1
|
Harrison‐Bernard LM, Raij L, Tian RX, Jaimes EA. Genetically conditioned interaction among microRNA-155, alpha-klotho, and intra-renal RAS in male rats: Link to CKD progression. Physiol Rep 2024; 12:e16172. [PMID: 39375174 PMCID: PMC11458328 DOI: 10.14814/phy2.16172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 07/23/2024] [Accepted: 07/23/2024] [Indexed: 10/09/2024] Open
Abstract
Incident chronic kidney disease (CKD) varies in populations with hypertension of similar severity. Proteinuria promotes CKD progression in part due to activation of plasminogen to plasmin in the podocytes, resulting in oxidative stress-mediated injury. Additional mechanisms include deficiency of renal alpha-klotho, that inhibits Wnt/beta-catenin, an up regulator of intra-renal renin angiotensin system (RAS) genes. Alpha-klotho deficiency therefore results in upregulation of the intra-renal RAS via Wnt/beta-catenin. In hypertensive, Dahl salt sensitive (DS) and spontaneously hypertensive rats (SHR), we investigated renal and vascular injury, miR-155, AT1R, alpha-klotho, and TNF-α. Hypertensive high salt DS (DS-HS), but not SHR developed proteinuria, plasminuria, and glomerulosclerosis. Compared to DS low salt (DS-LS), in hypertensive DS-HS alpha-klotho decreased 5-fold in serum and 2.6-fold in kidney, whereas serum mir-155 decreased 3.3-fold and AT1R increased 52% in kidney and 77% in aorta. AT1R, alpha-klotho, and miR-155 remained unchanged in prehypertensive and hypertensive SHR. TNF-α increased by 3-fold in serum and urine of DS-HS rats. These studies unveiled in salt sensitive DS-HS, but not in SHR, a genetically conditioned dysfunction of the intermolecular network integrated by alpha-klotho, RAS, miR-155, and TNF-α that is at the helm of their end-organ susceptibility while plasminuria may participate as a second hit.
Collapse
Affiliation(s)
- L. M. Harrison‐Bernard
- Department of PhysiologyLouisiana State University Health Sciences CenterNew OrleansLouisianaUSA
| | - L. Raij
- Katz Family Division of NephrologyUniversity of Miami Miller School of MedicineMiamiFloridaUSA
| | - R. X. Tian
- South Florida Veterans Administration FoundationMiamiFloridaUSA
| | - E. A. Jaimes
- Renal ServiceMemorial Sloan Kettering Cancer Center and Weill Cornell Medical CollegeNew YorkNew YorkUSA
| |
Collapse
|
2
|
Delrue C, Speeckaert R, Moresco RN, Speeckaert MM. Cyclic Adenosine Monophosphate Signaling in Chronic Kidney Disease: Molecular Targets and Therapeutic Potentials. Int J Mol Sci 2024; 25:9441. [PMID: 39273390 PMCID: PMC11395066 DOI: 10.3390/ijms25179441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2024] [Revised: 08/27/2024] [Accepted: 08/29/2024] [Indexed: 09/15/2024] Open
Abstract
Chronic kidney disease (CKD) is characterized by a steady decline in kidney function and affects roughly 10% of the world's population. This review focuses on the critical function of cyclic adenosine monophosphate (cAMP) signaling in CKD, specifically how it influences both protective and pathogenic processes in the kidney. cAMP, a critical secondary messenger, controls a variety of cellular functions, including transcription, metabolism, mitochondrial homeostasis, cell proliferation, and apoptosis. Its compartmentalization inside cellular microdomains ensures accurate signaling. In kidney physiology, cAMP is required for hormone-regulated activities, particularly in the collecting duct, where it promotes water reabsorption through vasopressin signaling. Several illnesses, including Fabry disease, renal cell carcinoma, nephrogenic diabetes insipidus, Bartter syndrome, Liddle syndrome, diabetic nephropathy, autosomal dominant polycystic kidney disease, and renal tubular acidosis, have been linked to dysfunction in the cAMP system. Both cAMP analogs and phosphodiesterase inhibitors have the potential to improve kidney function and reduce kidney damage. Future research should focus on developing targeted PDE inhibitors for the treatment of CKD.
Collapse
Affiliation(s)
- Charlotte Delrue
- Department of Nephrology, Ghent University Hospital, 9000 Ghent, Belgium
| | | | - Rafael Noal Moresco
- Graduate Program in Pharmaceutical Sciences, Center of Health Sciences, Federal University of Santa Maria, Santa Maria 97105-900, Brazil
| | - Marijn M Speeckaert
- Department of Nephrology, Ghent University Hospital, 9000 Ghent, Belgium
- Research Foundation-Flanders (FWO), 1000 Brussels, Belgium
| |
Collapse
|
3
|
Haydak J, Azeloglu EU. Role of biophysics and mechanobiology in podocyte physiology. Nat Rev Nephrol 2024; 20:371-385. [PMID: 38443711 DOI: 10.1038/s41581-024-00815-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 03/07/2024]
Abstract
Podocytes form the backbone of the glomerular filtration barrier and are exposed to various mechanical forces throughout the lifetime of an individual. The highly dynamic biomechanical environment of the glomerular capillaries greatly influences the cell biology of podocytes and their pathophysiology. Throughout the past two decades, a holistic picture of podocyte cell biology has emerged, highlighting mechanobiological signalling pathways, cytoskeletal dynamics and cellular adhesion as key determinants of biomechanical resilience in podocytes. This biomechanical resilience is essential for the physiological function of podocytes, including the formation and maintenance of the glomerular filtration barrier. Podocytes integrate diverse biomechanical stimuli from their environment and adapt their biophysical properties accordingly. However, perturbations in biomechanical cues or the underlying podocyte mechanobiology can lead to glomerular dysfunction with severe clinical consequences, including proteinuria and glomerulosclerosis. As our mechanistic understanding of podocyte mechanobiology and its role in the pathogenesis of glomerular disease increases, new targets for podocyte-specific therapeutics will emerge. Treating glomerular diseases by targeting podocyte mechanobiology might improve therapeutic precision and efficacy, with potential to reduce the burden of chronic kidney disease on individuals and health-care systems alike.
Collapse
Affiliation(s)
- Jonathan Haydak
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Evren U Azeloglu
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| |
Collapse
|
4
|
Saito K, Yokawa S, Kurihara H, Yaoita E, Mizuta S, Tada K, Oda M, Hatakeyama H, Ohta Y. FilGAP controls cell-extracellular matrix adhesion and process formation of kidney podocytes. FASEB J 2024; 38:e23504. [PMID: 38421271 DOI: 10.1096/fj.202301691rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 01/17/2024] [Accepted: 02/07/2024] [Indexed: 03/02/2024]
Abstract
The function of kidney podocytes is closely associated with actin cytoskeleton regulated by Rho small GTPases. Loss of actin-driven cell adhesions and processes is connected to podocyte dysfunction, proteinuria, and kidney diseases. FilGAP, a GTPase-activating protein for Rho small GTPase Rac1, is abundantly expressed in kidney podocytes, and its gene is linked to diseases in a family with focal segmental glomerulosclerosis. In this study, we have studied the role of FilGAP in podocytes in vitro. Depletion of FilGAP in cultured podocytes induced loss of actin stress fibers and increased Rac1 activity. Conversely, forced expression of FilGAP increased stress fiber formation whereas Rac1 activation significantly reduced its formation. FilGAP localizes at the focal adhesion (FA), an integrin-based protein complex closely associated with stress fibers, that mediates cell-extracellular matrix (ECM) adhesion, and FilGAP depletion decreased FA formation and impaired attachment to the ECM. Moreover, in unique podocyte cell cultures capable of inducing the formation of highly organized processes including major processes and foot process-like projections, FilGAP depletion or Rac1 activation decreased the formation of these processes. The reduction of FAs and process formations in FilGAP-depleted podocyte cells was rescued by inhibition of Rac1 or P21-activated kinase 1 (PAK1), a downstream effector of Rac1, and PAK1 activation inhibited their formations. Thus, FilGAP contributes to both cell-ECM adhesion and process formation of podocytes by suppressing Rac1/PAK1 signaling.
Collapse
Affiliation(s)
- Koji Saito
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Seiji Yokawa
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Hidetake Kurihara
- Department of Physical Therapy, Faculty of Health Sciences, Aino University, Osaka, Ibaraki, Japan
| | - Eishin Yaoita
- Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Niigata, Japan
| | - Sari Mizuta
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Kanae Tada
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Moemi Oda
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Hiroyasu Hatakeyama
- Department of Physiology, School of Medicine, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Yasutaka Ohta
- Division of Cell Biology, Department of Biosciences, School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| |
Collapse
|
5
|
Wang H, Liu H, Cheng H, Xue X, Ge Y, Wang X, Yuan J. Klotho Stabilizes the Podocyte Actin Cytoskeleton in Idiopathic Membranous Nephropathy through Regulating the TRPC6/CatL Pathway. Am J Nephrol 2024; 55:345-360. [PMID: 38330925 PMCID: PMC11152006 DOI: 10.1159/000537732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 02/05/2024] [Indexed: 02/10/2024]
Abstract
INTRODUCTION The aim of this study was to explore the renoprotective effects of Klotho on podocyte injury mediated by complement activation and autoantibodies in idiopathic membranous nephropathy (IMN). METHODS Rat passive Heymann nephritis (PHN) was induced as an IMN model. Urine protein levels, serum biochemistry, kidney histology, and podocyte marker levels were assessed. In vitro, sublytic podocyte injury was induced by C5b-9. The expression of Klotho, transient receptor potential channel 6 (TRPC6), and cathepsin L (CatL); its substrate synaptopodin; and the intracellular Ca2+ concentration were detected via immunofluorescence. RhoA/ROCK pathway activity was measured by an activity quantitative detection kit, and the protein expression of phosphorylated-LIMK1 (p-LIMK1) and p-cofilin in podocytes was detected via Western blotting. Klotho knockdown and overexpression were performed to evaluate its role in regulating the TRPC6/CatL pathway. RESULTS PHN rats exhibited proteinuria, podocyte foot process effacement, decreased Klotho and Synaptopodin levels, and increased TRPC6 and CatL expression. The RhoA/ROCK pathway was activated by the increased phosphorylation of LIMK1 and cofilin. Similar changes were observed in C5b-9-injured podocytes. Klotho knockdown exacerbated podocyte injury, while Klotho overexpression partially ameliorated podocyte injury. CONCLUSION Klotho may protect against podocyte injury in IMN patients by inhibiting the TRPC6/CatL pathway. Klotho is a potential target for reducing proteinuria in IMN patients.
Collapse
Affiliation(s)
- Hongyun Wang
- Hubei University of Chinese Medicine, Wuhan, China
| | - Hongyan Liu
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Hong Cheng
- Department of Nephrology, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
- Hubei Province Academy of Traditional Chinese Medicine, Wuhan, China
| | - Xue Xue
- Hubei University of Chinese Medicine, Wuhan, China
| | - Yamei Ge
- Hubei University of Chinese Medicine, Wuhan, China
| | - Xiaoqin Wang
- Department of Nephrology, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
- Hubei Province Academy of Traditional Chinese Medicine, Wuhan, China
| | - Jun Yuan
- Hubei University of Chinese Medicine, Wuhan, China
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, China
| |
Collapse
|
6
|
Lizotte F, Rousseau M, Denhez B, Lévesque D, Guay A, Liu H, Moreau J, Higgins S, Sabbagh R, Susztak K, Boisvert FM, Côté AM, Geraldes P. Deletion of protein tyrosine phosphatase SHP-1 restores SUMOylation of podocin and reverses the progression of diabetic kidney disease. Kidney Int 2023; 104:787-802. [PMID: 37507049 DOI: 10.1016/j.kint.2023.06.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/03/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023]
Abstract
Both clinical and experimental data suggest that podocyte injury is involved in the onset and progression of diabetic kidney disease (DKD). Although the mechanisms underlying the development of podocyte loss are not completely understood, critical structural proteins such as podocin play a major role in podocyte survival and function. We have reported that the protein tyrosine phosphatase SHP-1 expression increased in podocytes of diabetic mice and glomeruli of patients with diabetes. However, the in vivo contribution of SHP-1 in podocytes is unknown. Conditional podocyte-specific SHP-1-deficient mice (Podo-SHP-1-/-) were generated to evaluate the impact of SHP-1 deletion at four weeks of age (early) prior to the onset of diabetes and after 20 weeks (late) of diabetes (DM; Ins2+/C96Y) on kidney function (albuminuria and glomerular filtration rate) and kidney pathology. Ablation of the SHP-1 gene specifically in podocytes prevented and even reversed the elevated albumin/creatinine ratio, glomerular filtration rate progression, mesangial cell expansion, glomerular hypertrophy, glomerular basement membrane thickening and podocyte foot process effacement induced by diabetes. Moreover, podocyte-specific deletion of SHP-1 at an early and late stage prevented diabetes-induced expression of collagen IV, fibronectin, transforming growth factor-β, transforming protein RhoA, and serine/threonine kinase ROCK1, whereas it restored nephrin, podocin and cation channel TRPC6 expression. Mass spectrometry analysis revealed that SHP-1 reduced SUMO2 post-translational modification of podocin while podocyte-specific deletion of SHP-1 preserved slit diaphragm protein complexes in the diabetic context. Thus, our data uncovered a new role of SHP-1 in the regulation of cytoskeleton dynamics and slit diaphragm protein expression/stability, and its inhibition preserved podocyte function preventing DKD progression.
Collapse
Affiliation(s)
- Farah Lizotte
- Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Marina Rousseau
- Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Benoit Denhez
- Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Dominique Lévesque
- Department of Immunology and Cell Biology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Andréanne Guay
- Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - HongBo Liu
- Renal, Electrolyte, and Hypertension Division, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Penn/CHOP Kidney Innovation Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Genetics Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Julie Moreau
- Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Sarah Higgins
- Division of Nephrology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Robert Sabbagh
- Department of Surgery, Université de Sherbrooke, Québec, Canada
| | - Katalin Susztak
- Renal, Electrolyte, and Hypertension Division, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Penn/CHOP Kidney Innovation Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Department of Genetics Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Anne Marie Côté
- Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Division of Nephrology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Pedro Geraldes
- Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Division of Endocrinology, Department of Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada.
| |
Collapse
|
7
|
Rogg M, Maier JI, Helmstädter M, Sammarco A, Kliewe F, Kretz O, Weißer L, Van Wymersch C, Findeisen K, Koessinger AL, Tsoy O, Baumbach J, Grabbert M, Werner M, Huber TB, Endlich N, Schilling O, Schell C. A YAP/TAZ-ARHGAP29-RhoA Signaling Axis Regulates Podocyte Protrusions and Integrin Adhesions. Cells 2023; 12:1795. [PMID: 37443829 PMCID: PMC10340513 DOI: 10.3390/cells12131795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/28/2023] [Accepted: 07/01/2023] [Indexed: 07/15/2023] Open
Abstract
Glomerular disease due to podocyte malfunction is a major factor in the pathogenesis of chronic kidney disease. Identification of podocyte-specific signaling pathways is therefore a prerequisite to characterizing relevant disease pathways and developing novel treatment approaches. Here, we employed loss of function studies for EPB41L5 (Yurt) as a central podocyte gene to generate a cell type-specific disease model. Loss of Yurt in fly nephrocytes caused protein uptake and slit diaphragm defects. Transcriptomic and proteomic analysis of human EPB41L5 knockout podocytes demonstrated impaired mechanotransduction via the YAP/TAZ signaling pathway. Further analysis of specific inhibition of the YAP/TAZ-TEAD transcription factor complex by TEADi led to the identification of ARGHAP29 as an EPB41L5 and YAP/TAZ-dependently expressed podocyte RhoGAP. Knockdown of ARHGAP29 caused increased RhoA activation, defective lamellipodia formation, and increased maturation of integrin adhesion complexes, explaining similar phenotypes caused by loss of EPB41L5 and TEADi expression in podocytes. Detection of increased levels of ARHGAP29 in early disease stages of human glomerular disease implies a novel negative feedback loop for mechanotransductive RhoA-YAP/TAZ signaling in podocyte physiology and disease.
Collapse
Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Jasmin I. Maier
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Felix Kliewe
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489 Greifswald, Germany (N.E.)
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lisa Weißer
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Clara Van Wymersch
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Karla Findeisen
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Anna L. Koessinger
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Olga Tsoy
- Institute for Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany; (O.T.)
| | - Jan Baumbach
- Institute for Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany; (O.T.)
- Department of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense, Denmark
| | - Markus Grabbert
- Department of Urology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Tobias B. Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, 17489 Greifswald, Germany (N.E.)
| | - Oliver Schilling
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79106 Freiburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, 79106 Freiburg, Germany
| |
Collapse
|
8
|
Saleh MA, Shaaban AA, Talaat IM, Elmougy A, Adra SF, Ahmad F, Qaisar R, Elmoselhi AB, Abu-Gharbieh E, El-Huneidi W, Eladl MA, Shehatou G, Kafl HE. RhoA/ROCK inhibition attenuates endothelin-1-induced elevated glomerular permeability to albumin, inflammation, and fibrosis. Life Sci 2023; 323:121687. [PMID: 37030613 DOI: 10.1016/j.lfs.2023.121687] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/25/2023] [Accepted: 04/05/2023] [Indexed: 04/10/2023]
Abstract
Endothelin-1 (ET-1) contributes to the development of kidney diseases. However, the underlying molecular mechanism is largely undefined. Here we sought to investigate the potential role of ET-1 receptors, ETA and ETB in the regulation of increased glomerular permeability and underlying signaling pathways post-ET-1 infusion. Male Sprague-Dawley rats were infused with ET-1 (2 pmol/kg per minute, i.v.) for four weeks, and the effect on glomerular permeability to albumin (Palb) and albuminuria was measured. The selective ROCK-1/2 inhibitor, Y-27632, was administered to a separate group of rats to determine its effect on ET-1-induced Palb and albuminuria. The role of ETA and ETB receptors in regulating RhoA/ROCK activity was determined by incubating isolated glomeruli from normal rats with ET-1 and with selective ETA and ETB receptor antagonists. ET-1 infusion for four weeks significantly elevated Palb and albuminuria. Y-27632 significantly reduced the elevation of Palb and albuminuria. The activities of both RhoA and ROCK-1/2 were increased by ET-1 infusion. Selective ETB receptor antagonism had no effect on the elevated activity of both RhoA and ROCK-1/2 enzymes. Selective ETA receptor and combined ETA/ETB receptors blockade restored the activity of RhoA and ROCK-1/2 to normal levels. In addition, chronic ET-1 infusion increased the levels of glomerular inflammatory and fibrotic markers. These effects were all attenuated in rats following ROCK-1/2 inhibition. These observations suggest that ET-1 contributes to increased albuminuria, inflammation, and fibrosis by modulating the activity of the ETA-RhoA/ROCK-1/2 pathway. Selective ETA receptor blockade may represent a potential therapeutic strategy to limit glomerular injury and albuminuria in kidney disease.
Collapse
Affiliation(s)
- Mohamed A Saleh
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates; Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt.
| | - Ahmed A Shaaban
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt; Department of Pharmacology and Biochemistry, Faculty of Pharmacy, Delta University for Science and Technology, Gamasa City 35712, Egypt
| | - Iman M Talaat
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates; Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates; Pathology Department, Faculty of Medicine, Alexandria University, Alexandria 21526, Egypt
| | - Atef Elmougy
- Pediatric Nephrology Unit, Mansoura University Children's Hospital, Mansoura University, Mansoura 35516, Egypt
| | - Saryia F Adra
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Firdos Ahmad
- Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Biomedical Sciences, College of Health Sciences, Abu Dhabi University, Abu Dhabi 59911, United Arab Emirates
| | - Rizwan Qaisar
- Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Adel B Elmoselhi
- Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Eman Abu-Gharbieh
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates; Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Waseem El-Huneidi
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates; Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Mohamed A Eladl
- Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - George Shehatou
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt; Department of Pharmacology and Biochemistry, Faculty of Pharmacy, Delta University for Science and Technology, Gamasa City 35712, Egypt
| | - Hoda E Kafl
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| |
Collapse
|
9
|
Boi R, Bergwall L, Ebefors K, Bergö MO, Nyström J, Buvall L. Podocyte Geranylgeranyl Transferase Type-I Is Essential for Maintenance of the Glomerular Filtration Barrier. J Am Soc Nephrol 2023; 34:641-655. [PMID: 36735952 PMCID: PMC10103324 DOI: 10.1681/asn.0000000000000062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/25/2022] [Indexed: 01/22/2023] Open
Abstract
SIGNIFICANCE STATEMENT A tightly regulated actin cytoskeleton attained through balanced activity of RhoGTPases is crucial to maintaining podocyte function. However, how RhoGTPases are regulated by geranylgeranylation, a post-translational modification, has been unexplored. The authors found that loss of the geranylgeranylation enzyme geranylgeranyl transferase type-I (GGTase-I) in podocytes led to progressive albuminuria and foot process effacement in podocyte-specific GGTase-I knockout mice. In cultured podocytes, the absence of geranylgeranylation resulted in altered activity of its downstream substrates Rac1, RhoA, Cdc42, and Rap1, leading to alterations of β1-integrins and actin cytoskeleton structural changes. These findings highlight the importance of geranylgeranylation in the dynamic management of RhoGTPases and Rap1 to control podocyte function, providing new knowledge about podocyte biology and glomerular filtration barrier function. BACKGROUND Impairment of the glomerular filtration barrier is in part attributed to podocyte foot process effacement (FPE), entailing disruption of the actin cytoskeleton and the slit diaphragm. Maintenance of the actin cytoskeleton, which contains a complex signaling network through its connections to slit diaphragm and focal adhesion proteins, is thus considered crucial to preserving podocyte structure and function. A dynamic yet tightly regulated cytoskeleton is attained through balanced activity of RhoGTPases. Most RhoGTPases are post-translationally modified by the enzyme geranylgeranyl transferase type-I (GGTase-I). Although geranylgeranylation has been shown to regulate activities of RhoGTPases and RasGTPase Rap1, its significance in podocytes is unknown. METHODS We used immunofluorescence to localize GGTase-I, which was expressed mainly by podocytes in the glomeruli. To define geranylgeranylation's role in podocytes, we generated podocyte-specific GGTase-I knockout mice. We used transmission electron microscopy to evaluate FPE and measurements of urinary albumin excretion to analyze filtration barrier function. Geranylgeranylation's effects on RhoGTPases and Rap1 function were studied in vitro by knockdown or inhibition of GGTase-I. We used immunocytochemistry to study structural modifications of the actin cytoskeleton and β1 integrins. RESULTS Depletion of GGTase-I in podocytes in vivo resulted in FPE and concomitant early-onset progressive albuminuria. A reduction of GGTase-I activity in cultured podocytes disrupted RhoGTPase balance by markedly increasing activity of RhoA, Rac1, and Cdc42 together with Rap1, resulting in dysregulation of the actin cytoskeleton and altered distribution of β1 integrins. CONCLUSIONS These findings indicate that geranylgeranylation is of crucial importance for the maintenance of the delicate equilibrium of RhoGTPases and Rap1 in podocytes and consequently for the maintenance of glomerular integrity and function.
Collapse
Affiliation(s)
- Roberto Boi
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lovisa Bergwall
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Kerstin Ebefors
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Martin O. Bergö
- Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Institute of Biosciences and Nutrition, Karolinska Institute, Solna, Sweden
| | - Jenny Nyström
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lisa Buvall
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Bioscience Renal, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| |
Collapse
|
10
|
Matsuda J, Takano T. Monitoring of Rho GTPase Activity in Podocytes. Methods Mol Biol 2023; 2664:343-349. [PMID: 37423999 DOI: 10.1007/978-1-0716-3179-9_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The glomerulus is the filtration unit of the kidney, where the first step of urine formation occurs. Podocytes are characterized by their actin-based projections called foot processes. Podocyte foot processes play a critical role in the permselective filtration barrier, along with fenestrated endothelial cells and the glomerular basement membrane. The Rho family of small GTPases (Rho GTPases) is the master regulators of the actin cytoskeleton and functions as molecular switches. Recent studies have shown that disruption of Rho GTPase activity and subsequent changes in foot process structure cause proteinuria. Here, we describe an effector pull-down assay using GST-fusion proteins to monitor the activity of RhoA, Rac1, and Cdc42, which are prototypical Rho GTPases in podocytes.
Collapse
Affiliation(s)
- Jun Matsuda
- Department of Nephrology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
| | - Tomoko Takano
- Division of Nephrology, McGill University Health Centre, Montreal, QC, Canada
| |
Collapse
|
11
|
Tseng CC, Zheng RH, Lin TW, Chou CC, Shih YC, Liang SW, Lee HH. α-Actinin-4 recruits Shp2 into focal adhesions to potentiate ROCK2 activation in podocytes. Life Sci Alliance 2022; 5:5/11/e202201557. [PMID: 36096674 PMCID: PMC9468603 DOI: 10.26508/lsa.202201557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/24/2022] Open
Abstract
α-Actinin-4 is crucial in the regulation of Shp2 FA targeting to enhance ROCK2-mediated actomyosin contractility and thereby strengthening cell adhesion and cytoskeletal architecture in podocytes. Cell–matrix adhesions are mainly provided by integrin-mediated focal adhesions (FAs). We previously found that Shp2 is essential for FA maturation by promoting ROCK2 activation at FAs. In this study, we further delineated the role of α-actinin-4 in the FA recruitment and activation of Shp2. We used the conditional immortalized mouse podocytes to examine the role of α-actinin-4 in the regulation of Shp2 and ROCK2 signaling. After the induction of podocyte differentiation, Shp2 and ROCK2 were strongly activated, concomitant with the formation of matured FAs, stress fibers, and interdigitating intracellular junctions in a ROCK-dependent manner. Gene knockout of α-actinin-4 abolished the Shp2 activation and subsequently reduced matured FAs in podocytes. We also demonstrated that gene knockout of ROCK2 impaired the generation of contractility and interdigitating intercellular junctions. Our results reveal the role of α-actinin-4 in the recruitment of Shp2 at FAs to potentiate ROCK2 activation for the maintenance of cellular contractility and cytoskeletal architecture in the cultured podocytes.
Collapse
Affiliation(s)
- Chien-Chun Tseng
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ru-Hsuan Zheng
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ting-Wei Lin
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chih-Chiang Chou
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yu-Chia Shih
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Shao-Wei Liang
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hsiao-Hui Lee
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan .,Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Yang Ming Chiao Tung University, Taipei, Taiwan
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Semenikhina M, Stefanenko M, Spires DR, Ilatovskaya DV, Palygin O. Nitric-Oxide-Mediated Signaling in Podocyte Pathophysiology. Biomolecules 2022; 12:biom12060745. [PMID: 35740870 PMCID: PMC9221338 DOI: 10.3390/biom12060745] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/16/2022] [Accepted: 05/23/2022] [Indexed: 11/23/2022] Open
Abstract
Nitric oxide (NO) is a potent signaling molecule involved in many physiological and pathophysiological processes in the kidney. NO plays a complex role in glomerular ultrafiltration, vasodilation, and inflammation. Changes in NO bioavailability in pathophysiological conditions such as hypertension or diabetes may lead to podocyte damage, proteinuria, and rapid development of chronic kidney disease (CKD). Despite the extensive data highlighting essential functions of NO in health and pathology, related signaling in glomerular cells, particularly podocytes, is understudied. Several reports indicate that NO bioavailability in glomerular cells is decreased during the development of renal pathology, while restoring NO level can be beneficial for glomerular function. At the same time, the compromised activity of nitric oxide synthase (NOS) may provoke the formation of peroxynitrite and has been linked to autoimmune diseases such as systemic lupus erythematosus. It is known that the changes in the distribution of NO sources due to shifts in NOS subunits expression or modifications of NADPH oxidases activity may be linked to or promote the development of pathology. However, there is a lack of information about the detailed mechanisms describing the production and release of NO in the glomerular cells. The interaction of NO and other reactive oxygen species in podocytes and how NO-calcium crosstalk regulates glomerular cells’ function is still largely unknown. Here, we discuss recent reports describing signaling, synthesis, and known pathophysiological mechanisms mediated by the changes in NO homeostasis in the podocyte. The understanding and further investigation of these essential mechanisms in glomerular cells will facilitate the design of novel strategies to prevent or manage health conditions that cause glomerular and kidney damage.
Collapse
Affiliation(s)
- Marharyta Semenikhina
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA; (M.S.); (M.S.)
| | - Mariia Stefanenko
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA; (M.S.); (M.S.)
| | - Denisha R. Spires
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (D.R.S.); (D.V.I.)
| | - Daria V. Ilatovskaya
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (D.R.S.); (D.V.I.)
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA; (M.S.); (M.S.)
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA
- Correspondence:
| |
Collapse
|
14
|
Mechanisms of podocyte injury and implications for diabetic nephropathy. Clin Sci (Lond) 2022; 136:493-520. [PMID: 35415751 PMCID: PMC9008595 DOI: 10.1042/cs20210625] [Citation(s) in RCA: 65] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 02/25/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023]
Abstract
Albuminuria is the hallmark of both primary and secondary proteinuric glomerulopathies, including focal segmental glomerulosclerosis (FSGS), obesity-related nephropathy, and diabetic nephropathy (DN). Moreover, albuminuria is an important feature of all chronic kidney diseases (CKDs). Podocytes play a key role in maintaining the permselectivity of the glomerular filtration barrier (GFB) and injury of the podocyte, leading to foot process (FP) effacement and podocyte loss, the unifying underlying mechanism of proteinuric glomerulopathies. The metabolic insult of hyperglycemia is of paramount importance in the pathogenesis of DN, while insults leading to podocyte damage are poorly defined in other proteinuric glomerulopathies. However, shared mechanisms of podocyte damage have been identified. Herein, we will review the role of haemodynamic and oxidative stress, inflammation, lipotoxicity, endocannabinoid (EC) hypertone, and both mitochondrial and autophagic dysfunction in the pathogenesis of the podocyte damage, focussing particularly on their role in the pathogenesis of DN. Gaining a better insight into the mechanisms of podocyte injury may provide novel targets for treatment. Moreover, novel strategies for boosting podocyte repair may open the way to podocyte regenerative medicine.
Collapse
|
15
|
Lin DW, Chang CC, Hsu YC, Lin CL. New Insights into the Treatment of Glomerular Diseases: When Mechanisms Become Vivid. Int J Mol Sci 2022; 23:3525. [PMID: 35408886 PMCID: PMC8998908 DOI: 10.3390/ijms23073525] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/18/2022] [Accepted: 03/22/2022] [Indexed: 12/23/2022] Open
Abstract
Treatment for glomerular diseases has been extrapolated from the experience of other autoimmune disorders while the underlying pathogenic mechanisms were still not well understood. As the classification of glomerular diseases was based on patterns of juries instead of mechanisms, treatments were typically the art of try and error. With the advancement of molecular biology, the role of the immune agent in glomerular diseases is becoming more evident. The four-hit theory based on the discovery of gd-IgA1 gives a more transparent outline of the pathogenesis of IgA nephropathy (IgAN), and dysregulation of Treg plays a crucial role in the pathogenesis of minimal change disease (MCD). An epoch-making breakthrough is the discovery of PLA2R antibodies in the primary membranous nephropathy (pMN). This is the first biomarker applied for precision medicine in kidney disease. Understanding the immune system's role in glomerular diseases allows the use of various immunosuppressants or other novel treatments, such as complement inhibitors, to treat glomerular diseases more reasonable. In this era of advocating personalized medicine, it is inevitable to develop precision medicine with mechanism-based novel biomarkers and novel therapies in kidney disease.
Collapse
Affiliation(s)
- Da-Wei Lin
- Department of Internal Medicine, St. Martin De Porres Hospital, Chiayi 60069, Taiwan;
| | - Cheng-Chih Chang
- Department of Surgery, Chang Gung Memorial Hospital, Chiayi 613016, Taiwan;
| | - Yung-Chien Hsu
- Department of Nephrology, Chang Gung Memorial Hospital, Chiayi 613016, Taiwan
- Kidney and Diabetic Complications Research Team (KDCRT), Chang Gung Memorial Hospital, Chiayi 613016, Taiwan
| | - Chun-Liang Lin
- Department of Nephrology, Chang Gung Memorial Hospital, Chiayi 613016, Taiwan
- Kidney and Diabetic Complications Research Team (KDCRT), Chang Gung Memorial Hospital, Chiayi 613016, Taiwan
- Division of Chinese Materia Medica Development, National Research Institute of Chinese Medicine, Taipei 613016, Taiwan
- Kidney Research Center, Chang Gung Memorial Hospital, Taipei 613016, Taiwan
- Center for Shockwave Medicine and Tissue Engineering, Chang Gung Memorial Hospital, Kaohsiung 833253, Taiwan
| |
Collapse
|
16
|
Steichen C, Hervé C, Hauet T, Bourmeyster N. Rho GTPases in kidney physiology and diseases. Small GTPases 2022; 13:141-161. [PMID: 34138686 PMCID: PMC9707548 DOI: 10.1080/21541248.2021.1932402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 05/08/2021] [Accepted: 05/17/2021] [Indexed: 02/06/2023] Open
Abstract
Rho family GTPases are molecular switches best known for their pivotal role in dynamic regulation of the actin cytoskeleton, but also of cellular morphology, motility, adhesion and proliferation. The prototypic members of this family (RhoA, Rac1 and Cdc42) also contribute to the normal kidney function and play important roles in the structure and function of various kidney cells including tubular epithelial cells, mesangial cells and podocytes. The kidney's vital filtration function depends on the structural integrity of the glomerulus, the proximal portion of the nephron. Within the glomerulus, the architecturally actin-based cytoskeleton podocyte forms the final cellular barrier to filtration. The glomerulus appears as a highly dynamic signalling hub that is capable of integrating intracellular cues from its individual structural components. Dynamic regulation of the podocyte cytoskeleton is required for efficient barrier function of the kidney. As master regulators of actin cytoskeletal dynamics, Rho GTPases are therefore of critical importance for sustained kidney barrier function. Dysregulated activities of the Rho GTPases and of their effectors are implicated in the pathogenesis of both hereditary and idiopathic forms of kidney diseases. Diabetic nephropathy is a progressive kidney disease that is caused by injury to kidney glomeruli. High glucose activates RhoA/Rho-kinase in mesangial cells, leading to excessive extracellular matrix production (glomerulosclerosis). This RhoA/Rho-kinase pathway also seems involved in the post-transplant hypertension frequently observed during treatment with calcineurin inhibitors, whereas Rac1 activation was observed in post-transplant ischaemic acute kidney injury.
Collapse
Affiliation(s)
- Clara Steichen
- Inserm UMR-1082 Irtomit, Poitiers, France
- Faculté De Médecine Et De Pharmacie, Université De Poitiers, Poitiers, France
| | | | - Thierry Hauet
- Inserm UMR-1082 Irtomit, Poitiers, France
- Faculté De Médecine Et De Pharmacie, Université De Poitiers, Poitiers, France
- Department of Medical Biology, Service De Biochimie, CHU De Poitiers, Poitiers, France
| | - Nicolas Bourmeyster
- Faculté De Médecine Et De Pharmacie, Université De Poitiers, Poitiers, France
- Department of Medical Biology, Service De Biochimie, CHU De Poitiers, Poitiers, France
- Laboratoire STIM CNRS ERL 7003, Université de Poitiers, Poitiers Cédex, France
| |
Collapse
|
17
|
Koehler S, Odenthal J, Ludwig V, Jess DU, Höhne M, Jüngst C, Grawe F, Helmstädter M, Janku JL, Bergmann C, Hoyer PF, Hagmann HHH, Walz G, Bloch W, Niessen C, Schermer B, Wodarz A, Denholm B, Benzing T, Iden S, Brinkkoetter PT. Scaffold polarity proteins Par3A and Par3B share redundant functions while Par3B acts independent of atypical protein kinase C/Par6 in podocytes to maintain the kidney filtration barrier. Kidney Int 2021; 101:733-751. [PMID: 34929254 DOI: 10.1016/j.kint.2021.11.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 11/08/2021] [Accepted: 11/22/2021] [Indexed: 10/19/2022]
Abstract
Glomerular diseases are a major cause for chronic kidney disorders. In most cases podocyte injury is causative for disease development. Cytoskeletal rearrangements and morphological changes are hallmark features of podocyte injury and result in dedifferentiation and loss of podocytes. Here, we establish a link between the Par3 polarity complex and actin regulators necessary to establish and maintain podocyte architecture by utilizing mouse and Drosophila models to characterize the functional role of Par3A and Par3B and its fly homologue Bazooka in vivo. Only simultaneous inactivation of both Par3 proteins caused a severe disease phenotype. Rescue experiments in Drosophila nephrocytes revealed atypical protein kinase C (aPKC)-Par6 dependent and independent effects. While Par3A primarily acts via aPKC-Par6, Par3B function was independent of Par6. Actin-associated synaptopodin protein levels were found to be significantly upregulated upon loss of Par3A/B in mouse podocytes. Tropomyosin2, which shares functional similarities with synaptopodin, was also elevated in Bazooka depleted nephrocytes. The simultaneous depletion of Bazooka and Tropomyosin2 resulted in a partial rescue of the Bazooka knockdown phenotype and prevented increased Rho1, a member of a GTPase protein family regulating the cytoskeleton. The latter contribute to the nephrocyte phenotype observed upon loss of Bazooka. Thus, we demonstrate that Par3 proteins share a high functional redundancy but also have specific functions. Par3A acts in an aPKC-Par6 dependent way and regulates RhoA-GTP levels, while Par3B exploits Par6 independent functions influencing synaptopodin localization. Hence, Par3A and Par3B link elements of polarity signaling and actin regulators to maintain podocyte architecture.
Collapse
Affiliation(s)
- Sybille Koehler
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK.
| | - Johanna Odenthal
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Vivian Ludwig
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - David Unnersjö Jess
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Christian Jüngst
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Ferdi Grawe
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Molecular Cell Biology, Institute I for Anatomy, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Martin Helmstädter
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Johanna L Janku
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Carsten Bergmann
- Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany; Department of Medicine, Nephrology, University Hospital Freiburg, Germany
| | - Peter F Hoyer
- Klinik für Kinderheilkunde 2, Zentrum für Kinder- und Jugendmedizin, Universitätsklinikum Essen, Essen, Germany
| | - H H Henning Hagmann
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Wilhelm Bloch
- Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine, German Sport University Cologne, Cologne, Germany
| | - Carien Niessen
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Department of Dermatology, University Hospital of Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Andreas Wodarz
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Molecular Cell Biology, Institute I for Anatomy, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Barry Denholm
- Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Thomas Benzing
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Sandra Iden
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Institute for Cell and Developmental Biology, Saarland University, Homburg/Saar, Germany
| | - Paul T Brinkkoetter
- Department II of Internal Medicine; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
| |
Collapse
|
18
|
Wang L, Tang Y, Buckley AF, Spurney RF. Blockade of the natriuretic peptide clearance receptor attenuates proteinuria in a mouse model of focal segmental glomerulosclerosis. Physiol Rep 2021; 9:e15095. [PMID: 34755480 PMCID: PMC8578888 DOI: 10.14814/phy2.15095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/23/2021] [Accepted: 09/23/2021] [Indexed: 12/31/2022] Open
Abstract
Glomerular podocytes play a key role in proteinuric diseases. Accumulating evidence suggests that cGMP signaling has podocyte protective effects. The major source of cGMP generation in podocytes is natriuretic peptides. The natriuretic peptide clearance receptor (NPRC) binds and degrades natriuretic peptides. As a result, NPRC inhibits natriuretic peptide-induced cGMP generation. To enhance cGMP generation in podocytes, we blocked natriuretic peptide clearance using the specific NPRC ligand ANP(4-23). We then studied the effects of NPRC blockade in both cultured podocytes and in a mouse transgenic (TG) model of focal segmental glomerulosclerosis (FSGS) created in our laboratory. In this model, a single dose of the podocyte toxin puromycin aminonucleoside (PAN) causes robust albuminuria in TG mice, but only mild disease in non-TG animals. We found that natriuretic peptides protected cultured podocytes from PAN-induced apoptosis, and that ANP(4-23) enhanced natriuretic peptide-induced cGMP generation in vivo. PAN-induced heavy proteinuria in vehicle-treated TG mice, and this increase in albuminuria was reduced by treatment with ANP(4-23). Treatment with ANP(4-23) also reduced the number of mice with glomerular injury and enhanced urinary cGMP excretion, but these differences were not statistically significant. Systolic BP was similar in vehicle and ANP(4-23)-treated mice. These data suggest that: 1. Pharmacologic blockade of NPRC may be useful for treating glomerular diseases such as FSGS, and 2. Treatment outcomes might be improved by optimizing NPRC blockade to inhibit natriuretic peptide clearance more effectively.
Collapse
Affiliation(s)
- Liming Wang
- Division of NephrologyDepartment of MedicineDuke University and Durham VA Medical CentersDurhamNorth CarolinaUSA
| | - Yuping Tang
- Division of NephrologyDepartment of MedicineDuke University and Durham VA Medical CentersDurhamNorth CarolinaUSA
| | - Anne F. Buckley
- Department of PathologyDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Robert F. Spurney
- Division of NephrologyDepartment of MedicineDuke University and Durham VA Medical CentersDurhamNorth CarolinaUSA
| |
Collapse
|
19
|
Ye Q, Zhang Y, Zhuang J, Bi Y, Xu H, Shen Q, Liu J, Fu H, Wang J, Feng C, Tang X, Liu F, Gu W, Zhao F, Zhang J, Qin Y, Shang S, Shen H, Chen X, Shen H, Liu A, Xia Y, Lu Z, Shu Q, Mao J. The important roles and molecular mechanisms of annexin A 2 autoantibody in children with nephrotic syndrome. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1452. [PMID: 34734004 PMCID: PMC8506724 DOI: 10.21037/atm-21-3988] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/01/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND In recent years, B-cell dysfunction has been found to play an important role in the pathogenesis of primary nephrotic syndrome (PNS). B cells play a pathogenic role by secreting antibodies against their target antigens after transforming into plasma cells. Therefore, this study aimed to screen the autoantibodies that cause PNS and explore their pathogenic mechanisms. METHODS Western blotting and mass spectrometry were employed to screen and identify autoantibodies against podocytes in children with PNS. Both in vivo and in vitro experiments were used to study the pathogenic mechanism of PNS. The results were confirmed in a large multicenter clinical study in children. RESULTS Annexin A2 autoantibody was highly expressed in children with PNS with a pathological type of minimal change disease (MCD) or focal segmental glomerulosclerosis without genetic factors. The mouse model showed that anti-Annexin A2 antibody could induce proteinuria in vivo. Mechanistically, the effect of Annexin A2 antibody on the Rho signaling pathway was realized through promoting the phosphorylation of Annexin A2 at Tyr24 on podocytes by reducing its binding to PTP1B, which led to the cytoskeletal rearrangement and damage of podocytes, eventually causing proteinuria and PNS. CONCLUSIONS Annexin A2 autoantibody may be responsible for some cases of PNS with MCD/FSGS in children.
Collapse
Affiliation(s)
- Qing Ye
- Department of Clinical Laboratory, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Yingying Zhang
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jieqiu Zhuang
- Department of Pediatric Nephrology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Ye Bi
- Department of Pediatric Nephrology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China
| | - Hong Xu
- Department of Nephrology, Children’s Hospital of Fudan University, National Pediatric Medical Center of China, Shanghai, China
| | - Qian Shen
- Department of Nephrology, Children’s Hospital of Fudan University, National Pediatric Medical Center of China, Shanghai, China
| | - Jialu Liu
- Department of Nephrology, Children’s Hospital of Fudan University, National Pediatric Medical Center of China, Shanghai, China
| | - Haidong Fu
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jingjing Wang
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Chunyue Feng
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Xiaoxiao Tang
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Fei Liu
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Weizhong Gu
- Department of Pathology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Fei Zhao
- Department of Nephrology, Children’s Hospital of Nanjing Medical University, Nanjing, China
| | - Jianjiang Zhang
- Department of Pediatrics, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yuanhan Qin
- Department of Pediatric Nephrology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Shiqiang Shang
- Department of Clinical Laboratory, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Hongqiang Shen
- Department of Clinical Laboratory, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Xuejun Chen
- Department of Clinical Laboratory, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Huijun Shen
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Aimin Liu
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Yonghui Xia
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Zhihong Lu
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Qiang Shu
- Department of Thoracic and Cardiovascular Surgery, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Jianhua Mao
- Department of Nephrology, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| |
Collapse
|
20
|
Li G, Kidd J, Gehr TWB, Li PL. Podocyte Sphingolipid Signaling in Nephrotic Syndrome. Cell Physiol Biochem 2021; 55:13-34. [PMID: 33861526 PMCID: PMC8193717 DOI: 10.33594/000000356] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2021] [Indexed: 11/25/2022] Open
Abstract
Podocytes play a vital role in the pathogenesis of nephrotic syndrome (NS), which is clinically characterized by heavy proteinuria, hypoalbuminemia, hyperlipidemia, and peripheral edema. The pathogenesis of NS has evolved through several hypotheses ranging from immune dysregulation theory and increased glomerular permeability theory to the current concept of podocytopathy. Podocytopathy is characterized by dysfunction or depletion of podocytes, which may be caused by unknown permeability factor, genetic disorders, drugs, infections, systemic disorders, and hyperfiltration. Over the last two decades, numerous studies have been done to explore the molecular mechanisms of podocyte injuries or NS and to develop the novel therapeutic strategies targeting podocytopathy for treatment of NS. Recent studies have shown that normal sphingolipid metabolism is essential for structural and functional integrity of podocytes. As a basic component of the plasma membrane, sphingolipids not only support the assembly of signaling molecules and interaction of receptors and effectors, but also mediate various cellular activities, such as apoptosis, proliferation, stress responses, necrosis, inflammation, autophagy, senescence, and differentiation. This review briefly summarizes current evidence demonstrating the regulation of sphingolipid metabolism in podocytes and the canonical or noncanonical roles of podocyte sphingolipid signaling in the pathogenesis of NS and associated therapeutic strategies.
Collapse
Affiliation(s)
- Guangbi Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Jason Kidd
- Division of Nephrology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Todd W B Gehr
- Division of Nephrology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Pin-Lan Li
- Department of Pharmacology and Toxicology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA,
| |
Collapse
|
21
|
Novel insights in the genetics of steroid-sensitive nephrotic syndrome in childhood. Pediatr Nephrol 2021; 36:2165-2175. [PMID: 33084934 DOI: 10.1007/s00467-020-04780-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/10/2020] [Accepted: 09/14/2020] [Indexed: 10/23/2022]
Abstract
Steroid-sensitive nephrotic syndrome (SSNS) is the most common form of nephrotic syndrome in childhood and there is growing evidence that genetics play a role in the susceptibility for the disease. Familial clustering has been observed and has led to several studies on familial SSNS trying to identify a monogenic cause of the disease. Until now, however, none of these have provided convincing evidence for Mendelian inheritance. This and the phenotypic variability within SSNS suggest a complex inheritance pattern, where multiple variants and interactions between those and the environment play roles in disease development. Genome-wide association studies (GWASs) have been used to investigate this complex disease. We herein highlight new insights in the genetics of the disease provided by GWAS and identify how these insights fit into our understanding of the pathogenesis of SSNS.
Collapse
|
22
|
Rogacka D, Piwkowska A. Beneficial effects of metformin on glomerular podocytes in diabetes. Biochem Pharmacol 2021; 192:114687. [PMID: 34274355 DOI: 10.1016/j.bcp.2021.114687] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 01/15/2023]
Abstract
Podocytes and their foot processes form an important cellular layer of the glomerular barrier involved in regulating glomerular permeability. Disturbances in podocyte function play a central role in the development of proteinuria in diabetic nephropathy. The retraction of podocyte foot processes forming a slit diaphragm is a common feature of proteinuria. Metformin is an oral antidiabetic agent of the biguanide class that is widely recommended for the treatment of high blood glucose in patients with type 2 diabetes mellitus. In addition to lowering glucose, several recent studies have reported potential beneficial effects of metformin on diabetic kidney function. Furthermore, a key molecule of the antidiabetic mechanism of action of metformin is adenosine 5'-monophospate-activated protein kinase (AMPK), as the metformin-induced activation of AMPK is well documented. The present review summarizes current knowledge on the protective effects of metformin against pathological changes in podocytes that are induced by hyperglycemia.
Collapse
Affiliation(s)
- Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland; Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute Polish Academy of Sciences, Wita Stwosza 63, Gdansk 80-308, Poland; Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, Gdansk 80-308, Poland.
| |
Collapse
|
23
|
Role of Rho GTPase Interacting Proteins in Subcellular Compartments of Podocytes. Int J Mol Sci 2021; 22:ijms22073656. [PMID: 33915776 PMCID: PMC8037304 DOI: 10.3390/ijms22073656] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 03/22/2021] [Accepted: 03/26/2021] [Indexed: 01/15/2023] Open
Abstract
The first step of urine formation is the selective filtration of the plasma into the urinary space at the kidney structure called the glomerulus. The filtration barrier of the glomerulus allows blood cells and large proteins such as albumin to be retained while eliminating the waste products of the body. The filtration barrier consists of three layers: fenestrated endothelial cells, glomerular basement membrane, and podocytes. Podocytes are specialized epithelial cells featured by numerous, actin-based projections called foot processes. Proteins on the foot process membrane are connected to the well-organized intracellular actin network. The Rho family of small GTPases (Rho GTPases) act as intracellular molecular switches. They tightly regulate actin dynamics and subsequent diverse cellular functions such as adhesion, migration, and spreading. Previous studies using podocyte-specific transgenic or knockout animal models have established that Rho GTPases are crucial for the podocyte health and barrier function. However, little attention has been paid regarding subcellular locations where distinct Rho GTPases contribute to specific functions. In the current review, we discuss cellular events involving the prototypical Rho GTPases (RhoA, Rac1, and Cdc42) in podocytes, with particular focus on the subcellular compartments where the signaling events occur. We also provide our synthesized views of the current understanding and propose future research directions.
Collapse
|
24
|
Activin A and Cell-Surface GRP78 Are Novel Targetable RhoA Activators for Diabetic Kidney Disease. Int J Mol Sci 2021; 22:ijms22062839. [PMID: 33799579 PMCID: PMC8000060 DOI: 10.3390/ijms22062839] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/03/2021] [Accepted: 03/08/2021] [Indexed: 12/19/2022] Open
Abstract
Diabetic kidney disease (DKD) is the leading cause of kidney failure. RhoA/Rho-associated protein kinase (ROCK) signaling is a recognized mediator of its pathogenesis, largely through mediating the profibrotic response. While RhoA activation is not feasible due to the central role it plays in normal physiology, ROCK inhibition has been found to be effective in attenuating DKD in preclinical models. However, this has not been evaluated in clinical studies as of yet. Alternate means of inhibiting RhoA/ROCK signaling involve the identification of disease-specific activators. This report presents evidence showing the activation of RhoA/ROCK signaling both in vitro in glomerular mesangial cells and in vivo in diabetic kidneys by two recently described novel pathogenic mediators of fibrosis in DKD, activins and cell-surface GRP78. Neither are present in normal kidneys. Activin inhibition with follistatin and neutralization of cell-surface GRP78 using a specific antibody blocked RhoA activation in mesangial cells and in diabetic kidneys. These data identify two novel RhoA/ROCK activators in diabetic kidneys that can be evaluated for their efficacy in inhibiting the progression of DKD.
Collapse
|
25
|
Rogg M, Maier JI, Dotzauer R, Artelt N, Kretz O, Helmstädter M, Abed A, Sammarco A, Sigle A, Sellung D, Dinse P, Reiche K, Yasuda-Yamahara M, Biniossek ML, Walz G, Werner M, Endlich N, Schilling O, Huber TB, Schell C. SRGAP1 Controls Small Rho GTPases To Regulate Podocyte Foot Process Maintenance. J Am Soc Nephrol 2021; 32:563-579. [PMID: 33514561 PMCID: PMC7920176 DOI: 10.1681/asn.2020081126] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/15/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Previous research demonstrated that small Rho GTPases, modulators of the actin cytoskeleton, are drivers of podocyte foot-process effacement in glomerular diseases, such as FSGS. However, a comprehensive understanding of the regulatory networks of small Rho GTPases in podocytes is lacking. METHODS We conducted an analysis of podocyte transcriptome and proteome datasets for Rho GTPases; mapped in vivo, podocyte-specific Rho GTPase affinity networks; and examined conditional knockout mice and murine disease models targeting Srgap1. To evaluate podocyte foot-process morphology, we used super-resolution microscopy and electron microscopy; in situ proximity ligation assays were used to determine the subcellular localization of the small GTPase-activating protein SRGAP1. We performed functional analysis of CRISPR/Cas9-generated SRGAP1 knockout podocytes in two-dimensional and three-dimensional cultures and quantitative interaction proteomics. RESULTS We demonstrated SRGAP1 localization to podocyte foot processes in vivo and to cellular protrusions in vitro. Srgap1fl/fl*Six2Cre but not Srgap1fl/fl*hNPHS2Cre knockout mice developed an FSGS-like phenotype at adulthood. Podocyte-specific deletion of Srgap1 by hNPHS2Cre resulted in increased susceptibility to doxorubicin-induced nephropathy. Detailed analysis demonstrated significant effacement of podocyte foot processes. Furthermore, SRGAP1-knockout podocytes showed excessive protrusion formation and disinhibition of the small Rho GTPase machinery in vitro. Evaluation of a SRGAP1-dependent interactome revealed the involvement of SRGAP1 with protrusive and contractile actin networks. Analysis of glomerular biopsy specimens translated these findings toward human disease by displaying a pronounced redistribution of SRGAP1 in FSGS. CONCLUSIONS SRGAP1, a podocyte-specific RhoGAP, controls podocyte foot-process architecture by limiting the activity of protrusive, branched actin networks. Therefore, elucidating the complex regulatory small Rho GTPase affinity network points to novel targets for potentially precise intervention in glomerular diseases.
Collapse
Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Jasmin I. Maier
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Robert Dotzauer
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Nadine Artelt
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Oliver Kretz
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Ahmed Abed
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - August Sigle
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Urology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Dominik Sellung
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Patrick Dinse
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Karoline Reiche
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Mako Yasuda-Yamahara
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Department of Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Martin L. Biniossek
- Institute of Molecular Medicine and Cell Research, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Gerd Walz
- Department of Medicine IV, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Oliver Schilling
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany
| | - Tobias B. Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center – University of Freiburg, Freiburg, Germany,Berta-Ottenstein Program, Medical Faculty, Medical Center – University of Freiburg, Freiburg, Germany
| |
Collapse
|
26
|
Li Q, Gulati A, Lemaire M, Nottoli T, Bale A, Tufro A. Rho-GTPase Activating Protein myosin MYO9A identified as a novel candidate gene for monogenic focal segmental glomerulosclerosis. Kidney Int 2021; 99:1102-1117. [PMID: 33412162 DOI: 10.1016/j.kint.2020.12.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 12/04/2020] [Accepted: 12/10/2020] [Indexed: 01/18/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a podocytopathy leading to kidney failure, whose molecular cause frequently remains unresolved. Here, we describe a rare MYO9A loss of function nonsense heterozygous mutation (p.Arg701∗) as a possible contributor to disease in a sibling pair with familial FSGS/proteinuria. MYO9A variants of uncertain significance were identified by whole exome sequencing in a cohort of 94 biopsy proven patients with FSGS. MYO9A is an unconventional myosin with a Rho-GAP domain that controls epithelial cell junction assembly, crosslinks and bundles actin and deactivates the small GTPase protein encoded by the RHOA gene. RhoA activity is associated with cytoskeleton regulation of actin stress fiber formation and actomyosin contractility. Myo9A was detected in mouse and human podocytes in vitro and in vivo. Knockin mice carrying the p.Arg701∗MYO9A (Myo9AR701X) generated by gene editing developed proteinuria, podocyte effacement and FSGS. Kidneys and podocytes from Myo9AR701X/+ mutant mice revealed Myo9A haploinsufficiency, increased RhoA activity, decreased Myo9A-actin-calmodulin interaction, impaired podocyte attachment and migration. Our results indicate that Myo9A is a novel component of the podocyte cytoskeletal apparatus that regulates RhoA activity and podocyte function. Thus, Myo9AR701X/+ knock-in mice recapitulate the proband FSGS phenotype, demonstrate that p.R701X Myo9A is an FSGS-causing mutation in mice and suggest that heterozygous loss-of-function MYO9A mutations may cause a novel form of human autosomal dominant FSGS. Hence, identification of MYO9A pathogenic variants in additional individuals with familial or sporadic FSGS is needed to ascertain the gene contribution to disease.
Collapse
Affiliation(s)
- Qi Li
- Department of Pediatrics, Nephrology Section, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ashima Gulati
- Department of Internal Medicine, Nephrology Section, Yale School of Medicine, New Haven, Connecticut, USA
| | - Mathieu Lemaire
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Timothy Nottoli
- Yale Gene Editing Center, Yale School of Medicine, New Haven, Connecticut, USA
| | - Allen Bale
- Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
| | - Alda Tufro
- Department of Pediatrics, Nephrology Section, Yale School of Medicine, New Haven, Connecticut, USA; Department of Cell and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA.
| |
Collapse
|
27
|
Gao W, Liu Y, Fan L, Zheng B, Jefferson JR, Wang S, Zhang H, Fang X, Nguyen BV, Zhu T, Roman RJ, Fan F. Role of γ-adducin in actin cytoskeleton rearrangements in podocyte pathophysiology. Am J Physiol Renal Physiol 2021; 320:F97-F113. [PMID: 33308016 PMCID: PMC7847051 DOI: 10.1152/ajprenal.00423.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022] Open
Abstract
We recently reported that the enhanced susceptibility to chronic kidney disease (CKD) in the fawn-hooded hypertensive (FHH) rat is caused, at least in part, by a mutation in γ-adducin (ADD3) that attenuates renal vascular function. The present study explored whether Add3 contributes to the modulation of podocyte structure and function using FHH and FHH.Add3 transgenic rats. The expression of ADD3 on the membrane of primary podocytes isolated from FHH was reduced compared with FHH.Add3 transgenic rats. We found that F-actin nets, which are typically localized in the lamellipodia, replaced unbranched stress fibers in conditionally immortalized mouse podocytes transfected with Add3 Dicer-substrate short interfering RNA (DsiRNA) and primary podocytes isolated from FHH rats. There were increased F/G-actin ratios and expression of the Arp2/3 complexes throughout FHH podocytes in association with reduced synaptopodin and RhoA but enhanced Rac1 and CDC42 expression in the renal cortex, glomeruli, and podocytes of FHH rats. The expression of nephrin at the slit diaphragm and the levels of focal adhesion proteins integrin-α3 and integrin-β1 were decreased in the glomeruli of FHH rats. Cell migration was enhanced and adhesion was reduced in podocytes of FHH rats as well as in immortalized mouse podocytes transfected with Add3 DsiRNA. Mean arterial pressures were similar in FHH and FHH.Add3 transgenic rats at 16 wk of age; however, FHH rats exhibited enhanced proteinuria associated with podocyte foot process effacement. These results demonstrate that reduced ADD3 function in FHH rats alters baseline podocyte pathophysiology by rearrangement of the actin cytoskeleton at the onset of proteinuria in young animals.
Collapse
Affiliation(s)
- Wenjun Gao
- Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Yedan Liu
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Letao Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Baoying Zheng
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Joshua R Jefferson
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Shaoxun Wang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Huawei Zhang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Xing Fang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Bond V Nguyen
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Tongyu Zhu
- Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| |
Collapse
|
28
|
Schneider R, Deutsch K, Hoeprich GJ, Marquez J, Hermle T, Braun DA, Seltzsam S, Kitzler TM, Mao Y, Buerger F, Majmundar AJ, Onuchic-Whitford AC, Kolvenbach CM, Schierbaum L, Schneider S, Halawi AA, Nakayama M, Mann N, Connaughton DM, Klämbt V, Wagner M, Riedhammer KM, Renders L, Katsura Y, Thumkeo D, Soliman NA, Mane S, Lifton RP, Shril S, Khokha MK, Hoefele J, Goode BL, Hildebrandt F. DAAM2 Variants Cause Nephrotic Syndrome via Actin Dysregulation. Am J Hum Genet 2020; 107:1113-1128. [PMID: 33232676 DOI: 10.1016/j.ajhg.2020.11.008] [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] [Received: 09/15/2020] [Accepted: 11/05/2020] [Indexed: 01/10/2023] Open
Abstract
The discovery of >60 monogenic causes of nephrotic syndrome (NS) has revealed a central role for the actin regulators RhoA/Rac1/Cdc42 and their effectors, including the formin INF2. By whole-exome sequencing (WES), we here discovered bi-allelic variants in the formin DAAM2 in four unrelated families with steroid-resistant NS. We show that DAAM2 localizes to the cytoplasm in podocytes and in kidney sections. Further, the variants impair DAAM2-dependent actin remodeling processes: wild-type DAAM2 cDNA, but not cDNA representing missense variants found in individuals with NS, rescued reduced podocyte migration rate (PMR) and restored reduced filopodia formation in shRNA-induced DAAM2-knockdown podocytes. Filopodia restoration was also induced by the formin-activating molecule IMM-01. DAAM2 also co-localizes and co-immunoprecipitates with INF2, which is intriguing since variants in both formins cause NS. Using in vitro bulk and TIRF microscopy assays, we find that DAAM2 variants alter actin assembly activities of the formin. In a Xenopus daam2-CRISPR knockout model, we demonstrate actin dysregulation in vivo and glomerular maldevelopment that is rescued by WT-DAAM2 mRNA. We conclude that DAAM2 variants are a likely cause of monogenic human SRNS due to actin dysregulation in podocytes. Further, we provide evidence that DAAM2-associated SRNS may be amenable to treatment using actin regulating compounds.
Collapse
|
29
|
Matsuda J, Asano-Matsuda K, Kitzler TM, Takano T. Rho GTPase regulatory proteins in podocytes. Kidney Int 2020; 99:336-345. [PMID: 33122025 DOI: 10.1016/j.kint.2020.08.035] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
The Rho family of small GTPases (Rho GTPases) are the master regulators of the actin cytoskeleton and consist of 22 members. Previous studies implicated dysregulation of Rho GTPases in podocytes in the pathogenesis of proteinuric glomerular diseases. Rho GTPases are primarily regulated by the three families of proteins; guanine nucleotide exchange factors (GEFs; 82 members), GTPase-activating proteins (GAPs; 69 members), and GDP dissociation inhibitors (GDIs; 3 members). Since the regulatory proteins far outnumber their substrate Rho GTPases and act in concert in a cell/context-dependent manner, the upstream regulatory mechanism directing Rho GTPases in podocytes is largely unknown. In this review, we summarize recent advances in the understanding of the role of Rho GTPase regulatory proteins in podocytes, including the known mutations of these proteins that cause proteinuria in humans. We also provide critical appraisal of the in vivo and in vitro studies and identify the knowledge gap in the field that will require further studies.
Collapse
Affiliation(s)
- Jun Matsuda
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Kana Asano-Matsuda
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Thomas M Kitzler
- Research Institute, McGill University Health Centre, Montreal, Quebec, Canada; Division of Medical Genetics, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Tomoko Takano
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada.
| |
Collapse
|
30
|
Extracellular ATP modulates podocyte function through P2Y purinergic receptors and pleiotropic effects on AMPK and cAMP/PKA signaling pathways. Arch Biochem Biophys 2020; 695:108649. [PMID: 33122160 DOI: 10.1016/j.abb.2020.108649] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/25/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023]
Abstract
Podocytes and their foot processes interlinked by slit diaphragms, constitute a continuous outermost layer of the glomerular capillary and seem to be crucial for maintaining the integrity of the glomerular filtration barrier. Purinergic signaling is involved in a wide range of physiological processes in the renal system, including regulating glomerular filtration. We evaluated the role of nucleotide receptors in cultured rat podocytes using non-selective P2 receptor agonists and agonists specific for the P2Y1, P2Y2, and P2Y4 receptors. The results showed that extracellular ATP evokes cAMP-dependent pathways through P2 receptors and influences remodeling of the podocyte cytoskeleton and podocyte permeability to albumin via coupling with RhoA signaling. Our findings highlight the relevance of the P2Y4 receptor in protein kinase A-mediated signal transduction to the actin cytoskeleton. We observed increased cAMP concentration and decreased RhoA activity after treatment with a P2Y4 agonist. Moreover, protein kinase A inhibitors reversed P2Y4-induced changes in RhoA activity and intracellular F-actin staining. P2Y4 stimulation resulted in enhanced AMPK phosphorylation and reduced reactive oxygen species generation. Our findings identify P2Y-PKA-RhoA signaling as the regulatory mechanism of the podocyte contractile apparatus and glomerular filtration. We describe a protection mechanism for the glomerular barrier linked to reduced oxidative stress and reestablished energy balance.
Collapse
|
31
|
The potential roles of NAD(P)H:quinone oxidoreductase 1 in the development of diabetic nephropathy and actin polymerization. Sci Rep 2020; 10:17735. [PMID: 33082368 PMCID: PMC7576596 DOI: 10.1038/s41598-020-74493-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 09/30/2020] [Indexed: 11/08/2022] Open
Abstract
Diabetic nephropathy (DN) is a major complication of diabetes mellitus. NAD(P)H:quinone oxidoreductase 1 (NQO1) is an antioxidant enzyme that has been involved in the progression of several kidney injuries. However, the roles of NQO1 in DN are still unclear. We investigated the effects of NQO1 deficiency in streptozotocin (STZ)-induced DN mice. NQO1 was upregulated in the glomerulus and podocytes under hyperglycemic conditions. NQO1 knockout (NKO) mice showed more severe changes in blood glucose and body weight than WT mice after STZ treatment. Furthermore, STZ-mediated pathological parameters including glomerular injury, blood urea nitrogen levels, and foot process width were more severe in NKO mice than WT mice. Importantly, urine albumin-to-creatinine ratio (ACR) was higher in healthy, non-treated NKO mice than WT mice. ACR response to STZ or LPS was dramatically increased in the urine of NKO mice compared to vehicle controls, while it maintained a normal range following treatment of WT mice. More importantly, we found that NQO1 can stimulate actin polymerization in an in vitro biochemical assay without directly the accumulation on F-actin. In summary, NQO1 has an important role against the development of DN pathogenesis and is a novel contributor in actin reorganization via stimulating actin polymerization.
Collapse
|
32
|
Matoba K, Takeda Y, Nagai Y, Sekiguchi K, Yokota T, Utsunomiya K, Nishimura R. The Physiology, Pathology, and Therapeutic Interventions for ROCK Isoforms in Diabetic Kidney Disease. Front Pharmacol 2020; 11:585633. [PMID: 33101039 PMCID: PMC7545791 DOI: 10.3389/fphar.2020.585633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/07/2020] [Indexed: 01/14/2023] Open
Abstract
Rho-associated coiled-coil-containing protein kinase (ROCK) is a serine/threonine kinase that was originally identified as RhoA interacting protein. A diverse array of cellular functions, including migration, proliferation, and phenotypic modulation, are orchestrated by ROCK through a mechanism involving cytoskeletal rearrangement. Mammalian cells express two ROCK isoforms: ROCK1 (Rho-kinase β/ROKβ) and ROCK2 (Rho-kinase α/ROKα). While both isoforms have structural similarities and are widely expressed across multiple tissues, investigations in gene knockout animals and cell-based studies have revealed distinct functions of ROCK1 and ROCK2. With respect to the kidney, inhibiting ROCK activity has proven effective for the preventing diabetic kidney disease (DKD) in both type 1 and type 2 diabetic rodent models. However, despite significant progress in the understanding of the renal ROCK biology over the past decade, the pathogenic roles of the ROCK isoforms is only beginning to be elucidated. Recent studies have demonstrated the involvement of renal ROCK1 in mitochondrial dynamics and cellular transdifferentiation, whereas ROCK2 activation leads to inflammation, fibrosis, and cell death in the diabetic kidney. This review provides a conceptual framework for dissecting the molecular underpinnings of ROCK-driven renal injury, focusing on the differences between ROCK1 and ROCK2.
Collapse
Affiliation(s)
- Keiichiro Matoba
- Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yusuke Takeda
- Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yosuke Nagai
- Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kensuke Sekiguchi
- Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Tamotsu Yokota
- Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazunori Utsunomiya
- Center for Preventive Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Rimei Nishimura
- Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| |
Collapse
|
33
|
Blaine J, Dylewski J. Regulation of the Actin Cytoskeleton in Podocytes. Cells 2020; 9:cells9071700. [PMID: 32708597 PMCID: PMC7408282 DOI: 10.3390/cells9071700] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/30/2020] [Accepted: 07/07/2020] [Indexed: 12/13/2022] Open
Abstract
Podocytes are an integral part of the glomerular filtration barrier, a structure that prevents filtration of large proteins and macromolecules into the urine. Podocyte function is dependent on actin cytoskeleton regulation within the foot processes, structures that link podocytes to the glomerular basement membrane. Actin cytoskeleton dynamics in podocyte foot processes are complex and regulated by multiple proteins and other factors. There are two key signal integration and structural hubs within foot processes that regulate the actin cytoskeleton: the slit diaphragm and focal adhesions. Both modulate actin filament extension as well as foot process mobility. No matter what the initial cause, the final common pathway of podocyte damage is dysregulation of the actin cytoskeleton leading to foot process retraction and proteinuria. Disruption of the actin cytoskeleton can be due to acquired causes or to genetic mutations in key actin regulatory and signaling proteins. Here, we describe the major structural and signaling components that regulate the actin cytoskeleton in podocytes as well as acquired and genetic causes of actin dysregulation.
Collapse
Affiliation(s)
- Judith Blaine
- Renal Division, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - James Dylewski
- Renal Division, University of Colorado Anschutz Medical Campus and Denver Health Medical Center, Aurora, CO 80045, USA
- Correspondence: ; Tel.: +303-724-4841
| |
Collapse
|
34
|
Trionfini P, Ciampi O, Todeschini M, Ascanelli C, Longaretti L, Perico L, Remuzzi G, Benigni A, Tomasoni S. CRISPR-Cas9-Mediated Correction of the G189R-PAX2 Mutation in Induced Pluripotent Stem Cells from a Patient with Focal Segmental Glomerulosclerosis. CRISPR J 2020; 2:108-120. [PMID: 30998089 DOI: 10.1089/crispr.2018.0048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is defined by focal (involving few glomeruli) and segmental sclerosis of the glomerular tuft that manifests with nephrotic syndrome. Mutations in genes involved in the maintenance of structure and function of podocytes have been found in a minority of these patients. A family with adult-onset autosomal dominant FSGS was recently found to carry a new germline missense heterozygous mutation (p.G189R) in the octapeptide domain of the transcription factor PAX2. Here, we efficiently corrected this point mutation in patient-derived induced pluripotent stem cells (iPSCs) by means of CRISPR-Cas9-based homology-directed repair. The iPSC lines were differentiated into podocytes, which were tested for their motility. Editing the PAX2 p.G189R mutation restored podocyte motility, which was altered in podocytes derived from patient iPSCs.
Collapse
Affiliation(s)
- Piera Trionfini
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| | - Osele Ciampi
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| | - Marta Todeschini
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| | - Camilla Ascanelli
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| | - Lorena Longaretti
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| | - Luca Perico
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| | - Giuseppe Remuzzi
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy.,2 L. Sacco' Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Ariela Benigni
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| | - Susanna Tomasoni
- 1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; University of Milan, Milan, Italy
| |
Collapse
|
35
|
Hosseiniyan Khatibi SM, Ardalan M, Abediazar S, Zununi Vahed S. The impact of steroids on the injured podocytes in nephrotic syndrome. J Steroid Biochem Mol Biol 2020; 196:105490. [PMID: 31586640 DOI: 10.1016/j.jsbmb.2019.105490] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/03/2019] [Accepted: 09/30/2019] [Indexed: 12/17/2022]
Abstract
Nephrotic syndrome (NS), a common chronic kidney disease, embraces a variety of kidney disorders. Though Glucocorticoids (GCs) are generally used in the treatment of NS, their mechanism of action is poorly understood. A plethora of evidence indicates that podocytes are considered as the main target cells for the therapeutic strategies to prevent NS. GCs regulate the transactivation and transrepression of genes in podocytes that affect their morphological and cytoskeletal features, motility, apoptosis and survival rate. Moreover, they prevent protein leakage through the glomerular barrier membrane by affecting the synthesis, trafficking and posttranslational modifications of slit diaphragms components, podocytes' intercellular junctions. The response to the treatment is variable among different ethnics and populations and resistance to the steroids is detected in almost 50% of adult patients. Not only do pharmacokinetics and pharmacogenetics of steroids play a role in GC resistance but also the genetic variations in one or more podocyte related genes are connected with the steroid resistance in cases with NS. The focus of this review is to explain the underlying cellular and molecular mechanisms of GCs in podocytes. Understanding the mechanisms by which the GCs and GCs receptors in podocytes regulate the gene expression network and crosstalk with other molecular pathways would guarantee an optimum therapeutic benefit of steroid treatment.
Collapse
Affiliation(s)
| | | | - Sima Abediazar
- Kidney Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | |
Collapse
|
36
|
Xie F, Lei J, Ran M, Li Y, Deng L, Feng J, Zhong Y, Li J. Attenuation of Diabetic Nephropathy in Diabetic Mice by Fasudil through Regulation of Macrophage Polarization. J Diabetes Res 2020; 2020:4126913. [PMID: 32685556 PMCID: PMC7345603 DOI: 10.1155/2020/4126913] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/11/2020] [Accepted: 06/11/2020] [Indexed: 12/24/2022] Open
Abstract
Inflammation and fibrosis induced by hyperglycemia are considered to play a critical role in the pathogenesis of diabetic nephropathy. As macrophage polarization may determine the severity and progression of inflammation, regulation of macrophage polarization may be an effective method to treat diabetic complications. Fasudil, a potent Rho-kinase inhibitor, reportedly exhibits anti-inflammatory activity. However, whether fasudil reduces hyperglycemia-induced diabetic nephropathy via regulation of macrophage polarization remains unclear. In this study, we investigate the effect of fasudil on diabetic nephropathy in streptozotocin-induced type 1 diabetic mice. Our data showed that fasudil significantly decreased urinary protein and serum creatinine in diabetic mice, whereas it had no effect on the body weight and blood glucose. We also found increased M1-type macrophages and related proinflammatory cytokines, adverse fibrosis in renal tissue of diabetic mice. Interestingly, treatment of diabetic mice with fasudil increased the number of M2-type macrophages and related anti-inflammatory cytokines, which attenuated renal injury in diabetic mice. Taken together, the results of this study suggest that fasudil could slow the progression of diabetic nephropathy. The possible mechanism might be associated with its induction of M2 macrophage polarization and the reduction of M1 macrophage polarization and inflammation.
Collapse
Affiliation(s)
- Fajiang Xie
- Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
- Department of Cardiology, Dazhou Central Hospital, Dazhou, Sichuan, China
| | - Jiesen Lei
- Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Maoxia Ran
- Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
- Department of Cardiology, Dazhou Central Hospital, Dazhou, Sichuan, China
| | - Yan Li
- Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Li Deng
- Department of Rheumatology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Jian Feng
- Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yi Zhong
- Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Jiafu Li
- Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Department of Cardiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| |
Collapse
|
37
|
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.
Collapse
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
| |
Collapse
|
38
|
The Use of High-Throughput Transcriptomics to Identify Pathways with Therapeutic Significance in Podocytes. Int J Mol Sci 2019; 21:ijms21010274. [PMID: 31906131 PMCID: PMC6981397 DOI: 10.3390/ijms21010274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/24/2019] [Accepted: 12/26/2019] [Indexed: 12/25/2022] Open
Abstract
Podocytes have a unique structure that supports glomerular filtration function, and many glomerular diseases result in loss of this structure, leading to podocyte dysfunction and ESRD (end stage renal disease). These structural and functional changes involve a complex set of molecular and cellular mechanisms that remain poorly understood. To understand the molecular signature of podocyte injury, we performed transcriptome analysis of cultured human podocytes injured either with PAN (puromycin aminonucleoside) or doxorubicin/adriamycin (ADR). The pathway analysis through DE (differential expression) and gene-enrichment analysis of the injured podocytes showed Tumor protein p53 (P53) as one of the major signaling pathways that was significantly upregulated upon podocyte injury. Accordingly, P53 expression was also up-regulated in the glomeruli of nephrotoxic serum (NTS) and ADR-injured mice. To further confirm these observations, cultured podocytes were treated with the P53 inhibitor pifithrin-α, which showed significant protection from ADR-induced actin cytoskeleton damage. In conclusion, signaling pathways that are involved in podocyte pathogenesis and can be therapeutically targeted were identified by high-throughput transcriptomic analysis of injured podocytes.
Collapse
|
39
|
Hall G, Wang L, Spurney RF. TRPC Channels in Proteinuric Kidney Diseases. Cells 2019; 9:cells9010044. [PMID: 31877991 PMCID: PMC7016871 DOI: 10.3390/cells9010044] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 12/20/2022] Open
Abstract
Over a decade ago, mutations in the gene encoding TRPC6 (transient receptor potential cation channel, subfamily C, member 6) were linked to development of familial forms of nephrosis. Since this discovery, TRPC6 has been implicated in the pathophysiology of non-genetic forms of kidney disease including focal segmental glomerulosclerosis (FSGS), diabetic nephropathy, immune-mediated kidney diseases, and renal fibrosis. On the basis of these findings, TRPC6 has become an important target for the development of therapeutic agents to treat diverse kidney diseases. Although TRPC6 has been a major focus for drug discovery, more recent studies suggest that other TRPC family members play a role in the pathogenesis of glomerular disease processes and chronic kidney disease (CKD). This review highlights the data implicating TRPC6 and other TRPC family members in both genetic and non-genetic forms of kidney disease, focusing on TRPC3, TRPC5, and TRPC6 in a cell type (glomerular podocytes) that plays a key role in proteinuric kidney diseases.
Collapse
|
40
|
Chen Y, Liu Q, Shan Z, Mi W, Zhao Y, Li M, Wang B, Zheng X, Feng W. Catalpol Ameliorates Podocyte Injury by Stabilizing Cytoskeleton and Enhancing Autophagy in Diabetic Nephropathy. Front Pharmacol 2019; 10:1477. [PMID: 31920663 PMCID: PMC6914850 DOI: 10.3389/fphar.2019.01477] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 11/13/2019] [Indexed: 12/30/2022] Open
Abstract
Catalpol, an iridoid glycoside extracted from Rehmannia glutinosa, has been found to ameliorate diabetic nephropathy (DN), but the mechanism has not been clarified. Podocyte injury play a key role in the pathogenesis of DN. This study mainly investigated the protective effect and potential mechanism of catalpol on podocyte injury of DN in vivo and in vitro. The results indicated that the pathological features of DN in mice were markedly ameliorated after treatment with catalpol. Moreover, podocyte foot process effacement, and down-regulation of nephrin and synaptopodin expression in DN mice were also significantly improved after treatment with catalpol. In vitro, catalpol rescued disrupted cytoskeleton and increased migration ratio in podocytes induced by high glucose, the effect might be attributable to the inhibition of RhoA and Cdc42 activities but not Rac1. Furthermore, the impaired podocyte autophagy in DN mice was significantly enhanced after catalpol treatment. And catalpol also enhanced autophagy and lysosome biogenesis in cultured podocytes under high glucose condition. In addition, we found that catalpol could inhibit mTOR activity and promote TFEB nuclear translocation in vivo and in vitro experiments. Our study demonstrated that catalpol could ameliorate podocyte injury in DN, and the protective effect of catalpol might be attributed to the stabilization of podocyte cytoskeleton and the improvement of impaired podocyte autophagy.
Collapse
Affiliation(s)
- Yan Chen
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China
| | - Qingpu Liu
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China
| | - Zengfu Shan
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China
| | - Wangyang Mi
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China
| | - Yingying Zhao
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China
| | - Meng Li
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China
| | - Baiyan Wang
- College of Basic Medicine, Henan University of Chinese Medicine, Zhengzhou, China
| | - Xiaoke Zheng
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China.,Co-Construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan & Education Ministry of P.R. China, Henan University of Chinese Medicine, Zhengzhou, China
| | - Weisheng Feng
- College of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China.,Co-Construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan & Education Ministry of P.R. China, Henan University of Chinese Medicine, Zhengzhou, China
| |
Collapse
|
41
|
Meyer-Schwesinger C. An unexpected role of steroid on podocytes: from zebrafish to human nephrotic syndrome? Kidney Int 2019; 95:1015-1017. [PMID: 31010473 DOI: 10.1016/j.kint.2019.01.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 01/19/2019] [Accepted: 01/23/2019] [Indexed: 10/27/2022]
Abstract
In this issue of Kidney International, Jobst-Schwan et al. developed a zebrafish model of MAGI2-deficiency, which recapitulates findings of human nephrotic syndrome due to MAGI2 mutations. The authors use this model system to screen for drugs that might target and alleviate MAGI2-associated nephrotic syndrome pathways. The scientific context of this publication and the significance of its key findings are discussed in this commentary.
Collapse
Affiliation(s)
- Catherine Meyer-Schwesinger
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| |
Collapse
|
42
|
Felizardo RJF, de Almeida DC, Pereira RL, Watanabe IKM, Doimo NTS, Ribeiro WR, Cenedeze MA, Hiyane MI, Amano MT, Braga TT, Ferreira CM, Parmigiani RB, Andrade-Oliveira V, Volpini RA, Vinolo MAR, Mariño E, Robert R, Mackay CR, Camara NOS. Gut microbial metabolite butyrate protects against proteinuric kidney disease through epigenetic- and GPR109a-mediated mechanisms. FASEB J 2019; 33:11894-11908. [PMID: 31366236 DOI: 10.1096/fj.201901080r] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Butyrate is a short-chain fatty acid derived from the metabolism of indigestible carbohydrates by the gut microbiota. Butyrate contributes to gut homeostasis, but it may also control inflammatory responses and host physiology in other tissues. Butyrate inhibits histone deacetylases, thereby affecting gene transcription, and also signals through the metabolite-sensing G protein receptor (GPR)109a. We produced an mAb to mouse GPR109a and found high expression on podocytes in the kidney. Wild-type and Gpr109a-/- mice were induced to develop nephropathy by a single injection of Adriamycin and treated with sodium butyrate or high butyrate-releasing high-amylose maize starch diet. Butyrate improved proteinuria by preserving podocyte at glomerular basement membrane and attenuated glomerulosclerosis and tissue inflammation. This protective phenotype was associated with increased podocyte-related proteins and a normalized pattern of acetylation and methylation at promoter sites of genes essential for podocyte function. We found that GPR109a is expressed by podocytes, and the use of Gpr109a-/- mice showed that the protective effects of butyrate depended on GPR109a expression. A prebiotic diet that releases high amounts of butyrate also proved highly effective for protection against kidney disease. Butyrate and GPR109a play a role in the pathogenesis of kidney disease and provide one of the important molecular connections between diet, the gut microbiota, and kidney disease.-Felizardo, R. J. F., de Almeida, D. C., Pereira, R. L., Watanabe, I. K. M., Doimo, N. T. S., Ribeiro, W. R., Cenedeze, M. A., Hiyane, M. I., Amano, M. T., Braga, T. T., Ferreira, C. M., Parmigiani, R. B., Andrade-Oliveira, V., Volpini, R. A., Vinolo, M. A. R., Mariño, E., Robert, R., Mackay, C. R., Camara, N. O. S. Gut microbial metabolite butyrate protects against proteinuric kidney disease through epigenetic- and GPR109a-mediated mechanisms.
Collapse
Affiliation(s)
- Raphael J F Felizardo
- Nephrology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, Brazil.,Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil.,Department of Biochemistry and Molecular Biology, Biodiscovery Institute, Monash University, Clayton, Victoria, Australia
| | - Danilo C de Almeida
- Nephrology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, Brazil.,Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil
| | - Rafael L Pereira
- Department of Physiology, Universidade Federal do Paraná, Curitiba, Brazil
| | - Ingrid K M Watanabe
- Nephrology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, Brazil.,Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil
| | - Nayara T S Doimo
- Center for Molecular Oncology, Hospital Sírio-Libanês, São Paulo, Brazil
| | - Willian R Ribeiro
- Department of Pharmaceutics Sciences, Institute of Environmental Chemistry and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, Brazil
| | - Marcos A Cenedeze
- Nephrology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Meire I Hiyane
- Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil
| | - Mariane T Amano
- Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil.,Center for Molecular Oncology, Hospital Sírio-Libanês, São Paulo, Brazil
| | - Tárcio T Braga
- Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil
| | - Caroline M Ferreira
- Department of Pharmaceutics Sciences, Institute of Environmental Chemistry and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, Brazil
| | | | - Vinicius Andrade-Oliveira
- Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil
| | - Rildo A Volpini
- Laboratório de Investigação Médica 12 (LIM12), Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Marco Aurélio R Vinolo
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, Universidade Estadual de Campinas, Campinas, Brazil
| | - Eliana Mariño
- Department of Biochemistry and Molecular Biology, Biodiscovery Institute, Monash University, Clayton, Victoria, Australia
| | - Remy Robert
- Department of Biochemistry and Molecular Biology, Biodiscovery Institute, Monash University, Clayton, Victoria, Australia
| | - Charles R Mackay
- Department of Biochemistry and Molecular Biology, Biodiscovery Institute, Monash University, Clayton, Victoria, Australia
| | - Niels O S Camara
- Nephrology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, Brazil.,Department of Immunology, Institute of Biomedical Sciences IV, Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|
43
|
Jobst-Schwan T, Hoogstraten CA, Kolvenbach CM, Schmidt JM, Kolb A, Eddy K, Schneider R, Ashraf S, Widmeier E, Majmundar AJ, Hildebrandt F. Corticosteroid treatment exacerbates nephrotic syndrome in a zebrafish model of magi2a knockout. Kidney Int 2019; 95:1079-1090. [PMID: 31010479 DOI: 10.1016/j.kint.2018.12.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/21/2018] [Accepted: 12/13/2018] [Indexed: 01/31/2023]
Abstract
Recently, recessive mutations of MAGI2 were identified as a cause of steroid-resistant nephrotic syndrome (SRNS) in humans and mice. To further delineate the pathogenesis of MAGI2 loss of function, we generated stable knockout lines for the two zebrafish orthologues magi2a and magi2b by CRISPR/Cas9. We also developed a novel assay for the direct detection of proteinuria in zebrafish independent of transgenic background. Whereas knockout of magi2b did not yield a nephrotic syndrome phenotype, magi2a-/- larvae developed ascites, periorbital edema, and proteinuria, as indicated by increased excretion of low molecular weight protein. Electron microscopy demonstrated extensive podocyte foot process effacement. As in human SRNS, we observed genotype/phenotype correlation, with edema onset occurring earlier in zebrafish with truncating alleles (5-6 days post fertilization) versus hypomorphic alleles (19-20 days post fertilization). Paradoxically, corticosteroid treatment exacerbated the phenotype, with earlier onset of edema. In contrast, treatment with cyclosporine A or tacrolimus had no significant effect. Although RhoA signaling has been implicated as a downstream mediator of MAGI2 activity, targeting of the RhoA pathway did not modify the nephrotic syndrome phenotype. In the first CRISPR/Cas9 zebrafish knockout model of SRNS, we found that corticosteroids may have a paradoxical effect in the setting of specific genetic mutations.
Collapse
Affiliation(s)
- Tilman Jobst-Schwan
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Charlotte A Hoogstraten
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Caroline M Kolvenbach
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Johanna Magdalena Schmidt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Amy Kolb
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Kaitlyn Eddy
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ronen Schneider
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Shazia Ashraf
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Eugen Widmeier
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Amar J Majmundar
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
| |
Collapse
|
44
|
First identification of PODXL nonsense mutations in autosomal dominant focal segmental glomerulosclerosis. Clin Sci (Lond) 2019; 133:9-21. [PMID: 30523047 DOI: 10.1042/cs20180676] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/16/2018] [Accepted: 12/05/2018] [Indexed: 01/17/2023]
Abstract
Recently, a novel heterozygous missense mutation c.T1421G (p. L474R) in the PODXL gene encoding podocalyxin was identified in an autosomal dominant focal segmental glomerulosclerosis (AD-FSGS) pedigree. However, this PODXL mutation appeared not to impair podocalyxin function, and it is necessary to identify new PODXL mutations and determine their causative role for FSGS. In the present study, we report the identification of a heterozygous nonsense PODXL mutation (c.C976T; p. Arg326X) in a Chinese pedigree featured by proteinuria and renal insufficiency with AD inheritance by whole exome sequencing (WES). Total mRNA and PODXL protein abundance were decreased in available peripheral blood cell samples of two affected patients undergoing hemodialysis, compared with those in healthy controls and hemodialysis controls without PODXL mutation. We identified another novel PODXL heterozygous nonsense mutation (c.C1133G; p.Ser378X) in a British-Indian pedigree of AD-FSGS by WES. In vitro study showed that, human embryonic kidney 293T cells transfected with the pEGFP-PODXL-Arg326X or pEGFP-PODXL-Ser378X plasmid expressed significantly lower mRNA and PODXL protein compared with cells transfected with the wild-type plasmid. Blocking nonsense-mediated mRNA decay (NMD) significantly restored the amount of mutant mRNA and PODXL proteins, which indicated that the pathogenic effect of PODXL nonsense mutations is likely due to NMD, resulting in podocalyxin deficiency. Functional consequences caused by the PODXL nonsense mutations were inferred by siRNA knockdown in cultured podocytes and podocalyxin down-regulation by siRNA resulted in decreased RhoA and ezrin activities, cell migration and stress fiber formation. Our results provided new data implicating heterozygous PODXL nonsense mutations in the development of FSGS.
Collapse
|
45
|
Asada Y, Takayanagi T, Kawakami T, Tomatsu E, Masuda A, Yoshino Y, Sekiguchi-Ueda S, Shibata M, Ide T, Niimi H, Yaoita E, Seino Y, Sugimura Y, Suzuki A. Risedronate Attenuates Podocyte Injury in Phosphate Transporter-Overexpressing Rats. Int J Endocrinol 2019; 2019:4194853. [PMID: 31772574 PMCID: PMC6854176 DOI: 10.1155/2019/4194853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/29/2019] [Indexed: 01/01/2023] Open
Abstract
Osteoporosis patients with chronic kidney disease (CKD) are becoming common in our superaging society. Renal dysfunction causes phosphorus accumulation in the circulating plasma and leads to the development of CKD-mineral bone disorder (MBD). We have previously reported that type III Pi transporter-overexpressing transgenic (Pit-1 TG) rats manifest phosphate (Pi)-dependent podocyte injury. In the present study, we explored the effect of risedronate on Pi-induced podocyte injury in vivo. Pit-1 TG rats and wild-type rats at 5 weeks old were divided into a risedronate-treated group and an untreated group. We subcutaneously administered 5 μg/kg body weight of risedronate or saline twice a week during the experimental period. Risedronate did not alter serum creatinine levels at 5, 8, and 12 weeks of age. However, electron microscopy images showed that thickening of the glomerular basement membrane was improved in the risedronate treatment group. Furthermore, immunostaining for podocyte injury markers revealed that both desmin- and connexin43-positive areas were smaller in the risedronate-treated group than in the untreated group, suggesting that bisphosphonates could rescue Pi-induced podocyte injury. In conclusion, our findings suggest that risedronate could maintain glomerular barrier function by rescuing Pi-induced podocyte injury.
Collapse
Affiliation(s)
- Yohei Asada
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Takeshi Takayanagi
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Tsukasa Kawakami
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Eisuke Tomatsu
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Atsushi Masuda
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Yasumasa Yoshino
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Sahoko Sekiguchi-Ueda
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Megumi Shibata
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Tomihiko Ide
- Joint Research Support Promotion Facility, Center for Research Promotion and Support, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Hajime Niimi
- Department of Anatomy, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Eishin Yaoita
- Department of Structural Pathology, Institute of Nephrology, Niigata University Graduate School of Medical and Dental Sciences, Niigata 950-2102, Japan
| | - Yusuke Seino
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Yoshihisa Sugimura
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Atsushi Suzuki
- Department of Endocrinology and Metabolism, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| |
Collapse
|
46
|
Spyrou N, Avgerinos KI, Mantzoros CS, Dalamaga M. Classic and Novel Adipocytokines at the Intersection of Obesity and Cancer: Diagnostic and Therapeutic Strategies. Curr Obes Rep 2018; 7:260-275. [PMID: 30145771 DOI: 10.1007/s13679-018-0318-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW In this review, we investigate the role of classic and novel adipocytokines in cancer pathogenesis synopsizing the mechanisms underlying the association between adipocytokines and malignancy. Special emphasis is given on novel adipocytokines as new evidence is emerging regarding their entanglement in neoplastic development. RECENT FINDINGS Recent data have emphasized the role of the triad of overweight/obesity, insulin resistance and adipocytokines in cancer. In the setting of obesity, classic and novel adipocytokines present independent and joint effects on activation of major intracellular signaling pathways implicated in cell proliferation, expansion, survival, adhesion, invasion, and metastasis. Until now, more than 15 adipocytokines have been associated with cancer, and this list continues to expand. While the plethora of circulating pro-inflammatory adipocytokines, such as leptin, resistin, extracellular nicotinamide phosphoribosyl transferase, and chemerin are elevated in malignancies, some adipocytokines such as adiponectin and omentin-1 are generally decreased in cancers and are considered protective against carcinogenesis. Elucidating the intertwining of inflammation, cellular bioenergetics, and adiposopathy is significant for the development of preventive, diagnostic, and therapeutic strategies against cancer. Novel more effective and safe adipocytokine-centered therapeutic interventions may pave the way for targeted oncotherapy.
Collapse
Affiliation(s)
- Nikolaos Spyrou
- 251 Airforce General Hospital, Kanellopoulou 3, 11525, Athens, Greece
| | | | - Christos S Mantzoros
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
- Section of Endocrinology, VA Boston Healthcare System, Boston, MA, USA
| | - Maria Dalamaga
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Mikras Asias 75, Goudi, 11527, Athens, Greece.
| |
Collapse
|
47
|
Wei C, Banu K, Garzon F, Basgen JM, Philippe N, Yi Z, Liu R, Choudhuri J, Fribourg M, Liu T, Cumpelik A, Wong J, Khan M, Das B, Keung K, Salem F, Campbell KN, Kaufman L, Cravedi P, Zhang W, O'Connell PJ, He JC, Murphy B, Menon MC. SHROOM3-FYN Interaction Regulates Nephrin Phosphorylation and Affects Albuminuria in Allografts. J Am Soc Nephrol 2018; 29:2641-2657. [PMID: 30341149 PMCID: PMC6218856 DOI: 10.1681/asn.2018060573] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/14/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND We previously showed that the presence of a CKD-associated locus in SHROOM3 in a donor kidney results in increased expression of SHROOM3 (an F-actin-binding protein important for epithelial morphogenesis, via rho-kinase [ROCK] binding); this facilitates TGF-b signaling and allograft fibrosis. However, other evidence suggests Shroom3 may have a protective role in glomerular development. METHODS We used human data, Shroom3 knockdown podocytes, and inducible shRNA-mediated knockdown mice to study the role of Shroom3 in adult glomeruli. RESULTS Expression data from the Nephroseq database showed glomerular and nonglomerular SHROOM3 had opposing associations with renal function in CKD biopsy samples. In human allografts, homozygosity at rs17319721, the SHROOM3 locus linked with lower GFR, was associated with reduced albuminuria by 2 years after transplant. Although our previous data showed reduced renal fibrosis with tubular Shroom3 knockdown, this study found that glomerular but not tubular Shroom3 knockdown induced albuminuria. Electron microscopy revealed diffuse foot process effacement, and glomerular RNA-sequencing showed enrichment of tyrosine kinase signaling and podocyte actin cytoskeleton pathways in knockdown mice. Screening SHROOM3-interacting proteins identified FYN (a src-kinase) as a candidate.We confirmed the interaction of endogenous SHROOM3 with FYN in human podocytes via a critical Src homology 3-binding domain, distinct from its ROCK-binding domain. Shroom3-Fyn interaction was required in vitro and in vivo for activation of Fyn kinase and downstream nephrin phosphorylation in podocytes. SHROOM3 knockdown altered podocyte morphology, cytoskeleton, adhesion, and migration. CONCLUSIONS We demonstrate a novel mechanism that may explain SHROOM3's dichotomous associations in glomerular versus nonglomerular compartments in CKD.
Collapse
Affiliation(s)
- Chengguo Wei
- Division of Nephrology, Department of Medicine and
| | - Khadija Banu
- Division of Nephrology, Department of Medicine and
| | | | - John M Basgen
- Morphometry and Stereology Laboratory, Charles R. Drew University of Medicine and Science, Los Angeles, California
| | | | - Zhengzi Yi
- Division of Nephrology, Department of Medicine and
| | - Ruijie Liu
- Division of Nephrology, Department of Medicine and
| | | | - Miguel Fribourg
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Tong Liu
- Center for Advanced Proteomics, Department of Biochemistry and Molecular Biology, New Jersey Medical School, Newark, New Jersey; and
| | | | - Jenny Wong
- Division of Nephrology, Department of Medicine and
| | - Mubeen Khan
- Division of Nephrology, Department of Medicine and
| | - Bhaskar Das
- Division of Nephrology, Department of Medicine and
| | - Karen Keung
- Renal Unit, University of Sydney at Westmead Hospital, Sydney, Australia
| | - Fadi Salem
- Division of Nephrology, Department of Medicine and
| | | | | | | | - Weijia Zhang
- Division of Nephrology, Department of Medicine and
| | - Philip J O'Connell
- Renal Unit, University of Sydney at Westmead Hospital, Sydney, Australia
| | | | | | | |
Collapse
|
48
|
Yu SMW, Nissaisorakarn P, Husain I, Jim B. Proteinuric Kidney Diseases: A Podocyte's Slit Diaphragm and Cytoskeleton Approach. Front Med (Lausanne) 2018; 5:221. [PMID: 30255020 PMCID: PMC6141722 DOI: 10.3389/fmed.2018.00221] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/18/2018] [Indexed: 01/19/2023] Open
Abstract
Proteinuric kidney diseases are a group of disorders with diverse pathological mechanisms associated with significant losses of protein in the urine. The glomerular filtration barrier (GFB), comprised of the three important layers, the fenestrated glomerular endothelium, the glomerular basement membrane (GBM), and the podocyte, dictates that disruption of any one of these structures should lead to proteinuric disease. Podocytes, in particular, have long been considered as the final gatekeeper of the GFB. This specialized visceral epithelial cell contains a complex framework of cytoskeletons forming foot processes and mediate important cell signaling to maintain podocyte health. In this review, we will focus on slit diaphragm proteins such as nephrin, podocin, TRPC6/5, as well as cytoskeletal proteins Rho/small GTPases and synaptopodin and their respective roles in participating in the pathogenesis of proteinuric kidney diseases. Furthermore, we will summarize the potential therapeutic options targeting the podocyte to treat this group of kidney diseases.
Collapse
Affiliation(s)
- Samuel Mon-Wei Yu
- Department of Medicine, Jacobi Medical Center, Bronx, NY, United States
| | | | - Irma Husain
- Department of Medicine, James J. Peters VA Medical Center, Bronx, NY, United States
| | - Belinda Jim
- Department of Medicine, Jacobi Medical Center, Bronx, NY, United States.,Renal Division, Jacobi Medical Center, Bronx, NY, United States
| |
Collapse
|
49
|
Regulation of cofilin phosphorylation in glomerular podocytes by testis specific kinase 1 (TESK1). Sci Rep 2018; 8:12286. [PMID: 30115939 PMCID: PMC6095849 DOI: 10.1038/s41598-018-30115-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 07/20/2018] [Indexed: 12/14/2022] Open
Abstract
Expression of a constitutively active Rho A (V14Rho) in podocytes in vivo induces albuminuria and foot process (FP) effacement. These effects may be mediated by the Rho A effector Rho kinase (ROK); but inhibition of ROK with Y27632 failed to attenuate albuminuria or FP effacement in V14Rho mice. ROK activates LIM kinases (LIMKs), which phosphorylate and inhibit the actin depolymerizing factor cofilin 1 (CFL1). Sustained phosphorylation of CFL1 is implicated in human nephrotic diseases, but Y27632 did not inhibit phosphorylation of CFL1 in vivo, despite effective ROK inhibition. CFL1 is also phosphorylated by testis-specific kinase 1 (TESK1) on the same serine residue. TESK1 was expressed in podocytes, and, similar to the in vivo situation, Y27632 had little effect on phospho-CFL1 (pCFL1) levels in cultured podocytes. In contrast, Y27632 reduced pCFL1 levels in TESK1 knockout (KO) cells. ROK inhibition enhanced podocyte motility but, the motility promoting effect of Y27632 was absent in TESK1 KO podocytes. Thus, TESK1 regulates podocyte cytoskeletal dynamics in glomerular podocytes and may play an important role in regulating glomerular filtration barrier integrity in glomerular disease processes.
Collapse
|
50
|
Maeda K, Otomo K, Yoshida N, Abu-Asab MS, Ichinose K, Nishino T, Kono M, Ferretti A, Bhargava R, Maruyama S, Bickerton S, Fahmy TM, Tsokos MG, Tsokos GC. CaMK4 compromises podocyte function in autoimmune and nonautoimmune kidney disease. J Clin Invest 2018; 128:3445-3459. [PMID: 29985166 DOI: 10.1172/jci99507] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 05/17/2018] [Indexed: 12/31/2022] Open
Abstract
Podocyte malfunction occurs in autoimmune and nonautoimmune kidney disease. Calcium signaling is essential for podocyte injury, but the role of Ca2+/calmodulin-dependent kinase (CaMK) signaling in podocytes has not been fully explored. We report that podocytes from patients with lupus nephritis and focal segmental glomerulosclerosis and lupus-prone and lipopolysaccharide- or adriamycin-treated mice display increased expression of CaMK IV (CaMK4), but not CaMK2. Mechanistically, CaMK4 modulated podocyte motility by altering the expression of the GTPases Rac1 and RhoA and suppressed the expression of nephrin, synaptopodin, and actin fibers in podocytes. In addition, it phosphorylated the scaffold protein 14-3-3β, which resulted in the release and degradation of synaptopodin. Targeted delivery of a CaMK4 inhibitor to podocytes preserved their ultrastructure, averted immune complex deposition and crescent formation, and suppressed proteinuria in lupus-prone mice and proteinuria in mice exposed to lipopolysaccharide-induced podocyte injury by preserving nephrin/synaptopodin expression. In animals exposed to adriamycin, podocyte-specific delivery of a CaMK4 inhibitor prevented and reversed podocyte injury and renal disease. We conclude that CaMK4 is pivotal in immune and nonimmune podocyte injury and that its targeted cell-specific inhibition preserves podocyte structure and function and should have therapeutic value in lupus nephritis and podocytopathies, including focal segmental glomerulosclerosis.
Collapse
Affiliation(s)
- Kayaho Maeda
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Kotaro Otomo
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Nobuya Yoshida
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Mones S Abu-Asab
- Histopathology Core, National Eye Institute, NIH, Bethesda, Maryland, USA
| | - Kunihiro Ichinose
- Department of Immunology and Rheumatology, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Tomoya Nishino
- Department of Nephrology, Nagasaki University Hospital, Nagasaki, Japan
| | - Michihito Kono
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Andrew Ferretti
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Rhea Bhargava
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Shoichi Maruyama
- Department of Nephrology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sean Bickerton
- Department of Biomedical Engineering, Yale University and Yale University School of Medicine, New Haven, Connecticut, USA
| | - Tarek M Fahmy
- Department of Biomedical Engineering, Department of Chemical and Environmental Engineering, Department of Immunobiology, Yale University and Yale University School of Medicine, New Haven, Connecticut, USA
| | - Maria G Tsokos
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - George C Tsokos
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|