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Venugopal S, Dan Q, Sri Theivakadadcham VS, Wu B, Kofler M, Layne MD, Connelly KA, Rzepka MF, Friedberg MK, Kapus A, Szászi K. Regulation of the RhoA exchange factor GEF-H1 by profibrotic stimuli through a positive feedback loop involving RhoA, MRTF, and Sp1. Am J Physiol Cell Physiol 2024; 327:C387-C402. [PMID: 38912734 DOI: 10.1152/ajpcell.00088.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 06/03/2024] [Accepted: 06/14/2024] [Indexed: 06/25/2024]
Abstract
RhoA and its effectors, the transcriptional coactivators myocardin-related transcription factor (MRTF) and serum response factor (SRF), control epithelial phenotype and are indispensable for profibrotic epithelial reprogramming during fibrogenesis. Context-dependent control of RhoA and fibrosis-associated changes in its regulators, however, remain incompletely characterized. We previously identified the guanine nucleotide exchange factor GEF-H1 as a central mediator of RhoA activation in renal tubular cells exposed to inflammatory or fibrotic stimuli. Here we found that GEF-H1 expression and phosphorylation were strongly elevated in two animal models of fibrosis. In the Unilateral Ureteral Obstruction mouse kidney fibrosis model, GEF-H1 was upregulated predominantly in the tubular compartment. GEF-H1 was also elevated and phosphorylated in a rat pulmonary artery banding (PAB) model of right ventricular fibrosis. Prolonged stimulation of LLC-PK1 tubular cells with tumor necrosis factor (TNF)-α or transforming growth factor (TGF)-β1 increased GEF-H1 expression and activated a luciferase-coupled GEF-H1 promoter. Knockdown and overexpression studies revealed that these effects were mediated by RhoA, cytoskeleton remodeling, and MRTF, indicative of a positive feedback cycle. Indeed, silencing endogenous GEF-H1 attenuated activation of the GEF-H1 promoter. Of importance, inhibition of MRTF using CCG-1423 prevented GEF-H1 upregulation in both animal models. MRTF-dependent increase in GEF-H1 was prevented by inhibition of the transcription factor Sp1, and mutating putative Sp1 binding sites in the GEF-H1 promoter eliminated its MRTF-dependent activation. As the GEF-H1/RhoA axis is key for fibrogenesis, this novel MRTF/Sp1-dependent regulation of GEF-H1 abundance represents a potential target for reducing renal and cardiac fibrosis.NEW & NOTEWORTHY We show that expression of the RhoA regulator GEF-H1 is upregulated in tubular cells exposed to fibrogenic cytokines and in animal models of kidney and heart fibrosis. We identify a pathway wherein GEF-H1/RhoA-dependent MRTF activation through its noncanonical partner Sp1 upregulates GEF-H1. Our data reveal the existence of a positive feedback cycle that enhances Rho signaling through control of both GEF-H1 activation and expression. This feedback loop may play an important role in organ fibrosis.
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Affiliation(s)
- Shruthi Venugopal
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
| | - Qinghong Dan
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
| | - Veroni S Sri Theivakadadcham
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
| | - Brian Wu
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
| | - Michael Kofler
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
| | - Matthew D Layne
- Department of Biochemistry & Cell Biology, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Kim A Connelly
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
| | - Mark F Rzepka
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Mark K Friedberg
- Division of Cardiology, Labatt Family Heart Center Toronto, Hospital for Sick Children, Toronto, Ontario, Canada
- Translational Medicine, Hospital for Sick Children Research Institute and University of Toronto, Toronto, Ontario, Canada
| | - András Kapus
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Katalin Szászi
- Keenan Research Centre for Biomedical Science of the St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
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2
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Fu R, Wang W, Huo Y, Li L, Chen R, Lin Z, Tao Y, Peng X, Huang W, Guo C. The mechanosensitive ion channel Piezo1 contributes to podocyte cytoskeleton remodeling and development of proteinuria in lupus nephritis. Kidney Int 2024:S0085-2538(24)00529-5. [PMID: 39084260 DOI: 10.1016/j.kint.2024.06.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 06/10/2024] [Accepted: 06/24/2024] [Indexed: 08/02/2024]
Abstract
Piezo1 functions as a special transducer of mechanostress into electrochemical signals and is implicated in the pathogenesis of various diseases across different disciplines. However, whether Piezo1 contributes to the pathogenesis of lupus nephritis (LN) remains elusive. To study this, we applied an agonist and antagonist of Piezo1 to treat lupus-prone MRL/lpr mice. Additionally, a podocyte-specific Piezo1 knockout mouse model was also generated to substantiate the role of Piezo1 in podocyte injury induced by pristane, a murine model of LN. A marked upregulation of Piezo1 was found in podocytes in both human and murine LN. The Piezo1 antagonist, GsMTx4, significantly alleviated glomerulonephritis and tubulointerstitial damage, improved kidney function, decreased proteinuria, and mitigated podocyte foot process effacement in MRL/lpr mice. Moreover, podocyte-specific Piezo1 deletion showed protective effects on the progression of proteinuria and podocyte foot process effacement in the murine LN model. Mechanistically, Piezo1 expression was upregulated by inflammatory cytokines (IL-6, TNF-α and IFN-γ), soluble urokinase Plasminogen Activator Receptor and its own activation. Activation of Piezo1 elicited calcium influx, which subsequently enhanced Rac1 activity and increased active paxillin, thereby promoting cytoskeleton remodeling and decreasing podocyte motility. Thus, our work demonstrated that Piezo1 contributed to podocyte injury and proteinuria progression in LN. Hence, targeted therapy aimed at decreasing or inhibiting Piezo1 could represent a novel strategy to treat LN.
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Affiliation(s)
- Rong Fu
- Department of Rheumatology, Guangzhou, China
| | | | - Yongbao Huo
- Department of Rheumatology, Guangzhou, China
| | - Liu Li
- Department of Rheumatology, Guangzhou, China
| | - Ruilin Chen
- Department of Rheumatology, Guangzhou, China
| | - Zeying Lin
- Department of Rheumatology, Guangzhou, China
| | - Yi Tao
- Department of Rheumatology, Guangzhou, China
| | - Xuan Peng
- Department of Nephrology, Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | | | - Chaohuan Guo
- Department of Rheumatology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
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Xu Q, Li J, Zhuo L, Gao H, Yang Y, Li W. RACGAP1 is a pivotal gene in lung adenocarcinoma-associated membranous nephropathy: Based on comprehensive bioinformatics analysis and machine learning. Int Immunopharmacol 2024; 139:112783. [PMID: 39068752 DOI: 10.1016/j.intimp.2024.112783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 06/05/2024] [Accepted: 07/23/2024] [Indexed: 07/30/2024]
Abstract
BACKGROUND This study performs a detailed bioinformatics and machine learning analysis to investigate the genetic foundations of membranous nephropathy (MN) in lung adenocarcinoma (LUAD). METHODS In this study, the gene expression profiles of MN microarray datasets (GSE99339) and LUAD dataset (GSE43767) were downloaded from the Gene Expression Omnibus database, common differentially expressed genes (DEGs) were obtained using the limma R package. The biological functions were analyzed with R Cluster Profiler package according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Machine learning algorithms, including LASSO regression, support vector machine (SVM), Random Forest, and Boruta analysis, were applied to identify hubgenes linked to LUAD-associated MN. These genes' prognostic values were evaluated in the TCGA-LUAD cohort and validated through immunohistochemistry on renal biopsy specimens. RESULTS A total of 36 DEGs in common were identified for downstream analyses. Functional enrichment analysis highlighted the involvement of the Toll-like receptor 4 pathway and several immune recognition pathways in LUAD-associated MN. COL3A1, PSENEN, RACGAP1, and TNFRSF10B were identified as hub genes in LUAD-associated MN using machine learning algorithms. ROC analysis demonstrated their effective discrimination of MN with high accuracy. Survival analysis showed that lung adenocarcinoma patients with higher expression of these genes had significantly reduced overall survival. In patients with lung adenocarcinoma-associated MN, RACGAP1, COL3A1, PSENEN, and TNFRSF10B were higher expressed in the glomerular, especially RACGAP1, indicating an important role in the pathogenesis of LUAD-associated membranous nephropathy. CONCLUSIONS Our study underscores the critical role of RACGAP1, COL3A1, PSENEN, and TNFRSF10B in the development of LUAD-associated MN, providing important insights for future research and the development of potential therapeutic strategies.
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Affiliation(s)
- Qianqian Xu
- Department of Nephrology, China-Japan Friendship Hospital, Beijing, China
| | - Jiayi Li
- Department of Nephrology, China-Japan Friendship Hospital, Beijing, China; Department of Nephrology, Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China
| | - Li Zhuo
- Department of Nephrology, China-Japan Friendship Hospital, Beijing, China
| | - Hongmei Gao
- Department of Nephrology, China-Japan Friendship Hospital, Beijing, China
| | - Yue Yang
- Department of Nephrology, China-Japan Friendship Hospital, Beijing, China
| | - Wenge Li
- Department of Nephrology, China-Japan Friendship Hospital, Beijing, China; Department of Nephrology, Peking University China-Japan Friendship School of Clinical Medicine, Beijing, China
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4
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Haydak J, Azeloglu EU. Role of biophysics and mechanobiology in podocyte physiology. Nat Rev Nephrol 2024; 20:371-385. [PMID: 38443711 DOI: 10.1038/s41581-024-00815-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 03/07/2024]
Abstract
Podocytes form the backbone of the glomerular filtration barrier and are exposed to various mechanical forces throughout the lifetime of an individual. The highly dynamic biomechanical environment of the glomerular capillaries greatly influences the cell biology of podocytes and their pathophysiology. Throughout the past two decades, a holistic picture of podocyte cell biology has emerged, highlighting mechanobiological signalling pathways, cytoskeletal dynamics and cellular adhesion as key determinants of biomechanical resilience in podocytes. This biomechanical resilience is essential for the physiological function of podocytes, including the formation and maintenance of the glomerular filtration barrier. Podocytes integrate diverse biomechanical stimuli from their environment and adapt their biophysical properties accordingly. However, perturbations in biomechanical cues or the underlying podocyte mechanobiology can lead to glomerular dysfunction with severe clinical consequences, including proteinuria and glomerulosclerosis. As our mechanistic understanding of podocyte mechanobiology and its role in the pathogenesis of glomerular disease increases, new targets for podocyte-specific therapeutics will emerge. Treating glomerular diseases by targeting podocyte mechanobiology might improve therapeutic precision and efficacy, with potential to reduce the burden of chronic kidney disease on individuals and health-care systems alike.
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Affiliation(s)
- Jonathan Haydak
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Evren U Azeloglu
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Mendoza-Soto P, Jara C, Torres-Arévalo Á, Oyarzún C, Mardones GA, Quezada-Monrás C, San Martín R. Pharmacological Blockade of the Adenosine A 2B Receptor Is Protective of Proteinuria in Diabetic Rats, through Affecting Focal Adhesion Kinase Activation and the Adhesion Dynamics of Podocytes. Cells 2024; 13:846. [PMID: 38786068 PMCID: PMC11119713 DOI: 10.3390/cells13100846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/24/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024] Open
Abstract
Induction of the adenosine receptor A2B (A2BAR) expression in diabetic glomeruli correlates with an increased abundance of its endogenous ligand adenosine and the progression of kidney dysfunction. Remarkably, A2BAR antagonism protects from proteinuria in experimental diabetic nephropathy. We found that A2BAR antagonism preserves the arrangement of podocytes on the glomerular filtration barrier, reduces diabetes-induced focal adhesion kinase (FAK) activation, and attenuates podocyte foot processes effacement. In spreading assays using human podocytes in vitro, adenosine enhanced the rate of cell body expansion on laminin-coated glass and promoted peripheral pY397-FAK subcellular distribution, while selective A2BAR antagonism impeded these effects and attenuated the migratory capability of podocytes. Increased phosphorylation of the Myosin2A light chain accompanied the effects of adenosine. Furthermore, when the A2BAR was stimulated, the cells expanded more broadly and more staining of pS19 myosin was detected which co-localized with actin cables, suggesting increased contractility potential in cells planted onto a matrix with a stiffness similar to of the glomerular basement membrane. We conclude that A2BAR is involved in adhesion dynamics and contractile actin bundle formation, leading to podocyte foot processes effacement. The antagonism of this receptor may be an alternative to the intervention of glomerular barrier deterioration and proteinuria in the diabetic kidney disease.
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Affiliation(s)
- Pablo Mendoza-Soto
- Molecular Pathology Laboratory, Institute of Biochemistry and Microbiology, Science Faculty, Universidad Austral de Chile, Valdivia 5110566, Chile; (P.M.-S.); (C.J.); (Á.T.-A.); (C.O.)
| | - Claudia Jara
- Molecular Pathology Laboratory, Institute of Biochemistry and Microbiology, Science Faculty, Universidad Austral de Chile, Valdivia 5110566, Chile; (P.M.-S.); (C.J.); (Á.T.-A.); (C.O.)
| | - Ángelo Torres-Arévalo
- Molecular Pathology Laboratory, Institute of Biochemistry and Microbiology, Science Faculty, Universidad Austral de Chile, Valdivia 5110566, Chile; (P.M.-S.); (C.J.); (Á.T.-A.); (C.O.)
| | - Carlos Oyarzún
- Molecular Pathology Laboratory, Institute of Biochemistry and Microbiology, Science Faculty, Universidad Austral de Chile, Valdivia 5110566, Chile; (P.M.-S.); (C.J.); (Á.T.-A.); (C.O.)
| | - Gonzalo A. Mardones
- Institute of Physiology, Medicine Faculty, Universidad Austral de Chile, Valdivia 5090000, Chile;
| | - Claudia Quezada-Monrás
- Tumor Biology Laboratory, Institute of Biochemistry and Microbiology, Science Faculty, Universidad Austral de Chile, Valdivia 5110566, Chile;
- Millennium Institute on Immunology and Immunotherapy, Universidad Austral de Chile, Valdivia 5110566, Chile
| | - Rody San Martín
- Molecular Pathology Laboratory, Institute of Biochemistry and Microbiology, Science Faculty, Universidad Austral de Chile, Valdivia 5110566, Chile; (P.M.-S.); (C.J.); (Á.T.-A.); (C.O.)
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6
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Finn LS. Nephrotic Syndrome Throughout Childhood: Diagnosing Podocytopathies From the Womb to the Dorm. Pediatr Dev Pathol 2024:10935266241242669. [PMID: 38745407 DOI: 10.1177/10935266241242669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The etiologies of podocyte dysfunction that lead to pediatric nephrotic syndrome (NS) are vast and vary with age at presentation. The discovery of numerous novel genetic podocytopathies and the evolution of diagnostic technologies has transformed the investigation of steroid-resistant NS while simultaneously promoting the replacement of traditional morphology-based disease classifications with a mechanistic approach. Podocytopathies associated with primary and secondary steroid-resistant NS manifest as diffuse mesangial sclerosis, minimal change disease, focal segmental glomerulosclerosis, and collapsing glomerulopathy. Molecular testing, once an ancillary option, has become a vital component of the clinical investigation and when paired with kidney biopsy findings, provides data that can optimize treatment and prognosis. This review focuses on the causes including selected monogenic defects, clinical phenotypes, histopathologic findings, and age-appropriate differential diagnoses of nephrotic syndrome in the pediatric population with an emphasis on podocytopathies.
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Affiliation(s)
- Laura S Finn
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at The University of Pennsylvania, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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7
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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.
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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
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8
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Liu W, Han J, Yang Q, Xia L, Chen C, Song J, Cai Y. Knockdown of ARHGAP24 reduces intimal hyperplasia through inhibiting the proliferation and phenotypic switching of smooth muscle cells possibly by inactivating both AKT and ERK1/2 signaling pathways. Biochem Biophys Rep 2024; 37:101591. [PMID: 38074998 PMCID: PMC10698571 DOI: 10.1016/j.bbrep.2023.101591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/10/2023] [Accepted: 11/20/2023] [Indexed: 02/29/2024] Open
Abstract
Intimal hyperplasia is one of the common pathophysiological foundations of vascular remodeling including restenosis and atherosclerosis. The Rho GTPase activating protein 24 (ARHGAP24) has been reported as a tumor suppressor in multiple cancers. Nevertheless, the role of ARHGAP24 in intimal hyperplasia is unclear. Interestingly, our results showed that ARHGAP24 was significantly up-regulated in dedifferentiated VSMC in vitro and vivo, which suggested that ARHGAP24 could promote VSMC dedifferentiation and proliferation. Knockdown of ARHGAP24 effectively inhibited VSMC dedifferentiation and proliferation in the absence and present of PDGF-BB, which might inactivate both ATK and ERK1/2 signaling pathways. Moreover, AAV9-mediated silencing of Arhgap24 also alleviates VSMC dedifferentiation and proliferation in the wire-injured mouse femoral arteries, contributing to reducing neointima formation. AAV9-mediated overexpression of Arhgap24 exacerbates intimal hyperplasia. We demonstrate that decreased ARHGAP24 expression restrained VSMC proliferation and dedifferentiation possibly by inactivating both AKT and ERK1/2 signaling pathways, which may provide a potential therapeutic strategy for diseases associated with intimal hyperplasia including restenosis and atherosclerosis.
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Affiliation(s)
- Wei Liu
- Department of Pediatrics, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, Guangdong Province, China
| | - Jing Han
- Neonatal Intensive Care Unit, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Longgang Maternity and Child Institute of Shantou University Medical College, Shenzhen, 518172, Guangdong Province, China
| | - Qiuping Yang
- Department of Pediatrics, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, Guangdong Province, China
| | - Luoxing Xia
- Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, 511436, Guangdong Province, China
| | - Cheng Chen
- Neonatal Intensive Care Unit, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City, Longgang Maternity and Child Institute of Shantou University Medical College, Shenzhen, 518172, Guangdong Province, China
| | - Jie Song
- Department of Pediatrics, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, 519000, Guangdong Province, China
| | - Yao Cai
- Department of Pediatrics, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510655, Guangdong Province, China
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9
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Gleason N, Kowluru A. Hyperglycemic Stress Induces Expression, Degradation, and Nuclear Association of Rho GDP Dissociation Inhibitor 2 (RhoGDIβ) in Pancreatic β-Cells. Cells 2024; 13:272. [PMID: 38334664 PMCID: PMC10854874 DOI: 10.3390/cells13030272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/21/2024] [Accepted: 01/31/2024] [Indexed: 02/10/2024] Open
Abstract
Small G proteins (e.g., Rac1) play critical regulatory roles in islet β-cell function in health (physiological insulin secretion) and in metabolic stress (cell dysfunction and demise). Multiple regulatory factors for these G proteins, such as GDP dissociation inhibitors (GDIs), have been implicated in the functional regulation of these G proteins. The current set of investigations is aimed at understanding impact of chronic hyperglycemic stress on the expression and subcellular distribution of three known isoforms of RhoGDIs (RhoGDIα, RhoGDIβ, and RhoGDIγ) in insulin-secreting β-cells. The data accrued in these studies revealed that the expression of RhoGDIβ, but not RhoGDIα or RhoGDIγ, is increased in INS-1 832/13 cells, rat islets, and human islets. Hyperglycemic stress also promoted the cleavage of RhoGDIβ, leading to its translocation to the nuclear compartment. We also report that RhoGDIα, but not RhoGDIγ, is associated with the nuclear compartment. However, unlike RhoGDIβ, hyperglycemic conditions exerted no effects on RhoGDIα's association with nuclear fraction. Based on these observations, and our earlier findings of the translocation of Rac1 to the nuclear compartment under the duress of metabolic stress, we conclude that the RhoGDIβ-Rac1 signaling module promotes signals from the cytosolic to the nucleus, culminating in accelerated β-cell dysfunction under metabolic stress.
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Affiliation(s)
- Noah Gleason
- Research Service, John D. Dingell VA Medical Center, Detroit, MI 48201, USA;
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Anjaneyulu Kowluru
- Research Service, John D. Dingell VA Medical Center, Detroit, MI 48201, USA;
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
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10
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Huang H, Wang S, Guan Y, Ren J, Liu X. Molecular basis and current insights of atypical Rho small GTPase in cancer. Mol Biol Rep 2024; 51:141. [PMID: 38236467 DOI: 10.1007/s11033-023-09140-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024]
Abstract
Atypical Rho GTPases are a subtype of the Rho GTPase family that are involved in diverse cellular processes. The typical Rho GTPases, led by RhoA, Rac1 and Cdc42, have been well studied, while relative studies on atypical Rho GTPases are relatively still limited and have great exploration potential. With the increase in studies, current evidence suggests that atypical Rho GTPases regulate multiple biological processes and play important roles in the occurrence and development of human cancers. Therefore, this review mainly discusses the molecular basis of atypical Rho GTPases and their roles in cancer. We summarize the sequence characteristics, subcellular localization and biological functions of each atypical Rho GTPase. Moreover, we review the recent advances and potential mechanisms of atypical Rho GTPases in the development of multiple cancers. A comprehensive understanding and extensive exploration of the biological functions of atypical Rho GTPases and their molecular mechanisms in tumors will provide important insights into the pathophysiology of tumors and the development of cancer therapeutic strategies.
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Affiliation(s)
- Hua Huang
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China
| | - Sijia Wang
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China
| | - Yifei Guan
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China
| | - Jing Ren
- Department of Plastic and Reconstructive Surgery, The First Medical Center, Chinese PLA (People's Liberation Army) General Hospital, Beijing, 100853, China.
| | - Xinhui Liu
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China.
- Faculty of Environment and Life, Beijing University of Technology, Beijing, 100124, China.
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11
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Ma S, Qiu Y, Zhang C. Cytoskeleton Rearrangement in Podocytopathies: An Update. Int J Mol Sci 2024; 25:647. [PMID: 38203817 PMCID: PMC10779434 DOI: 10.3390/ijms25010647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/14/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024] Open
Abstract
Podocyte injury can disrupt the glomerular filtration barrier (GFB), leading to podocytopathies that emphasize podocytes as the glomerulus's key organizer. The coordinated cytoskeleton is essential for supporting the elegant structure and complete functions of podocytes. Therefore, cytoskeleton rearrangement is closely related to the pathogenesis of podocytopathies. In podocytopathies, the rearrangement of the cytoskeleton refers to significant alterations in a string of slit diaphragm (SD) and focal adhesion proteins such as the signaling node nephrin, calcium influx via transient receptor potential channel 6 (TRPC6), and regulation of the Rho family, eventually leading to the disorganization of the original cytoskeletal architecture. Thus, it is imperative to focus on these proteins and signaling pathways to probe the cytoskeleton rearrangement in podocytopathies. In this review, we describe podocytopathies and the podocyte cytoskeleton, then discuss the molecular mechanisms involved in cytoskeleton rearrangement in podocytopathies and summarize the effects of currently existing drugs on regulating the podocyte cytoskeleton.
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Affiliation(s)
| | | | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China; (S.M.); (Y.Q.)
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12
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Qiu Y, Lei C, Zeng J, Xie Y, Cao Y, Yuan Q, Su H, Zhang Z, Zhang C. Asparagine endopeptidase protects podocytes in adriamycin-induced nephropathy by regulating actin dynamics through cleaving transgelin. Mol Ther 2023; 31:3337-3354. [PMID: 37689970 PMCID: PMC10638058 DOI: 10.1016/j.ymthe.2023.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 08/04/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is the most common glomerular disorder causing end-stage renal diseases worldwide. Central to the pathogenesis of FSGS is podocyte dysfunction, which is induced by diverse insults. However, the mechanism governing podocyte injury and repair remains largely unexplored. Asparagine endopeptidase (AEP), a lysosomal protease, regulates substrates by residue-specific cleavage or degradation. We identified the increased AEP expression in the primary proteinuria model which was induced by adriamycin (ADR) to mimic human FSGS. In vivo, global AEP knockout mice manifested increased injury-susceptibility of podocytes in ADR-induced nephropathy (ADRN). Podocyte-specific AEP knockout mice exhibited much more severe glomerular lesions and podocyte injury after ADR injection. In contrast, podocyte-specific augmentation of AEP in mice protected against ADRN. In vitro, knockdown and overexpression of AEP in human podocytes revealed the cytoprotection of AEP as a cytoskeleton regulator. Furthermore, transgelin, an actin-binding protein regulating actin dynamics, was cleaved by AEP, and, as a result, removed its actin-binding regulatory domain. The truncated transgelin regulated podocyte actin dynamics and repressed podocyte hypermotility, compared to the native full-length transgelin. Together, our data reveal a link between lysosomal protease AEP and podocyte cytoskeletal homeostasis, which suggests a potential therapeutic role for AEP in proteinuria disease.
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Affiliation(s)
- Yang Qiu
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Chuntao Lei
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Jieyu Zeng
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Yaru Xie
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Yiling Cao
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Qian Yuan
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Hua Su
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China
| | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China.
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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.
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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
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14
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Tian F, Huang S, Xu W, Xie G, Gan Y, Huang F, Fan Y, Bao J. Fasudil compensates podocyte injury via CaMK4/Rho GTPases signal and actin cytoskeleton-dependent activation of YAP in MRL/lpr mice. Int Immunopharmacol 2023; 119:110199. [PMID: 37094544 DOI: 10.1016/j.intimp.2023.110199] [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: 01/20/2023] [Revised: 03/15/2023] [Accepted: 04/11/2023] [Indexed: 04/26/2023]
Abstract
Deposition of immune complexes in the glomerulus leads to irreversible renal damage in lupus nephritis (LN), of which podocyte malfunction arises earlier. Fasudil, the only Rho GTPases inhibitor approved in clinical settings, possesses well-established renoprotective actions; yet, no studies addressed the amelioration derived from fasudil in LN. To clarify, we investigated whether fasudil exerted renal remission in lupus-prone mice. In this study, fasudil (20 mg/kg) was intraperitoneally administered to female MRL/lpr mice for 10 weeks. We report that fasudil administration swept antibodies (anti-dsDNA) and attenuated systemic inflammatory response in MRL/lpr mice, accompanied by preserving podocyte ultrastructure and averting immune complex deposition. Mechanistically, it repressed the expression of CaMK4 in glomerulopathy by preserving nephrin and synaptopodin expression. And fasudil further blocked cytoskeletal breakage in the Rho GTPases-dependent action. Further analyses showed that beneficial actions of fasudil on the podocytes required intra-nuclear YAP activation underlying actin dynamics. In addition, in vitro assays revealed that fasudil normalized the motile imbalance by suppressing intracellular calcium enrichment, thereby contributing to the resistance of apoptosis in podocytes. Altogether, our findings suggest that the precise manners of crosstalks between cytoskeletal assembly and YAP activation underlying the upstream CaMK4/Rho GTPases signal in podocytes is a reliable target for podocytopathies treatment, and fasudil might serve as a promising therapeutic agent to compensate for the podocyte injury in LN.
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Affiliation(s)
- Fengyuan Tian
- General Practice, The First Affiliated Hospital of Zhejiang Chinese Medicine University, Hangzhou, PR China
| | - Shuo Huang
- First School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Wangda Xu
- First School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Guanqun Xie
- Key Laboratory of Chinese Medicine Rheumatology of Zhejiang Province, School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Yihong Gan
- First School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Fugang Huang
- First School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Yongsheng Fan
- Key Laboratory of Chinese Medicine Rheumatology of Zhejiang Province, School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, PR China.
| | - Jie Bao
- Key Laboratory of Chinese Medicine Rheumatology of Zhejiang Province, School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, PR China.
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15
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Ru Q, Wang Y, Zhou E, Chen L, Wu Y. The potential therapeutic roles of Rho GTPases in substance dependence. Front Mol Neurosci 2023; 16:1125277. [PMID: 37063367 PMCID: PMC10097952 DOI: 10.3389/fnmol.2023.1125277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/14/2023] [Indexed: 04/03/2023] Open
Abstract
Rho GTPases family are considered to be molecular switches that regulate various cellular processes, including cytoskeleton remodeling, cell polarity, synaptic development and maintenance. Accumulating evidence shows that Rho GTPases are involved in neuronal development and brain diseases, including substance dependence. However, the functions of Rho GTPases in substance dependence are divergent and cerebral nuclei-dependent. Thereby, comprehensive integration of their roles and correlated mechanisms are urgently needed. In this review, the molecular functions and regulatory mechanisms of Rho GTPases and their regulators such as GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs) in substance dependence have been reviewed, and this is of great significance for understanding their spatiotemporal roles in addictions induced by different addictive substances and in different stages of substance dependence.
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Affiliation(s)
| | | | | | - Lin Chen
- *Correspondence: Lin Chen, ; Yuxiang Wu,
| | - Yuxiang Wu
- *Correspondence: Lin Chen, ; Yuxiang Wu,
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16
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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.
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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
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17
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Preston R, Meng QJ, Lennon R. The dynamic kidney matrisome - is the circadian clock in control? Matrix Biol 2022; 114:138-155. [PMID: 35569693 DOI: 10.1016/j.matbio.2022.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/21/2022] [Accepted: 05/10/2022] [Indexed: 02/06/2023]
Abstract
The circadian clock network in mammals is responsible for the temporal coordination of numerous physiological processes that are necessary for homeostasis. Peripheral tissues demonstrate circadian rhythmicity and dysfunction of core clock components has been implicated in the pathogenesis of diseases that are characterized by abnormal extracellular matrix, such as fibrosis (too much disorganized matrix) and tissue breakdown (too little matrix). Kidney disease is characterized by proteinuria, which along with the rate of filtration, displays robust circadian oscillation. Clinical observation and mouse studies suggest the presence of 24 h kidney clocks responsible for circadian oscillation in kidney function. Recent experimental evidence has also revealed that cell-matrix interactions and the biomechanical properties of extracellular matrix have key roles in regulating peripheral circadian clocks and this mechanism appears to be cell- and tissue-type specific. Thus, establishing a temporally resolved kidney matrisome may provide a useful tool for studying the two-way interactions between the extracellular matrix and the intracellular time-keeping mechanisms in this critical niche tissue. This review summarizes the latest genetic and biochemical evidence linking kidney physiology and disease to the circadian system with a particular focus on the extracellular matrix. We also review the experimental approaches and methodologies required to dissect the roles of circadian pathways in specific tissues and outline the translational aspects of circadian biology, including how circadian medicine could be used for the treatment of kidney disease.
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Affiliation(s)
- Rebecca Preston
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK
| | - Qing-Jun Meng
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK.
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, UK; Department of Pediatric Nephrology, Royal Manchester Children's Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK.
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18
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Xu J, Liu Y, Li H, Tarashansky AJ, Kalicki CH, Hung RJ, Hu Y, Comjean A, Kolluru SS, Wang B, Quake SR, Luo L, McMahon AP, Dow JAT, Perrimon N. Transcriptional and functional motifs defining renal function revealed by single-nucleus RNA sequencing. Proc Natl Acad Sci U S A 2022; 119:e2203179119. [PMID: 35696569 PMCID: PMC9231607 DOI: 10.1073/pnas.2203179119] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/11/2022] [Indexed: 01/09/2023] Open
Abstract
Recent advances in single-cell sequencing provide a unique opportunity to gain novel insights into the diversity, lineage, and functions of cell types constituting a tissue/organ. Here, we performed a single-nucleus study of the adult Drosophila renal system, consisting of Malpighian tubules and nephrocytes, which shares similarities with the mammalian kidney. We identified 11 distinct clusters representing renal stem cells, stellate cells, regionally specific principal cells, garland nephrocyte cells, and pericardial nephrocytes. Characterization of the transcription factors specific to each cluster identified fruitless (fru) as playing a role in stem cell regeneration and Hepatocyte nuclear factor 4 (Hnf4) in regulating glycogen and triglyceride metabolism. In addition, we identified a number of genes, including Rho guanine nucleotide exchange factor at 64C (RhoGEF64c), Frequenin 2 (Frq2), Prip, and CG1093 that are involved in regulating the unusual star shape of stellate cells. Importantly, the single-nucleus dataset allows visualization of the expression at the organ level of genes involved in ion transport and junctional permeability, providing a systems-level view of the organization and physiological roles of the tubules. Finally, a cross-species analysis allowed us to match the fly kidney cell types to mouse kidney cell types and planarian protonephridia, knowledge that will help the generation of kidney disease models. Altogether, our study provides a comprehensive resource for studying the fly kidney.
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Affiliation(s)
- Jun Xu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Yifang Liu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Hongjie Li
- Department of Biology, Stanford University, Stanford, CA 94305
- HHMI, Stanford University, Stanford, CA 94305
| | - Alexander J. Tarashansky
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Colin H. Kalicki
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Ruei-Jiun Hung
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Yanhui Hu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Aram Comjean
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
| | - Sai Saroja Kolluru
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Stephen R. Quake
- Department of Bioengineering, Stanford University, Stanford, CA 94305
- Chan Zuckerberg Biohub, San Francisco, CA 94158
| | - Liqun Luo
- Department of Biology, Stanford University, Stanford, CA 94305
- HHMI, Stanford University, Stanford, CA 94305
| | - Andrew P. McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine of the University of Southern California, Los Angeles, CA 90089
| | - Julian A. T. Dow
- Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Harvard University, Boston, MA 02115
- HHMI, Harvard University, Boston, MA 02115
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19
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Ye Q, Lan B, Liu H, Persson PB, Lai EY, Mao J. A critical role of the podocyte cytoskeleton in the pathogenesis of glomerular proteinuria and autoimmune podocytopathies. Acta Physiol (Oxf) 2022; 235:e13850. [PMID: 35716094 DOI: 10.1111/apha.13850] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/23/2022] [Accepted: 06/13/2022] [Indexed: 01/19/2023]
Abstract
Selective glomerular filtration relies on the membrane separating the glomerular arterioles from the Bowman space. As a major component of the glomerular filtration barrier, podocytes form foot processes by the actin cytoskeleton, which dynamically adjusts in response to environmental changes to maintain filtration barrier integrity. The slit diaphragms bridge the filtration slits between neighboring foot processes and act as signaling hubs interacting with the actin cytoskeleton. Focal adhesions relay signals to regulate actin dynamics while allowing podocyte adherence to the basement membrane. Mutations in actin regulatory and signaling proteins may disrupt the actin cytoskeleton, resulting in foot process retraction, effacement, and proteinuria. Large-scale gene expression profiling platforms, transgenic animal models, and other in vivo gene delivery methods now enhance our understanding of the interactions among podocyte focal adhesions, slit diaphragms, and actin dynamics. In addition, our team found that at least 66% of idiopathic nephrotic syndrome (INS) children have podocyte autoantibodies, which was defined as a new disease subgroup-, autoimmune podocytopathies. This review outlines the pathophysiological mechanisms of podocyte cytoskeleton protein interactions in proteinuria and glomerular podocytopathy.
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Affiliation(s)
- Qing Ye
- Department of Clinical Laboratory, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, China
| | - Bing Lan
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, China
| | - Huihui Liu
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, China
| | - Pontus B Persson
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Translational Physiology, Berlin, Germany
| | - En Yin Lai
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Translational Physiology, Berlin, Germany.,Department of Physiology, School of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianhua Mao
- Department of Nephrology, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou, China
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20
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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: 47] [Impact Index Per Article: 23.5] [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.
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21
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NUP133 Controls Nuclear Pore Assembly, Transcriptome Composition, and Cytoskeleton Regulation in Podocytes. Cells 2022; 11:cells11081259. [PMID: 35455939 PMCID: PMC9025798 DOI: 10.3390/cells11081259] [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: 02/11/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 02/04/2023] Open
Abstract
Steroid-resistant nephrotic syndrome (SRNS) frequently leads to end-stage renal disease, ultimately requiring kidney replacement therapies. SRNS is often caused by hereditary monogenic mutations, specifically affecting specialized epithelial cells (podocytes) of the glomerular filtration barrier. Mutations in several components of the nuclear pore complex, including NUP133 and NUP107, have been recently identified to cause hereditary SRNS. However, underlying pathomechanisms, eliciting podocyte-specific manifestations of these nucleoporopathies, remained largely elusive. Here, we generated an in vitro model of NUP133-linked nucleoporopathies using CRISPR/Cas9-mediated genome editing in human podocytes. Transcriptome, nuclear pore assembly, and cytoskeleton regulation of NUP133 loss-of-function, mutant, and wild-type podocytes were analyzed. Loss of NUP133 translated into a disruption of the nuclear pore, alterations of the podocyte-specific transcriptome, and impaired cellular protrusion generation. Surprisingly, comparative analysis of the described SRNS-related NUP133 mutations revealed only mild defects. Am impaired protein interaction in the Y-complex and decrease of NUP133 protein levels might be the primary and unifying consequence of mutant variants, leading to a partial loss-of-function phenotype and disease manifestation in susceptible cell types, such as podocytes.
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22
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Rogg M, Maier JI, Van Wymersch C, Helmstädter M, Sammarco A, Lindenmeyer M, Zareba P, Montanez E, Walz G, Werner M, Endlich N, Benzing T, Huber TB, Schell C. α-Parvin Defines a Specific Integrin Adhesome to Maintain the Glomerular Filtration Barrier. J Am Soc Nephrol 2022; 33:786-808. [PMID: 35260418 PMCID: PMC8970443 DOI: 10.1681/asn.2021101319] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/17/2022] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The cell-matrix adhesion between podocytes and the glomerular basement membrane is essential for the integrity of the kidney's filtration barrier. Despite increasing knowledge about the complexity of integrin adhesion complexes, an understanding of the regulation of these protein complexes in glomerular disease remains elusive. METHODS We mapped the in vivo composition of the podocyte integrin adhesome. In addition, we analyzed conditional knockout mice targeting a gene (Parva) that encodes an actin-binding protein (α-parvin), and murine disease models. To evaluate podocytes in vivo, we used super-resolution microscopy, electron microscopy, multiplex immunofluorescence microscopy, and RNA sequencing. We performed functional analysis of CRISPR/Cas9-generated PARVA single knockout podocytes and PARVA and PARVB double knockout podocytes in three- and two-dimensional cultures using specific extracellular matrix ligands and micropatterns. RESULTS We found that PARVA is essential to prevent podocyte foot process effacement, detachment from the glomerular basement membrane, and the development of FSGS. Through the use of in vitro and in vivo models, we identified an inherent PARVB-dependent compensatory module at podocyte integrin adhesion complexes, sustaining efficient mechanical linkage at the filtration barrier. Sequential genetic deletion of PARVA and PARVB induces a switch in structure and composition of integrin adhesion complexes. This redistribution of these complexes translates into a loss of the ventral actin cytoskeleton, decreased adhesion capacity, impaired mechanical resistance, and dysfunctional extracellular matrix assembly. CONCLUSIONS The findings reveal adaptive mechanisms of podocyte integrin adhesion complexes, providing a conceptual framework for therapeutic strategies to prevent podocyte detachment in glomerular disease.
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Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, 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
| | - Clara Van Wymersch
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- 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
| | - Maja Lindenmeyer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paulina Zareba
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Eloi Montanez
- Department of Physiological Sciences, Faculty of Medicine, University of Barcelona and Health Sciences and Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - 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
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - 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 .,Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany
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23
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Wang F, Fan J, Pei T, He Z, Zhang J, Ju L, Han Z, Wang M, Xiao W. Effects of Shenkang Pills on Early-Stage Diabetic Nephropathy in db/db Mice via Inhibiting AURKB/RacGAP1/RhoA Signaling Pathway. Front Pharmacol 2022; 13:781806. [PMID: 35222021 PMCID: PMC8873791 DOI: 10.3389/fphar.2022.781806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/17/2022] [Indexed: 12/22/2022] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of end-stage renal disease, so there is an urgent need to suppress its development at early stage. Shenkang pills (SKP) are a hospital prescription selected and optimized from effective traditional Chinese medicinal formulas for clinical treatment of DN. In the present study, liquid chromatography-quadrupole-time of flight-mass spectrometry (LC-Q-TOF-MS) and total contents qualification were applied to generate a quality control standard of SKP. For verifying the therapeutic effects of SKP, db/db mice were administered intragastrically with SKP at a human-equivalent dose (1.82 g/kg) for 4 weeks. Moreover, the underlying mechanism of SKP were analyzed by the renal RNA sequencing and network pharmacology. LC-Q-TOF-MS identified 46 compounds in SKP. The total polysaccharide and organic acid content in SKP were 4.60 and 0.11 mg/ml, respectively, while the total flavonoid, saponin, and protein content were 0.25, 0.31, and 0.42 mg/ml, respectively. Treatment of SKP significantly reduced fasting blood glucose, improved renal function, and ameliorated glomerulosclerosis and focal foot processes effacement in db/db mice. In addition, SKP protected podocytes from injury by increasing nephrin and podocin expression. Furthermore, transcriptome analyses revealed that 430 and 288 genes were up and down-regulated in mice treated with SKP, relative to untreated controls. Gene ontology enrichment analysis revealed that the differentially expressed genes mainly involved in modulation of cell division and chromosome segregation. Weighted gene co-expression network analysis and network pharmacology analysis indicated that aurora kinase B (AURKB), Rac GTPase activating protein 1 (RacGAP1) and SHC binding, and spindle associated 1 (shcbp1) might be the core targets of SKP. This protein and Ras homolog family member A (RhoA) were found overexpression in db/db mice, but significantly decreased with SKP treatment. We conclude that SKP can effectively treat early-stage DN and improve renal podocyte dysfunction. The mechanism may involve down-regulation of the AURKB/RacGAP1/RhoA pathway.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Wei Xiao
- *Correspondence: Mingqing Wang, ; Wei Xiao,
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24
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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.
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Affiliation(s)
- Clara Steichen
- Inserm UMR-1082 Irtomit, Poitiers, France,Faculté De Médecine Et De Pharmacie, Université De Poitiers, Poitiers, France
| | - Claude Hervé
- Inserm UMR-1082 Irtomit, Poitiers, France,CONTACT Claude HervéInserm UMR-1082 Irtomit, 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
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25
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Eroglu FK, Yazar V, Guler U, Yıldırım M, Yildirim T, Gungor T, Celikkaya E, Karakaya D, Turay N, Ciftci Dede E, Korkusuz P, Salih B, Bulbul M, Gursel I. Circulating extracellular vesicles of patients with steroid-sensitive nephrotic syndrome have higher RAC1 and induce recapitulation of nephrotic syndrome phenotype in podocytes. Am J Physiol Renal Physiol 2021; 321:F659-F673. [PMID: 34569252 DOI: 10.1152/ajprenal.00097.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Since previous research suggests a role of a circulating factor in the pathogenesis of steroid-sensitive nephrotic syndrome (NS), we speculated that circulating plasma extracellular vesicles (EVs) are a candidate source of such a soluble mediator. Here, we aimed to characterize and try to delineate the effects of these EVs in vitro. Plasma EVs from 20 children with steroid-sensitive NS in relapse and remission, 10 healthy controls, and 6 disease controls were obtained by serial ultracentrifugation. Characterization of these EVs was performed by electron microscopy, flow cytometry, and Western blot analysis. Major proteins from plasma EVs were identified via mass spectrometry. Gene Ontology classification analysis and Ingenuity Pathway Analysis were performed on selectively expressed EV proteins during relapse. Immortalized human podocyte culture was used to detect the effects of EVs on podocytes. The protein content and particle number of plasma EVs were significantly increased during NS relapse. Relapse NS EVs selectively expressed proteins that involved actin cytoskeleton rearrangement. Among these, the level of RAC-GTP was significantly increased in relapse EVs compared with remission and disease control EVs. Relapse EVs were efficiently internalized by podocytes and induced significantly enhanced motility and albumin permeability. Moreover, relapse EVs induced significantly higher levels of RAC-GTP and phospho-p38 and decreased the levels of synaptopodin in podocytes. Circulating relapse EVs are biologically active molecules that carry active RAC1 as cargo and induce recapitulation of the NS phenotype in podocytes in vitro.NEW & NOTEWORTHY Up to now, the role of extracellular vesicles (EVs) in the pathogenesis of steroid-sensitive nephrotic syndrome (NS) has not been studied. Here, we found that relapse NS EVs contain significantly increased active RAC1, induce enhanced podocyte motility, and increase expression of RAC-GTP and phospho-p38 expression in vitro. These results suggest that plasma EVs are biologically active molecules in the pathogenesis of NS.
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Affiliation(s)
- Fehime K Eroglu
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey.,SBU Dr Sami Ulus Maternity Child Health and Diseases Training and Research Hospital, Ankara, Turkey
| | - Volkan Yazar
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey
| | - Ulku Guler
- Department of Chemistry, Hacettepe University, Ankara, Turkey
| | - Muzaffer Yıldırım
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey
| | - Tugce Yildirim
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey
| | - Tulin Gungor
- SBU Dr Sami Ulus Maternity Child Health and Diseases Training and Research Hospital, Ankara, Turkey
| | - Evra Celikkaya
- SBU Dr Sami Ulus Maternity Child Health and Diseases Training and Research Hospital, Ankara, Turkey
| | - Deniz Karakaya
- SBU Dr Sami Ulus Maternity Child Health and Diseases Training and Research Hospital, Ankara, Turkey
| | - Nilsu Turay
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey
| | - Eda Ciftci Dede
- Department of Histology and Embryology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Petek Korkusuz
- Department of Histology and Embryology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Bekir Salih
- Department of Chemistry, Hacettepe University, Ankara, Turkey
| | - Mehmet Bulbul
- SBU Dr Sami Ulus Maternity Child Health and Diseases Training and Research Hospital, Ankara, Turkey
| | - Ihsan Gursel
- Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey
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26
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Schlöndorff JS. My, oh, MYO9A! Just how complex can regulation of the podocyte actin cytoskeleton get? Kidney Int 2021; 99:1065-1067. [PMID: 33892856 DOI: 10.1016/j.kint.2021.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/13/2021] [Indexed: 01/15/2023]
Abstract
Genetics contributes significantly to the development of kidney diseases. In the case of glomerular diseases such as focal segmental glomerulosclerosis, over a dozen genes involved in maintaining and regulating the actin cytoskeleton of podocytes have been implicated. A new study adds the atypical myosin, MYO9A, to that list using a combination of human and mouse genetics, suggesting a link to enhanced RhoA activity. Unraveling the growing web of actin regulators remains a key challenge to understanding podocytopathies.
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Affiliation(s)
- Johannes S Schlöndorff
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
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27
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Miranda MZ, Lichner Z, Szászi K, Kapus A. MRTF: Basic Biology and Role in Kidney Disease. Int J Mol Sci 2021; 22:ijms22116040. [PMID: 34204945 PMCID: PMC8199744 DOI: 10.3390/ijms22116040] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/21/2021] [Accepted: 05/30/2021] [Indexed: 12/23/2022] Open
Abstract
A lesser known but crucially important downstream effect of Rho family GTPases is the regulation of gene expression. This major role is mediated via the cytoskeleton, the organization of which dictates the nucleocytoplasmic shuttling of a set of transcription factors. Central among these is myocardin-related transcription factor (MRTF), which upon actin polymerization translocates to the nucleus and binds to its cognate partner, serum response factor (SRF). The MRTF/SRF complex then drives a large cohort of genes involved in cytoskeleton remodeling, contractility, extracellular matrix organization and many other processes. Accordingly, MRTF, activated by a variety of mechanical and chemical stimuli, affects a plethora of functions with physiological and pathological relevance. These include cell motility, development, metabolism and thus metastasis formation, inflammatory responses and—predominantly-organ fibrosis. The aim of this review is twofold: to provide an up-to-date summary about the basic biology and regulation of this versatile transcriptional coactivator; and to highlight its principal involvement in the pathobiology of kidney disease. Acting through both direct transcriptional and epigenetic mechanisms, MRTF plays a key (yet not fully appreciated) role in the induction of a profibrotic epithelial phenotype (PEP) as well as in fibroblast-myofibroblast transition, prime pathomechanisms in chronic kidney disease and renal fibrosis.
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Affiliation(s)
- Maria Zena Miranda
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
| | - Zsuzsanna Lichner
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
| | - Katalin Szászi
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
- Department of Surgery, University of Toronto, Toronto, ON M5T 1P5, Canada
| | - András Kapus
- Keenan Research Centre for Biomedical Science of the St. Michael’s Hospital, Toronto, ON M5B 1W8, Canada; (M.Z.M.); (Z.L.); (K.S.)
- Department of Surgery, University of Toronto, Toronto, ON M5T 1P5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
- Correspondence:
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28
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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.
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