1
|
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.
Collapse
|
2
|
Hatje FA, Wedekind U, Sachs W, Loreth D, Reichelt J, Demir F, Kosub C, Heintz L, Tomas NM, Huber TB, Skuza S, Sachs M, Zielinski S, Rinschen MM, Meyer-Schwesinger C. Tripartite Separation of Glomerular Cell Types and Proteomes from Reporter-Free Mice. J Am Soc Nephrol 2021; 32:2175-2193. [PMID: 34074698 PMCID: PMC8729851 DOI: 10.1681/asn.2020091346] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 04/09/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The glomerulus comprises podocytes, mesangial cells, and endothelial cells, which jointly determine glomerular filtration. Understanding this intricate functional unit beyond the transcriptome requires bulk isolation of these cell types for biochemical investigations. We developed a globally applicable tripartite isolation method for murine mesangial and endothelial cells and podocytes (timMEP). METHODS We separated glomerular cell types from wild-type or mT/mG mice via a novel FACS approach, and validated their purity. Cell type proteomes were compared between strains, ages, and sex. We applied timMEP to the podocyte-targeting, immunologic, THSD7A-associated, model of membranous nephropathy. RESULTS timMEP enabled protein-biochemical analyses of podocytes, mesangial cells, and endothelial cells derived from reporter-free mice, and allowed for the characterization of podocyte, endothelial, and mesangial proteomes of individual mice. We identified marker proteins for mesangial and endothelial proteins, and outlined protein-based, potential communication networks and phosphorylation patterns. The analysis detected cell type-specific proteome differences between mouse strains and alterations depending on sex, age, and transgene. After exposure to anti-THSD7A antibodies, timMEP resolved a fine-tuned initial stress response, chiefly in podocytes, that could not be detected by bulk glomerular analyses. The combination of proteomics with super-resolution imaging revealed a specific loss of slit diaphragm, but not of other foot process proteins, unraveling a protein-based mechanism of podocyte injury in this animal model. CONCLUSION timMEP enables glomerular cell type-resolved investigations at the transcriptional and protein-biochemical level in health and disease, while avoiding reporter-based artifacts, paving the way toward the comprehensive and systematic characterization of glomerular cell biology.
Collapse
Affiliation(s)
- Favian A. Hatje
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Uta Wedekind
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wiebke Sachs
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Desiree Loreth
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julia Reichelt
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fatih Demir
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Christopher Kosub
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lukas Heintz
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola M. Tomas
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B. Huber
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sinah Skuza
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marlies Sachs
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stephanie Zielinski
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus M. Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark,III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany,Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
3
|
Rinschen MM, Saez-Rodriguez J. The tissue proteome in the multi-omic landscape of kidney disease. Nat Rev Nephrol 2020; 17:205-219. [PMID: 33028957 DOI: 10.1038/s41581-020-00348-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2020] [Indexed: 02/07/2023]
Abstract
Kidney research is entering an era of 'big data' and molecular omics data can provide comprehensive insights into the molecular footprints of cells. In contrast to transcriptomics, proteomics and metabolomics generate data that relate more directly to the pathological symptoms and clinical parameters observed in patients. Owing to its complexity, the proteome still holds many secrets, but has great potential for the identification of drug targets. Proteomics can provide information about protein synthesis, modification and degradation, as well as insight into the physical interactions between proteins, and between proteins and other biomolecules. Thus far, proteomics in nephrology has largely focused on the discovery and validation of biomarkers, but the systematic analysis of the nephroproteome can offer substantial additional insights, including the discovery of mechanisms that trigger and propagate kidney disease. Moreover, proteome acquisition might provide a diagnostic tool that complements the assessment of a kidney biopsy sample by a pathologist. Such applications are becoming increasingly feasible with the development of high-throughput and high-coverage technologies, such as versatile mass spectrometry-based techniques and protein arrays, and encourage further proteomics research in nephrology.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark. .,III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. .,Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany. .,Department of Chemistry, Scripps Center for Metabolomics and Mass Spectrometry, Scripps Research, La Jolla, CA, USA.
| | - Julio Saez-Rodriguez
- Institute for Computational Biomedicine, Faculty of Medicine, Heidelberg University, and Heidelberg University Hospital, Bioquant, Heidelberg, Germany.,Joint Research Center for Computational Biomedicine, RWTH Aachen University Hospital, Aachen, Germany.,Molecular Medicine Partnership Unit, European Molecular Biology Laboratory and Heidelberg University, Heidelberg, Germany
| |
Collapse
|
4
|
Feng D. Phosphorylation of key podocyte proteins and the association with proteinuric kidney disease. Am J Physiol Renal Physiol 2020; 319:F284-F291. [PMID: 32686524 DOI: 10.1152/ajprenal.00002.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Podocyte dysfunction contributes to proteinuric chronic kidney disease. A number of key proteins are essential for podocyte function, including nephrin, podocin, CD2-associated protein (CD2AP), synaptopodin, and α-actinin-4 (ACTN4). Although most of these proteins were first identified through genetic studies associated with human kidney disease, subsequent studies have identified phosphorylation of these proteins as an important posttranslational event that regulates their function. In this review, a brief overview of the function of these key podocyte proteins is provided. Second, the role of phosphorylation in regulating the function of these proteins is described. Third, the association between these phosphorylation pathways and kidney disease is reviewed. Finally, challenges and future directions in studying phosphorylation are discussed. Better characterization of these phosphorylation pathways and others yet to be discovered holds promise for translating this knowledge into new therapies for patients with proteinuric chronic kidney disease.
Collapse
Affiliation(s)
- Di Feng
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
5
|
Maddala R, Rao PV. Global phosphotyrosinylated protein profile of cell-matrix adhesion complexes of trabecular meshwork cells. Am J Physiol Cell Physiol 2020; 319:C288-C299. [PMID: 32432933 DOI: 10.1152/ajpcell.00537.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Dysregulation of the mechanical properties and cell adhesive interactions of trabecular meshwork (TM) are known to impair aqueous humor drainage and elevate intraocular pressure in glaucoma patients. The identity of regulatory mechanisms underlying TM mechanotransduction, however, remains elusive. Here we analyzed the phosphotyrosine proteome of human TM cell-extracellular matrix (ECM) adhesion complexes, which play a key role in sensing and transducing extracellular chemical and mechanical cues into intracellular activities, using a two-level affinity pull-down (phosphotyrosine antibody and titanium dioxide beads) method and mass spectrometry. This analysis identified ~1,000 tyrosine-phosphorylated proteins of TM cell-ECM adhesion complexes. Many consensus adhesome proteins were found to be tyrosine phosphorylated. Interestingly, several of the phosphotyrosinylated proteins found in TM cell-ECM adhesion complexes are known to be required for podocyte glomerular filtration, indicating the existence of molecular parallels that are likely relevant to the shared fluid barrier and filtration functions of the two mechanosensitive cell types.
Collapse
Affiliation(s)
- Rupalatha Maddala
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
| | - Ponugoti Vasantha Rao
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina.,Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
| |
Collapse
|
6
|
BENZING THOMAS. MOLECULAR DESIGN OF THE KIDNEY FILTRATION BARRIER. TRANSACTIONS OF THE AMERICAN CLINICAL AND CLIMATOLOGICAL ASSOCIATION 2020; 131:125-139. [PMID: 32675853 PMCID: PMC7358502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Kidneys are the central regulators of organismal homeostasis. These organs filter enormous amounts of fluid from plasma; excrete toxic waste products; maintain salt, water, and volume balance; coordinate blood pressure regulation; and maintain the acid-base equilibrium essential for life. Although it has been known for decades that renal glomeruli serve as the site of plasma ultrafiltration and urine production, both the molecular design and function of the kidney filtration barrier have remained elusive. Indeed, the past two decades have witnessed enormous breakthroughs in our fundamental understanding of kidney filtration and the critical role that podocytes, specialized terminally differentiated epithelial cells at the glomerular capillaries, fulfill in the function of the kidney filtration barrier. Here we discuss recent advances in this field that will change the way we think about plasma ultrafiltration in health and proteinuria as a manifestation of glomerular diseases.
Collapse
Affiliation(s)
- THOMAS BENZING
- Correspondence and reprint requests: Thomas Benzing, MD, Department II of Internal Medicine, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany+ 49 221 4784480, 49 221 4785959
| |
Collapse
|
7
|
Rinschen MM, Palygin O, Guijas C, Palermo A, Palacio-Escat N, Domingo-Almenara X, Montenegro-Burke R, Saez-Rodriguez J, Staruschenko A, Siuzdak G. Metabolic rewiring of the hypertensive kidney. Sci Signal 2019; 12:12/611/eaax9760. [PMID: 31822592 DOI: 10.1126/scisignal.aax9760] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hypertension is a persistent epidemic across the developed world that is closely associated with kidney disease. Here, we applied a metabolomic, phosphoproteomic, and proteomic strategy to analyze the effect of hypertensive insults on kidneys. Our data revealed the metabolic aspects of hypertension-induced glomerular sclerosis, including lipid breakdown at early disease stages and activation of anaplerotic pathways to regenerate energy equivalents to counter stress. For example, branched-chain amino acids and proline, required for collagen synthesis, were depleted in glomeruli at early time points. Furthermore, indicators of metabolic stress were reflected by low amounts of ATP and NADH and an increased abundance of oxidized lipids derived from lipid breakdown. These processes were specific to kidney glomeruli where metabolic signaling occurred through mTOR and AMPK signaling. Quantitative phosphoproteomics combined with computational modeling suggested that these processes controlled key molecules in glomeruli and specifically podocytes, including cytoskeletal components and GTP-binding proteins, which would be expected to compete for decreasing amounts of GTP at early time points. As a result, glomeruli showed increased expression of metabolic enzymes of central carbon metabolism, amino acid degradation, and lipid oxidation, findings observed in previously published studies from other disease models and patients with glomerular damage. Overall, multilayered omics provides an overview of hypertensive kidney damage and suggests that metabolic or dietary interventions could prevent and treat glomerular disease and hypertension-induced nephropathy.
Collapse
Affiliation(s)
- Markus M Rinschen
- Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA 92122, USA.,Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, Cologne 50931, Germany
| | - Oleg Palygin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Carlos Guijas
- Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA 92122, USA
| | - Amelia Palermo
- Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA 92122, USA
| | - Nicolas Palacio-Escat
- COMBINE-Joint Research Center for Computational Biomedicine RWTH Aachen University, Aachen 52074, Germany.,Institute of Computational Biomedicine, Bioquant, Faculty of Medicine and Heidelberg University Hospital, Heidelberg University, Heidelberg 69120, Germany.,Faculty of Biosciences, University of Heidelberg, Heidelberg 69120, Germany
| | - Xavier Domingo-Almenara
- Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA 92122, USA
| | - Rafael Montenegro-Burke
- Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA 92122, USA
| | - Julio Saez-Rodriguez
- COMBINE-Joint Research Center for Computational Biomedicine RWTH Aachen University, Aachen 52074, Germany.,Institute of Computational Biomedicine, Bioquant, Faculty of Medicine and Heidelberg University Hospital, Heidelberg University, Heidelberg 69120, Germany.,Molecular Medicine Partnership Unit (MMPU), European Molecular Biology Laboratory and Heidelberg University, Heidelberg 69120, Germany
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA. .,Clement J. Zablocki VA Medical Center, Milwaukee, WI 53295, USA
| | - Gary Siuzdak
- Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA 92122, USA.
| |
Collapse
|
8
|
Rinschen MM, Gödel M, Grahammer F, Zschiedrich S, Helmstädter M, Kretz O, Zarei M, Braun DA, Dittrich S, Pahmeyer C, Schroder P, Teetzen C, Gee H, Daouk G, Pohl M, Kuhn E, Schermer B, Küttner V, Boerries M, Busch H, Schiffer M, Bergmann C, Krüger M, Hildebrandt F, Dengjel J, Benzing T, Huber TB. A Multi-layered Quantitative In Vivo Expression Atlas of the Podocyte Unravels Kidney Disease Candidate Genes. Cell Rep 2019; 23:2495-2508. [PMID: 29791858 PMCID: PMC5986710 DOI: 10.1016/j.celrep.2018.04.059] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 02/07/2018] [Accepted: 04/15/2018] [Indexed: 12/31/2022] Open
Abstract
Damage to and loss of glomerular podocytes has been identified as the culprit lesion in progressive kidney diseases. Here, we combine mass spectrometry-based proteomics with mRNA sequencing, bioinformatics, and hypothesis-driven studies to provide a comprehensive and quantitative map of mammalian podocytes that identifies unanticipated signaling pathways. Comparison of the in vivo datasets with proteomics data from podocyte cell cultures showed a limited value of available cell culture models. Moreover, in vivo stable isotope labeling by amino acids uncovered surprisingly rapid synthesis of mitochondrial proteins under steady-state conditions that was perturbed under autophagy-deficient, disease-susceptible conditions. Integration of acquired omics dimensions suggested FARP1 as a candidate essential for podocyte function, which could be substantiated by genetic analysis in humans and knockdown experiments in zebrafish. This work exemplifies how the integration of multi-omics datasets can identify a framework of cell-type-specific features relevant for organ health and disease. Deep proteome and transcriptome analyses of native podocytes unravel druggable targets Static and dynamic proteomics uncover features of podocyte identity and proteostasis Candidate genes for nephrotic syndrome were predicted based on multi-omic integration FARP1 is a previously unreported candidate gene for human proteinuric kidney disease
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, 50931 Cologne, Germany.
| | - Markus Gödel
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Florian Grahammer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Stefan Zschiedrich
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - Mostafa Zarei
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Center for Systems Biology (ZBSA), Albert Ludwigs University, 79104 Freiburg, Germany
| | - Daniela A Braun
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sebastian Dittrich
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Caroline Pahmeyer
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Patricia Schroder
- Department of Medicine/Nephrology, Hannover Medical School, 30625 Hannover, Germany; Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04609, USA
| | - Carolin Teetzen
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany
| | - HeonYung Gee
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04609, USA; Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Ghaleb Daouk
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Martin Pohl
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Medical Center and Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Elisa Kuhn
- Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, 50931 Cologne, Germany
| | - Victoria Küttner
- Department for Neuroanatomy, University of Freiburg, 79104 Freiburg, Germany; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Department of Dermatology, Medical Center - University of Freiburg, 79106 Freiburg, Germany
| | - Melanie Boerries
- Systems Biology of the Cellular Microenvironment Group, Institute of Molecular Medicine and Cell Research, Albert Ludwigs University Freiburg, 79106 Freiburg, Germany; German Cancer Consortium (DKTK), 79106 Freiburg, Germany; German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Hauke Busch
- Systems Biology of the Cellular Microenvironment Group, Institute of Molecular Medicine and Cell Research, Albert Ludwigs University Freiburg, 79106 Freiburg, Germany; Lübeck Institute for Experimental Dermatology (LIED), University of Lübeck, 23562 Lübeck, Germany
| | - Mario Schiffer
- Department of Medicine/Nephrology, Hannover Medical School, 30625 Hannover, Germany; Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04609, USA
| | - Carsten Bergmann
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
| | - Marcus Krüger
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Friedhelm Hildebrandt
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Joern Dengjel
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Center for Systems Biology (ZBSA), Albert Ludwigs University, 79104 Freiburg, Germany; Department of Dermatology, Medical Center - University of Freiburg, 79106 Freiburg, Germany; Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland; BIOSS Centre for Biological Signaling Studies, Albert Ludwigs University Freiburg, 79104 Freiburg, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, 50931 Cologne, Germany.
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, 79110 Freiburg, Germany; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79104 Freiburg, Germany; Center for Systems Biology (ZBSA), Albert Ludwigs University, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, Albert Ludwigs University Freiburg, 79104 Freiburg, Germany.
| |
Collapse
|
9
|
Rinschen MM, Limbutara K, Knepper MA, Payne DM, Pisitkun T. From Molecules to Mechanisms: Functional Proteomics and Its Application to Renal Tubule Physiology. Physiol Rev 2019; 98:2571-2606. [PMID: 30182799 DOI: 10.1152/physrev.00057.2017] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Classical physiological studies using electrophysiological, biophysical, biochemical, and molecular techniques have created a detailed picture of molecular transport, bioenergetics, contractility and movement, and growth, as well as the regulation of these processes by external stimuli in cells and organisms. Newer systems biology approaches are beginning to provide deeper and broader understanding of these complex biological processes and their dynamic responses to a variety of environmental cues. In the past decade, advances in mass spectrometry-based proteomic technologies have provided invaluable tools to further elucidate these complex cellular processes, thereby confirming, complementing, and advancing common views of physiology. As one notable example, the application of proteomics to study the regulation of kidney function has yielded novel insights into the chemical and physical processes that tightly control body fluids, electrolytes, and metabolites to provide optimal microenvironments for various cellular and organ functions. Here, we systematically review, summarize, and discuss the most significant key findings from functional proteomic studies in renal epithelial physiology. We also identify further improvements in technological and bioinformatics methods that will be essential to advance precision medicine in nephrology.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - Kavee Limbutara
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - Mark A Knepper
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - D Michael Payne
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| | - Trairak Pisitkun
- Department II of Internal Medicine, University Hospital Cologne , Cologne , Germany ; Center for Molecular Medicine Cologne, University of Cologne , Cologne , Germany ; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne , Cologne , Germany ; Division of Nephrology, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand ; Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland ; and Center of Excellence in Systems Biology, Research Affairs, Faculty of Medicine, Chulalongkorn University , Bangkok , Thailand
| |
Collapse
|
10
|
Rinschen MM. Single glomerular proteomics: A novel tool for translational glomerular cell biology. Methods Cell Biol 2019; 154:1-14. [DOI: 10.1016/bs.mcb.2019.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
11
|
Höhne M, Frese CK, Grahammer F, Dafinger C, Ciarimboli G, Butt L, Binz J, Hackl MJ, Rahmatollahi M, Kann M, Schneider S, Altintas MM, Schermer B, Reinheckel T, Göbel H, Reiser J, Huber TB, Kramann R, Seeger-Nukpezah T, Liebau MC, Beck BB, Benzing T, Beyer A, Rinschen MM. Single-nephron proteomes connect morphology and function in proteinuric kidney disease. Kidney Int 2018; 93:1308-1319. [PMID: 29530281 DOI: 10.1016/j.kint.2017.12.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/01/2017] [Accepted: 12/14/2017] [Indexed: 12/25/2022]
Abstract
In diseases of many parenchymatous organs, heterogeneous deterioration of individual functional units determines the clinical prognosis. However, the molecular characterization at the level of such individual subunits remains a technological challenge that needs to be addressed in order to better understand pathological mechanisms. Proteinuric glomerular kidney diseases are frequent and assorted diseases affecting a fraction of glomeruli and their draining tubules to variable extents, and for which no specific treatment exists. Here, we developed and applied a mass spectrometry-based methodology to investigate heterogeneity of proteomes from individually isolated nephron segments from mice with proteinuric kidney disease. In single glomeruli from two different mouse models of sclerotic glomerular disease, we identified a coherent protein expression module consisting of extracellular matrix protein deposition (reflecting glomerular sclerosis), glomerular albumin (reflecting proteinuria) and LAMP1, a lysosomal protein. This module was associated with a loss of podocyte marker proteins while genetic ablation of LAMP1-correlated lysosomal proteases could ameliorate glomerular damage in vivo. Furthermore, proteomic analyses of individual glomeruli from patients with genetic sclerotic and non-sclerotic proteinuric diseases revealed increased abundance of lysosomal proteins, in combination with a decreased abundance of mutated gene products. Thus, altered protein homeostasis (proteostasis) is a conserved key mechanism in proteinuric kidney diseases. Moreover, our technology can capture intra-individual variability in diseases of the kidney and other tissues at a sub-biopsy scale.
Collapse
Affiliation(s)
- Martin Höhne
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; 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; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Christian K Frese
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Florian Grahammer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Claudia Dafinger
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Department of Pediatrics, Division of Pediatric Nephrology, University Hospital of Cologne, Cologne, Germany
| | | | - Linus Butt
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Julia Binz
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Matthias J Hackl
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Mahdieh Rahmatollahi
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Martin Kann
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Simon Schneider
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Bernhard Schermer
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; 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; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Thomas Reinheckel
- Institut of Molecular Medicine and Cell Research, Faculty of Medicine, University of Freiburg, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies and Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs-University, Freiburg, Germany
| | - Heike Göbel
- Institute of Pathology, University Hospital Cologne, Cologne, Germany
| | - Jochen Reiser
- Rush University Medical Center, Chicago, Illinois, USA
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies and Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs-University, Freiburg, Germany
| | - Rafael Kramann
- Division of Nephrology, RWTH Aachen University, Aachen, Germany
| | | | - Max C Liebau
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; 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; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany; Department of Pediatrics, Division of Pediatric Nephrology, University Hospital of Cologne, Cologne, Germany
| | - Bodo B Beck
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany; Department of Human Genetics, University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; 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; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Andreas Beyer
- 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; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine, University of Cologne, Cologne, Germany; 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; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany.
| |
Collapse
|
12
|
Schroeter CB, Koehler S, Kann M, Schermer B, Benzing T, Brinkkoetter PT, Rinschen MM. Protein half-life determines expression of proteostatic networks in podocyte differentiation. FASEB J 2018; 32:4696-4713. [PMID: 29694247 DOI: 10.1096/fj.201701307r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Podocytes are highly specialized, epithelial, postmitotic cells, which maintain the renal filtration barrier. When adapting to considerable metabolic and mechanical stress, podocytes need to accurately maintain their proteome. Immortalized podocyte cell lines are a widely used model for studying podocyte biology in health and disease in vitro. In this study, we performed a comprehensive proteomic analysis of the cultured human podocyte proteome in both proliferative and differentiated conditions at a depth of >7000 proteins. Similar to mouse podocytes, human podocyte differentiation involved a shift in proteostasis: undifferentiated podocytes have high expression of proteasomal proteins, whereas differentiated podocytes have high expression of lysosomal proteins. Additional analyses with pulsed stable-isotope labeling by amino acids in cell culture and protein degradation assays determined protein dynamics and half-lives. These studies unraveled a globally increased stability of proteins in differentiated podocytes. Mitochondrial, cytoskeletal, and membrane proteins were stabilized, particularly in differentiated podocytes. Importantly, protein half-lives strongly contributed to protein abundance in each state. These data suggest that regulation of protein turnover of particular cellular functions determines podocyte differentiation, a paradigm involving mitophagy and, potentially, of importance in conditions of increased podocyte stress and damage.-Schroeter, C. B., Koehler, S., Kann, M., Schermer, B., Benzing, T., Brinkkoetter, P. T., Rinschen, M. M. Protein half-life determines expression of proteostatic networks in podocyte differentiation.
Collapse
Affiliation(s)
- Christina B Schroeter
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Sybille Koehler
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Martin Kann
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,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.,Systems Biology of Ageing Cologne (SybaCol), Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,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.,Systems Biology of Ageing Cologne (SybaCol), Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany.,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.,Systems Biology of Ageing Cologne (SybaCol), Cologne, Germany
| |
Collapse
|
13
|
Hagmann H, Mangold N, Rinschen MM, Koenig T, Kunzelmann K, Schermer B, Benzing T, Brinkkoetter PT. Proline-dependent and basophilic kinases phosphorylate human TRPC6 at serine 14 to control channel activity through increased membrane expression. FASEB J 2017; 32:208-219. [PMID: 28877958 DOI: 10.1096/fj.201700309r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 08/21/2017] [Indexed: 01/01/2023]
Abstract
Signaling via the transient receptor potential (TRP) ion channel C6 plays a pivotal role in hereditary and sporadic glomerular kidney disease. Several studies have identified gain-of-function mutations of TRPC6 and report induced expression and enhanced channel activity of TRPC6 in association with glomerular diseases. Interfering with TRPC6 activity may open novel therapeutic pathways. TRPC6 channel activity is controlled by protein expression and stability as well as intracellular trafficking. Identification of regulatory phosphorylation sites in TRPC6 and corresponding protein kinases is essential to understand the regulation of TRPC6 activity and may result in future therapeutic strategies. In this study, an unbiased phosphoproteomic screen of human TRPC6 identified several novel serine phosphorylation sites. The phosphorylation site at serine 14 of TRPC6 is embedded in a basophilic kinase motif that is highly conserved across species. We confirmed serine 14 as a target of MAPKs and proline-directed kinases like cyclin-dependent kinase 5 (Cdk5) in cell-based as well as in vitro kinase assays and quantitative phosphoproteomic analysis of TRPC6. Phosphorylation of TRPC6 at serine 14 enhances channel conductance by boosting membrane expression of TRPC6, whereas protein stability and multimerization of TRPC6 are not altered, making serine 14 phosphorylation a potential drug target to interfere with TRPC6 channel activity.-Hagmann, H., Mangold, N., Rinschen, M. M., Koenig, T., Kunzelmann, K., Schermer, B., Benzing, T., Brinkkoetter, P. T. Proline-dependent and basophilic kinases phosphorylate human TRPC6 at serine 14 to control channel activity through increased membrane expression.
Collapse
Affiliation(s)
- Henning Hagmann
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Nicole Mangold
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Tim Koenig
- Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; and
| | - Karl Kunzelmann
- Department of Physiology, University Regensburg, Regensburg, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany;
| |
Collapse
|
14
|
Rinschen MM, Hoppe AK, Grahammer F, Kann M, Völker LA, Schurek EM, Binz J, Höhne M, Demir F, Malisic M, Huber TB, Kurschat C, Kizhakkedathu JN, Schermer B, Huesgen PF, Benzing T. N-Degradomic Analysis Reveals a Proteolytic Network Processing the Podocyte Cytoskeleton. J Am Soc Nephrol 2017; 28:2867-2878. [PMID: 28724775 DOI: 10.1681/asn.2016101119] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 05/08/2017] [Indexed: 11/03/2022] Open
Abstract
Regulated intracellular proteostasis, controlled in part by proteolysis, is essential in maintaining the integrity of podocytes and the glomerular filtration barrier of the kidney. We applied a novel proteomics technology that enables proteome-wide identification, mapping, and quantification of protein N-termini to comprehensively characterize cleaved podocyte proteins in the glomerulus in vivo We found evidence that defined proteolytic cleavage results in various proteoforms of important podocyte proteins, including those of podocin, nephrin, neph1, α-actinin-4, and vimentin. Quantitative mapping of N-termini demonstrated perturbation of protease action during podocyte injury in vitro, including diminished proteolysis of α-actinin-4. Differentially regulated protease substrates comprised cytoskeletal proteins as well as intermediate filaments. Determination of preferential protease motifs during podocyte damage indicated activation of caspase proteases and inhibition of arginine-specific proteases. Several proteolytic processes were clearly site-specific, were conserved across species, and could be confirmed by differential migration behavior of protein fragments in gel electrophoresis. Some of the proteolytic changes discovered in vitro also occurred in two in vivo models of podocyte damage (WT1 heterozygous knockout mice and puromycin aminonucleoside-treated rats). Thus, we provide direct and systems-level evidence that the slit diaphragm and podocyte cytoskeleton are regulated targets of proteolytic modification, which is altered upon podocyte damage.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Ann-Kathrin Hoppe
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Florian Grahammer
- Department of Medicine III, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine IV, Medical Center and Faculty of Medicine - University of Freiburg, Freiburg, Germany
| | - Martin Kann
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Linus A Völker
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Eva-Maria Schurek
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Julie Binz
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Martin Höhne
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Fatih Demir
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
| | - Milena Malisic
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany
| | - Tobias B Huber
- Department of Medicine III, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine IV, Medical Center and Faculty of Medicine - University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies and Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs-University, Freiburg, Germany; and
| | - Christine Kurschat
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC)
| | - Jayachandran N Kizhakkedathu
- Centre for Blood Research, Department of Pathology and Laboratory Medicine, Department of Chemistry, University of British Columbia, Vancouver, Canada
| | - Bernhard Schermer
- Department II of Internal Medicine.,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA-3, Forschungszentrum Jülich, Jülich, Germany;
| | - Thomas Benzing
- Department II of Internal Medicine, .,Center for Molecular Medicine Cologne (CMMC).,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| |
Collapse
|
15
|
Diedrich B, Dengjel J. Insights into autosomal dominant polycystic kidney disease by quantitative mass spectrometry-based proteomics. Cell Tissue Res 2017; 369:41-51. [DOI: 10.1007/s00441-017-2617-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/21/2017] [Indexed: 12/12/2022]
|
16
|
Rinschen MM, Grahammer F, Hoppe AK, Kohli P, Hagmann H, Kretz O, Bertsch S, Höhne M, Göbel H, Bartram MP, Gandhirajan RK, Krüger M, Brinkkoetter PT, Huber TB, Kann M, Wickström SA, Benzing T, Schermer B. YAP-mediated mechanotransduction determines the podocyte's response to damage. Sci Signal 2017; 10:10/474/eaaf8165. [PMID: 28400537 DOI: 10.1126/scisignal.aaf8165] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Podocytes are terminally differentiated cells of the kidney filtration barrier. They are subjected to physiological filtration pressure and considerable mechanical strain, which can be further increased in various kidney diseases. When injury causes cytoskeletal reorganization and morphological alterations of these cells, the filtration barrier may become compromised and allow proteins to leak into the urine (a condition called proteinuria). Using time-resolved proteomics, we showed that podocyte injury stimulated the activity of the transcriptional coactivator YAP and the expression of YAP target genes in a rat model of glomerular disease before the development of proteinuria. Although the activities of YAP and its ortholog TAZ are activated by mechanical stress in most cell types, injury reduced YAP and TAZ activity in cultured human and mouse podocyte cell lines grown on stiff substrates. Culturing these cells on soft matrix or inhibiting stress fiber formation recapitulated the damage-induced YAP up-regulation observed in vivo, indicating a mechanotransduction-dependent mechanism of YAP activation in podocytes. YAP overexpression in cultured podocytes increased the abundance of extracellular matrix-related proteins that can contribute to fibrosis. YAP activity was increased in mouse models of diabetic nephropathy, and the YAP target CTGF was highly expressed in renal biopsies from glomerular disease patients. Although overexpression of human YAP in mice induced mild proteinuria, pharmacological inhibition of the interaction between YAP and its partner TEAD in rats ameliorated glomerular disease and reduced damage-induced mechanosignaling in the glomeruli. Thus, perturbation of YAP-dependent mechanosignaling is a potential therapeutic target for treating some glomerular diseases.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| | - Florian Grahammer
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany.,III. Medical Clinic and Polyclinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ann-Kathrin Hoppe
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Priyanka Kohli
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany
| | - Henning Hagmann
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Oliver Kretz
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany.,III. Medical Clinic and Polyclinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Neuroanatomy, Institute of Anatomy, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sabine Bertsch
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Martin Höhne
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| | - Heike Göbel
- Institute of Pathology, University of Cologne, Cologne, Germany
| | - Malte P Bartram
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | | | - Marcus Krüger
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany
| | - Paul-Thomas Brinkkoetter
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Tobias B Huber
- Department of Medicine IV, Medical Center and Faculty of Medicine, University of Freiburg, Freiburg, Germany.,III. Medical Clinic and Polyclinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Martin Kann
- Department of Internal Medicine II, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Sara A Wickström
- Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany.,Skin Homeostasis and Ageing, Paul Gerson Unna Research Group, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Thomas Benzing
- Department of Internal Medicine II, University of Cologne, Cologne, Germany. .,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department of Internal Medicine II, University of Cologne, Cologne, Germany. .,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases, University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
17
|
Rinschen MM, Schroeter CB, Koehler S, Ising C, Schermer B, Kann M, Benzing T, Brinkkoetter PT. Quantitative deep mapping of the cultured podocyte proteome uncovers shifts in proteostatic mechanisms during differentiation. Am J Physiol Cell Physiol 2016; 311:C404-17. [PMID: 27357545 DOI: 10.1152/ajpcell.00121.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 06/27/2016] [Indexed: 11/22/2022]
Abstract
The renal filtration barrier is maintained by the renal podocyte, an epithelial postmitotic cell. Immortalized mouse podocyte cell lines-both in the differentiated and undifferentiated state-are widely utilized tools to estimate podocyte injury and cytoskeletal rearrangement processes in vitro. Here, we mapped the cultured podocyte proteome at a depth of more than 8,800 proteins and quantified 7,240 proteins. Copy numbers of proteins mutated in forms of hereditary nephrotic syndrome or focal segmental glomerulosclerosis (FSGS) were assessed. We found that cultured podocytes express abundant copy numbers of endogenous receptors, such as tyrosine kinase membrane receptors, the G protein-coupled receptor (GPCR), NPR3 (ANP receptor), and several poorly characterized GPCRs. The data set was correlated with deep mapping mRNA sequencing ("mRNAseq") data from the native mouse podocyte, the native mouse podocyte proteome and staining intensities from the human protein atlas. The generated data set was similar to these previously published resources, but several native and high-abundant podocyte-specific proteins were not identified in the data set. Notably, this data set detected general perturbations in proteostatic mechanisms as a dominant alteration during podocyte differentiation, with high proteasome activity in the undifferentiated state and markedly increased expression of lysosomal proteins in the differentiated state. Phosphoproteomics analysis of mouse podocytes at a resolution of more than 3,000 sites suggested a preference of phosphorylation of actin filament-associated proteins in the differentiated state. The data set obtained here provides a resource and provides the means for deep mapping of the native podocyte proteome and phosphoproteome in a similar manner.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany; and Systems Biology of Ageing Cologne, SybaCol, Cologne, Germany
| | - Christina B Schroeter
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Sybille Koehler
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Christina Ising
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany; and Systems Biology of Ageing Cologne, SybaCol, Cologne, Germany
| | - Martin Kann
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany; and Systems Biology of Ageing Cologne, SybaCol, Cologne, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine, University Hospital Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
18
|
Trost B, Kusalik A, Napper S. Computational Analysis of the Predicted Evolutionary Conservation of Human Phosphorylation Sites. PLoS One 2016; 11:e0152809. [PMID: 27046079 PMCID: PMC4821552 DOI: 10.1371/journal.pone.0152809] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/19/2016] [Indexed: 11/19/2022] Open
Abstract
Protein kinase-mediated phosphorylation is among the most important post-translational modifications. However, few phosphorylation sites have been experimentally identified for most species, making it difficult to determine the degree to which phosphorylation sites are conserved. The goal of this study was to use computational methods to characterize the conservation of human phosphorylation sites in a wide variety of eukaryotes. Using experimentally-determined human sites as input, homologous phosphorylation sites were predicted in all 432 eukaryotes for which complete proteomes were available. For each pair of species, we calculated phosphorylation site conservation as the number of phosphorylation sites found in both species divided by the number found in at least one of the two species. A clustering of the species based on this conservation measure was concordant with phylogenies based on traditional genomic measures. For a subset of the 432 species, phosphorylation site conservation was compared to conservation of both protein kinases and proteins in general. Protein kinases exhibited the highest degree of conservation, while general proteins were less conserved and phosphorylation sites were least conserved. Although preliminary, these data tentatively suggest that variation in phosphorylation sites may play a larger role in explaining phenotypic differences among organisms than differences in the complements of protein kinases or general proteins.
Collapse
Affiliation(s)
- Brett Trost
- Department of Computer Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail:
| | - Anthony Kusalik
- Department of Computer Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Scott Napper
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| |
Collapse
|
19
|
Rinschen MM, Bharill P, Wu X, Kohli P, Reinert MJ, Kretz O, Saez I, Schermer B, Höhne M, Bartram MP, Aravamudhan S, Brooks BR, Vilchez D, Huber TB, Müller RU, Krüger M, Benzing T. The ubiquitin ligase Ubr4 controls stability of podocin/MEC-2 supercomplexes. Hum Mol Genet 2016; 25:1328-44. [PMID: 26792178 DOI: 10.1093/hmg/ddw016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/16/2016] [Indexed: 11/13/2022] Open
Abstract
The PHB-domain protein podocin maintains the renal filtration barrier and its mutation is an important cause of hereditary nephrotic syndrome. Podocin and its Caenorhabditis elegans orthologue MEC-2 have emerged as key components of mechanosensitive membrane protein signalling complexes. Whereas podocin resides at a specialized cell junction at the podocyte slit diaphragm, MEC-2 is found in neurons required for touch sensitivity. Here, we show that the ubiquitin ligase Ubr4 is a key component of the podocin interactome purified both from cultured podocytes and native glomeruli. It colocalizes with podocin and regulates its stability. In C. elegans, this process is conserved. Here, Ubr4 is responsible for the degradation of mislocalized MEC-2 multimers. Ubiquitylomic analysis of mouse glomeruli revealed that podocin is ubiquitylated at two lysine residues. These sites were Ubr4-dependent and were conserved across species. Molecular dynamics simulations revealed that ubiquitylation of one site, K301, do not only target podocin/MEC-2 for proteasomal degradation, but may also affect stability and disassembly of the multimeric complex. We suggest that Ubr4 is a key regulator of podocyte foot process proteostasis.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany,
| | - Puneet Bharill
- Department II of Internal Medicine, Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Xiongwu Wu
- Laboratory of Computational Biology, National Heart, Blood, and Lung Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Priyanka Kohli
- Department II of Internal Medicine, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | | | - Oliver Kretz
- Renal Division, University Hospital Freiburg, Freiburg, Germany, Neuroanatomy, University of Freiburg, Freiburg, Germany
| | - Isabel Saez
- Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | - Bernhard Schermer
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | | | - Sriram Aravamudhan
- Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany and
| | - Bernard R Brooks
- Laboratory of Computational Biology, National Heart, Blood, and Lung Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Vilchez
- Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | - Tobias B Huber
- Renal Division, University Hospital Freiburg, Freiburg, Germany, BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Roman-Ulrich Müller
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Marcus Krüger
- Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and
| | - Thomas Benzing
- Department II of Internal Medicine, Center for Molecular Medicine Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD) and Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany,
| |
Collapse
|
20
|
Rinschen MM, Benzing T, Limbutara K, Pisitkun T. Proteomic analysis of the kidney filtration barrier--Problems and perspectives. Proteomics Clin Appl 2015; 9:1053-68. [PMID: 25907645 DOI: 10.1002/prca.201400201] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/21/2015] [Accepted: 04/20/2015] [Indexed: 12/12/2022]
Abstract
Diseases of the glomerular filter of the kidney are a leading cause of end-stage renal failure. The kidney filter is localized within the renal glomeruli, small microvascular units that are responsible for ultrafiltration of about 180 liters of primary urine every day. The renal filter consists of three layers, fenestrated endothelial cells, glomerular basement membrane, and the podocytes, terminally differentiated, arborized epithelial cells. This review demonstrates the use of proteomics to generate insights into the regulation of the renal filtration barrier at a molecular level. The advantages and disadvantages of different glomerular purification methods are examined, and the technical limitations that have been significantly improved by in silico or biochemical approaches are presented. We also comment on phosphoproteomic studies that have generated considerable molecular-level understanding of the physiological regulation of the kidney filter. Lastly, we conclude with an analysis of urinary exosomes as a potential filter-derived resource for the noninvasive discovery of glomerular disease mechanisms.
Collapse
Affiliation(s)
- Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany
| | - Kavee Limbutara
- Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Trairak Pisitkun
- Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| |
Collapse
|