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Saqib U, Munjuluri S, Sarkar S, Biswas S, Mukherjee O, Satsangi H, Baig MS, Obukhov AG, Hajela K. Transient Receptor Potential Canonical 6 (TRPC6) Channel in the Pathogenesis of Diseases: A Jack of Many Trades. Inflammation 2023:10.1007/s10753-023-01808-3. [PMID: 37072606 PMCID: PMC10112830 DOI: 10.1007/s10753-023-01808-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/18/2023] [Accepted: 03/23/2023] [Indexed: 04/20/2023]
Abstract
The mammalian Transient Receptor Potential Canonical (TRPC) subfamily comprises seven transmembrane proteins (TRPC1-7) forming cation channels in the plasma membrane of mammalian cells. TRPC channels mediate Ca2+ and Na+ influx into the cells. Amongst TRPCs, TRPC6 deficiency or increased activity due to gain-of-function mutations has been associated with a multitude of diseases, such as kidney disease, pulmonary disease, and neurological disease. Indeed, the TRPC6 protein is expressed in various organs and is involved in diverse signalling pathways. The last decade saw a surge in the investigative studies concerning the physiological roles of TRPC6 and describing the development of new pharmacological tools modulating TRPC6 activity. The current review summarizes the progress achieved in those investigations.
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Affiliation(s)
- Uzma Saqib
- School of Life Sciences, Devi Ahilya Vishwavidyalaya, Vigyan Bhawan, Khandwa Road Campus, Indore, 452 001, MP, India
| | - Sreepadaarchana Munjuluri
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Sutripta Sarkar
- Post Graduate Department of Food and Nutrition, Barrackpore Rastraguru Surendranath College, 85, Middle Road, Barrackpore, 700120, West Bengal, India
| | - Subir Biswas
- Ramky One Galaxia, Nallagandla, Hyderabad, 500019, Telangana, India
| | - Oyshi Mukherjee
- Post Graduate Department of Food and Nutrition, Barrackpore Rastraguru Surendranath College, 85, Middle Road, Barrackpore, 700120, West Bengal, India
| | | | - Mirza S Baig
- Department of Biosciences and Biomedical Engineering (BSBE), Indian Institute of Technology Indore (IITI), Indore, India
| | - Alexander G Obukhov
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
| | - Krishnan Hajela
- School of Life Sciences, Devi Ahilya Vishwavidyalaya, Vigyan Bhawan, Khandwa Road Campus, Indore, 452 001, MP, India.
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Wang D, Gust M, Ferrell N. Kidney-on-a-Chip: Mechanical Stimulation and Sensor Integration. SENSORS (BASEL, SWITZERLAND) 2022; 22:6889. [PMID: 36146238 PMCID: PMC9503911 DOI: 10.3390/s22186889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Bioengineered in vitro models of the kidney offer unprecedented opportunities to better mimic the in vivo microenvironment. Kidney-on-a-chip technology reproduces 2D or 3D features which can replicate features of the tissue architecture, composition, and dynamic mechanical forces experienced by cells in vivo. Kidney cells are exposed to mechanical stimuli such as substrate stiffness, shear stress, compression, and stretch, which regulate multiple cellular functions. Incorporating mechanical stimuli in kidney-on-a-chip is critically important for recapitulating the physiological or pathological microenvironment. This review will explore approaches to applying mechanical stimuli to different cell types using kidney-on-a-chip models and how these systems are used to study kidney physiology, model disease, and screen for drug toxicity. We further discuss sensor integration into kidney-on-a-chip for monitoring cellular responses to mechanical or other pathological stimuli. We discuss the advantages, limitations, and challenges associated with incorporating mechanical stimuli in kidney-on-a-chip models for a variety of applications. Overall, this review aims to highlight the importance of mechanical stimuli and sensor integration in the design and implementation of kidney-on-a-chip devices.
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Affiliation(s)
- Dan Wang
- Division of Nephrology, Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
| | - Matthew Gust
- Division of Nephrology, Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
- Department of Statistics, College of Arts and Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Nicholas Ferrell
- Division of Nephrology, Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
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Rachubik P, Szrejder M, Rogacka D, Typiak M, Audzeyenka I, Kasztan M, Pollock DM, Angielski S, Piwkowska A. Insulin controls cytoskeleton reorganization and filtration barrier permeability via the PKGIα-Rac1-RhoA crosstalk in cultured rat podocytes. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119301. [PMID: 35642843 DOI: 10.1016/j.bbamcr.2022.119301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Podocyte foot processes are an important cellular layer of the glomerular barrier that regulates glomerular permeability. Insulin via the protein kinase G type Iα (PKGIα) signaling pathway regulates the balance between contractility and relaxation (permeability) of the podocyte barrier by regulation of the actin cytoskeleton. This mechanism was shown to be disrupted in diabetes. Rho family guanosine-5'-triphosphates (GTPases) are dynamic modulators of the actin cytoskeleton and expressed in cells that form the glomerular filtration barrier. Thus, changes in Rho GTPase activity may affect glomerular permeability to albumin. The present study showed that Rho family GTPases control podocyte migration and permeability. Moreover these processes are regulated by insulin in PKGIα-dependent manner. Modulation of the PKGI-dependent activity of Rac1 and RhoA GTPases with inhibitors or small-interfering RNA impair glomerular permeability to albumin. We also demonstrated this mechanism in obese, insulin-resistant Zucker rats. We propose that PKGIα-Rac1-RhoA crosstalk is necessary in proper organization of the podocyte cytoskeleton and consequently the stabilization of glomerular architecture and regulation of filtration barrier permeability.
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Affiliation(s)
- Patrycja Rachubik
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Maria Szrejder
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Dorota Rogacka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Chemistry, Department of Molecular Biotechnology, Gdańsk, Poland
| | - Marlena Typiak
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Biology, Department of General and Medical Biochemistry, Gdańsk, Poland
| | - Irena Audzeyenka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Chemistry, Department of Molecular Biotechnology, Gdańsk, Poland
| | - Małgorzata Kasztan
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Stefan Angielski
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
| | - Agnieszka Piwkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; University of Gdańsk, Faculty of Chemistry, Department of Molecular Biotechnology, Gdańsk, Poland.
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Jo HA, Hyeon JS, Yang SH, Jung Y, Ha H, Jeong CW, Kwak C, Kim Y, Lee H, Lee JP, Joo KW, Lim CS, Kim YS, Hwang GS, Kim DK. Fumarate modulates phospholipase A2 receptor autoimmunity-induced podocyte injury in membranous nephropathy. Kidney Int 2020; 99:443-455. [PMID: 32712166 DOI: 10.1016/j.kint.2020.06.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 05/19/2020] [Accepted: 06/04/2020] [Indexed: 10/23/2022]
Abstract
Downstream mechanisms that lead to podocyte injury following phospholipase A2 receptor (PLA2R) autoimmunity remain elusive. To help define this we compared urinary metabolomic profiles of patients with PLA2R-associated membranous nephropathy (MN) at the time of kidney biopsy with those of patients with minimal change disease (MCD) and to healthy individuals. Among the metabolites differentially expressed in patients with PLA2R-associated MN compared to healthy individuals, fumarate was the only significant differentially expressed metabolite in PLA2R-associated MN compared to MCD [fold-difference vs. healthy controls and vs. MCD: 1.76 and 1.60, respectively]. High urinary fumarate levels could predict the composite outcome of PLA2R-associated MN. Fumarate hydratase, which hydrolyzes fumarate, colocalized with podocalyxin, and its expression was lower in glomerular sections from patients with PLA2R-associated MN than in those from healthy individuals, patients with non-PLA2R-associated MN or MCD. Podocytes stimulated with IgG purified from serum with a high anti-PLA2R titer (MN-IgG) decreased expression of fumarate hydratase and increased fumarate levels. These changes were coupled to alterations in the expression of molecules involved in the phenotypic profile of podocytes (WT1, ZO-1, Snail, and fibronectin), an increase in albumin flux across the podocyte layer and the production of reactive oxygen species in podocytes. However, overexpression of fumarate hydratase ameliorated these alterations. Furthermore, knockdown of fumarate hydratase exhibited synergistic effects with MN-IgG treatment. Thus, fumarate may promote changes in the phenotypic profiles of podocytes after the development of PLA2R autoimmunity. These findings suggest that fumarate could serve as a potential target for the treatment of PLA2R-associated MN.
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Affiliation(s)
- Hyung Ah Jo
- Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea; Department of Internal Medicine, Inje University Ilsan Paik Hospital, Ilsan, Korea
| | - Jin Seong Hyeon
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea; Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, Korea
| | - Seung Hee Yang
- Kidney Research Institute, Seoul National University, Seoul, Korea
| | - Youngae Jung
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea
| | - Hunjoo Ha
- Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, Korea
| | - Chang Wook Jeong
- Department of Urology, Seoul National University Hospital, Seoul, Korea
| | - Cheol Kwak
- Department of Urology, Seoul National University Hospital, Seoul, Korea
| | - Yaerim Kim
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
| | - Hajeong Lee
- Kidney Research Institute, Seoul National University, Seoul, Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
| | - Jung Pyo Lee
- Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea; Kidney Research Institute, Seoul National University, Seoul, Korea; Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
| | - Kwon Wook Joo
- Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea; Kidney Research Institute, Seoul National University, Seoul, Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
| | - Chun Soo Lim
- Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea; Kidney Research Institute, Seoul National University, Seoul, Korea; Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
| | - Yon Su Kim
- Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea; Kidney Research Institute, Seoul National University, Seoul, Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
| | - Geum-Sook Hwang
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea; Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Korea.
| | - Dong Ki Kim
- Department of Internal Medicine, College of Medicine, Seoul National University, Seoul, Korea; Kidney Research Institute, Seoul National University, Seoul, Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
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Wang Q, Tian X, Wang Y, Wang Y, Li J, Zhao T, Li P. Role of Transient Receptor Potential Canonical Channel 6 (TRPC6) in Diabetic Kidney Disease by Regulating Podocyte Actin Cytoskeleton Rearrangement. J Diabetes Res 2020; 2020:6897390. [PMID: 31998809 PMCID: PMC6964719 DOI: 10.1155/2020/6897390] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/17/2019] [Accepted: 12/23/2019] [Indexed: 01/19/2023] Open
Abstract
Podocyte injury is an important pathogenesis step causing proteinuric kidney diseases such as diabetic kidney disease (DKD). Actin cytoskeleton rearrangement in podocyte induced by multiple pathogenic factors is believed to be the key process resulting in glomerular injury. Many studies have recently shown that transient receptor potential canonical channel 6 (TRPC6) in podocyte plays a critical role in the development and progression of proteinuric kidney disease by regulating its actin cytoskeleton rearrangement. This review is aimed at summarizing the role of TRPC6 on DKD by regulating the podocyte actin cytoskeleton rearrangement, thereby help further broaden our views and understanding on the mechanism of DKD and provide a theoretic basis for exploring new therapeutic targets for DKD patients.
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Affiliation(s)
- Qian Wang
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
- Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xuefei Tian
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Yuyang Wang
- Department of Nephrology, Guang'anmen Hospital of China Academy of Traditional Chinese Medical Sciences, Beijing 100053, China
| | - Yan Wang
- Beijing Key Laboratory of Diabetes Research and Care, Center for Endocrine Metabolism and Immune Diseases, Luhe Hospital, Capital Medical University, Beijing 101149, China
| | - Jialin Li
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
- Beijing University of Chinese Medicine, Beijing 100029, China
| | - Tingting Zhao
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
| | - Ping Li
- Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, Institute of Clinical Medical Sciences, China-Japan Friendship Hospital, Beijing 100029, China
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6
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Anguita E, Villalobo A. Ca 2+ signaling and Src-kinases-controlled cellular functions. Arch Biochem Biophys 2018; 650:59-74. [DOI: 10.1016/j.abb.2018.05.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/26/2018] [Accepted: 05/07/2018] [Indexed: 12/16/2022]
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Lachowicz-Scroggins ME, Gordon ED, Wesolowska-Andersen A, Jackson ND, MacLeod HJ, Sharp LZ, Sun M, Seibold MA, Fahy JV. Cadherin-26 (CDH26) regulates airway epithelial cell cytoskeletal structure and polarity. Cell Discov 2018; 4:7. [PMID: 29449961 PMCID: PMC5809386 DOI: 10.1038/s41421-017-0006-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 12/06/2017] [Accepted: 12/15/2017] [Indexed: 01/27/2023] Open
Abstract
Polarization of the airway epithelial cells (AECs) in the airway lumen is critical to the proper function of the mucociliary escalator and maintenance of lung health, but the cellular requirements for polarization of AECs are poorly understood. Using human AECs and cell lines, we demonstrate that cadherin-26 (CDH26) is abundantly expressed in differentiated AECs, localizes to the cell apices near ciliary membranes, and has functional cadherin domains with homotypic binding. We find a unique and non-redundant role for CDH26, previously uncharacterized in AECs, in regulation of cell-cell contact and cell integrity through maintaining cytoskeletal structures. Overexpression of CDH26 in cells with a fibroblastoid phenotype increases contact inhibition and promotes monolayer formation and cortical actin structures. CDH26 expression is also important for localization of planar cell polarity proteins. Knockdown of CDH26 in AECs results in loss of cortical actin and disruption of CRB3 and other proteins associated with apical polarity. Together, our findings uncover previously unrecognized functions for CDH26 in the maintenance of actin cytoskeleton and apicobasal polarity of AECs.
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Affiliation(s)
- Marrah E. Lachowicz-Scroggins
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143 USA
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Erin D. Gordon
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco, CA 94143 USA
| | | | - Nathan D. Jackson
- Center for Genes, Environment, and Health, National Jewish Health, Denver, CO 80206 USA
| | - Hannah J. MacLeod
- Johns Hopkins Bloomberg School of Public Health, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Baltimore, MD 21205 USA
| | - Louis Z. Sharp
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Matthew Sun
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143 USA
| | - Max A. Seibold
- Center for Genes, Environment, and Health, National Jewish Health, Denver, CO 80206 USA
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045 USA
| | - John V. Fahy
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143 USA
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco, CA 94143 USA
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8
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Rogacka D, Audzeyenka I, Rachubik P, Rychłowski M, Kasztan M, Jankowski M, Angielski S, Piwkowska A. Insulin increases filtration barrier permeability via TRPC6-dependent activation of PKGIα signaling pathways. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1312-1325. [DOI: 10.1016/j.bbadis.2017.03.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 02/04/2017] [Accepted: 03/01/2017] [Indexed: 11/25/2022]
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Ma JH, Wang JJ, Li J, Pfeffer BA, Zhong Y, Zhang SX. The Role of IRE-XBP1 Pathway in Regulation of Retinal Pigment Epithelium Tight Junctions. Invest Ophthalmol Vis Sci 2017; 57:5244-5252. [PMID: 27701635 PMCID: PMC5054729 DOI: 10.1167/iovs.16-19232] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Purpose The retinal pigment epithelium (RPE) tight junctions play a pivotal role in maintaining the homeostatic environment of the neural retina. Herein, we investigated the role of X-box binding protein 1 (XBP1), an endoplasmic reticulum (ER) stress-responsive transcription factor, in regulation of RPE tight junctions. Methods Human RPE cell line (ARPE-19) and primary primate RPE cells were used for in vitro experiments and RPE-specific XBP1 knockout (KO) mice were used for in vivo study. Endoplasmic reticulum stress was induced by a sublethal dose of thapsigargin or tunicamycin. XBP1 activation was manipulated by IRE inhibitor 4μ8C, which suppresses XBP1 mRNA splicing. The integrity of tight junctions and the involvement of calcium-dependent RhoA/Rho kinase pathway were examined. Results Induction of ER stress by thapsigargin, but not tunicamycin, disrupted RPE tight junctions in ARPE-19 cells. Inhibition of XBP1 activation by 4μ8C resulted in a remarkable downregulation of tight junction proteins (ZO-1 and occludin) and defects in tight junction formation in the presence or absence of ER stress inducers. Overexpression of active XBP1 partially reversed 4μ8C-induced anomalies in tight junctions. Mechanistically, XBP1 inhibition resulted in increased intracellular Ca2+ concentration, upregulation of RhoA expression, redistribution of F-actin, and tight junction damage, which was attenuated by Rho kinase inhibitor Y27632. In vivo, deletion of XBP1 in the RPE resulted in defective RPE tight junctions accompanied by increased VEGF expression. Conclusions Taken together, these results suggest a protective role of XBP1 in maintaining RPE tight junctions possibly through regulation of calcium-dependent RhoA/Rho kinase signaling and actin cytoskeletal reorganization.
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Affiliation(s)
- Jacey H Ma
- Departments of Ophthalmology and Biochemistry, University at Buffalo, State University of New York, Buffalo, New York, United States 2SUNY Eye Institute, State University of New York, New York, United States 3Aier School of Ophthalmology, Central South University, Changsha, Hunan, China
| | - Joshua J Wang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, State University of New York, Buffalo, New York, United States 2SUNY Eye Institute, State University of New York, New York, United States
| | - Junhua Li
- Departments of Ophthalmology and Biochemistry, University at Buffalo, State University of New York, Buffalo, New York, United States 2SUNY Eye Institute, State University of New York, New York, United States
| | - Bruce A Pfeffer
- Departments of Ophthalmology and Biochemistry, University at Buffalo, State University of New York, Buffalo, New York, United States 2SUNY Eye Institute, State University of New York, New York, United States 4Research Service, Veterans Administration Western New York Healthcare System, Buffalo, New York, United States
| | - Yiming Zhong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Sarah X Zhang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, State University of New York, Buffalo, New York, United States 2SUNY Eye Institute, State University of New York, New York, United States
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Piwkowska A. Role of Protein Kinase G and Reactive Oxygen Species in the Regulation of Podocyte Function in Health and Disease. J Cell Physiol 2016; 232:691-697. [PMID: 27662602 DOI: 10.1002/jcp.25613] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/22/2016] [Indexed: 11/09/2022]
Abstract
Podocytes and their foot processes form an important cellular layer of the glomerular barrier involved in the regulation of glomerular permeability. Disturbing the function of podocytes plays a central role in the development of proteinuria in diabetic nephropathy. Retraction of the podocyte foot processes that form slit diaphragms is a common feature of proteinuria; although, the correlation between these events in not well understood. Notably, it is unclear whether podocyte foot processes are able to regulate slit diaphragm permeability and glomerular ultrafiltration. The occurrence of reactive oxygen species generation, insulin resistance, and hyperglycemia characterizes early stages of type 2 diabetes. Protein kinase G type I alpha (PKGIα) is an intracellular target for vasorelaxant factors. It is activated in both cGMP-dependent and cGMP-independent manners. Recently, we demonstrated a relationship between oxidative stress, PKGIα activation, actin reorganization, and changes in the permeability of the filtration barrier. This review discusses how redox imbalance affects both the activity of PKGIα and PKGI-dependent signaling pathways in podocytes. J. Cell. Physiol. 232: 691-697, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Agnieszka Piwkowska
- Mossakowski Medical Research Centre Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland
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11
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Piwkowska A, Rogacka D, Audzeyenka I, Kasztan M, Angielski S, Jankowski M. Intracellular calcium signaling regulates glomerular filtration barrier permeability: the role of the PKGIα-dependent pathway. FEBS Lett 2016; 590:1739-48. [DOI: 10.1002/1873-3468.12228] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/17/2016] [Accepted: 05/24/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology; Mossakowski Medical Research Centre Polish Academy of Sciences; Gdańsk Poland
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology; Mossakowski Medical Research Centre Polish Academy of Sciences; Gdańsk Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology; Mossakowski Medical Research Centre Polish Academy of Sciences; Gdańsk Poland
| | - Małgorzata Kasztan
- Department of Medicine; Cardio-Renal Physiology and Medicine; University of Alabama at Birmingham; AL USA
| | - Stefan Angielski
- Laboratory of Molecular and Cellular Nephrology; Mossakowski Medical Research Centre Polish Academy of Sciences; Gdańsk Poland
| | - Maciej Jankowski
- Laboratory of Molecular and Cellular Nephrology; Mossakowski Medical Research Centre Polish Academy of Sciences; Gdańsk Poland
- Department of Clinical Chemistry; Medical University of Gdańsk; Poland
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12
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Piwkowska A, Rogacka D, Audzeyenka I, Kasztan M, Angielski S, Jankowski M. Insulin increases glomerular filtration barrier permeability through PKGIα-dependent mobilization of BKCa channels in cultured rat podocytes. Biochim Biophys Acta Mol Basis Dis 2015; 1852:1599-609. [DOI: 10.1016/j.bbadis.2015.04.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/23/2015] [Accepted: 04/27/2015] [Indexed: 12/29/2022]
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13
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Mashmoushi AK, Oates JC. Lipopolysaccharide induces inducible nitric oxide synthase-dependent podocyte dysfunction via a hypoxia-inducible factor 1α and cell division control protein 42 and Ras-related C3 botulinum toxin substrate 1 pathway. Free Radic Biol Med 2015; 84:185-195. [PMID: 25765888 PMCID: PMC4457627 DOI: 10.1016/j.freeradbiomed.2015.02.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 02/26/2015] [Accepted: 02/26/2015] [Indexed: 11/29/2022]
Abstract
Urine protein loss in immune complex-mediated diseases such as lupus nephritis is associated with podocyte foot process effacement (podocytopathy) but is not always dependent on glomerular immune complex deposition. Several murine and human studies have associated lupus nephritis with inducible nitric oxide synthase (iNOS) expression in what appear to be podocytes. This study was conducted to determine mechanisms of immune-complex-independent and iNOS-dependent podocyte dysfunction. Conditionally immortalized podocytes were cultured with lipopolysaccharide (LPS) and nitric oxide (NO), superoxide (SO), or peroxynitrite donors in the presence or absence of inhibitors of iNOS, reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase or monocyte chemotactic protein 1 (MCP-1), or with sepiapterin to increase coupling of iNOS homodimers. Podocyte NO, SO, and MCP-1 production and nitrotyrosine modifications were determined. The podocytopathy phenotype was determined by measuring cell motility and membrane permeability to albumin. This study determined that NO produced by iNOS is sufficient and necessary to induce podocytopathy. NO probably induces this phenotype via hypoxia-inducible factor 1α and cell division control protein 42 and Ras-related C3 botulinum toxin substrate 1 pathways. With LPS stimulation, neither SO nor peroxynitrite produced by uncoupled iNOS or NADPH oxidase nor MCP-1 was sufficient to induce the full phenotype. This study supports the notion that iNOS may induce autocrine podocyte dysfunction. Thus, targeting iNOS or the pathways of its induction may have therapeutic benefit.
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Affiliation(s)
- Ahmad K Mashmoushi
- Division of Rheumatology and Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Jim C Oates
- Division of Rheumatology and Immunology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA; Rheumatology Section, Medical Service, Ralph H. Johnson VA Medical Center, Charleston, SC 29401, USA.
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14
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Eijkelkamp N, Quick K, Wood JN. Transient Receptor Potential Channels and Mechanosensation. Annu Rev Neurosci 2013; 36:519-46. [DOI: 10.1146/annurev-neuro-062012-170412] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Niels Eijkelkamp
- Laboratory of Neuroimmunology and Developmental Origins of Disease, University Medical Center Utrecht, 3584 EA Utrecht, The Netherlands;
| | - Kathryn Quick
- Wolfson Institute for Biomedical Research, University College London, London WC1 6BT, United Kingdom; ,
| | - John N. Wood
- Wolfson Institute for Biomedical Research, University College London, London WC1 6BT, United Kingdom; ,
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15
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Bi J, Chase SE, Pellenz CD, Kurihara H, Fanning AS, Krendel M. Myosin 1e is a component of the glomerular slit diaphragm complex that regulates actin reorganization during cell-cell contact formation in podocytes. Am J Physiol Renal Physiol 2013; 305:F532-44. [PMID: 23761676 DOI: 10.1152/ajprenal.00223.2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glomerular visceral epithelial cells, also known as podocytes, are critical to both normal kidney function and the development of kidney disease. Podocyte actin cytoskeleton and their highly specialized cell-cell junctions (also called slit diaphragm complexes) play key roles in controlling glomerular filtration. Myosin 1e (myo1e) is an actin-based molecular motor that is expressed in renal glomeruli. Disruption of the Myo1e gene in mice and humans promotes podocyte injury and results in the loss of the integrity of the glomerular filtration barrier. Here, we have used biochemical and microscopic approaches to determine whether myo1e is associated with the slit diaphragm complexes in glomerular podocytes. Myo1e was consistently enriched in the slit diaphragm fraction during subcellular fractionation of renal glomeruli and colocalized with the slit diaphragm markers in mouse kidney. Live cell imaging studies showed that myo1e was recruited to the newly formed cell-cell junctions in cultured podocytes, where it colocalized with the actin filament cables aligned with the nascent contacts. Myo1e-null podocytes expressing FSGS-associated myo1e mutant (A159P) did not efficiently assemble actin cables along new cell-cell junctions. We have mapped domains in myo1e that were critical for its localization to cell-cell junctions and determined that the SH3 domain of myo1e tail interacts with ZO-1, a component of the slit diaphragm complex and tight junctions. These findings suggest that myo1e represents a component of the slit diaphragm complex and may contribute to regulating junctional integrity in kidney podocytes.
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Affiliation(s)
- J Bi
- Dept. of Cell and Developmental Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210.
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16
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Piwkowska A, Rogacka D, Kasztan M, Angielski S, Jankowski M. Insulin increases glomerular filtration barrier permeability through dimerization of protein kinase G type Iα subunits. Biochim Biophys Acta Mol Basis Dis 2013; 1832:791-804. [DOI: 10.1016/j.bbadis.2013.02.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 02/04/2013] [Accepted: 02/06/2013] [Indexed: 12/11/2022]
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17
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Yamashita M, Millward CA, Inoshita H, Saikia P, Chattopadhyay S, Sen GC, Emancipator SN. Antiviral innate immunity disturbs podocyte cell function. J Innate Immun 2012; 5:231-41. [PMID: 23296190 DOI: 10.1159/000345255] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/21/2012] [Indexed: 11/19/2022] Open
Abstract
Immunoglobulin A nephropathy (IgAN) is the most common form of glomerulonephritis throughout the world. A majority (approx. 60%) of patients with IgAN experience disease exacerbations associated with an acute respiratory or gastrointestinal illness that appears to represent a viral infection. However, the exact mechanism of the disease exacerbation by viral infection is not understood, especially at the cellular and molecular levels. Here we report that glomerular podocytes express the major sensors for double-stranded RNA (dsRNA), a common byproduct of viral replication. In addition to these receptors, Toll-like receptor 3 (TLR3) and retinoic acid-inducible gene 1 (RIG-I)-like helicases (RLHs), podocytes express the collateral proteins required to support intracellular signaling. The pathways that mediate responses to dsRNA are fully functional in podocytes. The transcription factor interferon regulatory factor 3 (IRF3) and nuclear factor kappa B (NF-ĸB) are phosphorylated and translocate to the nucleus, and dsRNA increases synthesis of proteins driven by IRF3 (P54, P56 and P60) or NF-ĸB (interleukin 8 and A20). Furthermore, dsRNA suppresses podocyte cell migration, alters the expression of a panel of podocyte essential proteins (nephrin, podocin and CD2-associated protein or CD2AP) and changes transepithelial albumin flux. These effects are dsRNA sensor-specific: TLR3-/- podocytes do not respond to extracellular dsRNA, while intracellular dsRNA has no effect on podocytes bearing a dominant negative form of the major active RLH. These results demonstrate that innate responses to viruses can disturb podocyte cell function in vitro.
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Affiliation(s)
- Michifumi Yamashita
- Department of Pathology, University Hospitals Case Medical Center, Cleveland Clinic, Cleveland, OH 44106, USA.
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18
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Savin VJ, McCarthy ET, Sharma M. Permeability factors in nephrotic syndrome and focal segmental glomerulosclerosis. Kidney Res Clin Pract 2012; 31:205-13. [PMID: 26889423 PMCID: PMC4716100 DOI: 10.1016/j.krcp.2012.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 09/25/2012] [Accepted: 10/04/2012] [Indexed: 12/23/2022] Open
Abstract
Circulating permeability factors have been identified in the plasma of patients with focal segmental glomerulosclerosis (FSGS). Post-transplant recurrence of proteinuria, improvement of proteinuria after treatment with plasmapheresis, and induction of proteinuria in experimental animals by plasma fractions each provide evidence for such plasma factors. Advanced proteomic methods have identified candidate molecules in recurrent FSGS. We have proposed cardiotrophin-like cytokine-1 as an active factor in FSGS. Another potential permeability factor in FSGS is soluble urokinase receptor. In our studies, in vitro plasma permeability activity is blocked by substances that may decrease active molecules or block their effects. We have shown that the simple sugar galactose blocks the effect of FSGS serum in vitro and decreases permeability activity when administered to patients. Since the identities of permeability factors and their mechanisms of action are not well defined, treatment of FSGS is empiric. Corticosteroids are the most common agents for initial treatment. Calcineurin inhibitors, such as cyclosporine A, and tacrolimus and immunosuppressive medications, including mycophenylate, induce remission is some patients with steroid-resistant or -dependent nephrotic syndrome. Therapies that diminish proteinuria and slow progression in FSGS as well as other conditions include renin-angiotensin blockade, blood pressure lowering and plasma lipid control. Use of findings from in vitro studies, coupled with definitive identification of pathogenic molecules, may lead to new treatments to arrest FSGS progression and prevent recurrence after transplantation.
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Affiliation(s)
- Virginia J Savin
- Kansas City Veterans Administration Medical Center, Kansas City, MO, United States
| | - Ellen T McCarthy
- Kansas City Veterans Administration Medical Center, Kansas City, MO, United States
| | - Mukut Sharma
- Kansas City Veterans Administration Medical Center, Kansas City, MO, United States
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19
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Chen CA, Chen TS, Chen HC. Extracellular signal-regulated kinase plays a proapoptotic role in podocytes after reactive oxygen species treatment and inhibition of integrin-extracellular matrix interaction. Exp Biol Med (Maywood) 2012; 237:777-83. [PMID: 22829704 DOI: 10.1258/ebm.2012.011157] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The effect of reactive oxygen species (ROS) and blocking integrin-extracellular matrix (ECM) interaction on apoptosis in podocytes, and the related signal transduction pathways remain unclear. Primary cultured rat podocytes were exposed to ROS. Integrin-ECM interaction was inhibited with anti-β1-integrin monoclonal antibody (mAb) or RGDS (Arg-Gly-Asp-Ser). Extracellular signal-regulated kinase (ERK) activation was evaluated with Western blotting. U0126 was used to inhibit ERK activation. Terminal deoxynucleotidyl transferase-mediated dUTP-peroxidase nick end-labeling of DNA (TUNEL) was used to evaluate apoptosis. We found that ROS-treated podocytes exhibited increased apoptosis, and both anti-β1-integrin mAb and RGDS induce apoptosis. Addition of ROS to either anti-β1-integrin mAb or RGDS enhanced apoptosis in both conditions. ERK activation was increased by either ROS or blocking integrin-ECM interaction. Preincubation with U0126 decreased apoptosis induced by ROS, anti-β1-integrin mAb or RGDS, respectively. Our study demonstrated that ROS and blocking integrin-ECM interaction induce podocyte apoptosis, which is mediated by ERK activation.
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Affiliation(s)
- Chien-An Chen
- Division of Nephrology, Tainan Sinlau Hospital, Tainan 701, Taiwan
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20
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Effect of TRPC6 knockdown on puromycin aminonucleoside-induced podocyte injury. ACTA ACUST UNITED AC 2012; 32:340-345. [DOI: 10.1007/s11596-012-0059-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Indexed: 12/24/2022]
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Piwkowska A, Rogacka D, Jankowski M, Kocbuch K, Angielski S. Hydrogen peroxide induces dimerization of protein kinase G type Iα subunits and increases albumin permeability in cultured rat podocytes. J Cell Physiol 2012; 227:1004-16. [PMID: 21520075 DOI: 10.1002/jcp.22810] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Podocytes help regulate filtration barrier permeability in the kidneys. They express contractile proteins that are characteristic of smooth muscle cells as well as receptors for vasoactive factors such as angiotensin II and atrial natriuretic peptide (ANP). The later one generates intracellular cGMP, with subsequent activation of cGMP-dependent protein kinase; PKG (isoform PKGIα and PKGIβ). In this study, we asked whether hydrogen peroxide (H(2)O(2)), a physiological vasorelaxing factor, affected podocyte permeability and the podoctye PKGIα signaling pathway. Expression of PKGIα was confirmed in cultured rat podocytes using RT-PCR, immunofluorescence, and Western blotting. Exposure of podocytes to exogenous H(2)O(2) (100 µM) in non-reducing conditions increased the formation of PKGIα interprotein disulfide bonds, affected the phosphorylation of PKG target proteins, namely MYPT1 (maximal increase of about 57% at 30 min) and MLC (maximal decrease of about 62% at 10 min). Furthermore, H(2)O(2) increased the permeability of a layer of podocytes to albumin: Transmembrane flux for albumin increased five-fold (106.6 ± 5.2 µg/ml vs. 20.2 ± 2.5 µg/ml, P < 0.05, n = 5), and the PKG inhibitor Rp-8-Br-cGMPS (100 µM) prevented the flux increase. These data suggest that oxidative modulation of PKGIα in podocytes plays an important
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Affiliation(s)
- Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Centre Polish Academy of Sciences, Gdańsk, Poland.
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22
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Bruggeman LA, Doan RP, Loftis J, Darr A, Calabro A. A cell culture system for the structure and hydrogel properties of basement membranes; Application to capillary walls. Cell Mol Bioeng 2012; 5:194-204. [PMID: 23087767 DOI: 10.1007/s12195-012-0221-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In specialized capillary beds such as the kidney glomerulus, the sheet-like structure of the basement membrane in conjunction with opposing monolayers of endothelium and epithelium form the functioning filtration unit of the kidney. Using a novel cross-linking method on a collagen substrate, we have created a novel hydrogel scaffold to substitute for the basement membrane. Using a simple casting method to create thin films of the hydrogel scaffold (1-5μm), the scaffolds were suitable for long-term static culture, and supported cell attachment and long term cell viability similar to a standard type I collagen substrate. Bulk diffusion and protein permeability of the hydrogel scaffold were evaluated, in addition to its use in a perfusion chamber where it withstood hydraulic pressures typical for glomerular capillaries. This system thus provided a suitable cell substrate for the co-culture of renal epithelial podocytes and endothelial cells in a device that replicates the geometry of the in vivo juxtaposition of the two cell types in relation to their basement membrane.
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Affiliation(s)
- Leslie A Bruggeman
- Department of Medicine and Rammelkamp Center for Education and Research, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH 44109
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23
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Herman-Edelstein M, Thomas MC, Thallas-Bonke V, Saleem M, Cooper ME, Kantharidis P. Dedifferentiation of immortalized human podocytes in response to transforming growth factor-β: a model for diabetic podocytopathy. Diabetes 2011; 60:1779-88. [PMID: 21521871 PMCID: PMC3114395 DOI: 10.2337/db10-1110] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Diabetic nephropathy is associated with dedifferentiation of podocytes, losing the specialized features required for efficient glomerular function and acquiring a number of profibrotic, proinflammatory, and proliferative features. These result from tight junction and cytoskeletal rearrangement, augmented proliferation, and apoptosis. RESEARCH DESIGN AND METHODS Experiments were performed in conditionally immortalized human podocytes developed by transfection with the temperature-sensitive SV40-T gene. Cells were then cultured in the presence of transforming growth factor (TGF)-β1 or angiotensin II in the presence or absence of a selective inhibitor of the TGF-β type I receptor kinase, SB-431542. Gene and protein expression were then examined by real-time RT-PCR and immunofluorescence, and correlated with changes observed in vivo in experimental diabetes. RESULTS Treatment of cells with TGF-β1 resulted in dynamic changes in their morphology, starting with retraction and shortening of foot processes and finishing with the formation of broad and complex tight junctions between adjacent podocytes. This dedifferentiation was also associated with dose- and time-dependent reduction in the expression of glomerular epithelial markers (nephrin, p-cadherin, zonnula occludens-1) and increased expression of mesenchymal markers (α-smooth muscle actin, vimentin, nestin), matrix components (fibronectin, collagen I, and collagen IV α3), cellular proliferation, and apoptosis. The induction of diabetes in mice was also associated with similar changes in morphology, protein expression, and proliferation in glomerular podocytes. CONCLUSIONS In response to TGF-β and other TGF-dependent stimuli, mature podocytes undergo dedifferentiation that leads to effacement of foot processes, morphologic flattening, and increased formation of intercellular tight junctions. This simplification of their phenotype to a more embryonic form is also associated with reentry of mature podocytes into the cell cycle, which results in enhanced proliferation and apoptosis. These "pathoadaptive" changes are seen early in the diabetic glomerulus and ultimately contribute to albuminuria, glomerulosclerosis, and podocytopenia.
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Affiliation(s)
- Michal Herman-Edelstein
- JDRF Danielle Alberti Memorial Centre for Diabetes Complications, Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Department of Nephrology and Hypertension, Rabin Medical Center-Hasharon Hospital, Ackler School of Medicine Tel-Aviv University, Petach-Tikva, Israel
| | - Merlin C. Thomas
- JDRF Danielle Alberti Memorial Centre for Diabetes Complications, Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Vicki Thallas-Bonke
- JDRF Danielle Alberti Memorial Centre for Diabetes Complications, Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Moin Saleem
- Academic and Children’s Renal Unit, University of Bristol, Bristol, U.K
| | - Mark E. Cooper
- JDRF Danielle Alberti Memorial Centre for Diabetes Complications, Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Phillip Kantharidis
- JDRF Danielle Alberti Memorial Centre for Diabetes Complications, Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Corresponding author: Phillip Kantharidis,
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24
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Tian D, Jacobo SMP, Billing D, Rozkalne A, Gage SD, Anagnostou T, Pavenstädt H, Pavenstaedt H, Hsu HH, Schlondorff J, Ramos A, Greka A. Antagonistic regulation of actin dynamics and cell motility by TRPC5 and TRPC6 channels. Sci Signal 2010; 3:ra77. [PMID: 20978238 DOI: 10.1126/scisignal.2001200] [Citation(s) in RCA: 201] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Rho family of small guanosine triphosphatases (Rho GTPases: RhoA, Cdc42, and Rac1) regulates many aspects of cell behavior, including actin dynamics and cell migration. The generation of calcium ion (Ca(2+)) microdomains is critical in promoting cell migration because they control the localized activity of Rho GTPases. We identified receptor-activated TRPC5 and TRPC6 (transient receptor potential canonical type 5 and 6) channels as antagonistic regulators of actin remodeling and cell motility in fibroblasts and kidney podocytes. We show that TRPC5 is in a molecular complex with Rac1, whereas TRPC6 is in a molecular complex with RhoA. TRPC5-mediated Ca(2+) influx induces Rac1 activation, thereby promoting cell migration, whereas TRPC6-mediated Ca(2+) influx increases RhoA activity, thereby inhibiting cell migration. Our data unveil antagonistic Ca(2+) influx pathways as a conserved signaling mechanism for the integrated regulation of cell migration.
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Affiliation(s)
- Dequan Tian
- Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA
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25
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Dryer SE, Reiser J. TRPC6 channels and their binding partners in podocytes: role in glomerular filtration and pathophysiology. Am J Physiol Renal Physiol 2010; 299:F689-701. [PMID: 20685822 DOI: 10.1152/ajprenal.00298.2010] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Loss or dysfunction of podocytes is a major cause of glomerular kidney disease. Several genetic forms of glomerular disease are caused by mutations in genes that encode structural elements of the slit diaphragm or the underlying cytoskeleton of podocyte foot processes. The recent discovery that gain-of-function mutations in Ca(2+)-permeable canonical transient receptor potential-6 channels (TRPC6) underlie a subset of familial forms of focal segmental glomerulosclerosis (FSGS) has focused attention on the basic cellular physiology of podocytes. Several recent studies have examined the role of Ca(2+) dynamics in normal podocyte function and their possible contributions to glomerular disease. This review summarizes the properties of TRPC6 and related channels, focusing on their permeation and gating properties, the nature of mutations associated with familial FSGS, and the role of TRPC channels in podocyte cell biology as well as in glomerular pathophysiology. TRPC6 interacts with several proteins in podocytes, including essential slit diaphragm proteins and mechanosensitive large-conductance Ca(2+)-activated K(+) channels. The signaling dynamics controlling ion channel function and localization in podocytes appear to be quite complex.
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Affiliation(s)
- Stuart E Dryer
- Dept. of Biology and Biochemistry, Univ. of Houston, 4800 Calhoun, Houston, TX 77204-5001, USA.
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26
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Inhibition of integrin-linked kinase blocks podocyte epithelial-mesenchymal transition and ameliorates proteinuria. Kidney Int 2010; 78:363-73. [PMID: 20505657 DOI: 10.1038/ki.2010.137] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Proteinuria is a primary clinical symptom of a large number of glomerular diseases that progress to end-stage renal failure. Podocyte dysfunctions play a fundamental role in defective glomerular filtration in many common forms of proteinuric kidney disorders. Since binding of these cells to the basement membrane is mediated by integrins, we determined the role of integrin-linked kinase (ILK) in podocyte dysfunction and proteinuria. ILK expression was induced in mouse podocytes by various injurious stimuli known to cause proteinuria including TGF-beta1, adriamycin, puromycin, and high ambient glucose. Podocyte ILK was also found to be upregulated in human proteinuric glomerular diseases. Ectopic expression of ILK in podocytes decreased levels of the epithelial markers nephrin and ZO-1, induced mesenchymal markers such as desmin, fibronectin, matrix metalloproteinase-9 (MMP-9), and alpha-smooth muscle actin (alpha-SMA), promoted cell migration, and increased the paracellular albumin flux across podocyte monolayers. ILK also induced Snail, a key transcription factor mediating epithelial-mesenchymal transition (EMT). Blockade of ILK activity with a highly selective small molecule inhibitor reduced Snail induction and preserved podocyte phenotypes following TGF-beta1 or adriamycin stimulation. In vivo, this ILK inhibitor ameliorated albuminuria, repressed glomerular induction of MMP-9 and alpha-SMA, and preserved nephrin expression in murine adriamycin nephropathy. Our results show that upregulation of ILK is a convergent pathway leading to podocyte EMT, migration, and dysfunction. ILK may be an attractive target for therapeutic intervention of proteinuric kidney diseases.
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Fan Q, Zhang H, Ding J, Liu S, Miao J, Xing Y, Yu Z, Guan N. R168H and V165X mutant podocin might induce different degrees of podocyte injury via different molecular mechanisms. Genes Cells 2009; 14:1079-90. [PMID: 19674119 DOI: 10.1111/j.1365-2443.2009.01336.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A lot of mutations of podocin, a key protein of podocyte slit diaphragm (SD), have been found both in hereditary and sporadic focal segmental glomeruloscleorosis (FSGS). Nevertheless, the mechanisms of podocyte injury induced by mutant podocins are still unclear. A compound heterozygous podocin mutation was identified in our FSGS patient, leading to a truncated (podocin (V165X)) and a missense mutant protein (podocin (R168H)), respectively. Here, it was explored whether and how both mutant podocins induce podocyte injury in the in vitro cultured podocyte cell line. Our results showed that podocin (R168H) induced more significant podocyte apoptosis and expression changes in more podocyte molecules than podocin (V165X). Podocyte injury caused by the normal localized podocin(V165X) was effectively inhibited by TRPC6 knockdown. The abnormal retention of podocin(R168H) in endoplasmic reticulum (ER) resulted in the mis-localizations of other critical SD molecules nephrin, CD2AP and TRPC6, and significantly up-regulated ER stress markers Bip/grp78, p-PERK and caspase-12. These results implicated that podocin (R168H) and podocin (V165X) induced different degrees of podocyte injury, which might be resulted from different molecular mechanisms. Our findings provided some possible clues for further exploring the pharmacological targets to the proteinuria induced by different mutant podocins.
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Affiliation(s)
- Qingfeng Fan
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
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Vogtländer NPJ, Visch HJ, Bakker MAH, Berden JHM, van der Vlag J. Ligation of alpha-dystroglycan on podocytes induces intracellular signaling: a new mechanism for podocyte effacement? PLoS One 2009; 4:e5979. [PMID: 19543532 PMCID: PMC2695560 DOI: 10.1371/journal.pone.0005979] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Accepted: 05/15/2009] [Indexed: 12/20/2022] Open
Abstract
Background α-Dystroglycan is a negatively charged glycoprotein that covers the apical and basolateral membrane of the podocyte. Its transmembrane binding to the cytoskeleton is regulated via tyrosine phosphorylation (pY892) of β-dystroglycan. At the basolateral side α-dystroglycan binds the glomerular basement membrane. At the apical membrane, it plays a role in the maintenance of the filtration slit. In this study, we evaluated whether ligation of α-dystroglycan with specific antibodies or natural ligands induces intracellular signaling, and whether there is an effect on podocyte architecture. Methodology/Principal Findings Conditionally immortalized podocytes were exposed in vitro to antibodies to α-dystroglycan, and to fibronectin, biglycan, laminin and agrin. Intracellular calcium fluxes, phosphorylation of β-dystroglycan and podocyte architecture were studied. Antibodies to α-dystroglycan could specifically induce calcium signaling. Fibronectin also induced calcium signaling, and led to dephosphorylation of pY892 in β-dystroglycan. Ligation of α-dystroglycan resulted in an altered actin architecture, a decreased number of podocyte pedicles and a more flattened appearance of the podocyte. Conclusions/Significance We conclude that ligation of α-dystroglycan on podocytes induces intracellular calcium signaling, which leads to an altered cytoskeleton architecture akin to the situation of foot process effacement. In particular the ability of fibronectin to induce intracellular signaling events is of interest, since the expression and excretion of this protein is upregulated in several proteinuric diseases. Therefore, fibronectin-induced signaling via dystroglycan may be a novel mechanism for foot process effacement in proteinuric diseases.
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Affiliation(s)
- Nils P. J. Vogtländer
- Nephrology Research Laboratory, Nijmegen Centre for Molecular Life Sciences, Division of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Henk Jan Visch
- Department of Biochemistry, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Marinka A. H. Bakker
- Nephrology Research Laboratory, Nijmegen Centre for Molecular Life Sciences, Division of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Jo H. M. Berden
- Nephrology Research Laboratory, Nijmegen Centre for Molecular Life Sciences, Division of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Johan van der Vlag
- Nephrology Research Laboratory, Nijmegen Centre for Molecular Life Sciences, Division of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- * E-mail:
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Martini S, Kretzler M. How to build a tight but permeable glomerular junction. J Am Soc Nephrol 2009; 20:1420-1. [PMID: 19520750 DOI: 10.1681/asn.2009050514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Sebastian Martini
- Department of Internal Medicine, Division of Nephrology, University of Michigan, Ann Arbor, Michigan, USA
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Kim EY, Choi KJ, Dryer SE. Nephrin binds to the COOH terminus of a large-conductance Ca2+-activated K+ channel isoform and regulates its expression on the cell surface. Am J Physiol Renal Physiol 2008; 295:F235-46. [PMID: 18480178 DOI: 10.1152/ajprenal.00140.2008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We carried out a yeast two-hybrid screen to identify proteins that interact with large-conductance Ca2+-activated K+ (BKCa) channels encoded by the Slo1 gene. Nephrin, an essential adhesion and scaffolding molecule expressed in podocytes, emerged in this screen. The Slo1-nephrin interaction was confirmed by coimmunoprecipitation from the brain and kidney, from HEK-293T cells expressing both proteins, and by glutathione S-transferase pull-down assays. We detected nephrin binding to the Slo1 VEDEC splice variant, which is typically retained in intracellular stores, and to the beta4-subunit. However, we did not detect significant binding of nephrin to the Slo1 QEERL or Slo1 EMVYR splice variants. Coexpression of nephrin with Slo1 VEDEC increased expression of functional BKCa channels on the surface of HEK-293T cells but did not affect steady-state surface expression of the other COOH-terminal Slo1 variants. Nephrin did not affect the kinetics or voltage dependence of channel activation in HEK-293T cells expressing Slo1. Stimulation of Slo1 VEDEC surface expression in HEK-293T cells was also observed by coexpressing a small construct encoding only the distal COOH-terminal domains of nephrin that interact with Slo1. Reduction of endogenous nephrin expression by application of small interfering RNA to differentiated cells of an immortalized podocyte cell line markedly reduced the steady-state surface expression of Slo1 as assessed by electrophysiology and cell-surface biotinylation assays. Nephrin therefore plays a role in organizing the surface expression of ion channel proteins in podocytes and may play a role in outside-in signaling to allow podocytes to adapt to mechanical or neurohumoral stimuli originating in neighboring cells.
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Affiliation(s)
- Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5001, USA
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Sawai K, Mukoyama M, Mori K, Kasahara M, Koshikawa M, Yokoi H, Yoshioka T, Ogawa Y, Sugawara A, Nishiyama H, Yamada S, Kuwahara T, Saleem MA, Shiota K, Ogawa O, Miyazato M, Kangawa K, Nakao K. Expression of CCN1 (CYR61) in developing, normal, and diseased human kidney. Am J Physiol Renal Physiol 2007; 293:F1363-72. [PMID: 17699553 DOI: 10.1152/ajprenal.00205.2007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
CCN1 (cysteine-rich protein 61; Cyr61) is an extracellular matrix-associated signaling molecule that functions in cell migration, adhesion, and differentiation. We previously reported that CCN1 is induced at podocytes in rat anti-Thy-1 glomerulonephritis, a well-known model of reversible glomerular injury, but its expression and significance in the human kidney remain totally unknown (Sawai K, Mori K, Mukoyama M, Sugawara A, Suganami T, Koshikawa M, Yahata K, Makino H, Nagae T, Fujinaga Y, Yokoi H, Yoshioka T, Yoshimoto A, Tanaka I, Nakao K. J Am Soc Nephrol 14: 1154-1163, 2003). Here we report that, in the human kidney, CCN1 expression was confined to podocytes in normal adult and embryonic glomeruli from the capillary loop stage. Podocyte CCN1 expression was decreased in IgA nephropathy, diabetic nephropathy, and membranous nephropathy, whereas it remained unchanged in minimal change disease and focal segmental glomerulosclerosis. Downregulation of CCN1 was significantly greater in diseased kidneys with severe mesangial expansion. CCN1 protein was also localized in the thick ascending limb of Henle's loop, distal and proximal tubules, and collecting ducts, which was not altered in diseased kidneys. In vitro, recombinant CCN1 protein enhanced endothelial cell adhesion, whereas it prominently inhibited mesangial cell adhesion. CCN1 also completely suppressed mesangial cell migration, suggesting its role as a mesangial-repellent factor. In cultured podocytes, CCN1 markedly induced the expression of cyclin-dependent kinase inhibitor p27(Kip1) as well as synaptopodin in a dose-dependent manner and suppressed podocyte migration. These data indicate that CCN1 is expressed in podocytes, can act on glomerular cells to modulate glomerular remodeling, and is downregulated in diseased kidneys, suggesting that impairment of CCN1 expression in podocytes may contribute to the progression of glomerular disease with mesangial expansion.
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Affiliation(s)
- Kazutomo Sawai
- Department of Medicine and Clinical Science, Kyoto University Graduate School of Medicine, Kawahara-cho, Sakyo-ku, Kyoto, Japan
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32
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Abstract
Human genetic and in vivo animal studies have helped to define the critical importance of podocytes for kidney function in health and disease. However, as in any other research area, by default these approaches do not allow for mechanistic studies. Such mechanistic studies require the availability of cells grown ex vivo (i.e., in culture) with the ability to directly study mechanistic events and control the environment such that specific hypotheses can be tested. A seminal breakthrough came about a decade ago with the documentation of differentiation in culture of primary rat and human podocytes and the subsequent development of conditionally immortalized differentiated podocyte cell lines that allow deciphering the decisive steps of differentiation and function of 'in vivo' podocytes. Although this paper is not intended to provide a comprehensive review of podocyte biology, nor their role in proteinuric renal diseases or progressive glomerulosclerosis, it will focus specifically on several aspects of podocytes in culture. In particular, we will discuss the scientific and research rationale and need for cultured podocytes, how podocyte cell-culture evolved, and how cultured podocytes are currently being used to uncover novel functions of podocytes that can then be validated in vivo in animal or human studies. In addition, we provide a detailed description of how to properly culture and characterize podocytes to avoid potential pitfalls.
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Affiliation(s)
- S J Shankland
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington, USA
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Bruggeman LA, Martinka S, Simske JS. Expression of TM4SF10, a Claudin/EMP/PMP22 family cell junction protein, during mouse kidney development and podocyte differentiation. Dev Dyn 2007; 236:596-605. [PMID: 17195181 DOI: 10.1002/dvdy.21052] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cell junctions in the nephron are highly specialized to perform specific and distinct filtration and reabsorption functions. The mature kidney forms complex cell junctions including slit diaphragms that prevent the passage of serum proteins into the filtrate, and tubule cell junctions that regulate specific paracellular ion reuptake. We have investigated the expression of TM4SF10 (Trans-Membrane tetra(4)-Span Family 10) in mouse kidneys. TM4SF10 is the vertebrate orthologue of Caenorhabditis elegans VAB-9, a tetraspan adherens junction protein in the PMP22/EMP/Claudin family of proteins. We found that TM4SF10 localizes at the basal-most region of podocyte precursors before the capillary loop stage, at some tubule precursors, and at the ureteric bud junction with S-shaped bodies. Overall expression of TM4SF10 peaked at postnatal day 4 and was virtually absent in adult kidneys. The very limited expression of TM4SF10 protein that persisted into adulthood was restricted to a few tubule segments but remained localized to the basal region of lateral membranes. In undifferentiated cultured podocytes, TM4SF10 localized to the perinuclear region and translocated to the cell membrane after Cadherin appearance at cell-cell contacts. TM4SF10 colocalized with ZO1 and p120ctn in undifferentiated confluent podocytes and also colocalized with the tips of actin filaments at cell contacts. Upon differentiation of cultured podocytes, TM4SF10 protein disappeared from cell contacts and expression ceased. These results suggest that TM4SF10 functions during differentiation of podocytes and may participate in the maturation of cell junctions from simple adherens junctions to elaborate slit diaphragms. TM4SF10 may define a new class of Claudin-like proteins that function during junctional development.
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Affiliation(s)
- Leslie A Bruggeman
- Rammelkamp Center for Education and Research Case Western Reserve University School of Medicine, MetroHealth Medical Center, Cleveland, Ohio 44109, USA
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Macconi D, Abbate M, Morigi M, Angioletti S, Mister M, Buelli S, Bonomelli M, Mundel P, Endlich K, Remuzzi A, Remuzzi G. Permselective dysfunction of podocyte-podocyte contact upon angiotensin II unravels the molecular target for renoprotective intervention. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:1073-85. [PMID: 16565484 PMCID: PMC1606571 DOI: 10.2353/ajpath.2006.050701] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/13/2005] [Indexed: 11/20/2022]
Abstract
Ameliorating the function of the glomerular barrier to circulating proteins by blocking angiotensin II (Ang II) translates into less risk of progression toward end-stage renal failure in diabetic and nondiabetic nephropathies. However, the mechanisms underlying this barrier protection are not clear. Specialized contacts between adjacent podocytes are major candidate targets, and the actin cytoskeleton is emerging as a regulatory element. Here, we present data demonstrating that Ang II induced reorganization of F-actin fibers and redistribution of zonula occludens-1 (ZO-1) that is physically associated with actin in murine podocytes. These effects were paralleled by increased albumin permeability across podocyte monolayers. The F-actin stabilizer jasplakinolide prevented both ZO-1 redistribution and albumin leakage, suggesting that actin cytoskeleton rearrangement is instrumental to podocyte permselective dysfunction induced by Ang II. Changes in both F-actin and ZO-1 patterns were confirmed in glomeruli of rat isolated perfused kidneys on short infusion of Ang II, leading to increased protein excretion. Podocyte dysfunction was mediated by Ang II type 1 receptor and was partly dependent on Src kinase-phospholipase C activation. These data demonstrate that strategies aimed at stabilizing podocyte-podocyte contacts and targeting the relevant intracellular signal transduction are crucial to renoprotection.
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Affiliation(s)
- Daniela Macconi
- "Mario Negri" Institute for Pharmacological Research, Via Gavazzeni 11, 24125 Bergamo, Italy.
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35
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Abstract
Cytoskeletal dynamics play important roles during normal podocyte development, in maintenance of the healthy glomerular filter, and in glomerular pathology. During the past few years, essential progress has been made in understanding the molecular mechanisms that govern podocyte cytoskeletal dynamics, nevertheless this knowledge remains incomplete. Examination of the podocyte cytoskeleton presents unique challenges to the experimentalist who is faced with attempting to model a morphologically complex cell that is situated in a complex microenvironment. This review will summarize recent progress in understanding cytoskeletal dynamics in the podocyte and will review modern imaging techniques relevant to studying this area of podocyte biology.
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Affiliation(s)
- Marcus J Moeller
- Division of Nephrology and Immunology, University Hospital, RWTH, Aachen, Germany
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