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Yang X, Zheng F, Zhang S, Lu J. Loss of RhoA expression prevents proliferation and metastasis of SPCA1 lung cancer cells in vitro. Biomed Pharmacother 2014; 69:361-6. [PMID: 25661383 DOI: 10.1016/j.biopha.2014.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 12/01/2014] [Indexed: 01/13/2023] Open
Abstract
Lung cancer is the leading cause of cancer-related death worldwide, mainly due to its highly metastatic properties. Previously, we reported an inverse correlation between Rho-kinase inhibitor and the progression of the lung cancer cells. The purpose of this study was to investigate the effects of RhoA on the proliferation, adhesion, invasion, and migration of SPCA1 lung carcinoma cells and to explore the underlying molecular mechanisms. RNA interference was used to downregulate RhoA expression in these cells. Through G418 screening, we generated SPCA1 lung cancer cell lines with stable RhoA silencing. We then observed the cell behaviour, and used matrix metalloproteinase (MMP) activity and western blot assays to evaluate the underlying molecular mechanisms. The proliferation, adhesion, migration, and invasion of SPCA1 lung cancer cells were decreased after knockdown of RhoA. At the molecular level, the total amounts of active MMP2 and MMP9 were decreased by about 17.21% (P<0.05) and 45.32% (P<0.01), respectively. Myosin phosphatase targeting subunit 1 phosphorylation (P-MYPT1) was reduced by 36.16% (P<0.05). Taken together, our findings show that the knockdown of RhoA prevents proliferation and metastasis in SPCA1 lung cancer cells. Changes in MMP2, MMP9, and P-MYPT1 levels and activity might be some of the molecular mechanisms underlying these effects.
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Affiliation(s)
- Xueying Yang
- Department of Thoracic Surgery, Shengjing Hospital, China Medical University, Shenyang, Liaoning, China
| | - Fushuang Zheng
- Department of Thoracic Surgery, Shengjing Hospital, China Medical University, Shenyang, Liaoning, China
| | - Suning Zhang
- Department of Thoracic Surgery, Shengjing Hospital, China Medical University, Shenyang, Liaoning, China
| | - Jibin Lu
- Department of Thoracic Surgery, Shengjing Hospital, China Medical University, Shenyang, Liaoning, China.
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2
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Wu SZ, Peng FF, Li JL, Ye F, Lei SQ, Zhang BF. Akt and RhoA activation in response to high glucose require caveolin-1 phosphorylation in mesangial cells. Am J Physiol Renal Physiol 2014; 306:F1308-17. [PMID: 24694591 DOI: 10.1152/ajprenal.00447.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glomerular matrix accumulation is a hallmark of diabetic renal disease. Serine/threonine kinase PKC-β1 mediates glucose-induced Akt S473 phosphorylation, RhoA activation, and transforming growth factor (TGF)-β1 upregulation and finally leads to matrix upregulation in mesangial cells (MCs). It has been reported that glucose-induced PKC-β1 activation is dependent on caveolin-1 and the presence of intact caveolae in MCs; however, whether activated PKC-β1 regulates caveolin-1 expression and phosphorylation are unknown. Here, we showed that, although the caveolin-1 protein level had no significant change, the PKC-β-specific inhibitor LY-333531 blocked caveolin-1 Y14 phosphorylation in high glucose (HG)-treated MCs and in the renal cortex of diabetic rats. The Src-specific inhibitor SU-6656 prevented the HG-induced association between PKC-β1 and caveolin-1 and PKC-β1 membrane translocation, whereas PKC-β1 small interfering RNA failed to block Src activation, indicating that Src kinase is upstream of PKC-β1 activation. Although LY-333531 blocked PKC-β1 membrane translocation, it had no effect on the PKC-β1/caveolin-1 association, suggesting that PKC-β1 activation requires the interaction of caveolin-1 and PKC-β1. PKC-β1-mediated Akt S473 phosphorylation, RhoA activation, and fibronectin upregulation in response to HG were prevented by SU-6656 and nonphosphorylatable mutant caveolin-1 Y14A. In conclusion, Src activation by HG mediates the PKC-β1/caveolin-1 association and PKC-β1 activation, which assists in caveolin-1 Y14 phosphorylation by Src kinase. The downstream effects, including Akt S473 phosphorylation, RhoA activation, and fibronectin upregulation, require caveolin-1 Y14 phosphorylation. Caveolin-1 is thus an important mediator of the profibrogenic process in diabetic renal disease.
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Affiliation(s)
- Su-Zhen Wu
- Department of Biochemistry, Wuhan University School of Basic Medical Sciences, Wuhan, People's Republic of China; and
| | - Fang-Fang Peng
- Department of Biochemistry, Wuhan University School of Basic Medical Sciences, Wuhan, People's Republic of China; and
| | - Jia-Lin Li
- Gannan Medical University, Ganzhou, People's Republic of China; and
| | - Feng Ye
- Department of Biochemistry, Wuhan University School of Basic Medical Sciences, Wuhan, People's Republic of China; and
| | - Shao-Qing Lei
- Department of Biochemistry, Wuhan University School of Basic Medical Sciences, Wuhan, People's Republic of China; and
| | - Bai-Fang Zhang
- Department of Biochemistry, Wuhan University School of Basic Medical Sciences, Wuhan, People's Republic of China; and Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, People's Republic of China
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Sun GD, Cui WP, Guo QY, Miao LN. Histone lysine methylation in diabetic nephropathy. J Diabetes Res 2014; 2014:654148. [PMID: 25215303 PMCID: PMC4158558 DOI: 10.1155/2014/654148] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/14/2014] [Indexed: 01/21/2023] Open
Abstract
Diabetic nephropathy (DN) belongs to debilitating microvascular complications of diabetes and is the leading cause of end-stage renal diseases worldwide. Furthermore, outcomes from the DCCT/EDIC study showed that DN often persists and progresses despite intensive glucose control in many diabetes patients, possibly as a result of prior episode of hyperglycemia, which is called "metabolic memory." The underlying mechanisms responsible for the development and progression of DN remain poorly understood. Activation of multiple signaling pathways and key transcription factors can lead to aberrant expression of DN-related pathologic genes in target renal cells. Increasing evidence suggests that epigenetic mechanisms in chromatin such as DNA methylation, histone acetylation, and methylation can influence the pathophysiology of DN and metabolic memory. Exciting researches from cell culture and experimental animals have shown that key histone methylation patterns and the related histone methyltransferases and histone demethylases can play important roles in the regulation of inflammatory and profibrotic genes in renal cells under diabetic conditions. Because histone methylation is dynamic and potentially reversible, it can provide a window of opportunity for the development of much-needed novel therapeutic potential for DN in the future. In this minireview, we discuss recent advances in the field of histone methylation and its roles in the pathogenesis and progression of DN.
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Affiliation(s)
- Guang-dong Sun
- Department of Nephrology, Second Hospital of Jilin University, Changchun 130041, China
- *Guang-dong Sun: and
| | - Wen-peng Cui
- Department of Nephrology, Second Hospital of Jilin University, Changchun 130041, China
| | - Qiao-yan Guo
- Department of Nephrology, Second Hospital of Jilin University, Changchun 130041, China
| | - Li-ning Miao
- Department of Nephrology, Second Hospital of Jilin University, Changchun 130041, China
- *Li-ning Miao:
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Targeting of Rho kinase ameliorates impairment of diabetic endothelial function in intrarenal artery. Int J Mol Sci 2013; 14:20282-98. [PMID: 24129169 PMCID: PMC3821615 DOI: 10.3390/ijms141020282] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 07/11/2013] [Accepted: 09/09/2013] [Indexed: 02/04/2023] Open
Abstract
Endothelial dysfunction in kidney vasculature is the initial and key element for nephropathy in diabetes mellitus. Accumulating evidence suggests the protective role of Rho kinase inhibitors in endothelial dysfunction via modulating eNOS activity and NO production. However, the role of Rho kinase in diabetes-related endothelial dysfunction in kidney vasculature and the relevant mechanisms remain unknown. We assessed whether pharmacological inhibition of Rho kinase attenuates endothelial dysfunction in intrarenal arteries from type 1 diabetic rats. Fasudil, a Rho kinase inhibitor effectively decreased the phosphorylated level of MYPT1 without affecting the expression of ROCKs in the kidney. Fasudil treatment showed no improvement in diabetes-related abnormality in metabolic indices, but it significantly ameliorated endothelial dysfunction in intrarenal arteries and lessened the mesangial matrix expansion in the kidney cortex. Mechanistically, superoxide production in the intrarenal artery and NOX4 member of NADPH oxidase in the renal cortex that contribute to diabetic nephropathy were also prevented by the Rho kinase inhibitor. In conclusion, the present results indicate that Rho kinase is involved in endothelial dysfunction in type 1 diabetes via enhancement of oxidative stress and provides new evidence for Rho kinase inhibitors as potential therapeutic agents for the treatment of diabetic nephropathy.
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Impellizzeri D, Mazzon E, Paterniti I, Esposito E, Cuzzocrea S. Effect of fasudil, a selective inhibitor of Rho kinase activity, in the secondary injury associated with the experimental model of spinal cord trauma. J Pharmacol Exp Ther 2012; 343:21-33. [PMID: 22733360 DOI: 10.1124/jpet.111.191239] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Rho kinase (ROK) may play an important role in regulating the biological events of cells, including proliferation, differentiation, and survival/death. Blockade of ROK promotes axonal regeneration and neuron survival in vivo and in vitro, thereby exhibiting potential clinical applications in spinal cord damage and stroke. The aim of this experimental study was to determine the role of ROK signaling pathways in the inflammatory response, in particular in the secondary injury associated with the experimental model of spinal cord trauma. The injury was induced by application of vascular clips to the dura via a four-level T5 to T8 laminectomy in mice. Fasudil was administered in mice (10 mg/kg i.p.) 1 and 6 h after the trauma. The treatment with fasudil significantly decreased 1) histological damage; 2) motor recovery; 3) nuclear factor-κB (NF-κB) expression; 4) ROK activity; 5) inflammasome activation (caspase-1 and NOD-like receptor family, pyrin domain-containing 3 expression); 6) production of proinflammatory cytokine such as tumor necrosis factor and interleukin-1β (IL-1β); 7) neutrophil infiltration; 8) nitrotyrosine and poly-ADP-ribose formation; 9) glial fibrillary acidic protein expression; 10) apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, FAS ligand expression, and Bax and Bcl-2 expression); and 11) mitogen-activated protein kinase activation (phospho-extracellular signal-regulated kinase and phospho-c-Jun NH(2)-terminal kinase expression). Our results indicate that inhibition of ROK by fasudil may represent a useful therapeutic perspective in the treatment of inflammation associated with spinal cord trauma.
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Affiliation(s)
- Daniela Impellizzeri
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, Italy
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Abstract
Small GTPases function as molecular switches in cell signaling, alternating between an inactive, GDP-bound state, and active GTP-bound state. βPix is one of guanine nucleotide exchange factors (GEFs) that catalyze the exchange of bound GDP for ambient GTP. The central goal of this review article is to summarize recent findings on βPix and the role it plays in kidney pathology and physiology. Recent studies shed new light on several key questions concerning the signaling mechanisms mediated by βPix. This manuscript provides a review of the various mechanisms whereby βPix has been shown to function within the kidney through a wide range of actions. Both canonical GEF activity and non-canonical signaling pathways mediated by βPix are discussed. Distribution patterns of βPix in the kidney will be also covered. Much has yet to be discerned, but it is clear that βPix plays a significant role in the kidney.
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7
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The Rho-kinase inhibitor inhibits proliferation and metastasis of small cell lung cancer. Biomed Pharmacother 2012; 66:221-7. [DOI: 10.1016/j.biopha.2011.11.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 11/07/2011] [Indexed: 12/31/2022] Open
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Tokuyama H, Wakino S, Hara Y, Washida N, Fujimura K, Hosoya K, Yoshioka K, Hasegawa K, Minakuchi H, Homma K, Hayashi K, Itoh H. Role of mineralocorticoid receptor/Rho/Rho-kinase pathway in obesity-related renal injury. Int J Obes (Lond) 2011; 36:1062-71. [PMID: 22184057 PMCID: PMC3419977 DOI: 10.1038/ijo.2011.232] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE: We examined whether aldosterone/Rho/Rho-kinase pathway contributed to obesity-associated nephropathy. SUBJECTS: C57BL/6J mice were fed a high fat or low fat diet, and mice on a high fat diet were treated with a mineralocorticoid receptor antagonist, eplerenone. RESULTS: The mice on a high fat diet not only developed obesity, but also manifested renal histological changes, including glomerular hypercellularity and increased mesangial matrix, which paralleled the increase in albuminuria. Furthermore, enhanced Rho-kinase activity was noted in kidneys from high fat diet-fed mice, as well as increased expressions of inflammatory chemokines. All of these changes were attenuated by eplerenone. In high fat diet-fed mice, mineralocorticoid receptor protein levels in the nuclear fraction and SGK1, an effector of aldosterone, were upregulated in kidneys, although serum aldosterone levels were unaltered. Furthermore, aldosterone and 3β-hydroxysteroid dehydrogenase in renal tissues were upregulated in high fat diet-fed mice. Finally, in cultured mesangial cells, stimulation with aldosterone enhanced Rho-kinase activity, and pre-incubation with eplerenone prevented the aldosterone-induced activation of Rho kinase. CONCLUSION: Excess fat intake causes obesity and renal injury in C57BL/6J mice, and these changes are mediated by an enhanced mineralocorticoid receptor/Rho/Rho-kinase pathway and inflammatory process. Mineralocorticoid receptor activation in the kidney tissue and the subsequent Rho-kinase stimulation are likely to participate in the development of obesity-associated nephropathy without elevation in serum aldosterone levels.
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Affiliation(s)
- H Tokuyama
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
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Kanwar YS, Sun L, Xie P, Liu FY, Chen S. A glimpse of various pathogenetic mechanisms of diabetic nephropathy. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2011; 6:395-423. [PMID: 21261520 DOI: 10.1146/annurev.pathol.4.110807.092150] [Citation(s) in RCA: 543] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Diabetic nephropathy is a well-known complication of diabetes and is a leading cause of chronic renal failure in the Western world. It is characterized by the accumulation of extracellular matrix in the glomerular and tubulointerstitial compartments and by the thickening and hyalinization of intrarenal vasculature. The various cellular events and signaling pathways activated during diabetic nephropathy may be similar in different cell types. Such cellular events include excessive channeling of glucose intermediaries into various metabolic pathways with generation of advanced glycation products, activation of protein kinase C, increased expression of transforming growth factor β and GTP-binding proteins, and generation of reactive oxygen species. In addition to these metabolic and biochemical derangements, changes in the intraglomerular hemodynamics, modulated in part by local activation of the renin-angiotensin system, compound the hyperglycemia-induced injury. Events involving various intersecting pathways occur in most cell types of the kidney.
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Affiliation(s)
- Yashpal S Kanwar
- Departments of Pathology, Northwestern University School of Medicine, Chicago, Illinois 60611, USA.
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10
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Park JW, Park CH, Kim IJ, Bae EH, Ma SK, Lee JU, Kim SW. Rho kinase inhibition by fasudil attenuates cyclosporine-induced kidney injury. J Pharmacol Exp Ther 2011; 338:271-9. [PMID: 21474569 DOI: 10.1124/jpet.111.179457] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It has been shown that the inhibition of the Rho/Rho kinase (ROCK) pathway prevents tubulointerstitial fibrosis and ameliorates renal function in various progressive renal disorders. The present study was to determine whether fasudil, a ROCK inhibitor, has a protective effect on cyclosporine A (CsA)-induced nephropathy. Male Sprague-Dawley rats were treated with CsA (n = 10, 20 mg · kg(-1) day(-1) s.c.), CsA + fasudil (n = 10, 3 mg · kg(-1) day(-1) i.p.), or vehicle alone (n = 10) for 28 days. Fasudil cotreatment ameliorated CsA-induced changes and restored renal function. CsA decreased the expression of endothelial nitric-oxide synthase and increased inducible nitric-oxide synthase/3-nitrotyrosine in the kidney. Accordingly, there was infiltration of inflammatory cells and up-regulation of inflammatory cytokines. Fasudil also significantly suppressed the expression of transforming growth factor-β1, Smad signaling, and subsequent epithelial-to-mesenchymal processes. In addition, fasudil augmented p27(kip1) expression and decreased the number of proliferating cell nuclear antigen-positive cells. In another series of experiments using HK-2 cells in culture, fasudil also suppressed CsA-induced increases in mitogen-activated protein kinase phosphorylation. CsA induced expression of p53, the degree of which was attenuated by fasudil in association with decreases of proapoptotic markers such as Bad, Bax, and total/cleaved caspase-3. These results suggest that inhibition of the Rho/ROCK pathway attenuates CsA-induced nephropathy through the suppression of the induction of inflammatory, apoptotic, and fibrogenic factors, along with inhibition of Smad, mitogen-activated protein kinases, and nitric oxide signaling pathways.
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Affiliation(s)
- Jeong Woo Park
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea
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11
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The RHO-1 RhoGTPase modulates fertility and multiple behaviors in adult C. elegans. PLoS One 2011; 6:e17265. [PMID: 21387015 PMCID: PMC3046162 DOI: 10.1371/journal.pone.0017265] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 01/28/2011] [Indexed: 11/21/2022] Open
Abstract
The Rho family of small GTPases are essential during early embryonic development making it difficult to study their functions in adult animals. Using inducible transgenes expressing either a constitutively active version of the single C. elegans Rho ortholog, RHO-1, or an inhibitor of endogenous Rho (C3 transferase), we demonstrate multiple defects caused by altering Rho signaling in adult C. elegans. Changes in RHO-1 signaling in cholinergic neurons affected locomotion, pharyngeal pumping and fecundity. Changes in RHO-1 signaling outside the cholinergic neurons resulted in defective defecation, ovulation, and changes in C. elegans body morphology. Finally both increased and decreased RHO-1 signaling in adults resulted in death within hours. The multiple post-developmental roles for Rho in C. elegans demonstrate that RhoA signaling pathways continue to be used post-developmentally and the resulting phenotypes provide an opportunity to further study post-developmental Rho signaling pathways using genetic screens.
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Yang X, Zhang Y, Wang S, Shi W. Effect of fasudil on growth, adhesion, invasion, and migration of 95D lung carcinoma cells in vitro. Can J Physiol Pharmacol 2011; 88:874-9. [PMID: 20921973 DOI: 10.1139/y10-047] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The objective of the study was to investigate the effects of a Rho-kinase inhibitor on 95D lung carcinoma cell growth, adhesion, invasion, and migration and to explore the underlying molecular mechanisms involved in this process. After treatment of 95D lung carcinoma cells with fasudil, an inhibitor of Rho-kinase, cell biological behaviors such as growth, adhesion, invasion, and migration were observed. Matrix metalloproteinase (MMP) activity and Western blot assay were used to evaluate underlying molecular mechanisms. The IC50 of fasudil to 95D lung carcinoma cells was approximately 0.79 mg/mL (95% confidence limits 0.58-1.11 mg/mL). After treatment with 0.75 mg/mL fasudil, the ability of 95D lung carcinoma cells for growth, adhesion, migration, and invasion was decreased significantly. Total active MMP2 was decreased approximately 22.7% (p < 0.05) and total MMP9 65.9% (p < 0.01). Myosin phosphatase target subunit 1 (MYPT1) was reduced by 29.4% (p < 0.05). We conclude that the Rho-kinase inhibitor prevents the growth, adhesion, invasion, and migration of 95D lung carcinoma cells by inhibiting the Rho/Rho-kinase pathway. Changes in MMP2, MMP9, and MYPT1 may be part of its molecular mechanisms.
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Affiliation(s)
- Xueying Yang
- Department of Thoracic Surgery, the Northern Hospital, Shenyang, Liaoning, China
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Henderson AJ, Hadden M, Guo C, Douglas N, Decornez H, Hellberg MR, Rusinko A, McLaughlin M, Sharif N, Drace C, Patil R. 2,3-Diaminopyrazines as rho kinase inhibitors. Bioorg Med Chem Lett 2010; 20:1137-40. [DOI: 10.1016/j.bmcl.2009.12.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 12/01/2009] [Accepted: 12/03/2009] [Indexed: 10/20/2022]
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Intact cytoskeleton is required for small G protein dependent activation of the epithelial Na+ channel. PLoS One 2010; 5:e8827. [PMID: 20098689 PMCID: PMC2809106 DOI: 10.1371/journal.pone.0008827] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 01/04/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The Epithelial Na(+) Channel (ENaC) plays a central role in control of epithelial surface hydration and vascular volume. Similar to other ion channels, ENaC activity is regulated, in part, by cortical cytoskeleton. Besides, the cytoskeleton is an established target for small G proteins signaling. Here we studied whether ENaC activity is modulated by changes in the state of the cytoskeleton and whether cytoskeletal elements are involved in small G protein mediated increase of ENaC activity. METHODS AND FINDINGS First, the functional importance of the cytoskeleton was established with whole-cell patch clamp experiments recording ENaC reconstituted in CHO cells. Pretreatment with Cytochalasin D (CytD; 10 microg/ml; 1-2 h) or colchicine (500 microM; 1-3 h) to disassembly F-actin and destroy microtubules, respectively, significantly decreased amiloride sensitive current. However, acute application of CytD induced rapid increase in macroscopic current. Single channel measurements under cell-attached conditions revealed similar observations. CytD rapidly increased ENaC activity in freshly isolated rat collecting duct, polarized epithelial mouse mpkCCD(c14) cells and HEK293 cells transiently transfected with ENaC subunits. In contrast, colchicine did not have an acute effect on ENaC activity. Small G proteins RhoA, Rac1 and Rab11a markedly increase ENaC activity. 1-2 h treatment with colchicine or CytD abolished effects of these GTPases. Interestingly, when cells were coexpressed with ENaC and RhoA, short-term treatment with CytD decreased ENaC activity. CONCLUSIONS We conclude that cytoskeleton is involved in regulation of ENaC and is necessary for small G protein mediated increase of ENaC activity.
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Yang X, Liu Y, Zong Z, Tian D. The Rho kinase inhibitor fasudil inhibits the migratory behaviour of 95-D lung carcinoma cells. Biomed Pharmacother 2010; 64:58-62. [DOI: 10.1016/j.biopha.2009.08.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Accepted: 08/24/2009] [Indexed: 01/21/2023] Open
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Deng B, Yang X, Zhu Z, Zhang C. A Rho-kinase inhibitor, fasudil, attenuates progressive glomerulosclerosis induced by daunorubicin in rats. ACTA ACUST UNITED AC 2009; 29:720-4. [DOI: 10.1007/s11596-009-0609-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2008] [Indexed: 11/29/2022]
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17
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Bielek H, Anselmo A, Dermardirossian C. Morphological and proliferative abnormalities in renal mesangial cells lacking RhoGDI. Cell Signal 2009; 21:1974-83. [PMID: 19765647 DOI: 10.1016/j.cellsig.2009.09.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Accepted: 09/09/2009] [Indexed: 11/28/2022]
Abstract
The regulation of Rho GTPase activities and expression is critical in the development and function of the kidney. Rho GTPase activities and cytosol-membrane cycling are regulated by Rho GDP Dissociation Inhibitor (RhoGDI), and RhoGDI knockout mice develop defects in kidney structure and function that lead to death due to renal failure. It is therefore important to understand the changes in RhoGDI-regulated Rho GTPase activities and cell morphology that lead to kidney failure in RhoGDI (-/-) mice. Here, we characterize a renal mesangial cell line derived from the RhoGDI (-/-) mouse in which we verify the absence of GDI proteins. In the absence of RhoGDI, we show an increase in the specific activity of Rac1, and to a lesser extent, RhoA and Cdc42 GTPases in these cells. This is accompanied by a compensatory decrease in the steady-state protein levels of Rho GTPases. Morphological analysis of RhoGDI (-/-) mesangial cells reveals a decrease in cell spreading and in focal contacts compared to wild-type cells. Finally, RhoGDI (-/-) mesangial cells show a decreased ability to proliferate and survive. These functional and structural changes are likely to contribute to the defects in renal architecture and function observed in the RhoGDI (-/-) mouse.
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Affiliation(s)
- Heike Bielek
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, United States
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Hutchison N, Hendry BM, Sharpe CC. Rho isoforms have distinct and specific functions in the process of epithelial to mesenchymal transition in renal proximal tubular cells. Cell Signal 2009; 21:1522-31. [PMID: 19477269 DOI: 10.1016/j.cellsig.2009.05.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 05/07/2009] [Accepted: 05/20/2009] [Indexed: 11/24/2022]
Abstract
Epithelial to mesenchymal transition (EMT) is involved in embryological development, cancerous metastatic spread and organ fibrosis, including the kidney. This process is largely driven by transforming growth factor-beta and recent evidence has implicated Rho as a key intracellular signalling molecule. In this study we have used RNA interference to silence the genetically distinct Rho (A, B and C) isoforms to define their individual functions in human kidney epithelial cells undergoing EMT. We demonstrate that the downregulation of the epithelial cell marker E-cadherin is dependent upon the Rho effector, Rho-kinase. However, silencing RhoA or RhoC expression also results in E-cadherin loss, though each by different mechanisms. Loss of RhoA leads to an upregulation of Snail1 and a reduction in the transcription of E-cadherin whereas loss of RhoC upregulates its breakdown via proteasomal degradation. During EMT, the upregulation of alpha-smooth muscle actin can be blocked by inhibiting the expression of RhoA, but not by that of RhoB or RhoC. This effect is independent of Rho-kinase activity. RhoC is the isoform solely responsible for stress fibre formation and inhibiting its expression reduces EMT-induced migration by 50%. RhoB appears to play a role in cell survival as inhibiting its expression leads to >300% increase in cell apoptosis and a relocalization of focal adhesion kinase. We conclude that Rho is a key signalling molecule in the process of EMT but that each isoform has a distinct and specific role.
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Affiliation(s)
- Nicol Hutchison
- King's College London, Department of Renal Medicine, London, UK
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Dolman M, Fretz M, Segers G, Lacombe M, Prakash J, Storm G, Hennink W, Kok R. Renal targeting of kinase inhibitors. Int J Pharm 2008; 364:249-57. [DOI: 10.1016/j.ijpharm.2008.04.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 04/25/2008] [Accepted: 04/28/2008] [Indexed: 01/19/2023]
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Peng F, Zhang B, Wu D, Ingram AJ, Gao B, Krepinsky JC. TGFbeta-induced RhoA activation and fibronectin production in mesangial cells require caveolae. Am J Physiol Renal Physiol 2008; 295:F153-64. [PMID: 18434385 DOI: 10.1152/ajprenal.00419.2007] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glomerular sclerosis of diverse etiologies is characterized by mesangial matrix accumulation, with transforming growth factor-beta (TGFbeta) an important pathogenic factor. The GTPase RhoA mediates TGFbeta-induced matrix accumulation in some settings. Here we study the role of the membrane microdomain caveolae in TGFbeta-induced RhoA activation and fibronectin upregulation in mesangial cells (MC). In primary rat MC, TGFbeta1 time dependently increased RhoA and downstream Rho kinase activation. Rho pathway inhibition blocked TGFbeta1-induced upregulation of fibronectin transcript and protein. TGFbeta1-induced RhoA activation was prevented by disrupting caveolae with cholesterol depletion and rescued by cholesterol repletion. Compared with wild types, RhoA/Rho kinase activation was absent in MC lacking caveolae. Reexpression of caveolin-1 (and caveolae) restored these responses. Phosphorylation of caveolin-1 on Y14, effected by Src kinases, has been implicated in signaling responses. Overexpression of nonphosphorylatable caveolin-1 Y14A prevented TGFbeta1-induced RhoA activation. TGFbeta1 also activated Src, and its inhibition blocked RhoA activation. Furthermore, TGFbeta1 led to association of RhoA and caveolin-1. This was prevented by Src or TGFbeta receptor I inhibition, and by caveolin-1 Y14A overexpression. Last, fibronectin upregulation by TGFbeta1 was blocked by Src inhibition, not seen in caveolin-1 knockout MC, and restored by caveolin-1 reexpression in the latter. TGFbeta1-induced collagen I accumulation also required caveolae. TGFbeta1-mediated Smad2/3 activation, however, did not require caveolae. We conclude that RhoA/Rho kinase mediates TGFbeta-induced fibronectin upregulation. This requires caveolae and caveolin-1 interaction with RhoA. Interference with caveolin/caveolae or RhoA signaling thus represents a potential target for the treatment of fibrotic renal disease.
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Affiliation(s)
- Fangfang Peng
- Division of Nephrology, McMaster University, Hamilton, Ontario, Canada
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Wang L, Ellis MJ, Fields TA, Howell DN, Spurney RF. Beneficial effects of the Rho kinase inhibitor Y27632 in murine puromycin aminonucleoside nephrosis. Kidney Blood Press Res 2008; 31:111-21. [PMID: 18367845 PMCID: PMC2821439 DOI: 10.1159/000121531] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 01/08/2008] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND AND AIMS Rho kinase (ROCK) inhibition reduces systemic blood pressure (BP) and decreases renal damage in animal models of kidney disease. The aim of this study was to determine if ROCK inhibition might have beneficial effects in glomerular disease processes that are independent of systemic BP. METHODS We investigated the effects of the ROCK inhibitor Y27632 and hydralazine in murine puromycin aminonucleoside (PAN) nephrosis. RESULTS Treatment with either Y27632 or hydralazine similarly reduced systolic BP compared to vehicle-treated controls. Seven days after treatment with PAN, albuminuria, proteinuria and effacement of podocyte foot processes were significantly reduced in Y27632- and hydralazine-treated mice compared to vehicle-treated animals. Treatment with PAN significantly reduced expression of the podocyte proteins nephrin and Neph1, and the loss of glomerular nephrin was attenuated by treatment with Y27632 but not by treatment with hydralazine. In cultured podocytes, PAN potently activated both Rho and ROCK, and PAN-induced ROCK activation was prevented by Y27632. CONCLUSIONS The ROCK inhibitor Y27632 attenuated glomerular nephrin loss in murine PAN nephrosis independent of its effects on systemic BP.
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Affiliation(s)
- Liming Wang
- Division of Nephrology, Department of Medicine, and Durham VA Medical Centers, Durham, N.C., USA
| | - Mathew J. Ellis
- Division of Nephrology, Department of Medicine, and Durham VA Medical Centers, Durham, N.C., USA
| | - Timothy A. Fields
- Department of Pathology, Duke University and Durham VA Medical Centers, Durham, N.C., USA
| | - David N. Howell
- Department of Pathology, Duke University and Durham VA Medical Centers, Durham, N.C., USA
| | - Robert F. Spurney
- Division of Nephrology, Department of Medicine, and Durham VA Medical Centers, Durham, N.C., USA
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Kanwar YS, Wada J, Sun L, Xie P, Wallner EI, Chen S, Chugh S, Danesh FR. Diabetic nephropathy: mechanisms of renal disease progression. Exp Biol Med (Maywood) 2008; 233:4-11. [PMID: 18156300 DOI: 10.3181/0705-mr-134] [Citation(s) in RCA: 426] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Diabetic nephropathy is characterized by excessive amassing of extracellular matrix (ECM) with thickening of glomerular and tubular basement membranes and increased amount of mesangial matrix, which ultimately progress to glomerulosclerosis and tubulo-interstitial fibrosis. In view of this outcome, it would mean that all the kidney cellular elements, i.e., glomerular endothelia, mesangial cells, podocytes, and tubular epithelia, are targets of hyperglycemic injury. Conceivably, high glucose activates various pathways via similar mechanisms in different cell types of the kidney except for minor exceptions that are related to the selective expression of a given molecule in a particular renal compartment. To begin with, there is an obligatory excessive channeling of glucose intermediaries into various metabolic pathways with generation of advanced glycation products (AGEs), activation of protein kinase C (PKC), increased expression of transforming growth factor-beta (TGF-beta), GTP-binding proteins, and generation of reactive oxygen species (ROS). The ROS seem to be the common denominator in various pathways and are central to the pathogenesis of hyperglycemic injury. In addition, there are marked alterations in intraglomerular hemodynamics, i.e., hyperfiltration, and this along with metabolic derangements adversely compounds the hyperglycemia-induced injury. Here, the information compiled under various subtitles of this article is derived from an enormous amount of data summarized in several excellent literature reviews, and thus their further reading is suggested to gain in-depth knowledge of each of the subject matter.
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Affiliation(s)
- Yashpal S Kanwar
- Department of Pathology, Northwestern University School of Medicine, Chicago, IL 60611, USA.
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Affiliation(s)
- Leon A Bach
- Department of Medicine, Monash University, Melbourne, Victoria, Australia.
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Kolavennu V, Zeng L, Peng H, Wang Y, Danesh FR. Targeting of RhoA/ROCK signaling ameliorates progression of diabetic nephropathy independent of glucose control. Diabetes 2008; 57:714-23. [PMID: 18083785 DOI: 10.2337/db07-1241] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE RhoA, a small GTPase protein, and its immediate downstream target, Rho kinase (ROCK), control a wide variety of signal transduction pathways. Recent studies have shown that fasudil, a selective ROCK inhibitor, may play a pivotal role in a number of pathological conditions, ranging from cardiovascular diseases to pulmonary hypertension and erectile dysfunction. Considerable evidence suggests that some of the beneficial effects of statins may also stem from their modulatory effects on RhoA/ROCK signaling. In the current study, we hypothesized that pharmacological blockade of the RhoA/ROCK pathway with either fasudil or simvastatin would ameliorate progression of diabetic nephropathy. RESEARCH DESIGN AND METHODS In two separate experiments, diabetic db/db mice received fasudil (10 mg x kg(-) x day(-) i.p.) or simvastatin (40 mg x kg(-) x day(-) p.o.) for 16 weeks. Untreated db/db and db/m mice served as controls. RESULTS The kidney cortices of untreated db/db mice displayed increased ROCK activity compared with db/m mice. The fasudil-treated mice exhibited a significant reduction in ROCK activity, albuminuria, glomerular collagen IV accumulation, and urinary collagen IV excretion compared with untreated db/db mice. Interestingly, blood glucose was unaffected by fasudil administration. Treatment with simvastatin significantly attenuated RhoA activation in the kidney cortices of db/db mice and resulted in a significant reduction of albuminuria and mesangial matrix expansion. CONCLUSIONS Based on these results, we propose that RhoA/ROCK blockade constitutes a novel approach to the treatment of diabetic nephropathy. Our data also suggest a critical role for RhoA/ROCK activation in the pathogenesis of diabetic nephropathy.
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Affiliation(s)
- Vasantha Kolavennu
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Houston, Texas, USA
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Christ GJ, Andersson KE. Rho-kinase and effects of Rho-kinase inhibition on the lower urinary tract. Neurourol Urodyn 2008; 26:948-54. [PMID: 17696159 DOI: 10.1002/nau.20475] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Altered smooth muscle cell contractility/tone contributes, at least in part, to the lower urinary tract symptoms (LUTS) seen in men with benign prostatic obstruction (BPO). Accordingly, many of the therapies to date have focused largely on blockade of individual membrane receptors to diminish smooth muscle contractility and provide symptomatic relief. This pharmacologic approach has been associated with variable results, limited efficacy, and untoward side effects. Such limited clinical success is not surprising given the plethora of neurotransmitters, neuromodulators, and hormones that are now known to modulate LUT smooth muscle cell tone. In the pursuit of improved treatment options, more recent investigations have focused attention on intracellular signal transduction events that represent convergence points for membrane receptor activation. In particular, calcium sensitization and the role of the Rho-kinase pathway has received much attention. In this report, we review the literature on the role of the Rho-kinase pathway in the modulation of LUT smooth muscle cell tone. In short, the available data support an important role for Rho-kinase in the physiologic and pathophysiologic regulation of LUT smooth muscle cell tone. Rho-kinase inhibitors thus appear to represent a potentially attractive therapeutic possibility for the treatment of LUTS.
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Affiliation(s)
- George J Christ
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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Giehl K, Graness A, Goppelt-Struebe M. The small GTPase Rac-1 is a regulator of mesangial cell morphology and thrombospondin-1 expression. Am J Physiol Renal Physiol 2007; 294:F407-13. [PMID: 18045834 DOI: 10.1152/ajprenal.00093.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Thrombospondin-1 (TSP-1), which is synthesized by mesangial cells, is known for its anti-angiogenic activity and its ability to activate latent TGF-beta. TSP-1 is upregulated in renal diseases associated with tissue remodeling. Therefore, we hypothesized that the expression of TSP-1 might be modulated by changes in cell morphology involving proteins of the Rho family. Spreading of mesangial cells after detachment and reseeding was characterized by the formation of lamellipodia and focal adhesions, pointing toward a Rac-1-mediated rearrangement of actin structures. Clustering of focal adhesion proteins was also observed in a model system of nocodazole-induced disruption of microtubules. These morphological alterations were impeded by pharmacological inhibition of Src family kinases, of the small GTPase Rac-1, or by downregulation of Rac-1 by siRNA. Upon cell spreading, TSP-1 was upregulated in the absence and much more prominently in the presence of serum, but also after nocodazole treatment. TSP-1 upregulation was controlled by activation of Src family kinases, ERK 1/2 and Rac-1, whereas activation of RhoA-ROCK signaling was not linked to TSP-1 induction. We thus provide evidence that TSP-1 expression is induced by common signaling pathways, which are activated by morphological alterations of renal mesangial cells or by soluble factors as contained in serum, and these pathways include Src family kinases, ERK 1/2 and Rac-1. Our data suggest that tissue remodeling activates gene expression of pathophysiologically relevant proteins such as TSP-1.
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Affiliation(s)
- Klaudia Giehl
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
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Khwaja A, Sharpe CC, Noor M, Hendry BM. The role of geranylgeranylated proteins in human mesangial cell proliferation. Kidney Int 2006; 70:1296-304. [PMID: 16929252 DOI: 10.1038/sj.ki.5001713] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The Rho family of guanine 5'-triphosphatases (GTPases) play a key role in regulating cell proliferation, tubulointerstitial fibrosis, and glomerular hemodynamics. The post-translational prenylation of RhoGTPases by the addition of a geranylgeranyl moiety is critical for cellular localization and signaling activity. This study investigates the effects of (i) inhibiting geranylgeranylation (GG) in human mesangial cell (HMC) proliferation and apoptosis, using GGTI 298, a specific inhibitor of GG and (ii) lovastatin, an HMG-coacetyl A-reductase inhibitor, which depletes the availability of prenylation substrates. HMC proliferation was assessed using an assay of viable cell number and measuring bromodeoxyuridine (BrdU) incorporation. Hoechst 33342 staining was used to determine apoptosis. Extracellular signal-regulated protein kinase (Erk)1/2 and Akt activation were analysed by Western blotting. Rho activation was determined using the Rhotekin pull-down assay. Immunocytochemistry was performed to study the effects on the actin cytoskeleton and RhoA localization. GGTI 298 (10-20 muM) and lovastatin (5-10 muM) potently inhibited platelet-derived growth factor and serum-stimulated HMC proliferation and induced apoptosis. These effects of lovastatin were attenuated by co-incubation with geranylgeranylpyrophosphate. C3 exoenzyme, a clostridial toxin that specifically targets Rho also inhibited BrdU incorporation and promoted apoptosis. GGTI 298 increased cytosolic expression of RhoA, prevented RhoA activation, and inhibited the activation of Erk1/2 and the survival protein Akt. GGTI 298, lovastatin, and C3 exoenzyme inhibit HMC proliferation and promote apoptosis. Inhibiting GG increases cytosolic RhoA expression, disrupts the actin cytoskeleton, and inhibits RhoA activation. These results suggest that targeting geranylgeranylated proteins with statins or GGTI 298 is a promising therapeutic strategy in human mesangioproliferative renal disease.
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Affiliation(s)
- A Khwaja
- Department of Renal Medicine, GKT School of Medicine, King's College London, Bessemer Road, London, UK
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Reuters I, Weber M, Schulze-Lohoff E. Rho/Rho kinase pathway regulates maintenance of the differentiated tubular epithelial cell phenotype on laminin-1. Nephron Clin Pract 2006; 104:p95-p106. [PMID: 16847378 DOI: 10.1159/000094573] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Accepted: 04/02/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Maintenance of a polarized tubular epithelium by appropriate intracellular signaling and extracellular matrix is critical both in normal renal function as well as in acute and chronic tubular injury. We examined the hypothesis that maintenance of a differentiated epithelial phenotype on the basement membrane glycoprotein laminin-1 is controlled by the Rho/Rho kinase pathway. METHODS Using the tubular epithelial cell lines LLC-PK1 and MDCK which were cultured on laminin-1 vs. collagen IV, we analyzed cell morphology and motility (cohort migration assay) as well as expression of differentiation and dedifferentiation markers (immunofluorescence microscopy). RESULTS Cohort migration of LLC-PK1 cells was significantly slowed down on laminin-1 (10.7 +/- 2.2 m.u. (migratory units)) compared with collagen IV (16.6 +/- 2.3 m.u.; BSA control: 2.8 +/- 2.5 m.u.). Inhibition of the Rho/Rho kinase pathway by C3 exotoxin (1 mug/ml) or the Rho kinase inhibitor Y27632 (10 microM) significantly augmented cohort migration on laminin-1 (14.5 +/- 1.4 and 16.0 +/- 1.8 m.u. vs. 10.7 +/- 2.2 m.u.). In parallel to the increased migratory activity, inhibition of the Rho/Rho kinase pathway resulted in a more mesenchymal phenotype of LLC-PK1 cells on laminin-1 with increased formation of lamellopodia and filopodia, distinct loss of focal contacts and stress fibers, upregulation of the dedifferentiation marker vimentin, and loss of cell-cell contacts with translocation of beta-catenin from the adherens junctions to the cytosol and nucleus. Similarly, cohort migration of MDCK cells was retarded on laminin-1 when compared with collagen IV, and addition of the Rho kinase inhibitor Y27632 resulted in enhanced motility and a change in cell morphology. CONCLUSION The study demonstrates that the Rho/Rho kinase pathway is required to maintain a non-migratory epithelial phenotype of cultured renal tubular LLC-PK1 and MDCK cells on the basement membrane glycoprotein laminin-1.
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Affiliation(s)
- Irith Reuters
- Department of Medicine I, Cologne General Hospital, Merheim Medical Center, Cologne, Germany
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Sun GP, Kohno M, Guo P, Nagai Y, Miyata K, Fan YY, Kimura S, Kiyomoto H, Ohmori K, Li DT, Abe Y, Nishiyama A. Involvements of Rho-Kinase and TGF-β Pathways in Aldosterone-Induced Renal Injury. J Am Soc Nephrol 2006; 17:2193-201. [PMID: 16790507 DOI: 10.1681/asn.2005121375] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Recent studies have suggested a role for aldosterone in the pathogenesis of renal injury. This study investigated the potential contributions of Rho-kinase and TGF-beta pathways to aldosterone-induced renal injury. Rats were uninephrectomized and then treated for 5 wk with 1% NaCl in a drinking solution and one of the following: Vehicle (2% ethanol, subcutaneously; n = 9); aldosterone (0.75 microg/h, subcutaneously; n = 9); or aldosterone + fasudil, a specific Rho-kinase inhibitor (10 mg/kg per d, subcutaneously; n = 8). Phosphorylation of myosin phosphate target subunit-1 (MYPT1) and Smad2/3 in renal cortical tissue was measured by Western blotting with anti-phospho MYPT1 and Smad2/3 antibodies, respectively. Rats that received aldosterone infusion exhibited hypertension and severe renal injury characterized by proteinuria, glomerular sclerosis, and tubulointerstitial fibrosis with increases in alpha-smooth muscle actin staining and numbers of monocytes/macrophages in the interstitium. Renal cortical mRNA levels of types I and III collagen, TGF-beta, connective tissue growth factor, and monocyte chemoattractant protein-1 as well as Smad2/3 phosphorylation were significantly increased in rats that received aldosterone infusion. All of these changes were associated with an increase in renal tissue MYPT1 phosphorylation. Treatment with fasudil did not alter BP but significantly ameliorated proteinuria and renal injury in rats that received aldosterone infusion. Furthermore, fasudil prevented MYPT1 phosphorylation and markedly decreased alpha-smooth muscle actin staining, numbers of monocytes/macrophages, mRNA levels of types I and III collagen, TGF-beta, connective tissue growth factor and monocyte chemoattractant protein-1, and Smad2/3 activity in renal cortical tissues. These results provide evidence, for the first time, that Rho-kinase is substantially involved in aldosterone-induced renal injury through activation of a TGF-beta-dependent pathway.
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Affiliation(s)
- Guang-Ping Sun
- Department of CardioRenal and Cerebrovascular Medicine, Kagawa University Medical School, Kagawa, Japan
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Kanwar YS, Akagi S, Nayak B, Sun L, Wada J, Xie P, Thakur A, Chugh SS, Danesh FR. Renal-specific oxidoreductase biphasic expression under high glucose ambience during fetal versus neonatal development. Kidney Int 2005; 68:1670-83. [PMID: 16164644 DOI: 10.1111/j.1523-1755.2005.00611.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Renal-specific oxidoreductase (RSOR) has been recently identified in mice kidneys of diabetic animals, and it is developmentally regulated. Its expression during fetal, neonatal, and postnatal periods was assessed under high glucose ambience. METHODS Whole-mount immunofluorescence and confocal microscopy were performed to assess the effect of high glucose on the morphogenesis of mice fetal kidneys. RSOR mRNA and protein expression was assessed by competitive polymerase chain reaction (PCR) and immunoprecipitation methods in embryonic kidneys (day E13 to E17) subjected to high glucose ambience and by Northern and Western blot analyses of kidneys of newborn and 1-week-old mice with hyperglycemia. The spatiotemporal changes in the RSOR expression were assessed by in situ hybridization analyses and immunofluorescence microscopy. In addition, the extent of apoptosis in the kidneys was determined by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) assay. RESULTS Whole-mount microscopy of the embryonic metanephroi revealed a dose-dependent disruption in the ureteric bud iterations with reduced population of the nascent nephrons. Both gene and protein expressions were reduced in day E13 to E17 metanephroi, while increased in kidneys of newborn and 1-week-old mice. In day E13 and day E15 kidneys, the RSOR was expressed in the ureteric bud branches and some of the immature tubules, and its expression was reduced with high glucose treatment. In day E17 kidneys the RSOR was expressed in the tubules of the deeper cortex, and its expression was marginally decreased. In newborn kidneys, this enzyme was expressed in the subcortical tubules and it spread to the entire width of the renal cortex in hyperglycemic state. In 1-week-old mice kidneys, the RSOR was localized to the entire cortex, and in animals with blood glucose above 300 mg/dL, its intensity increased with extension of expression into the outer medullary tubules. A dose-dependent fulminant apoptosis was observed in day E13 to E17 kidneys subjected to high glucose ambience. In newborn and 1-week-old mice control kidneys, the apoptosis was minimal although slightly increased during hyperglycemia. CONCLUSION High glucose has a differential effect on the RSOR expression in kidneys during the embryonic versus neonatal/postnatal period. This may partly be related to the differential degree of apoptosis, a process reflective of oxidant stress that is seen in diabetic milieu, which as previously has been shown to adversely effect the modulators of fetal development and thereby the morphogenesis of the kidney and RSOR expression.
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Affiliation(s)
- Yashpal S Kanwar
- Department of Pathology, Northwestern University Medical Center, Chicago, Illinois 60611, USA.
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Abstract
Rho kinases (ROCKs), the first Rho effectors to be described, are serine/threonine kinases that are important in fundamental processes of cell migration, cell proliferation and cell survival. Abnormal activation of the Rho/ROCK pathway has been observed in various disorders of the central nervous system. Injury to the adult vertebrate brain and spinal cord activates ROCKs, thereby inhibiting neurite growth and sprouting. Inhibition of ROCKs results in accelerated regeneration and enhanced functional recovery after spinal-cord injury in mammals, and inhibition of the Rho/ROCK pathway has also proved to be efficacious in animal models of stroke, inflammatory and demyelinating diseases, Alzheimer's disease and neuropathic pain. ROCK inhibitors therefore have potential for preventing neurodegeneration and stimulating neuroregeneration in various neurological disorders.
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Abstract
The worldwide rise in the number of patients with chronic kidney disease (CKD) and consequent end-stage renal failure necessitating renal replacement therapy is threatening to reach epidemic proportions over the next decade, and only a small number of countries have robust economies able to meet the challenges posed. A change in global approach to CKD from treatment of end-stage renal disease (ESRD) to much more aggressive primary and secondary prevention is therefore imperative. In this Seminar, we examine the epidemiology of CKD worldwide, with emphasis on early detection and prevention, and the feasibility of methods for detection and primary prevention of CKD. We also review the risk factors and markers of progressive CKD. We explore current understanding of the mechanisms underlying renal scarring leading to ESRD to inform on current and future interventions as well as evidence relating to interventions to slow the progression of CKD. Finally, we make strategic recommendations based on future research to stem the worldwide growth of CKD. Consideration is given to health economics. A global and concerted approach to CKD must be adopted in both more and less developed countries to avoid a major catastrophe.
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Affiliation(s)
- A Meguid El Nahas
- Sheffield Kidney Institute, Sheffield Teaching Hospital NHS Foundation Trust, Northern General Hospital Campus, University of Sheffield, Sheffield S5 7AU, UK.
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Kanwar YS, Akagi S, Sun L, Nayak B, Xie P, Wada J, Chugh SS, Danesh FR. Cell Biology of Diabetic Kidney Disease. ACTA ACUST UNITED AC 2005; 101:e100-10. [PMID: 16088221 DOI: 10.1159/000087339] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In large part cellular dysfunctions induced by chronic hyperglycemia are similar in type-1 and -2 diabetes. In both instances chronic hyperglycemia induces injury to a multitude of organs by affecting various target cells. The cells affected may include those derived from of epithelial or mesenchymal progenitors; and at times hyperglycemia may induce phenotypic changes with epithelial-mesenchymal transformation. In the majority of target cells the high-glucose ambience activates various intracellular pathways that are similar except for minor exceptions that are related to the selective expression of various molecules in a given cell type. Keeping in perspective a common paradigm applicable to most of the cells, a brief discussion of different hyperglycemia-induced cellular events pertaining to various pathways is described in this review. They include fluxes of glucose intermediaries in various cellular metabolic pathways, generation of advanced glycation end products (AGEs) and their extra- and intracellular effects, the role of protein kinase C, transforming growth factor-beta, guanosine triphosphate-binding proteins and reactive oxygen species (ROS) in various cellular signaling events. The latter, i.e., ROS, may be central to several intracellular pathways and modulate various events in a reciprocal manner. The information compiled under various subtitles of this synopsis is derived from an enormous amount of literature data summarized in several recent excellent reviews, and thus further reading of them is suggested to gather detailed comprehensive information on each of the subjects.
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Affiliation(s)
- Yashpal S Kanwar
- Department of Pathology, Northwestern University School of Medicine, Chicago, Ill 60611, USA.
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Turcotte S, Desrosiers RR, Brand G, Béliveau R. von Hippel-Lindau tumor suppressor protein stimulation by thrombin involves RhoA activation. Int J Cancer 2004; 112:777-86. [PMID: 15386385 DOI: 10.1002/ijc.20468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene is associated with the development of vascular tumors including renal cell carcinoma. Aside from the role played by the VHL protein (pVHL) in negative regulation of hypoxia-inducible factor, 41F-1alpha, pVHL also takes part in cytoskeletal organization. Thrombin is a serine protease involved in angiogenesis and in cancer progression and its action is mediated by the protease-activated receptors (PARs). In several cell types, thrombin induces reorganization of the cytoskeleton along with RhoA activation. Thus, we conducted an investigation on the capacity of thrombin to regulate pVHL expression. Our results demonstrated that VHL mRNA and protein levels were increased by thrombin in cultured renal cancer cells. Cytoplasmic pVHL was redistributed to perinuclear regions and membrane fractions following thrombin treatments. Stimulation of Caki-1 cells with PAR1, PAR2 and PAR4 agonist peptides demonstrated that PAR1 was the receptor involved in thrombin-induced pVHL expression. Western blot analysis confirmed that these cells express PAR1 and that its expression was increased by thrombin. PAR1 activation by both thrombin and an agonist peptide stimulated renal cancer cell invasion through Matrigel. Interestingly, the upregulation of pVHL was dependent on RhoA because C3 exotoxin abolished pVHL induction. However, the pharmacological Rho kinase inhibitor, Y27632, did not influence pVHL expression in the presence of thrombin, suggesting that other RhoA effectors were involved in the process. Together, these results demonstrate that thrombin induces both pVHL expression via PAR1/RhoA activation as well as the stimulation of renal cancer cell invasion suggesting a role for thrombin in tumor invasion.
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Affiliation(s)
- Sandra Turcotte
- Laboratoire de Médecine Moléculaire, Hôpital Sainte-Justine, Université du Québec à Montréal, Montréal, Québec
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Dubus I, L'Azou B, Gordien M, Delmas Y, Labouyrie JP, Bonnet J, Combe C. Cytoskeletal Reorganization by Mycophenolic Acid Alters Mesangial Cell Migration and Contractility. Hypertension 2003; 42:956-61. [PMID: 14557286 DOI: 10.1161/01.hyp.0000097806.45034.45] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cytoskeleton alterations are a hallmark of mesangial cell activation during glomerulosclerosis. The aim of this study was to investigate whether mycophenolic acid (MPA) affects cytoskeletal organization and motility of human mesangial cells. Using the IP15 cell line, we found that treatment with 1 μmol/L MPA inhibited both receptor-dependent (angiotensin II) and receptor-independent (KCl) contractile responses, as well as serum-induced migration activity, suggesting alterations in the intracellular mechanisms that control mesangial cell motility. Immunofluorescence studies of MPA-treated cells provided evidence for decreased membrane disassembly/reassembly of α-smooth muscle actin and F-actin fibers, which was correlated with sustained quantitative and qualitative modifications of actin-associated proteins: calponin was overexpressed and became associated with actin fibers, whereas phosphorylation levels of cofilin and myosin light chain increased, suggesting both an activation of the mechanisms responsible for actin polymerization and an inhibition of actin-depolymerizing processes. These observations support a stabilizing effect of MPA on the mesangial actin cytoskeleton, which constitutes an additive action by which MPA, beyond its anti-inflammatory, antiproliferative and antifibrotic properties, might protect against excessive mesangial activation in the context of various glomerulopathies and kidney transplantation.
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