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Gerhardt LMS. From the Beginning to the End: Effects of Proteinuria along the Renal Tubule. J Am Soc Nephrol 2024:00001751-990000000-00337. [PMID: 38814710 DOI: 10.1681/asn.0000000000000399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024] Open
Affiliation(s)
- Louisa M S Gerhardt
- Fifth Department of Medicine, Faculty of Medicine Mannheim of the University of Heidelberg, University Medical Center Mannheim, Mannheim, Germany
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2
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Faivre A, Bugarski M, Rinaldi A, Sakhi IB, Verissimo T, Legouis D, Correia S, Kaminska M, Dalga D, Malpetti D, Cippa PE, de Seigneux S, Hall AM. Spatiotemporal Landscape of Kidney Tubular Responses to Glomerular Proteinuria. J Am Soc Nephrol 2024:00001751-990000000-00299. [PMID: 38652545 DOI: 10.1681/asn.0000000000000357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 04/12/2024] [Indexed: 04/25/2024] Open
Abstract
Key Points
Glomerular proteinuria induces large-scale changes in gene expression along the nephron.Increased protein uptake in the proximal tubule results in axial remodeling and injury.Increased protein delivery to the distal tubule causes dedifferentiation of the epithelium.
Background
Large increases in glomerular protein filtration induce major changes in body homeostasis and are associated with a higher risk of kidney functional decline and cardiovascular disease. We investigated how elevated protein exposure modifies the landscape of tubular function along the entire nephron, to understand the cellular changes that mediate these important clinical phenomena.
Methods
We conducted single-nucleus RNA sequencing, functional intravital imaging, and antibody staining to spatially map transport processes along the mouse kidney tubule. We then delineated how these were altered in a transgenic mouse model of inducible glomerular proteinuria (POD-ATTAC) at 7 and 28 days.
Results
Glomerular proteinuria activated large-scale and pleiotropic changes in gene expression in all major nephron sections. Extension of protein uptake from early (S1) to later (S2) parts of the proximal tubule initially triggered dramatic expansion of a hybrid S1/2 population, followed by injury and failed repair, with the cumulative effect of loss of canonical S2 functions. Proteinuria also induced acute injury in S3. Meanwhile, overflow of luminal proteins to the distal tubule caused transcriptional convergence between specialized regions and generalized dedifferentiation.
Conclusions
Proteinuria modulated cell signaling in tubular epithelia and caused distinct patterns of remodeling and injury in a segment-specific manner.
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Affiliation(s)
- Anna Faivre
- Department of Medicine and Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Milica Bugarski
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Anna Rinaldi
- Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland
- Division of Nephrology, Department of Medicine, Ente Ospedaliero Cantonale, Lugano, Switzerland
| | - Imene B Sakhi
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Thomas Verissimo
- Department of Medicine and Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - David Legouis
- Department of Medicine and Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
- Division of Intensive Care, Department of Acute Medicine, University Hospital of Geneva, Geneva, Switzerland
| | - Sara Correia
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Monika Kaminska
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Delal Dalga
- Department of Medicine and Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Daniele Malpetti
- Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA), USI/SUPSI, Lugano, Switzerland
| | - Pietro E Cippa
- Laboratories for Translational Research, Ente Ospedaliero Cantonale, Bellinzona, Switzerland
- Division of Nephrology, Department of Medicine, Ente Ospedaliero Cantonale, Lugano, Switzerland
| | - Sophie de Seigneux
- Department of Medicine and Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
- Department of Medicine, Service of Nephrology, Geneva University Hospitals, Geneva, Switzerland
| | - Andrew M Hall
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
- Department of Nephrology, University Hospital Zurich, Zurich, Switzerland
- Zurich Kidney Center, Zurich, Switzerland
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3
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Satarug S. Is Chronic Kidney Disease Due to Cadmium Exposure Inevitable and Can It Be Reversed? Biomedicines 2024; 12:718. [PMID: 38672074 PMCID: PMC11048639 DOI: 10.3390/biomedicines12040718] [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: 02/19/2024] [Revised: 03/09/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024] Open
Abstract
Cadmium (Cd) is a metal with no nutritional value or physiological role. However, it is found in the body of most people because it is a contaminant of nearly all food types and is readily absorbed. The body burden of Cd is determined principally by its intestinal absorption rate as there is no mechanism for its elimination. Most acquired Cd accumulates within the kidney tubular cells, where its levels increase through to the age of 50 years but decline thereafter due to its release into the urine as the injured tubular cells die. This is associated with progressive kidney disease, which is signified by a sustained decline in the estimated glomerular filtration rate (eGFR) and albuminuria. Generally, reductions in eGFR after Cd exposure are irreversible, and are likely to decline further towards kidney failure if exposure persists. There is no evidence that the elimination of current environmental exposure can reverse these effects and no theoretical reason to believe that such a reversal is possible. This review aims to provide an update on urinary and blood Cd levels that were found to be associated with GFR loss and albuminuria in the general populations. A special emphasis is placed on the mechanisms underlying albumin excretion in Cd-exposed persons, and for an accurate measure of the doses-response relationships between Cd exposure and eGFR, its excretion rate must be normalised to creatinine clearance. The difficult challenge of establishing realistic Cd exposure guidelines such that human health is protected, is discussed.
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Affiliation(s)
- Soisungwan Satarug
- Kidney Disease Research Collaborative, Translational Research Institute, Woolloongabba, Brisbane, QLD 4102, Australia
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4
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Satarug S, Vesey DA, Gobe GC, Phelps KR. The pathogenesis of albuminuria in cadmium nephropathy. Curr Res Toxicol 2023; 6:100140. [PMID: 38116328 PMCID: PMC10726218 DOI: 10.1016/j.crtox.2023.100140] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/16/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023] Open
Abstract
Background Urinary cadmium excretion (ECd) rises with renal tissue content of the metal. Whereas glomerulopathies are sometimes associated with massive albuminuria, tubular accumulation of Cd typically causes modest albuminuria. Since β2-microglobulinuria (Eβ2M) is an established marker of proximal tubular dysfunction, we hypothesized that a comparison of albuminuria (Ealb) to Eβ2M in Cd-exposed subjects would provide evidence of similar mishandling of both proteins. Methods To depict excretion rates per functional nephron, ECd, Ealb, and Eβ2M were normalized to creatinine clearance (Ccr), a surrogate for the glomerular filtration rate (GFR). Estimation of GFR itself (eGFR) was accomplished with CKD-EPI formulas (2009). Linear and logistic regression analyses were performed to relate Ealb/Ccr, Eβ2M/Ccr, and eGFR to several independent variables. Simple linear regressions of eGFR, Ealb/Ccr, and Eβ2M/Ccr on ECd/Ccr were examined before and after adjustment of dependent variables for age. All regressions were performed after log-transformation of ratios and standardization of all variables. Increments in Ealb/Ccr and Eβ2M/Ccr and decrements in eGFR were quantified through four quartiles of ECd/Ccr. Results As age or ECd/Ccr rose, Ealb/Ccr and Eβ2M/Ccr also rose, and eGFR fell. In linear regressions, slopes relating Ealb/Ccr and Eβ2M/Ccr to ECd/Ccr were similar. After adjustment of dependent variables for age, coefficients of determination (R2) for all regressions rose by a multiple, and slopes approached unity. Ealb/Ccr and Eβ2M/Ccr were similarly associated with each other. Mean Ealb/Ccr and Eβ2M/Ccr rose and mean eGFR fell in stepwise fashion through quartiles of ECd/Ccr. Whereas Eβ2M/Ccr did not vary with blood pressure, Ealb/Ccr rose in association with hypertension in two of the four quartiles. Conclusions Our data indicate that Cd in renal tissue affected tubular reabsorption of albumin and β2M similarly in a large cohort of exposed subjects. The results suggest that Cd reduced receptor-mediated endocytosis and subsequent lysosomal degradation of each protein by a shared mechanism.
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Affiliation(s)
- Soisungwan Satarug
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
| | - David A. Vesey
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
- Department of Kidney and Transplant Services, Princess Alexandra Hospital, Brisbane, Australia
| | - Glenda C. Gobe
- Centre for Kidney Disease Research, Translational Research Institute, Brisbane, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
- NHMRC Centre of Research Excellence for CKD QLD, UQ Health Sciences, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Kenneth R. Phelps
- Stratton Veterans Affairs Medical Center and Albany Medical College, Albany, NY, USA
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Thévenod F, Herbrechter R, Schlabs C, Pethe A, Lee WK, Wolff NA, Roussa E. Role of the SLC22A17/lipocalin-2 receptor in renal endocytosis of proteins/metalloproteins: a focus on iron- and cadmium-binding proteins. Am J Physiol Renal Physiol 2023; 325:F564-F577. [PMID: 37589051 DOI: 10.1152/ajprenal.00020.2023] [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: 01/31/2023] [Revised: 08/15/2023] [Accepted: 08/15/2023] [Indexed: 08/18/2023] Open
Abstract
The transmembrane protein SLC22A17 [or the neutrophil gelatinase-associated lipocalin/lipocalin-2 (LCN2)/24p3 receptor] is an atypical member of the SLC22 family of organic anion and cation transporters: it does not carry typical substrates of SLC22 transporters but mediates receptor-mediated endocytosis (RME) of LCN2. One important task of the kidney is the prevention of urinary loss of proteins filtered by the glomerulus by bulk reabsorption of multiple ligands via megalin:cubilin:amnionless-mediated endocytosis in the proximal tubule (PT). Accordingly, overflow, glomerular, or PT damage, as in Fanconi syndrome, results in proteinuria. Strikingly, up to 20% of filtered proteins escape the PT under physiological conditions and are reabsorbed by the distal nephron. The renal distal tubule and collecting duct express SLC22A17, which mediates RME of filtered proteins that evade the PT but with limited capacity to prevent proteinuria under pathological conditions. The kidney also prevents excretion of filtered essential and nonessential transition metals, such as iron or cadmium, respectively, that are largely bound to proteins with high affinity, e.g., LCN2, transferrin, or metallothionein, or low affinity, e.g., microglobulins or albumin. Hence, increased uptake of transition metals may cause nephrotoxicity. Here, we assess the literature on SLC22A17 structure, topology, tissue distribution, regulation, and assumed functions, emphasizing renal SLC22A17, which has relevance for physiology, pathology, and nephrotoxicity due to the accumulation of proteins complexed with transition metals, e.g., cadmium or iron. Other putative renal functions of SLC22A17, such as its contribution to osmotic stress adaptation, protection against urinary tract infection, or renal carcinogenesis, are discussed.
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Affiliation(s)
- Frank Thévenod
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Robin Herbrechter
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
| | - Carolin Schlabs
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
| | - Abhishek Pethe
- Department of Molecular Embryology, Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Wing-Kee Lee
- Physiology and Pathophysiology of Cells and Membranes, Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Natascha A Wolff
- Institute for Physiology, Pathophysiology and Toxicology, Center for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany
| | - Eleni Roussa
- Department of Molecular Embryology, Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Freiburg im Breisgau, Germany
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6
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Chen M, Gu X. Emerging roles of proximal tubular endocytosis in renal fibrosis. Front Cell Dev Biol 2023; 11:1235716. [PMID: 37799275 PMCID: PMC10547866 DOI: 10.3389/fcell.2023.1235716] [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: 06/06/2023] [Accepted: 09/11/2023] [Indexed: 10/07/2023] Open
Abstract
Endocytosis is a crucial component of many pathological conditions. The proximal tubules are responsible for reabsorbing the majority of filtered water and glucose, as well as all the proteins filtered through the glomerular barrier via endocytosis, indicating an essential role in kidney diseases. Genetic mutations or acquired insults could affect the proximal tubule endocytosis processes, by disturbing or overstressing the endolysosomal system and subsequently activating different pathways, orchestrating renal fibrosis. This paper will review recent studies on proximal tubular endocytosis affected by other diseases and factors. Endocytosis plays a vital role in the development of renal fibrosis, and renal fibrosis could also, in turn, affect tubular endocytosis.
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Affiliation(s)
- Min Chen
- Department of Nephrology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiangchen Gu
- Department of Nephrology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Medicine, Shanghai Hospital of Civil Aviation Administration of China, Shanghai, China
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7
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Bordoni L, Kristensen AM, Sardella D, Kidmose H, Pohl L, Krag SRP, Schiessl IM. Longitudinal tracking of acute kidney injury reveals injury propagation along the nephron. Nat Commun 2023; 14:4407. [PMID: 37479698 PMCID: PMC10362041 DOI: 10.1038/s41467-023-40037-y] [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: 01/17/2023] [Accepted: 07/10/2023] [Indexed: 07/23/2023] Open
Abstract
Acute kidney injury (AKI) is an important risk factor for chronic kidney disease (CKD), but the underlying mechanisms of failed tubule repair and AKI-CKD transition are incompletely understood. In this study, we aimed for dynamic tracking of tubule injury and remodeling to understand if focal injury upon AKI may spread over time. Here, we present a model of AKI, in which we rendered only half of the kidney ischemic. Using serial intravital 2-photon microscopy and genetic identification of cycling cells, we tracked dynamic tissue remodeling in post- and non-ischemic kidney regions simultaneously and over 3 weeks. Spatial and temporal analysis of cycling cells relative to initial necrotic cell death demonstrated pronounced injury propagation and expansion into non-necrotic tissue regions, which predicted tubule atrophy with epithelial VCAM1 expression. In summary, our longitudinal analyses of tubule injury, remodeling, and fate provide important insights into AKI pathology.
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Affiliation(s)
- Luca Bordoni
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | | | - Donato Sardella
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Hanne Kidmose
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Layla Pohl
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Wagner MC, Sandoval RM, Yadav SPS, Campos SB, Rhodes GJ, Phillips CL, Molitoris BA. Lrpap1 (RAP) Inhibits Proximal Tubule Clathrin Mediated and Clathrin Independent Endocytosis, Ameliorating Renal Aminoglycoside Nephrotoxicity. KIDNEY360 2023; 4:591-605. [PMID: 36848531 PMCID: PMC10278819 DOI: 10.34067/kid.0000000000000094] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 01/31/2023] [Indexed: 03/01/2023]
Abstract
Key Points Proximal tubule endocytosis of toxins often leads to nephrotoxicity. Inhibition of endocytosis with receptor-associated protein may serve as a clinical approach to reduce or eliminate kidney damage from a potential nephrotoxin. Background Proximal tubules (PTs) are exposed to many exogenous and endogenous nephrotoxins that pass through the glomerular filter. This includes many small molecules, such as aminoglycoside and myeloma light chains. These filtered molecules are rapidly endocytosed by the PTs and lead to nephrotoxicity. Methods To investigate whether inhibition of PT uptake of filtered toxins can reduce toxicity, we evaluated the ability of Lrpap1 or receptor-associated protein (RAP) to prevent PT endocytosis. Munich Wistar Frömter rats were used since both glomerular filtration and PT uptake can be visualized and quantified. The injury model chosen was the well-established gentamicin-induced toxicity, which leads to significant reductions in GFR and serum creatinine increases. CKD was induced with a right uninephrectomy and left 40-minute pedicle clamp. Rats had 8 weeks to recover and to stabilize GFR and proteinuria. Multiphoton microscopy was used to evaluate endocytosis in vivo and serum creatinine, and 24-hour creatinine clearances were used to evaluate kidney functional changes. Results Studies showed that preadministration of RAP significantly inhibited both albumin and dextran endocytosis in outer cortical PTs. Importantly, this inhibition was found to be rapidly reversible with time. RAP was also found to be an excellent inhibitor of PT gentamicin endocytosis. Finally, gentamicin administration for 6 days resulted in significant elevation of serum creatinine in vehicle-treated rats, but not in those receiving daily infusion of RAP before gentamicin. Conclusions This study provides a model for the potential use of RAP to prevent, in a reversible manner, PT endocytosis of potential nephrotoxins, thus protecting the kidney from damage.
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Affiliation(s)
- Mark C Wagner
- Indiana Center for Biological Microscopy, Indiana University School of Medicine, Indianapolis, Indiana
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9
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Bryniarski MA, Sandoval RM, Ruszaj DM, Fraser-McArthur J, Yee BM, Yacoub R, Chaves LD, Campos-Bilderback SB, Molitoris BA, Morris ME. Defining the Intravital Renal Disposition of Fluorescence-Quenched Exenatide. Mol Pharm 2023; 20:987-996. [PMID: 36626167 PMCID: PMC9907348 DOI: 10.1021/acs.molpharmaceut.2c00671] [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: 08/09/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 01/11/2023]
Abstract
Despite the understanding that renal clearance is pivotal for driving the pharmacokinetics of numerous therapeutic proteins and peptides, the specific processes that occur following glomerular filtration remain poorly defined. For instance, sites of catabolism within the proximal tubule can occur at the brush border, within lysosomes following endocytosis, or even within the tubule lumen itself. The objective of the current study was to address these limitations and develop methodology to study the kidney disposition of a model therapeutic protein. Exenatide is a peptide used to treat type 2 diabetes mellitus. Glomerular filtration and ensuing renal catabolism have been shown to be its principal clearance pathway. Here, we designed and validated a Förster resonance energy transfer-quenched exenatide derivative to provide critical information on the renal handling of exenatide. A combination of in vitro techniques was used to confirm substantial fluorescence quenching of intact peptide that was released upon proteolytic cleavage. This evaluation was then followed by an assessment of the in vivo disposition of quenched exenatide directly within kidneys of living rats via intravital two-photon microscopy. Live imaging demonstrated rapid glomerular filtration and identified exenatide metabolism occurred within the subapical regions of the proximal tubule epithelia, with subsequent intracellular trafficking of cleaved fragments. These results provide a novel examination into the real-time, intravital disposition of a protein therapeutic within the kidney and offer a platform to build upon for future work.
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Affiliation(s)
- Mark A. Bryniarski
- Department
of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical
Sciences, University at Buffalo, 304 Pharmacy Building, Buffalo, New York 14215, United States
| | - Ruben M. Sandoval
- Department
of Medicine, Indiana University, Indianapolis, Indiana 46202, United States
| | - Donna M. Ruszaj
- Department
of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical
Sciences, University at Buffalo, 304 Pharmacy Building, Buffalo, New York 14215, United States
| | - John Fraser-McArthur
- Department
of Pharmacy, University of Rochester Medical
Center, Rochester, New York 14642, United States
| | - Benjamin M. Yee
- Department
of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical
Sciences, University at Buffalo, 304 Pharmacy Building, Buffalo, New York 14215, United States
| | - Rabi Yacoub
- Department
of Internal Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, United States
| | - Lee D. Chaves
- Department
of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical
Sciences, University at Buffalo, 304 Pharmacy Building, Buffalo, New York 14215, United States
- Department
of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, United States
| | | | - Bruce A. Molitoris
- Department
of Medicine, Indiana University, Indianapolis, Indiana 46202, United States
| | - Marilyn E. Morris
- Department
of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical
Sciences, University at Buffalo, 304 Pharmacy Building, Buffalo, New York 14215, United States
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Sardella D, Kristensen AM, Bordoni L, Kidmose H, Shahrokhtash A, Sutherland DS, Frische S, Schiessl IM. Serial intravital 2-photon microscopy and analysis of the kidney using upright microscopes. Front Physiol 2023; 14:1176409. [PMID: 37168225 PMCID: PMC10164931 DOI: 10.3389/fphys.2023.1176409] [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: 02/28/2023] [Accepted: 04/03/2023] [Indexed: 05/13/2023] Open
Abstract
Serial intravital 2-photon microscopy of the kidney and other abdominal organs is a powerful technique to assess tissue function and structure simultaneously and over time. Thus, serial intravital microscopy can capture dynamic tissue changes during health and disease and holds great potential to characterize (patho-) physiological processes with subcellular resolution. However, successful image acquisition and analysis require significant expertise and impose multiple potential challenges. Abdominal organs are rhythmically displaced by breathing movements which hamper high-resolution imaging. Traditionally, kidney intravital imaging is performed on inverted microscopes where breathing movements are partly compensated by the weight of the animal pressing down. Here, we present a custom and easy-to-implement setup for intravital imaging of the kidney and other abdominal organs on upright microscopes. Furthermore, we provide image processing protocols and a new plugin for the free image analysis software FIJI to process multichannel fluorescence microscopy data. The proposed image processing pipelines cover multiple image denoising algorithms, sample drift correction using 2D registration, and alignment of serial imaging data collected over several weeks using landmark-based 3D registration. The provided tools aim to lower the barrier of entry to intravital microscopy of the kidney and are readily applicable by biomedical practitioners.
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Affiliation(s)
- Donato Sardella
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Ina Maria Schiessl, ; Donato Sardella,
| | | | - Luca Bordoni
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Hanne Kidmose
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Ali Shahrokhtash
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | | | | | - Ina Maria Schiessl
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Ina Maria Schiessl, ; Donato Sardella,
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11
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Hall AM, Sakhi I. It is Good to Recycle: Bringing Megalin Back to the Membrane to Stop Proteinuria. FUNCTION (OXFORD, ENGLAND) 2022; 3:zqac056. [PMID: 36407086 PMCID: PMC9668066 DOI: 10.1093/function/zqac056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022]
Affiliation(s)
| | - Imene Sakhi
- Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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