
- Department of Urology, Mayo Clinic, Rochester, Minnesota
| | | | - Maxwell L. Smith
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona
| | - Mariam P. Alexander
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Lilach O. Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Laura Barisoni
- Department of Pathology and Medicine, Duke University, Durham, North Carolina
| | - Andrew D. Rule
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
- Division of Epidemiology, Mayo Clinic, Rochester, Minnesota
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25
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Hackl A, Nüsken E, Voggel J, Abo Zed SED, Binz-Lotter J, Unnersjö-Jess D, Müller C, Fink G, Bohl K, Wiesner E, Diefenhardt P, Dafinger C, Chen H, Wohlfarth M, Müller RU, Hackl MJ, Schermer B, Nüsken KD, Weber LT. The effect of mycophenolate mofetil on podocytes in nephrotoxic serum nephritis. Sci Rep 2023; 13:14167. [PMID: 37644089 PMCID: PMC10465485 DOI: 10.1038/s41598-023-41222-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023] Open
Abstract
Mycophenolate mofetil (MMF) is applied in proteinuric kidney diseases, but the exact mechanism of its effect on podocytes is still unknown. Our previous in vitro experiments suggested that MMF can ameliorate podocyte damage via restoration of the Ca2+-actin cytoskeleton axis. The goal of this study was to characterize podocyte biology during MMF treatment in nephrotoxic serum (NTS) nephritis (NTN). NTN was induced in three-week old wild-type mice. On day 3, half of the mice were treated with MMF (100 mg/kgBW/d p.o.) for one week. On day 10, we performed proteomic analysis of glomeruli as well as super-resolution imaging of the slit diaphragm. For multiphoton imaging of Ca2+ concentration ([Ca2+]i), the experimental design was repeated in mice expressing podocyte-specific Ca2+ sensor. MMF ameliorated the proteinuria and crescent formation induced by NTS. We identified significant changes in the abundance of proteins involved in Ca2+ signaling and actin cytoskeleton regulation, which was further confirmed by direct [Ca2+]i imaging in podocytes showing decreased Ca2+ levels after MMF treatment. This was associated with a tendency to restoration of podocyte foot process structure. Here, we provide evidence that MPA has a substantial direct effect on podocytes. MMF contributes to improvement of [Ca2+]i and amelioration of the disorganized actin cytoskeleton in podocytes. These data extend the knowledge of direct effects of immunosuppressants on podocytes that may contribute to a more effective treatment of proteinuric glomerulopathies with the least possible side effects.
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Affiliation(s)
- A Hackl
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany.
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany.
| | - E Nüsken
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - J Voggel
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - S E D Abo Zed
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - J Binz-Lotter
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - D Unnersjö-Jess
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - C Müller
- Department of Therapeutic Drug Monitoring, Pharmacology at the Laboratory Centre, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - G Fink
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - K Bohl
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - E Wiesner
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - P Diefenhardt
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - C Dafinger
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - H Chen
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - M Wohlfarth
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - R-U Müller
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Rare Kidney Diseases Cologne, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - M J Hackl
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - B Schermer
- CECAD, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
- Department 2 of Internal Medicine, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
| | - K-D Nüsken
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
| | - L T Weber
- Department of Pediatrics, Faculty of Medicine, University Hospital Cologne, University of Cologne, Kerpener Street 62, 50937, Cologne, Germany
- Center for Rare Kidney Diseases Cologne, Faculty of Medicine, University Hospital Cologne, University of Cologne, Cologne, Germany
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26
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Niu SW, Wu CH, Chen HC, Yang CJ, Chang JM, Chang EE, Chuang HH, Chiu YW, Zhen YY, Hung CC, Hwang SJ. Proteins Secreted by Lung Cancer Cells Induce the Onset of Proteinuria via Focal Adhesion Kinase Signaling in Mice. J Transl Med 2023; 103:100156. [PMID: 37119854 DOI: 10.1016/j.labinv.2023.100156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/24/2023] [Accepted: 04/11/2023] [Indexed: 05/01/2023] Open
Abstract
Paraneoplastic nephrotic syndrome (PNS) is a complication seen in cancer patients. Ultrastructural examination shows the accumulation of proteins and the presence of foot process (FP) effacement in the glomeruli of PNS patients. Previously, we reported that orthotopic xenografts of Lewis lung carcinoma 1 in C57BL/6 mice caused them to develop lung cancer with albuminuria. This implies that these mice can be used as a model of human disease and suggests that Lewis lung carcinoma 1 cell-secreted proteins (LCSePs) contain nephrotoxic molecules and cause inflammation in renal cells. As podocyte effacement was present in glomeruli in this model, such podocyte injury may be attributable to either soluble LCSeP or LCSeP deposits triggering pathological progression. LCSePs in conditioned media was concentrated for nephrotoxicity testing. Integrin-focal adhesion kinase (FAK) signaling and inflammatory responses were evaluated in podocytes either exposed to soluble LCSePs or seeded onto substrates with immobilized LCSePs. FAK phosphorylation and interleukin-6 expression were higher in podocytes attached to LCSePs substrates than in those exposed to soluble LCSePs. Notably, LCSeP-based haptotaxis gave rise to altered signaling in podocytes. When podocytes were stimulated by immobilized LCSePs, FAK accumulated at focal adhesions, synaptopodin dissociated from F-actin, and disrupting the interactions between synaptopodin and α-actinin was observed. When FAK was inhibited by PF-573228 in immobilized LCSePs, the association between synaptopodin and α-actinin was observed in the podocytes. The association of synaptopodin and α-actinin with F-actin allowed FP stretching, establishing a functional glomerular filtration barrier. Therefore, in this mouse model of lung cancer, FAK signaling prompts podocyte FP effacement and proteinuria, indicative of PNS.
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Affiliation(s)
- Sheng-Wen Niu
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Division of Nephrology, Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chien-Hsing Wu
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang-Gung Memorial Hospital, Kaohsiung, Taiwan; College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Hung-Chun Chen
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Jen Yang
- Division of Pulmonary and Critical care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Respiratory Therapy, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jer-Ming Chang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Eddy Essen Chang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hsiang-Hao Chuang
- Division of Pulmonary and Critical care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Wen Chiu
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yen-Yi Zhen
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chi-Chih Hung
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan.
| | - Shang-Jyh Hwang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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Nath P, Mahtaba KR, Ray A. Fluorescence-Based Portable Assays for Detection of Biological and Chemical Analytes. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23115053. [PMID: 37299780 DOI: 10.3390/s23115053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/16/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Fluorescence-based detection techniques are part of an ever-expanding field and are widely used in biomedical and environmental research as a biosensing tool. These techniques have high sensitivity, selectivity, and a short response time, making them a valuable tool for developing bio-chemical assays. The endpoint of these assays is defined by changes in fluorescence signal, in terms of its intensity, lifetime, and/or shift in spectrum, which is monitored using readout devices such as microscopes, fluorometers, and cytometers. However, these devices are often bulky, expensive, and require supervision to operate, which makes them inaccessible in resource-limited settings. To address these issues, significant effort has been directed towards integrating fluorescence-based assays into miniature platforms based on papers, hydrogels, and microfluidic devices, and to couple these assays with portable readout devices like smartphones and wearable optical sensors, thereby enabling point-of-care detection of bio-chemical analytes. This review highlights some of the recently developed portable fluorescence-based assays by discussing the design of fluorescent sensor molecules, their sensing strategy, and the fabrication of point-of-care devices.
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Affiliation(s)
- Peuli Nath
- Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606, USA
| | - Kazi Ridita Mahtaba
- Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606, USA
| | - Aniruddha Ray
- Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606, USA
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28
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Al-Azzawy MF, Al-Haggar M, ElSaid AM, El-Khawaga OY. Analysis of the association of NPHS2 and ACTN4 genes polymorphism with nephrotic syndrome in Egyptian children. Mol Biol Rep 2023; 50:4481-4490. [PMID: 37014572 PMCID: PMC10147774 DOI: 10.1007/s11033-023-08387-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/14/2023] [Indexed: 04/05/2023]
Abstract
BACKGROUND One of the most common kidney illnesses in developing countries is pediatric nephrotic syndrome (PNS), which is frequently associated with dyslipidemia and edema. The rapid discovery of genes related to NS has aided in the understanding of the molecular mechanics of glomerular filtration. The goal of this study is to determine the relationship between NPHS2 and ACTN4 in PNS youngsters. METHODS A study with 100 NS children and 100 healthy matched volunteers was conducted. Genomic DNA was extracted from peripheral blood. Single-nucleotide polymorphisms were genotyped using ARMS-PCR. RESULTS A substantial decline in the level of albumin was found in NS cases (P < 0.001) Further on, a significantly difference in T.C and TG level between healthy and NS patient. Molecular study showed a highly significant difference of NS patients from controls regarding NPHS2 rs3829795 polymorphic genotypes as the GA heterozygous genotype shows highly significant difference from controls (P < 0.001) as well as GA + AA genotypes (P < 0.001) in comparison with GG genotype. Regarding rs2274625, The GA heterozygous genotype showed no statistically significant difference between genotypes and alleles with NS (P = 0.246). Association of AG haplotype NPHS2 rs3829795-rs2274625 haplotypes found a significant association with the risk of developing NS (P = 0.008). Concerning the ACTN4 rs121908415 SNP, there was no link between this mutation and NS children. CONCLUSION The correlation of AG haplotype NPHS2 rs3829795-rs2274625 haplotypes identified a strong association with the likelihood of getting NS, according to our findings. There was no connection found between the ACTN4 rs121908415 SNP and NS children.
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Affiliation(s)
- Mohammed F Al-Azzawy
- Biochemistry Division, Chemistry Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt
| | - Mohammad Al-Haggar
- Genetic Unit, Department of Pediatrics, Faculty of Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Afaf M ElSaid
- Genetic Unit, Department of Pediatrics, Faculty of Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Omali Y El-Khawaga
- Biochemistry Division, Chemistry Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt.
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29
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Kylies D, Zimmermann M, Haas F, Schwerk M, Kuehl M, Brehler M, Czogalla J, Hernandez LC, Konczalla L, Okabayashi Y, Menzel J, Edenhofer I, Mezher S, Aypek H, Dumoulin B, Wu H, Hofmann S, Kretz O, Wanner N, Tomas NM, Krasemann S, Glatzel M, Kuppe C, Kramann R, Banjanin B, Schneider RK, Urbschat C, Arck P, Gagliani N, van Zandvoort M, Wiech T, Grahammer F, Sáez PJ, Wong MN, Bonn S, Huber TB, Puelles VG. Expansion-enhanced super-resolution radial fluctuations enable nanoscale molecular profiling of pathology specimens. NATURE NANOTECHNOLOGY 2023; 18:336-342. [PMID: 37037895 PMCID: PMC10115634 DOI: 10.1038/s41565-023-01328-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 01/13/2023] [Indexed: 06/19/2023]
Abstract
Expansion microscopy physically enlarges biological specimens to achieve nanoscale resolution using diffraction-limited microscopy systems1. However, optimal performance is usually reached using laser-based systems (for example, confocal microscopy), restricting its broad applicability in clinical pathology, as most centres have access only to light-emitting diode (LED)-based widefield systems. As a possible alternative, a computational method for image resolution enhancement, namely, super-resolution radial fluctuations (SRRF)2,3, has recently been developed. However, this method has not been explored in pathology specimens to date, because on its own, it does not achieve sufficient resolution for routine clinical use. Here, we report expansion-enhanced super-resolution radial fluctuations (ExSRRF), a simple, robust, scalable and accessible workflow that provides a resolution of up to 25 nm using LED-based widefield microscopy. ExSRRF enables molecular profiling of subcellular structures from archival formalin-fixed paraffin-embedded tissues in complex clinical and experimental specimens, including ischaemic, degenerative, neoplastic, genetic and immune-mediated disorders. Furthermore, as examples of its potential application to experimental and clinical pathology, we show that ExSRRF can be used to identify and quantify classical features of endoplasmic reticulum stress in the murine ischaemic kidney and diagnostic ultrastructural features in human kidney biopsies.
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Affiliation(s)
- Dominik Kylies
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Research Center On Rare Kidney Diseases (RECORD), University Hospital Erlangen, Erlangen, Germany
| | - Marina Zimmermann
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fabian Haas
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maria Schwerk
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Malte Kuehl
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Brehler
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan Czogalla
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lola C Hernandez
- Cell Communication and Migration Laboratory, Department of Biochemistry and Molecular Cell Biology (IBMZ), Center for Experimental Medicine, Hamburg, Germany
| | - Leonie Konczalla
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Mildred Scheel Cancer Career Center HaTriCS4, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Yusuke Okabayashi
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | | | - Ilka Edenhofer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sam Mezher
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hande Aypek
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Bernhard Dumoulin
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hui Wu
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Smilla Hofmann
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola Wanner
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola M Tomas
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Susanne Krasemann
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Kuppe
- Institute of Experimental Medicine and Systems Biology and Division of Nephrology and Clinical Immunology, RWTH Aachen University Medical Faculty, Aachen, Germany
| | - Rafael Kramann
- Institute of Experimental Medicine and Systems Biology and Division of Nephrology and Clinical Immunology, RWTH Aachen University Medical Faculty, Aachen, Germany
| | - Bella Banjanin
- Department of Developmental Biology, Erasmus Medical Center, Rotterdam, The Netherlands
- Oncode Institute, Erasmus Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Rebekka K Schneider
- Department of Developmental Biology, Erasmus Medical Center, Rotterdam, The Netherlands
- Oncode Institute, Erasmus Medical Center Cancer Institute, Rotterdam, The Netherlands
- Institute for Cell and Tumor Biology, RWTH Aachen University, Aachen, Germany
| | - Christopher Urbschat
- Department of Obstetrics and Fetal Medicine, Division of Experimental Feto-Maternal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Petra Arck
- Department of Obstetrics and Fetal Medicine, Division of Experimental Feto-Maternal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola Gagliani
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marc van Zandvoort
- Department of Genetics and Cell Biology, Maastricht University, School for Oncology and Reproduction GROW, School for Mental Health and Neuroscience MHeNS, and School for Cardiovascular Diseases CARIM, Maastricht University, Maastricht, The Netherlands
- Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
| | - Thorsten Wiech
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Florian Grahammer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Pablo J Sáez
- Cell Communication and Migration Laboratory, Department of Biochemistry and Molecular Cell Biology (IBMZ), Center for Experimental Medicine, Hamburg, Germany
| | - Milagros N Wong
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Stefan Bonn
- Institute of Medical Systems Biology, Center for Biomedical AI (bAIome), Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Victor G Puelles
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark.
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Kim DH, Jensen A, Jones K, Raghavan S, Phillips LS, Hung A, Sun YV, Li G, Reaven P, Zhou H, Zhou JJ. A platform for phenotyping disease progression and associated longitudinal risk factors in large-scale EHRs, with application to incident diabetes complications in the UK Biobank. JAMIA Open 2023; 6:ooad006. [PMID: 36789288 PMCID: PMC9912368 DOI: 10.1093/jamiaopen/ooad006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/19/2023] [Accepted: 01/31/2023] [Indexed: 02/12/2023] Open
Abstract
Objective Modern healthcare data reflect massive multi-level and multi-scale information collected over many years. The majority of the existing phenotyping algorithms use case-control definitions of disease. This paper aims to study the time to disease onset and progression and identify the time-varying risk factors that drive them. Materials and Methods We developed an algorithmic approach to phenotyping the incidence of diseases by consolidating data sources from the UK Biobank (UKB), including primary care electronic health records (EHRs). We focused on defining events, event dates, and their censoring time, including relevant terms and existing phenotypes, excluding generic, rare, or semantically distant terms, forward-mapping terminology terms, and expert review. We applied our approach to phenotyping diabetes complications, including a composite cardiovascular disease (CVD) outcome, diabetic kidney disease (DKD), and diabetic retinopathy (DR), in the UKB study. Results We identified 49 049 participants with diabetes. Among them, 1023 had type 1 diabetes (T1D), and 40 193 had type 2 diabetes (T2D). A total of 23 833 diabetes subjects had linked primary care records. There were 3237, 3113, and 4922 patients with CVD, DKD, and DR events, respectively. The risk prediction performance for each outcome was assessed, and our results are consistent with the prediction area under the ROC (receiver operating characteristic) curve (AUC) of standard risk prediction models using cohort studies. Discussion and Conclusion Our publicly available pipeline and platform enable streamlined curation of incidence events, identification of time-varying risk factors underlying disease progression, and the definition of a relevant cohort for time-to-event analyses. These important steps need to be considered simultaneously to study disease progression.
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Affiliation(s)
- Do Hyun Kim
- Department of Biostatistics, University of California, Los Angeles, California, USA
| | - Aubrey Jensen
- Department of Biostatistics, University of California, Los Angeles, California, USA
| | - Kelly Jones
- Department of Computer Science, Columbia University, New York, New York, USA
| | - Sridharan Raghavan
- Division of Hospital Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
| | - Lawrence S Phillips
- Division of Endocrinology, Emory University School of Medicine, Atlanta, Georgia, USA
- Atlanta VA Medical Center, Decatur, Georgia, USA
| | - Adriana Hung
- VA Tennessee Valley Healthcare System, Nashville, Tennessee, USA
- Vanderbilt University, Nashville, Tennessee, USA
| | - Yan V Sun
- Department of Epidemiology, Emory University, Atlanta, Georgia, USA
| | - Gang Li
- Department of Biostatistics, University of California, Los Angeles, California, USA
- Department of Computational Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Peter Reaven
- Phoenix VA Health Care System, Phoenix, Arizona, USA
| | - Hua Zhou
- Department of Biostatistics, University of California, Los Angeles, California, USA
- Department of Computational Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Jin J Zhou
- Department of Biostatistics, University of California, Los Angeles, California, USA
- Phoenix VA Health Care System, Phoenix, Arizona, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
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Abo Zed SED, Hackl A, Bohl K, Ebert L, Kieckhöfer E, Müller C, Becker K, Fink G, Nüsken KD, Nüsken E, Müller RU, Schermer B, Weber LT. Mycophenolic acid directly protects podocytes by preserving the actin cytoskeleton and increasing cell survival. Sci Rep 2023; 13:4281. [PMID: 36922538 PMCID: PMC10017704 DOI: 10.1038/s41598-023-31326-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/09/2023] [Indexed: 03/18/2023] Open
Abstract
Mycophenolate Mofetil (MMF) has an established role as a therapeutic agent in childhood nephrotic syndrome. While other immunosuppressants have been shown to positively affect podocytes, direct effects of MMF on podocytes remain largely unknown. The present study examines the effects of MMF's active component Mycophenolic Acid (MPA) on the transcriptome of podocytes and investigates its biological significance. We performed transcriptomics in cultured murine podocytes exposed to MPA to generate hypotheses on podocyte-specific effects of MPA. Accordingly, we further analyzed biological MPA effects on actin cytoskeleton morphology after treatment with bovine serum albumin (BSA) by immunofluorescence staining, as well as on cell survival following exposure to TNF-α and cycloheximide by neutral red assay. MPA treatment significantly (adjusted p < 0.05) affected expression of 351 genes in podocytes. Gene Ontology term enrichment analysis particularly clustered terms related to actin and inflammation-related cell death. Indeed, quantification of the actin cytoskeleton of BSA treated podocytes revealed a significant increase of thickness and number of actin filaments after treatment with MPA. Further, MPA significantly reduced TNFα and cycloheximide induced cell death. MPA has a substantial effect on the transcriptome of podocytes in vitro, particularly including functional clusters related to non-immune cell dependent mechanisms. This may provide a molecular basis for direct beneficial effects of MPA on the structural integrity and survival of podocytes under pro-inflammatory conditions.
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Affiliation(s)
- Seif El Din Abo Zed
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne, Cologne, Germany
- Faculty of Medicine and University Hospital Cologne, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Agnes Hackl
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne, Cologne, Germany.
- Faculty of Medicine and University Hospital Cologne, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.
| | - Katrin Bohl
- Faculty of Medicine and University Hospital Cologne, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Lena Ebert
- Faculty of Medicine and University Hospital Cologne, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Emilia Kieckhöfer
- Faculty of Medicine and University Hospital Cologne, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Carsten Müller
- Faculty of Medicine and University Hospital Cologne, Pharmacology at the Laboratory Center, Department of Therapeutic Drug Monitoring DE, University of Cologne, Cologne, Germany
| | - Kerstin Becker
- Faculty of Medicine and University Hospital Cologne, Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Gregor Fink
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne, Cologne, Germany
| | - Kai-Dietrich Nüsken
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne, Cologne, Germany
| | - Eva Nüsken
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne, Cologne, Germany
| | - Roman-Ulrich Müller
- Faculty of Medicine and University Hospital Cologne, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Faculty of Medicine and University Hospital Cologne, Center for Rare Kidney Diseases Cologne, University of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Faculty of Medicine and University Hospital Cologne, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Cologne Cluster of Excellence on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Lutz T Weber
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne, Cologne, Germany
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Unnersjö-Jess D, Butt L, Höhne M, Sergei G, Fatehi A, Witasp A, Wernerson A, Patrakka J, Hoyer PF, Blom H, Schermer B, Bozek K, Benzing T. Deep learning-based segmentation and quantification of podocyte foot process morphology suggests differential patterns of foot process effacement across kidney pathologies. Kidney Int 2023; 103:1120-1130. [PMID: 36990215 DOI: 10.1016/j.kint.2023.03.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/17/2023] [Accepted: 03/08/2023] [Indexed: 03/29/2023]
Abstract
Morphological alterations at the kidney filtration barrier increase intrinsic capillary wall permeability resulting in albuminuria. However, automated, quantitative assessment of these morphological changes has not been possible with electron or light microscopy. Here we present a deep learning-based approach for segmentation and quantitative analysis of foot processes in images acquired with confocal and super-resolution fluorescence microscopy. Our method, Automatic Morphological Analysis of Podocytes (AMAP), accurately segments podocyte foot processes and quantifies their morphology. AMAP applied to a set of kidney diseases in patient biopsies and a mouse model of focal segmental glomerulosclerosis allowed for accurate and comprehensive quantification of various morphometric features. With the use of AMAP, detailed morphology of podocyte foot process effacement was found to differ between categories of kidney pathologies, showed detailed variability between diverse patients with the same clinical diagnosis, and correlated with levels of proteinuria. AMAP could potentially complement other readouts such as various omics, standard histologic/electron microscopy and blood/urine assays for future personalized diagnosis and treatment of kidney disease. Thus, our novel finding could have implications to afford an understanding of early phases of kidney disease progression and may provide supplemental information in precision diagnostics.
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Affiliation(s)
- David Unnersjö-Jess
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany; MedTechLabs, Karolinska University Hospital, Solna, Sweden; Division of Renal Medicine, Department of Clinical Sciences, Intervention and Technology, Karolinska Institute, Stockholm, Sweden; Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden.
| | - Linus Butt
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
| | - Martin Höhne
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - German Sergei
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Arash Fatehi
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Anna Witasp
- Division of Renal Medicine, Department of Clinical Sciences, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
| | - Annika Wernerson
- Division of Renal Medicine, Department of Clinical Sciences, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
| | - Jaakko Patrakka
- KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Peter F Hoyer
- Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany
| | - Hans Blom
- MedTechLabs, Karolinska University Hospital, Solna, Sweden; Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden
| | - Bernhard Schermer
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
| | - Katarzyna Bozek
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
| | - Thomas Benzing
- Department II of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany
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Renal clearance of graphene oxide: glomerular filtration or tubular secretion and selective kidney injury association with its lateral dimension. J Nanobiotechnology 2023; 21:51. [PMID: 36765370 PMCID: PMC9913007 DOI: 10.1186/s12951-023-01781-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/12/2023] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND Renal excretion is one of the major routes of nanomaterial elimination from the body. Many previous studies have found that graphene oxide nanosheets are excreted in bulk through the kidneys. However, how the lateral size affects GO disposition in the kidneys including glomerular filtration, active tubular secretion and tubular reabsorption is still unknown. RESULTS The thin, two-dimensional graphene oxide nanosheets (GOs) was observed to excrete in urine through the kidneys, but the lateral dimension of GOs affects their renal clearance pathway and renal injury. The s-GOs could be renal excreted via the glomerular filtration, while the l-GOs were predominately excreted via proximal tubular secretion at a much faster renal clearance rate than the s-GOs. For the tubular secretion of l-GOs, the mRNA level of basolateral organic anion transporters Oat1 and Oat2 in the kidney presented dose dependent increase, while no obvious alterations of the efflux transporters such as Mdr1 and Mrp4 mRNA expression levels were observed, suggesting the accumulation of l-GOs. During the GO renal elimination, mostly the high dose of 15 mg/kg s-GO and l-GO treatment showed obvious kidney injuries but at different renal compartment, i.e., the s-GOs induced obvious glomerular changes in podocytes, while the l-GOs induced more obvious tubular injuries including necrosis of renal tubular epithelial cells, loss of brush border, cast formation and tubular dilatation. The specifically tubular injury biomarkers KIM1 and NGAL were shown slight increase with mRNA levels in l-GO administrated mice. CONCLUSIONS This study shows that the lateral size of GOs affected their interactions with different renal compartments, renal excretion pathways and potential kidney injuries.
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Shi J, Hu Y, Shao G, Zhu Y, Zhao Z, Xu Y, Zhang Z, Wu H. Quantifying Podocyte Number in a Small Sample Size of Glomeruli with CUBIC to Evaluate Podocyte Depletion of db/db Mice. J Diabetes Res 2023; 2023:1901105. [PMID: 36776229 PMCID: PMC9908347 DOI: 10.1155/2023/1901105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 12/31/2022] [Accepted: 01/04/2023] [Indexed: 02/04/2023] Open
Abstract
The loss of podocyte is crucial for diagnosis and prognosis of diabetic kidney disease, whereas commonly two-dimensional methods for quantifying podocyte number existed with issues of low fidelity and accuracy. In this study, clear, unobstructed brain imaging cocktails and computational analysis (CUBIC), one of three-dimensional optical clearing approaches, was used which combines tissue clearing, immunolabeling, and a light-sheet microscope to image and evaluate podocytes in C57BL/6 (C57) and db/db mice. We discovered that 77 podocytes per glomerulus were in C57 mice. On the subject of db/db mice, there were 74 podocytes by the age of 8 w, 72 podocytes by the age of 12 w, and 66 podocytes by the age of 16 w, compared with 76 podocytes in the control group, suggesting that there was a significant decrease in podocyte number in db/db mice with the age of 16 w, showing a trend which positively correlated to the deterioration of kidney function. Sample size estimation using the PASS software revealed that taking 5%, 7.5%, and 10% of the mean podocyte number per glomerulus as the statistical allowable error and 95% as total confidence interval, 33, 15, and 9 glomeruli were independently needed to be sampled in C57 mice to represent the overall glomeruli to calculate podocyte number. Furthermore, in the control group of db/db mice, 36, 18, and 11 glomeruli were needed, compared with 46, 24, and 14 glomeruli in db/db mice by the age of 8 w, 43, 21, and 12 glomeruli by the age of 12 w, and 52, 27, and 16 by the age of 16 w. These findings indicated that precise quantification of podocyte number could judge the progression of diabetic kidney disease. In addition, a small number of glomeruli could be actually representative of the whole sample size, which indicated apparent practicability of CUBIC for clinical use.
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Affiliation(s)
- Jiaoyu Shi
- Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yuan Hu
- Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
- Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Guangze Shao
- Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yixiang Zhu
- School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, NHC Key Lab of Health Technology Assessment, Fudan University, Shanghai 200032, China
| | - Zhonghua Zhao
- Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yanyong Xu
- Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
- Key Laboratory of Metabolism and Molecular Medicine of the Ministry of Education, Department of Pathology of School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
- Frontier Innovation Center, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Zhigang Zhang
- Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Huijuan Wu
- Department of Pathology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
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Xu Z, Yue P, Feng JJ. Poroelastic modelling reveals the cooperation between two mechanisms for albuminuria. J R Soc Interface 2023; 20:20220634. [PMID: 36628531 PMCID: PMC9832287 DOI: 10.1098/rsif.2022.0634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 12/08/2022] [Indexed: 01/12/2023] Open
Abstract
Albuminuria occurs when albumin leaks abnormally into the urine. Its mechanism remains unclear. A gel-compression hypothesis attributes the glomerular barrier to compression of the glomerular basement membrane (GBM) as a gel layer. Loss of podocyte foot processes would allow the gel layer to expand circumferentially, enlarge its pores and leak albumin into the urine. To test this hypothesis, we develop a poroelastic model of the GBM. It predicts GBM compression in healthy glomerulus and GBM expansion in the diseased state, essentially confirming the hypothesis. However, by itself, the gel compression and expansion mechanism fails to account for two features of albuminuria: the reduction in filtration flux and the thickening of the GBM. A second mechanism, the constriction of flow area at the slit diaphragm downstream of the GBM, must be included. The cooperation between the two mechanisms produces the amount of increase in GBM porosity expected in vivo in a mutant mouse model, and also captures the two in vivo features of reduced filtration flux and increased GBM thickness. Finally, the model supports the idea that in the healthy glomerulus, gel compression may help maintain a roughly constant filtration flux under varying filtration pressure.
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Affiliation(s)
- Zelai Xu
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z2
| | - Pengtao Yue
- Department of Mathematics, Virginia Tech, Blacksburg, VA 24061, USA
| | - James J. Feng
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z2
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z2
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Unnersjö-Jess D. Quantitative Imaging of Podocyte Foot Processes in the Kidney Using Confocal and STED Microscopy. Methods Mol Biol 2023; 2664:185-199. [PMID: 37423991 DOI: 10.1007/978-1-0716-3179-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Morphological alterations to the kidney filter, particularly to podocyte foot processes, are seen in most types of glomerular diseases. Due to the nanoscale dimensions of the filter, visualization of such alterations has historically relied on electron microscopy. However, with recent technical development, it is now possible to also visualize podocyte foot processes, as well as other parts of the kidney filtration barrier, with light microscopy. With developments both in sample preparation, imaging, and image analysis, these new tools are becoming increasingly applied in kidney research, due to their demonstrated quantitative potential. We here present an overview of these protocols that can be applied to samples that have been fixed and stored using most standard procedures used today (i.e., PFA fixed, fresh frozen, formalin-fixed and paraffin-embedded (FFPE)). We additionally introduce tools for quantitative image analysis of foot process morphology and foot process effacement.
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Affiliation(s)
- David Unnersjö-Jess
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
- MedTechLabs, Karolinska University Hospital, Solna, Sweden.
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Trimarco V, Izzo R, Mone P, Lembo M, Manzi MV, Pacella D, Falco A, Gallo P, Esposito G, Morisco C, Santulli G, Trimarco B. Therapeutic concordance improves blood pressure control in patients with resistant hypertension. Pharmacol Res 2023; 187:106557. [PMID: 36402254 PMCID: PMC9943685 DOI: 10.1016/j.phrs.2022.106557] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/10/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022]
Abstract
INTRODUCTION An empathetic approach may be particularly useful in patients with therapy-resistant hypertension (TRH), defined as the failure to achieve target blood pressure (BP) despite a maximal doses of 3 antihypertensive drugs including a diuretic. However, the effects of therapeutic concordance have not been determined in hypertensive patients. METHODS We designed a study to explore the impact of therapeutic concordance in patients with TRH, who were included in an intervention arm based on a protocol in which trained personnel periodically verified the pharmacological regimen of these patients. RESULTS From a cohort of 5331 hypertensive patients followed-up for 77.64 ± 34.44 months, 886 subjects were found to have TRH; of these, 322 had apparent TRH (aTRH: uncontrolled office BP but optimal home BP) and 285 refused to participate in a second follow-up study, yielding a population of 279 patients with true TRH (tTRH). These tTRH patients were followed according to the therapeutic concordance protocol for 91.91 ± 54.7 months, revealing that 210 patients (75.27%) remained with uncontrolled BP (uncontrolled tTRH, Group I) while 69 patients (24.73%) reached an optimal BP control (average BP <140/90 mmHg in at least 50% of follow-up visits, Group II). Strikingly, at the end of the second follow-up, the percentage of patients displaying a decline in kidney function was significantly smaller in Group II than in Group I (8.5% vs 23.4%, p < 0.012). CONCLUSIONS Taken together, our findings indicate for the first time that therapeutic concordance significantly improves the outcome of antihypertensive treatment in a population of patients with TRH.
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Affiliation(s)
- Valentina Trimarco
- Department of Neuroscience, Reproductive Sciences and Dentistry, “Federico II” University, Naples, Italy
| | - Raffaele Izzo
- Department of Advanced Biomedical Sciences, “Federico II” University, Naples, Italy
| | - Pasquale Mone
- Department of Medicine, Division of Cardiology, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, New York City, NY, USA
| | - Maria Lembo
- Department of Advanced Biomedical Sciences, “Federico II” University, Naples, Italy
| | - Maria Virginia Manzi
- Department of Advanced Biomedical Sciences, “Federico II” University, Naples, Italy
| | - Daniela Pacella
- Department of Public Health, “Federico II” University, Naples, Italy
| | - Angela Falco
- Department of Neuroscience, Reproductive Sciences and Dentistry, “Federico II” University, Naples, Italy
| | - Paola Gallo
- Department of Advanced Biomedical Sciences, “Federico II” University, Naples, Italy
| | - Giovanni Esposito
- Department of Advanced Biomedical Sciences, “Federico II” University, Naples, Italy
| | - Carmine Morisco
- Department of Advanced Biomedical Sciences, “Federico II” University, Naples, Italy,International Translational Research and Medical Education (ITME) Consortium, Naples, Italy
| | - Gaetano Santulli
- Department of Advanced Biomedical Sciences, "Federico II" University, Naples, Italy; Department of Medicine, Division of Cardiology, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, New York City, NY, USA; International Translational Research and Medical Education (ITME) Consortium, Naples, Italy; Department of Molecular Pharmacology, Fleischer Institute for Diabetes and Metabolism (FIDAM), Albert Einstein College of Medicine, New York City, NY, USA.
| | - Bruno Trimarco
- Department of Advanced Biomedical Sciences, “Federico II” University, Naples, Italy,International Translational Research and Medical Education (ITME) Consortium, Naples, Italy
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Staruschenko A, Ma R, Palygin O, Dryer SE. Ion channels and channelopathies in glomeruli. Physiol Rev 2023; 103:787-854. [PMID: 36007181 PMCID: PMC9662803 DOI: 10.1152/physrev.00013.2022] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 11/22/2022] Open
Abstract
An essential step in renal function entails the formation of an ultrafiltrate that is delivered to the renal tubules for subsequent processing. This process, known as glomerular filtration, is controlled by intrinsic regulatory systems and by paracrine, neuronal, and endocrine signals that converge onto glomerular cells. In addition, the characteristics of glomerular fluid flow, such as the glomerular filtration rate and the glomerular filtration fraction, play an important role in determining blood flow to the rest of the kidney. Consequently, disease processes that initially affect glomeruli are the most likely to lead to end-stage kidney failure. The cells that comprise the glomerular filter, especially podocytes and mesangial cells, express many different types of ion channels that regulate intrinsic aspects of cell function and cellular responses to the local environment, such as changes in glomerular capillary pressure. Dysregulation of glomerular ion channels, such as changes in TRPC6, can lead to devastating glomerular diseases, and a number of channels, including TRPC6, TRPC5, and various ionotropic receptors, are promising targets for drug development. This review discusses glomerular structure and glomerular disease processes. It also describes the types of plasma membrane ion channels that have been identified in glomerular cells, the physiological and pathophysiological contexts in which they operate, and the pathways by which they are regulated and dysregulated. The contributions of these channels to glomerular disease processes, such as focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy, as well as the development of drugs that target these channels are also discussed.
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Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
- James A. Haley Veterans Hospital, Tampa, Florida
| | - Rong Ma
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, Texas
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Kourpa A, Kaiser-Graf D, Sporbert A, Philippe A, Catar R, Rothe M, Mangelsen E, Schulz A, Bolbrinker J, Kreutz R, Panáková D. 15-keto-Prostaglandin E2 exhibits bioactive role by modulating glomerular cytoarchitecture through EP2/EP4 receptors. Life Sci 2022; 310:121114. [DOI: 10.1016/j.lfs.2022.121114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/06/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
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Naylor RW, Watson E, Williamson S, Preston R, Davenport JB, Thornton N, Lowe M, Williams M, Lennon R. Basement membrane defects in CD151-associated glomerular disease. Pediatr Nephrol 2022; 37:3105-3115. [PMID: 35278129 PMCID: PMC9587066 DOI: 10.1007/s00467-022-05447-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 01/10/2023]
Abstract
BACKGROUND CD151 is a cell-surface molecule of the tetraspanin family. Its lateral interaction with laminin-binding integrin ɑ3β1 is important for podocyte adhesion to the glomerular basement membrane (GBM). Deletion of Cd151 in mice induces glomerular dysfunction, with proteinuria and associated focal glomerulosclerosis, disorganisation of GBM and tubular cystic dilation. Despite this, CD151 is not routinely screened for in patients with nephrotic-range proteinuria. We aimed to better understand the relevance of CD151 in human kidney disease. METHODS Next-generation sequencing (NGS) was used to detect the variant in CD151. Electron and light microscopy were used to visualise the filtration barrier in the patient kidney biopsy, and immunoreactivity of patient red blood cells to anti-CD151/MER2 antibodies was performed. Further validation of the CD151 variant as disease-causing was performed in zebrafish using CRISPR-Cas9. RESULTS We report a young child with nail dystrophy and persistent urinary tract infections who was incidentally found to have nephrotic-range proteinuria. Through targeted NGS, a novel, homozygous truncating variant was identified in CD151, a gene rarely reported in patients with nephrotic syndrome. Electron microscopy imaging of patient kidney tissue showed thickening of GBM and podocyte effacement. Immunofluorescence of patient kidney tissue demonstrated that CD151 was significantly reduced, and we did not detect immunoreactivity to CD151/MER2 on patient red blood cells. CRISPR-Cas9 depletion of cd151 in zebrafish caused proteinuria, which was rescued by injection of wild-type CD151 mRNA, but not CD151 mRNA containing the variant sequence. CONCLUSIONS Our results indicate that a novel variant in CD151 is associated with nephrotic-range proteinuria and microscopic haematuria and provides further evidence for a role of CD151 in glomerular disease. Our work highlights a functional testing pipeline for future analysis of patient genetic variants. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, UK
| | - Elizabeth Watson
- South West Genomic Laboratory Hub, Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, Bristol, UK
| | - Samantha Williamson
- Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Rebecca Preston
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, UK
| | - J Bernard Davenport
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, UK
| | - Nicole Thornton
- International Blood Group Reference Laboratory, NHS Blood and Transplant, Filton, Bristol, UK
| | - Martin Lowe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Maggie Williams
- South West Genomic Laboratory Hub, Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, Bristol, UK
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, M13 9PT, UK.
- Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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Bryant C, Webb A, Banks AS, Chandler D, Govindarajan R, Agrawal S. Alternatively Spliced Landscape of PPARγ mRNA in Podocytes Is Distinct from Adipose Tissue. Cells 2022; 11:cells11213455. [PMID: 36359851 PMCID: PMC9653906 DOI: 10.3390/cells11213455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/13/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
Podocytes are highly differentiated epithelial cells, and their structural and functional integrity is compromised in a majority of glomerular and renal diseases, leading to proteinuria, chronic kidney disease, and kidney failure. Traditional agonists (e.g., pioglitazone) and selective modulators (e.g., GQ-16) of peroxisome-proliferator-activated-receptor-γ (PPARγ) reduce proteinuria in animal models of glomerular disease and protect podocytes from injury via PPARγ activation. This indicates a pivotal role for PPARγ in maintaining glomerular function through preservation of podocytes distinct from its well-understood role in driving insulin sensitivity and adipogenesis. While its transcriptional role in activating adipokines and adipogenic genes is well-established in adipose tissue, liver and muscle, understanding of podocyte PPARγ signaling remains limited. We performed a comprehensive analysis of PPARγ mRNA variants due to alternative splicing, in human podocytes and compared with adipose tissue. We found that podocytes express the ubiquitous PPARγ Var 1 (encoding γ1) and not Var2 (encoding γ2), which is mostly restricted to adipose tissue and liver. Additionally, we detected expression at very low level of Var4, and barely detectable levels of other variants, Var3, Var11, VartORF4 and Var9, in podocytes. Furthermore, a distinct podocyte vs. adipocyte PPAR-promoter-response-element containing gene expression, enrichment and pathway signature was observed, suggesting differential regulation by podocyte specific PPARγ1 variant, distinct from the adipocyte-specific γ2 variant. In summary, podocytes and glomeruli express several PPARγ variants, including Var1 (γ1) and excluding adipocyte-specific Var2 (γ2), which may have implications in podocyte specific signaling and pathophysiology. This suggests that that new selective PPARγ modulators can be potentially developed that will be able to distinguish between the two forms, γ1 and γ2, thus forming a basis of novel targeted therapeutic avenues.
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Affiliation(s)
- Claire Bryant
- Center for Clinical and Translational Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Amy Webb
- Department of Bioinformatics, The Ohio State University, Columbus, OH 43210, USA
| | - Alexander S. Banks
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Dawn Chandler
- Center for Childhood Cancer and Blood Disease, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Rajgopal Govindarajan
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
- Translational Therapeutics, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Shipra Agrawal
- Center for Clinical and Translational Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
- Division of Nephrology and Hypertension, Department of Medicine, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
- Correspondence:
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Odenthal J, Dittrich S, Ludwig V, Merz T, Reitmeier K, Reusch B, Höhne M, Cosgun ZC, Hohenadel M, Putnik J, Göbel H, Rinschen MM, Altmüller J, Koehler S, Schermer B, Benzing T, Beck BB, Brinkkötter PT, Habbig S, Bartram MP. Modeling of ACTN4-Based Podocytopathy Using Drosophila Nephrocytes. Kidney Int Rep 2022; 8:317-329. [PMID: 36815115 PMCID: PMC9939316 DOI: 10.1016/j.ekir.2022.10.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022] Open
Abstract
Introduction Genetic disorders are among the most prevalent causes leading to progressive glomerular disease and, ultimately, end-stage renal disease (ESRD) in children and adolescents. Identification of underlying genetic causes is indispensable for targeted treatment strategies and counseling of affected patients and their families. Methods Here, we report on a boy who presented at 4 years of age with proteinuria and biopsy-proven focal segmental glomerulosclerosis (FSGS) that was temporarily responsive to treatment with ciclosporin A. Molecular genetic testing identified a novel mutation in alpha-actinin-4 (p.M240T). We describe a feasible and efficient experimental approach to test its pathogenicity by combining in silico, in vitro, and in vivo analyses. Results The de novo p.M240T mutation led to decreased alpha-actinin-4 stability as well as protein mislocalization and actin cytoskeleton rearrangements. Transgenic expression of wild-type human alpha-actinin-4 in Drosophila melanogaster nephrocytes was able to ameliorate phenotypes associated with the knockdown of endogenous actinin. In contrast, p.M240T, as well as other established disease variants p.W59R and p.K255E, failed to rescue these phenotypes, underlining the pathogenicity of the novel alpha-actinin-4 variant. Conclusion Our data highlight that the newly identified alpha-actinin-4 mutation indeed encodes for a disease-causing variant of the protein and promote the Drosophila model as a simple and convenient tool to study monogenic kidney disease in vivo.
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Affiliation(s)
- Johanna Odenthal
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Sebastian Dittrich
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Vivian Ludwig
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Tim Merz
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Katrin Reitmeier
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Björn Reusch
- Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Institute of Human Genetics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Zülfü C. Cosgun
- Department of Pediatrics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Maximilian Hohenadel
- Department of Pediatrics, Division of Pediatric Nephrology, University of Bonn, Bonn, Germany
| | - Jovana Putnik
- Mother and Child Health Care Institute of Serbia “Dr Vukan Čupić,” Department of Nephrology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Heike Göbel
- Institute of Pathology, University Hospital of Cologne, Cologne, Germany
| | - Markus M. Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark,Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark,III Medical Clinic, University Hospital Hamburg Eppendorf, Hamburg, Germany
| | - Janine Altmüller
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine, Berlin, Germany,Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Sybille Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Bodo B. Beck
- Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Institute of Human Genetics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Paul T. Brinkkötter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Correspondence: Paul T. Brinkkoetter, Department II of Internal Medicine, Faculty of Medicine, University of Cologne, University Hospital Cologne, Kerpener Street 62, Cologne 50935, Germany.
| | - Sandra Habbig
- Department of Pediatrics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Malte P. Bartram
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
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A slit-diaphragm-associated protein network for dynamic control of renal filtration. Nat Commun 2022; 13:6446. [PMID: 36307401 PMCID: PMC9616960 DOI: 10.1038/s41467-022-33748-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 09/29/2022] [Indexed: 12/25/2022] Open
Abstract
The filtration of blood in the kidney which is crucial for mammalian life is determined by the slit-diaphragm, a cell-cell junction between the foot processes of renal podocytes. The slit-diaphragm is thought to operate as final barrier or as molecular sensor of renal filtration. Using high-resolution proteomic analysis of slit-diaphragms affinity-isolated from rodent kidney, we show that the native slit-diaphragm is built from the junction-forming components Nephrin, Neph1 and Podocin and a co-assembled high-molecular weight network of proteins. The network constituents cover distinct classes of proteins including signaling-receptors, kinases/phosphatases, transporters and scaffolds. Knockout or knock-down of either the core components or the selected network constituents tyrosine kinase MER (MERTK), atrial natriuretic peptide-receptor C (ANPRC), integral membrane protein 2B (ITM2B), membrane-associated guanylate-kinase, WW and PDZ-domain-containing protein1 (MAGI1) and amyloid protein A4 resulted in target-specific impairment or disruption of the filtration process. Our results identify the slit-diaphragm as a multi-component system that is endowed with context-dependent dynamics via a co-assembled protein network.
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44
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Naylor RW, Lemarie E, Jackson-Crawford A, Davenport JB, Mironov A, Lowe M, Lennon R. A novel nanoluciferase transgenic reporter measures proteinuria in zebrafish. Kidney Int 2022; 102:815-827. [PMID: 35716957 DOI: 10.1101/2021.07.19.452884] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 05/28/2023]
Abstract
The zebrafish is an important animal system for modeling human diseases. This includes kidney dysfunction as the embryonic kidney (pronephros) shares considerable molecular and morphological homology with the human nephron. A key clinical indicator of kidney disease is proteinuria, but a high-throughput readout of proteinuria in the zebrafish is currently lacking. To remedy this, we used the Tol2 transposon system to generate a transgenic zebrafish line that uses the fabp10a liver-specific promoter to over-express a nanoluciferase molecule fused with the D3 domain of Receptor-Associated Protein (a type of molecular chaperone) which we term NL-D3. Using a luminometer, we quantified proteinuria in NL-D3 zebrafish larvae by measuring the intensity of luminescence in the embryo medium. In the healthy state, NL-D3 is not excreted, but when embryos were treated with chemicals that affected either proximal tubular reabsorption (cisplatin, gentamicin) or glomerular filtration (angiotensin II, Hanks Balanced Salt Solution, Bovine Serum Albumin), NL-D3 is detected in fish medium. Similarly, depletion of several gene products associated with kidney disease (nphs1, nphs2, lrp2a, ocrl, col4a3, and col4a4) also induced NL-D3 proteinuria. Treating col4a4 depleted zebrafish larvae (a model of Alport syndrome) with captopril reduced proteinuria in this system. Thus, our findings validate the use of the NL-D3 transgenic zebrafish as a robust and quantifiable proteinuria reporter. Hence, given the feasibility of high-throughput assays in zebrafish, this novel reporter will permit screening for drugs that ameliorate proteinuria, thereby prioritizing candidates for further translational studies.
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Affiliation(s)
- Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Emmanuel Lemarie
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | | | - J Bernard Davenport
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Aleksandr Mironov
- EM Core Facility (RRID: SCR_021147), Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Martin Lowe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK; Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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45
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Naylor RW, Lemarie E, Jackson-Crawford A, Davenport JB, Mironov A, Lowe M, Lennon R. A novel nanoluciferase transgenic reporter measures proteinuria in zebrafish. Kidney Int 2022; 102:815-827. [PMID: 35716957 PMCID: PMC7614274 DOI: 10.1016/j.kint.2022.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 04/25/2022] [Accepted: 05/09/2022] [Indexed: 11/21/2022]
Abstract
The zebrafish is an important animal system for modeling human diseases. This includes kidney dysfunction as the embryonic kidney (pronephros) shares considerable molecular and morphological homology with the human nephron. A key clinical indicator of kidney disease is proteinuria, but a high-throughput readout of proteinuria in the zebrafish is currently lacking. To remedy this, we used the Tol2 transposon system to generate a transgenic zebrafish line that uses the fabp10a liver-specific promoter to over-express a nanoluciferase molecule fused with the D3 domain of Receptor-Associated Protein (a type of molecular chaperone) which we term NL-D3. Using a luminometer, we quantified proteinuria in NL-D3 zebrafish larvae by measuring the intensity of luminescence in the embryo medium. In the healthy state, NL-D3 is not excreted, but when embryos were treated with chemicals that affected either proximal tubular reabsorption (cisplatin, gentamicin) or glomerular filtration (angiotensin II, Hanks Balanced Salt Solution, Bovine Serum Albumin), NL-D3 is detected in fish medium. Similarly, depletion of several gene products associated with kidney disease (nphs1, nphs2, lrp2a, ocrl, col4a3, and col4a4) also induced NL-D3 proteinuria. Treating col4a4 depleted zebrafish larvae (a model of Alport syndrome) with captopril reduced proteinuria in this system. Thus, our findings validate the use of the NL-D3 transgenic zebrafish as a robust and quantifiable proteinuria reporter. Hence, given the feasibility of high-throughput assays in zebrafish, this novel reporter will permit screening for drugs that ameliorate proteinuria, thereby prioritizing candidates for further translational studies.
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Affiliation(s)
- Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Emmanuel Lemarie
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | | | - J Bernard Davenport
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Aleksandr Mironov
- EM Core Facility (RRID: SCR_021147), Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Martin Lowe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK; Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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46
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Jiang S, Alisafaei F, Huang YY, Hong Y, Peng X, Qu C, Puapatanakul P, Jain S, Miner JH, Genin GM, Suleiman HY. An ex vivo culture model of kidney podocyte injury reveals mechanosensitive, synaptopodin-templating, sarcomere-like structures. SCIENCE ADVANCES 2022; 8:eabn6027. [PMID: 36044576 PMCID: PMC9432837 DOI: 10.1126/sciadv.abn6027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Chronic kidney diseases are widespread and incurable. The biophysical mechanisms underlying them are unclear, in part because material systems for reconstituting the microenvironment of relevant kidney cells are limited. A critical question is how kidney podocytes (glomerular epithelial cells) regenerate foot processes of the filtration apparatus following injury. Recently identified sarcomere-like structures (SLSs) with periodically spaced myosin IIA and synaptopodin appear in injured podocytes in vivo. We hypothesized that SLSs template synaptopodin in the initial stages of recovery in response to microenvironmental stimuli and tested this hypothesis by developing an ex vivo culture system that allows control of the podocyte microenvironment. Results supported our hypothesis. SLSs in podocytes that migrated from isolated kidney glomeruli presented periodic synaptopodin-positive clusters that nucleated peripheral, foot process-like extensions. SLSs were mechanoresponsive to actomyosin inhibitors and substrate stiffness. Results suggest SLSs as mechanobiological mediators of podocyte recovery and as potential targets for therapeutic intervention.
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Affiliation(s)
- Shumeng Jiang
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Farid Alisafaei
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Yin-Yuan Huang
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Yuan Hong
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Xiangjun Peng
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Chengqing Qu
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Pongpratch Puapatanakul
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Sanjay Jain
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Jeffrey H. Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Guy M. Genin
- NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
- Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA
| | - Hani Y. Suleiman
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
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47
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Hsieh T, Jin J. Loss of Calponin 2 causes age-progressive proteinuria in mice. Physiol Rep 2022; 10:e15370. [PMID: 36117313 PMCID: PMC9483440 DOI: 10.14814/phy2.15370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023] Open
Abstract
Proteinuria is a major manifestation of kidney disease, reflecting injuries of glomerular podocytes. Actin cytoskeleton plays a pivotal role in stabilizing the foot processes of podocytes against the hydrostatic pressure of filtration. Calponin is an actin associated protein that regulates mechanical tension-related cytoskeleton functions and its role in podocytes has not been established. Here we studied the kidney phenotypes of calponin isoform 2 knockout (KO) mice. Urine samples were examined to quantify the ratio of albumin and creatinine. Kidney tissue samples were collected for histology and ultrastructural studies. A mouse podocyte cell line (E11) was used to study the expression and cellular localization of calponin 2. In comparison with wild-type (WT) controls, calponin 2 KO mice showed age-progressive high proteinuria and degeneration of renal glomeruli. High levels of calponin 2 are expressed in E11 podocytes and colocalized with actin stress fibers, tropomyosin and myosin IIA. Electron microscopy showed that aging calponin 2 KO mice had effacement of the podocyte foot processes and increased thickness of the glomerular basement membrane as compared to that of WT control. The findings demonstrate that deletion of calponin 2 aggravates age-progressive degeneration of the glomerular structure and function as filtration barrier. The critical role of calponin 2 in podocytes suggests a molecular target for understanding the pathogenesis of proteinuria and therapeutic development.
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Affiliation(s)
- Tzu‐Bou Hsieh
- Department of Obstetrics & GynecologyWayne State University School of MedicineDetroitMichiganUSA
| | - Jian‐Ping Jin
- Department of Obstetrics & GynecologyWayne State University School of MedicineDetroitMichiganUSA
- Department of PhysiologyWayne State University School of MedicineDetroitMichiganUSA
- Department of Physiology and BiophysicsUniversity of Illinois at Chicago College of MedicineChicagoIllinoisUSA
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48
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Cao Y, Shao L, Xin M, Zhang Y, Xu Y, Song Y, Lu H, Wang Y, Xia Y, Zhang M, Guo Y, Wang L, Qiao Z. Urine protein in patients with type I hypersensitivity is indicative of reversible renal tube injury. Life Sci 2022; 305:120735. [DOI: 10.1016/j.lfs.2022.120735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 04/07/2022] [Accepted: 06/23/2022] [Indexed: 11/24/2022]
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49
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Lausecker F, Koehler S, Fresquet M, Naylor RW, Tian P, Wanner N, Braun F, Butt L, Huber TB, Lennon R. Integrating basic science with translational research: the 13th International Podocyte Conference 2021. Kidney Int 2022; 102:708-719. [PMID: 35964799 PMCID: PMC9386279 DOI: 10.1016/j.kint.2022.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/20/2022] [Accepted: 07/26/2022] [Indexed: 11/30/2022]
Abstract
The 13th International Podocyte Conference was held in Manchester, UK, and online from July 28 to 30, 2021. Originally planned for 2020, this biannual meeting was postponed by a year because of the coronavirus disease 2019 (COVID-19) pandemic and proceeded as an innovative hybrid meeting. In addition to in-person attendance, online registration was offered, and this attracted 490 conference registrations in total. As a Podocyte Conference first, a day for early-career researchers was introduced. This premeeting included talks from graduate students and postdoctoral researchers. It gave early career researchers the opportunity to ask a panel, comprising academic leaders and journal editors, about career pathways and the future for podocyte research. The main meeting over 3 days included a keynote talk and 4 focused sessions each day incorporating invited talks, followed by selected abstract presentations, and an open panel discussion. The conference concluded with a Patient Day, which brought together patients, clinicians, researchers, and industry representatives. The Patient Day was an interactive and diverse day. As well as updates on improving diagnosis and potential new therapies, the Patient Day included a PodoArt competition, exercise and cooking classes with practical nutrition advice, and inspirational stories from patients and family members. This review summarizes the exciting science presented during the 13th International Podocyte Conference and demonstrates the resilience of researchers during a global pandemic.
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Affiliation(s)
- Franziska Lausecker
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Sybille Koehler
- Biomedical Sciences, University of Edinburgh, Edinburgh, UK; III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maryline Fresquet
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Richard W Naylor
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Pinyuan Tian
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Nicola Wanner
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fabian Braun
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Linus Butt
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK; Department of Paediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals National Health Service (NHS) Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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50
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Martin CE, Phippen NJ, Keyvani Chahi A, Tilak M, Banerjee SL, Lu P, New LA, Williamson CR, Platt MJ, Simpson JA, Krendel M, Bisson N, Gingras AC, Jones N. Complementary Nck1/2 Signaling in Podocytes Controls α Actinin-4-Mediated Actin Organization, Adhesion, and Basement Membrane Composition. J Am Soc Nephrol 2022; 33:1546-1567. [PMID: 35906089 PMCID: PMC9342632 DOI: 10.1681/asn.2021101343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 04/26/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Maintenance of the kidney filtration barrier requires coordinated interactions between podocytes and the underlying glomerular basement membrane (GBM). GBM ligands bind podocyte integrins, which triggers actin-based signaling events critical for adhesion. Nck1/2 adaptors have emerged as essential regulators of podocyte cytoskeletal dynamics. However, the precise signaling mechanisms mediated by Nck1/2 adaptors in podocytes remain to be fully elucidated. METHODS We generated podocytes deficient in Nck1 and Nck2 and used transcriptomic approaches to profile expression differences. Proteomic techniques identified specific binding partners for Nck1 and Nck2 in podocytes. We used cultured podocytes and mice deficient in Nck1 and/or Nck2, along with podocyte injury models, to comprehensively verify our findings. RESULTS Compound loss of Nck1/2 altered expression of genes involved in actin binding, cell adhesion, and extracellular matrix composition. Accordingly, Nck1/2-deficient podocytes showed defects in actin organization and cell adhesion in vitro, with podocyte detachment and altered GBM morphology present in vivo. We identified distinct interactomes for Nck1 and Nck2 and uncovered a mechanism by which Nck1 and Nck2 cooperate to regulate actin bundling at focal adhesions via α actinin-4. Furthermore, loss of Nck1 or Nck2 resulted in increased matrix deposition in vivo, with more prominent defects in Nck2-deficient mice, consistent with enhanced susceptibility to podocyte injury. CONCLUSION These findings reveal distinct, yet complementary, roles for Nck proteins in regulating podocyte adhesion, controlling GBM composition, and sustaining filtration barrier integrity.
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Affiliation(s)
- Claire E Martin
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada
| | - Noah J Phippen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Ava Keyvani Chahi
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Manali Tilak
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Sara L Banerjee
- Division of Oncology, Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Laval University, Quebec City, Quebec, Canada.,Centre de Recherche sur le Cancer de l'Université Laval, Quebec City, Quebec, Canada
| | - Peihua Lu
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Laura A New
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Casey R Williamson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Mathew J Platt
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Mira Krendel
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York
| | - Nicolas Bisson
- Division of Oncology, Centre de Recherche du Centre Hospitalier Universitaire de Quebec-Laval University, Quebec City, Quebec, Canada.,Centre de Recherche sur le Cancer de l'Université Laval, Quebec City, Quebec, Canada.,PROTEO-Quebec Network for Research on Protein Function, Engineering, and Applications Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Quebec, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Nina Jones
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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