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Xing J, Wang Y, Peng A, Li J, Niu X, Zhang K. The role of actin cytoskeleton CFL1 and ADF/cofilin superfamily in inflammatory response. Front Mol Biosci 2024; 11:1408287. [PMID: 39114368 PMCID: PMC11303188 DOI: 10.3389/fmolb.2024.1408287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 07/04/2024] [Indexed: 08/10/2024] Open
Abstract
Actin remodeling proteins are important in immune diseases and regulate cell cytoskeletal responses. These responses play a pivotal role in maintaining the delicate balance of biological events, protecting against acute or chronic inflammation in a range of diseases. Cofilin (CFL) and actin depolymerization factor (ADF) are potent actin-binding proteins that cut and depolymerize actin filaments to generate actin cytoskeleton dynamics. Although the molecular mechanism by which actin induces actin cytoskeletal reconstitution has been studied for decades, the regulation of actin in the inflammatory process has only recently become apparent. In this paper, the functions of the actin cytoskeleton and ADF/cofilin superfamily members are briefly introduced, and then focus on the role of CFL1 in inflammatory response.
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Affiliation(s)
| | | | | | | | | | - Kaiming Zhang
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Taiyuan Central Hospital, Dong San Dao Xiang, Taiyuan, China
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Xia X, Liu X, Xu Q, Gu J, Ling S, Liu Y, Li R, Zou M, Jiang S, Gao Z, Chen C, Liu S, Liu N. USP14 deficiency inhibits neointima formation following vascular injury via degradation of Skp2 protein. Cell Death Discov 2024; 10:295. [PMID: 38909015 PMCID: PMC11193710 DOI: 10.1038/s41420-024-02069-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 06/24/2024] Open
Abstract
Ubiquitin-proteasome system (UPS) is involved in vascular smooth muscle cell (VSMC) proliferation. Deubiquitinating enzymes (DUBs) have an essential role in the UPS-regulated stability of the substrate; however, the function of DUBs in intimal hyperplasia remains unclear. We screened DUBs to identify a protein responsible for regulating VSMC proliferation and identified USP14 protein that mediates cancer development, inflammation, and foam cell formation. USP14 promotes human aortic smooth muscle cell and A7r5 cell growth in vitro, and its inhibition or deficiency decreases the intimal area in the mice carotid artery ligation model. In addition, USP14 stabilizes Skp2 expression by decreasing its degradation, while Skp2 overexpression rescues USP14 loss-induced issues. The current findings suggested an essential role of USP14 in the pathology of vascular remodeling, deeming it a promising target for arterial restenosis therapy.
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Affiliation(s)
- Xiaohong Xia
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, 510095, China
| | - Xiaolin Liu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Qiong Xu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Jielei Gu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Sisi Ling
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Yajing Liu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Rongxue Li
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Min Zou
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Siqin Jiang
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Zhiwei Gao
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Canshan Chen
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Shiming Liu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
| | - Ningning Liu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
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Chen Y, Jiang X, Yuan Y, Chen Y, Wei S, Yu Y, Zhou Q, Yu Y, Wang J, Liu H, Hua X, Yang Z, Chen Z, Li Y, Wang Q, Chen J, Wang Y. Coptisine inhibits neointimal hyperplasia through attenuating Pak1/Pak2 signaling in vascular smooth muscle cells without retardation of re-endothelialization. Atherosclerosis 2024; 391:117480. [PMID: 38447436 DOI: 10.1016/j.atherosclerosis.2024.117480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 02/04/2024] [Accepted: 02/08/2024] [Indexed: 03/08/2024]
Abstract
BACKGROUND AND AIMS Vascular injury-induced endothelium-denudation and profound vascular smooth muscle cells (VSMCs) proliferation and dis-regulated apoptosis lead to post-angioplasty restenosis. Coptisine (CTS), an isoquinoline alkaloid, has multiple beneficial effects on the cardiovascular system. Recent studies identified it selectively inhibits VSMCs proliferation. However, its effects on neointimal hyperplasia, re-endothelialization, and the underlying mechanisms are still unclear. METHODS Cell viability was assayed by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and cell counting kit-8 (CCK-8). Cell proliferation and apoptosis were measured by flow cytometry and immunofluorescence of Ki67 and TUNEL. Quantitative phosphoproteomics (QPP) was employed to screen CTS-responsive phosphor-sites in the key regulators of cell proliferation and apoptosis. Neointimal hyperplasia was induced by balloon injury of rat left carotid artery (LCA). Adenoviral gene transfer was conducted in both cultured cells and LCA. Re-endothelialization was evaluated by Evan's blue staining of LCA. RESULTS 1) CTS had strong anti-proliferative and pro-apoptotic effects in cultured rat VSMCs, with the EC50 4∼10-folds lower than that in endothelial cells (ECs). 2) Rats administered with CTS, either locally to LCA's periadventitial space or orally, demonstrated a potently inhibited balloon injury-induced neointimal hyperplasia, but had no delaying effect on re-endothelialization. 3) The QPP results revealed that the phosphorylation levels of Pak1S144/S203, Pak2S20/S197, Erk1T202/Y204, Erk2T185/Y187, and BadS136 were significantly decreased in VSMCs by CTS. 4) Adenoviral expression of phosphomimetic mutants Pak1D144/D203/Pak2D20/D197 enhanced Pak1/2 activities, stimulated the downstream pErk1T202/Y204/pErk2T185/Y187/pErk3S189/pBadS136, attenuated CTS-mediated inhibition of VSMCs proliferation and promotion of apoptosis in vitro, and potentiated neointimal hyperplasia in vivo. 5) Adenoviral expression of phosphoresistant mutants Pak1A144/A203/Pak2A20/A197 inactivated Pak1/2 and totally simulated the inhibitory effects of CTS on platelet-derived growth factor (PDGF)-stimulated VSMCs proliferation and PDGF-inhibited apoptosis in vitro and neointimal hyperplasia in vivo. 6) LCA injury significantly enhanced the endogenous phosphorylation levels of all but pBadS136. CTS markedly attenuated all the enhanced levels. CONCLUSIONS These results indicate that CTS is a promising medicine for prevention of post-angioplasty restenosis without adverse impact on re-endothelialization. CTS-directed suppression of pPak1S144/S203/pPak2S20/S197 and the subsequent effects on downstream pErk1T202/Y204/pErk2T185/Y187/pErk3S189 and pBadS136 underline its mechanisms of inhibition of VSMCs proliferation and stimulation of apoptosis. Therefore, the phosphor-sites of Pak1S144/S203/Pak2S20/S197 constitute a potential drug-screening target for fighting neointimal hyperplasia restenosis.
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Affiliation(s)
- Yuhan Chen
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Xueze Jiang
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China; Department of Cardiology, Baoshan Branch of Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200444, China
| | - Yuchan Yuan
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Yuanyuan Chen
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Sisi Wei
- Children Inherited Metabolism and Endocrine Department, Guangdong Women and Children Hospital, Panyu District, Guangzhou, Guangdong, 511400, China
| | - Ying Yu
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Qing Zhou
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Yi Yu
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Julie Wang
- Department of Computer Science, Brown University, Providence, RI, 02912, USA
| | - Hua Liu
- Department of Intensive Care Med, Zhongshan Hospital of Fudan University, Shanghai, 200032, China
| | - Xuesheng Hua
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Zhenwei Yang
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Zhiyong Chen
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Yigang Li
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China
| | - Qunshan Wang
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
| | - Jie Chen
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
| | - Yuepeng Wang
- Molecular Cardiology Research Laboratory, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200092, China.
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McNeill MC, Li Mow Chee F, Ebrahimighaei R, Sala-Newby GB, Newby AC, Hathway T, Annaiah AS, Joseph S, Carrabba M, Bond M. Substrate stiffness promotes vascular smooth muscle cell calcification by reducing the levels of nuclear actin monomers. J Mol Cell Cardiol 2024; 187:65-79. [PMID: 38181546 DOI: 10.1016/j.yjmcc.2023.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/07/2024]
Abstract
BACKGROUND Vascular calcification (VC) is a prevalent independent risk factor for adverse cardiovascular events and is associated with diabetes, hypertension, chronic kidney disease, and atherosclerosis. However, the mechanisms regulating the osteogenic differentiation of vascular smooth muscle cells (VSMC) are not fully understood. METHODS Using hydrogels of tuneable stiffness and lysyl oxidase-mediated stiffening of human saphenous vein ex vivo, we investigated the role of substrate stiffness in the regulation of VSMC calcification. RESULTS We demonstrate that increased substrate stiffness enhances VSMC osteogenic differentiation and VSMC calcification. We show that the effects of substrate stiffness are mediated via a reduction in the level of actin monomer within the nucleus. We show that in cells interacting with soft substrate, elevated levels of nuclear actin monomer repress osteogenic differentiation and calcification by repressing YAP-mediated activation of both TEA Domain transcription factor (TEAD) and RUNX Family Transcription factor 2 (RUNX2). CONCLUSION This work highlights for the first time the role of nuclear actin in mediating substrate stiffness-dependent VSMC calcification and the dual role of YAP-TEAD and YAP-RUNX2 transcriptional complexes.
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Affiliation(s)
- M C McNeill
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom
| | - F Li Mow Chee
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom
| | - R Ebrahimighaei
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom
| | - G B Sala-Newby
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom
| | - A C Newby
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom
| | - T Hathway
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom
| | - A S Annaiah
- Bristol Heart Institute, University Hospital, Bristol NHS Foundation Trust, Bristol BS2 8HW, United Kingdom
| | - S Joseph
- Bristol Heart Institute, University Hospital, Bristol NHS Foundation Trust, Bristol BS2 8HW, United Kingdom
| | - M Carrabba
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom
| | - M Bond
- Department of Translational Health Sciences, Bristol Medical School, Bristol BS2 8HW, United Kingdom.
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Ebrahimighaei R, Tarassova N, Bond SC, McNeill MC, Hathway T, Vohra H, Newby AC, Bond M. Extracellular matrix stiffness controls cardiac fibroblast proliferation via the nuclear factor-Y (NF-Y) transcription factor. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119640. [PMID: 37996060 DOI: 10.1016/j.bbamcr.2023.119640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/10/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023]
Abstract
The proliferative expansion of cardiac fibroblasts (CF) contributes towards cardiac fibrosis, which results in myocardial stiffening, cardiac dysfunction, and heart failure. CF sense and respond to increased stiffness of their local extracellular matrix, modulating their phenotype towards increased collagen synthesis and higher proliferation, leading potentially to a vicious circle of positive feedback. Here we describe a novel mechanism that mediates increased CF proliferation in response to a pathologically stiff Exteracellular matrix (ECM). The mechanism we describe is independent of the well-characterised mechano-sensitive transcript factors, YAP-TEAD and MKL1-SRF, which our data indicate are only responsible for part of the genes induced by stiffened ECM. Instead, our data identify Nuclear Factor-Y (NF-Y) as a novel mechanosensitive transcription factor, which mediates enhanced CF proliferation in response to a stiff ECM. We show that levels of NF-YA protein, the major regulatory subunit of NF-Y, and NF-Y transcriptional activity, are increased by a stiff ECM. Indeed, NF-Y activity drives the expression of multiple cell-cycle genes. Furthermore, NF-YA protein levels are dependent on FAK signalling suggesting a mechanistic link to ECM composition. Consistent with its role as a mechano-sensor, inhibition of NF-Y using siRNA or dominant negative mutant blocks CF proliferation on plastic in vitro, which models a stiff ECM, whereas ectopic expression of NF-YA increases the proliferation of cells interacting under conditions that model a physiologically soft ECM. In summary, our data demonstrate that NF-Y is a biomechanically sensitive transcription factor that promotes CF proliferation in a model of pathologically stiffened ECM.
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Affiliation(s)
- Reza Ebrahimighaei
- Department of Translational Health Sciences, Bristol Medical School, Bristol, BS2 8HW, United Kingdom
| | - Nathalie Tarassova
- Department of Translational Health Sciences, Bristol Medical School, Bristol, BS2 8HW, United Kingdom.
| | - Samuel C Bond
- Clifton High School, Clifton, Bristol, BS8 3JD, United Kingdom.
| | - Madeleine C McNeill
- Department of Translational Health Sciences, Bristol Medical School, Bristol, BS2 8HW, United Kingdom.
| | - Tom Hathway
- Department of Translational Health Sciences, Bristol Medical School, Bristol, BS2 8HW, United Kingdom.
| | - Hunaid Vohra
- Department of Translational Health Sciences, Bristol Medical School, Bristol, BS2 8HW, United Kingdom.
| | - Andrew C Newby
- Department of Translational Health Sciences, Bristol Medical School, Bristol, BS2 8HW, United Kingdom.
| | - Mark Bond
- Department of Translational Health Sciences, Bristol Medical School, Bristol, BS2 8HW, United Kingdom.
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Ebrahimighaei R, Sala-Newby GB, Hudson C, Kimura TE, Hathway T, Hawkins J, McNeill MC, Richardson R, Newby AC, Bond M. Combined role for YAP-TEAD and YAP-RUNX2 signalling in substrate-stiffness regulation of cardiac fibroblast proliferation. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119329. [PMID: 35905788 PMCID: PMC7616274 DOI: 10.1016/j.bbamcr.2022.119329] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 07/16/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Cardiac fibrosis is associated with increased stiffness of the myocardial extracellular matrix (ECM) in part mediated by increased cardiac fibroblast proliferation However, our understanding of the mechanisms regulating cardiac fibroblast proliferation are incomplete. Here we characterise a novel mechanism involving a combined activation of Yes-associated protein (YAP) targets RUNX Family Transcription Factor 2 (RUNX2) and TEA Domain Transcription Factor (TEAD). We demonstrate that cardiac fibroblast proliferation is enhanced by interaction with a stiff ECM compared to a soft ECM. This is associated with activation of the transcriptional co-factor, YAP. We demonstrate that this stiffness induced activation of YAP enhances the transcriptional activity of both TEAD and RUNX2 transcription factors. Inhibition of either TEAD or RUNX2, using gene silencing, expression of dominant-negative mutants or pharmacological inhibition, reduces cardiac fibroblast proliferation. Using mutants of YAP, defective in TEAD or RUNX2 activation ability, we demonstrate a dual role of YAP-mediated activation of TEAD and RUNX2 for substrate stiffness induced cardiac fibroblast proliferation. Our data highlights a previously unrecognised role of YAP mediated RUNX2 activation for cardiac fibroblast proliferation in response to increased ECM stiffness.
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Affiliation(s)
- Reza Ebrahimighaei
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Graciela B Sala-Newby
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Claire Hudson
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Tomomi E Kimura
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Tom Hathway
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Joseph Hawkins
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Madeleine C McNeill
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Rebecca Richardson
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Andrew C Newby
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Mark Bond
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK.
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Cyclic-AMP Increases Nuclear Actin Monomer Which Promotes Proteasomal Degradation of RelA/p65 Leading to Anti-Inflammatory Effects. Cells 2022; 11:cells11091414. [PMID: 35563720 PMCID: PMC9101168 DOI: 10.3390/cells11091414] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/05/2022] [Accepted: 04/14/2022] [Indexed: 12/04/2022] Open
Abstract
The second messenger, cAMP has potent immunosuppressive and anti-inflammatory actions. These have been attributed, in part, to the ability of cAMP-induced signals to interfere with the function of the proinflammatory transcription factor Nuclear Factor-kappa B (NF-κB). However, the mechanisms underlying the modulation of NF-κB activity by cAMP remain unclear. Here we demonstrate an important role for cAMP-mediated increase in nuclear actin monomer levels in inhibiting NF-κB activity. Elevated cAMP or forced expression of a nuclear localised polymerisation defective actin mutant (NLS-ActinR62D) inhibited basal and TNFα induced mRNA levels of NF-κB-dependent genes and NF-κB-dependent reporter gene activity. Elevated cAMP or NLS-ActinR62D did not affect NF-κB nuclear translocation but did reduce total cellular and nuclear RelA/p65 levels. Preventing the cAMP-induced increase in nuclear actin monomer, either by expressing a nuclear localised active mutant of the actin polymerising protein mDIA, silencing components of the nuclear actin import complex IPO9 and CFL1 or overexpressing the nuclear export complex XPO6, rescued RelA/p65 levels and NF-κB reporter gene activity in forskolin-stimulated cells. Elevated cAMP or NLS-ActinR62D reduced the half-life of RelA/p65, which was reversed by the proteasome inhibitor MG132. Accordingly, forskolin stimulated association of RelA/p65 with ubiquitin affinity beads, indicating increased ubiquitination of RelA/p65 or associated proteins. Taken together, our data demonstrate a novel mechanism underlying the anti-inflammatory effects of cAMP and highlight the important role played by nuclear actin in the regulation of inflammation.
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Sutton SS, Magagnoli J, Cummings TH, Hardin JW. Targeting Rac1 for the prevention of atherosclerosis among U.S. Veterans with inflammatory bowel disease. Small GTPases 2022; 13:205-210. [PMID: 34320903 PMCID: PMC9707539 DOI: 10.1080/21541248.2021.1954863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Evidence suggests that Ras-related C3 botulinum toxin substrate 1 (Rac1) might be a target in atherosclerotic disease (AD). We hypothesize that due to their ability to inhibit Rac1, thiopurines are associated with a lower risk of AD. We fit a time-dependent cox proportional hazards model estimating the hazard of AD among a national cohort of US veterans with inflammatory bowel disease. Patients exposed to thiopurines had a 7.5% lower risk of AD (HR = 0.925; 95% CI = (0.87-0.984)) compared to controls. The propensity score weighted analysis reveals thiopurine exposure reduces the risk of AD by 6.6% (HR = 0.934; 95% CI = (0.896-0.975)), compared to controls. Further exploration and evaluation of Rac1 inhibition as a target for AD is warranted.
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Affiliation(s)
- S. Scott Sutton
- Dorn Research Institute, Columbia VA Health Care System, Columbia, SC, USA,Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - Joseph Magagnoli
- Dorn Research Institute, Columbia VA Health Care System, Columbia, SC, USA,Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA,CONTACT Joseph Magagnoli Dorn Research Institute, Columbia VA Health Care System, Columbia, SC, USA
| | - Tammy H. Cummings
- Dorn Research Institute, Columbia VA Health Care System, Columbia, SC, USA,Department of Clinical Pharmacy and Outcomes Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - James W. Hardin
- Dorn Research Institute, Columbia VA Health Care System, Columbia, SC, USA,Department of Epidemiology & Biostatistics, University of South Carolina, Columbia, SC, USA
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9
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Xia X, Liu X, Chai R, Xu Q, Luo Z, Gu J, Jin Y, Hu T, Yu C, Du B, Huang H, Ou W, Liu S, Liu N. USP10 exacerbates neointima formation by stabilizing Skp2 protein in vascular smooth muscle cells. J Biol Chem 2021; 297:101258. [PMID: 34599966 PMCID: PMC8524199 DOI: 10.1016/j.jbc.2021.101258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 09/14/2021] [Accepted: 09/27/2021] [Indexed: 12/16/2022] Open
Abstract
The underlying mechanism of neointima formation remains unclear. Ubiquitin-specific peptidase 10 (USP10) is a deubiquitinase that plays a major role in cancer development and progression. However, the function of USP10 in arterial restenosis is unknown. Herein, USP10 expression was detected in mouse arteries and increased after carotid ligation. The inhibition of USP10 exhibited thinner neointima in the model of mouse carotid ligation. In vitro data showed that USP10 deficiency reduced proliferation and migration of rat thoracic aorta smooth muscle cells (A7r5) and human aortic smooth muscle cells (HASMCs). Mechanically, USP10 can bind to Skp2 and stabilize its protein level by removing polyubiquitin on Skp2 in the cytoplasm. The overexpression of Skp2 abrogated cell cycle arrest induced by USP10 inhibition. Overall, the current study demonstrated that USP10 is involved in vascular remodeling by directly promoting VSMC proliferation and migration via stabilization of Skp2 protein expression.
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Affiliation(s)
- Xiaohong Xia
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China; Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Xiaolin Liu
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Renjie Chai
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Qiong Xu
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Zhenyu Luo
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Jielei Gu
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Yangshuo Jin
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Tumei Hu
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Cuifu Yu
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Bijun Du
- Department of Obstetrics, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Hongbiao Huang
- Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Wenchao Ou
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Shiming Liu
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Ningning Liu
- Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Cardiovascular Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
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10
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Zhou D, Feng H, Yang Y, Huang T, Qiu P, Zhang C, Olsen T, Zhang J, Chen YE, Mizrak D, Yang B. hiPSC Modeling of Lineage-Specific Smooth Muscle Cell Defects Caused by TGFBR1A230T Variant, and its Therapeutic Implications for Loeys-Dietz Syndrome. Circulation 2021; 144:1145-1159. [PMID: 34346740 DOI: 10.1161/circulationaha.121.054744] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background: Loeys-Dietz Syndrome (LDS) is an inherited disorder predisposing individuals to thoracic aortic aneurysm and dissection (TAAD). Currently, there are no medical treatments except surgical resection. Although the genetic basis of LDS is well-understood, molecular mechanisms underlying the disease remain elusive impeding the development of a therapeutic strategy. In addition, aortic smooth muscle cells (SMC) have heterogenous embryonic origins depending on their spatial location, and lineage-specific effects of pathogenic variants on SMC function, likely causing regionally constrained LDS manifestations, have been unexplored. Methods: We identified an LDS family with a dominant pathogenic variant in TGFBR1 gene (TGFBR1A230T) causing aortic root aneurysm and dissection. To accurately model the molecular defects caused by this mutation, we used human-induced pluripotent stem cells (hiPSC) from subject with normal aorta to generate hiPSC carrying TGFBR1A230T, and corrected the mutation in patient-derived hiPSC using CRISPR-Cas9 gene editing. Following their lineage-specific SMC differentiation through cardiovascular progenitor cell (CPC) and neural crest stem cell (NCSC) lineages, we employed conventional molecular techniques and single-cell RNA-sequencing (scRNA-seq) to characterize the molecular defects. The resulting data led to subsequent molecular and functional rescue experiments employing Activin A and rapamycin. Results: Our results indicate the TGFBR1A230T mutation impairs contractile transcript and protein levels, and function in CPC-SMC, but not in NCSC-SMC. ScRNA-seq results implicate defective differentiation even in TGFBR1A230T/+ CPC-SMC including disruption of SMC contraction, and extracellular matrix formation. Comparison of patient-derived and mutation-corrected cells supported the contractile phenotype observed in the mutant CPC-SMC. TGFBR1A230T selectively disrupted SMAD3 and AKT activation in CPC-SMC, and led to increased cell proliferation. Consistently, scRNA-seq revealed molecular similarities between a loss-of-function SMAD3 mutation (SMAD3c.652delA/+) and TGFBR1A230T/+. Lastly, combination treatment with Activin A and rapamycin during or after SMC differentiation significantly improved the mutant CPC-SMC contractile gene expression, and function; and rescued the mechanical properties of mutant CPC-SMC tissue constructs. Conclusions: This study reveals that a pathogenic TGFBR1 variant causes lineage-specific SMC defects informing the etiology of LDS-associated aortic root aneurysm. As a potential pharmacological strategy, our results highlight a combination treatment with Activin A and rapamycin that can rescue the SMC defects caused by the variant.
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Affiliation(s)
- Dong Zhou
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI; Xiangya School of Medicine, Central South University, Changsha, PRC
| | - Hao Feng
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI; Xiangya School of Medicine, Central South University, Changsha, PRC
| | - Ying Yang
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI
| | - Tingting Huang
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI; Xiangya School of Medicine, Central South University, Changsha, PRC
| | - Ping Qiu
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI
| | - Chengxin Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI
| | - Timothy Olsen
- Department of Systems Biology, Columbia University, New York, NY
| | - Jifeng Zhang
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Y Eugene Chen
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI; Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Dogukan Mizrak
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI
| | - Bo Yang
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI
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11
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Rac1 silencing, NSC23766 and EHT1864 reduce growth and actin organization of bladder smooth muscle cells. Life Sci 2020; 261:118468. [PMID: 32961232 DOI: 10.1016/j.lfs.2020.118468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/07/2020] [Accepted: 09/15/2020] [Indexed: 12/16/2022]
Abstract
AIMS RacGTPase-mediated proliferation and smooth muscle contraction in the lower urinary tract has been recently suggested and may offer putative targets for treamtment of lower urinary tract symptoms. However, RacGTPase function for proliferation of detrusor smooth muscle cells is unknown and the specificity of Rac inhibitors has been questioned. Here, we examined effects of Rac1 knockdown and of the Rac inhibitors NSC23766 and EHT1864 in human bladder smooth muscle cells (hBSMCs). MAIN METHODS Rac1 expression was silenced by shRNA expression. Effects of silencing and Rac inhibitors were assessed by CCK-8 assay, EdU staining, RT-PCR, colony formation assay, flow cytometry, and phalloidin staining. KEY FINDINGS Silencing of Rac1 expression reduced the viability (up to 83% compared to scramble shRNA) and proliferation (virtually completely in proliferation assay), increased apoptosis (124%) and the number of dead cells (51%), and caused breakdown of actin organization (56% reduction of polymerized actin compared to scramble shRNA). Effects on proliferation, viability, and actin organization were mimicked by NSC23766 and EHT1864, while both compounds showed divergent effects on cell death (32-fold increase of dead cells by EHT1864, but not NSC23766). Effects of NSC23766 and EHT1864 on viability of hBSMCs were not altered by Rac1 knockdown. SIGNIFICANCE Rac1 promotes proliferation, viability, and cytoskeletal organization, and suppresses apoptosis in bladder smooth muscle cells, which may be relevant in overactive bladder or diabetes-related bladder dysfunction. NSC23766 and EHT1864 mimick these effects, but may act Rac1-independently, by shared and divergent effects.
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12
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Li B, Wang R, Wang Y, Stief CG, Hennenberg M. Regulation of smooth muscle contraction by monomeric non-RhoA GTPases. Br J Pharmacol 2020; 177:3865-3877. [PMID: 32579705 PMCID: PMC7429483 DOI: 10.1111/bph.15172] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/05/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022] Open
Abstract
Smooth muscle contraction in the cardiovascular system, airways, prostate and lower urinary tract is involved in the pathophysiology of many diseases, including cardiovascular and obstructive lung disease plus lower urinary tract symptoms, which are associated with high prevalence of morbidity and mortality. This prominent clinical role of smooth muscle tone has led to the molecular mechanisms involved being subjected to extensive research. In general smooth muscle contraction is promoted by three major signalling pathways, including the monomeric GTPase RhoA pathway. However, emerging evidence suggests that monomeric GTPases other than RhoA may be involved in signal transduction in smooth muscle contraction, including Rac GTPases, cell division control protein 42 homologue, adenosine ribosylation factor 6, Ras, Rap1b and Rab GTPases. Here, we review these emerging functions of non-RhoA GTPases in smooth muscle contraction, which has now become increasingly more evident and constitutes an emerging and innovative research area of high clinical relevance.
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Affiliation(s)
- Bingsheng Li
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Ruixiao Wang
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Yiming Wang
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Christian G Stief
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Martin Hennenberg
- Department of Urology, University Hospital, LMU Munich, Munich, Germany
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13
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McNeill MC, Wray J, Sala-Newby GB, Hindmarch CCT, Smith SA, Ebrahimighaei R, Newby AC, Bond M. Nuclear actin regulates cell proliferation and migration via inhibition of SRF and TEAD. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2020; 1867:118691. [PMID: 32119877 PMCID: PMC7262588 DOI: 10.1016/j.bbamcr.2020.118691] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/20/2020] [Accepted: 02/25/2020] [Indexed: 12/20/2022]
Abstract
Actin dynamics regulate cell behaviour in response to physiological signals. Here we demonstrate a novel role for nuclear actin in inhibiting cell proliferation and migration. We demonstrate that physiological signals that elevate cAMP, which is anti-mitogenic in vascular smooth muscle cells, increases nuclear actin monomer levels. Expression of a nuclear-targeted polymerisation-defective actin mutant (NLS-ActinR62D) inhibited proliferation and migration. Preventing nuclear actin monomer accumulation by enhancing its nuclear export or polymerisation reversed the anti-mitogenic and anti-migratory effects of cAMP. Transcriptomic analysis identified repression of proliferation and migration associated genes regulated by serum response factor (SRF) and TEA Domain (TEAD) transcription factors. Accordingly, NLS-ActinR62D inhibited SRF and TEAD activity and target gene expression, and these effects were reversed by constitutively-active mutants of the TEAD and SRF co-factors YAP, TAZ and MKL1. In summary, intranuclear actin inhibits proliferation and migration by inhibiting YAP-TEAD and MKL-SRF activity. This mechanism explains the anti-mitogenic and anti-migratory properties of physiological signals that elevate cAMP. SUMMARY: McNeill et al show that increased levels of intranuclear actin monomer inhibit cell proliferation and migration by inhibiting MKL1-SRF and YAP/TAZ-TEAD-dependent gene expression. This mechanism mediates the anti-mitogenic and anti-migratory effects of physiological signals that elevate cyclic-AMP.
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Affiliation(s)
- Madeleine C McNeill
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Jason Wray
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Graciela B Sala-Newby
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Charles C T Hindmarch
- Queen's Cardiopulmonary Unit (QCPU), Translational Institute of Medicine (TIME), Department of Medicine, Queen's University, Kingston, ON K7L3N6, Canada
| | - Sarah A Smith
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Reza Ebrahimighaei
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Andrew C Newby
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Mark Bond
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK.
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14
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S-Phase Kinase-associated Protein-2 Rejuvenates Senescent Endothelial Progenitor Cells and Induces Angiogenesis in Vivo. Sci Rep 2020; 10:6646. [PMID: 32313103 PMCID: PMC7171137 DOI: 10.1038/s41598-020-63716-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 04/06/2020] [Indexed: 01/16/2023] Open
Abstract
Cell cycle slowdown or arrest is a prominent feature of cellular senescence. S-phase kinase-associated protein-2 (Skp2), an F-box subunit of SCFSkp2 ubiquitin ligase, is a key regulator of G1/S transition. We investigated whether Skp2 plays a role in the regulation of endothelial progenitor cell (EPC) senescence, which is closely associated with aging-related vasculopathy. Replication-induced senescent EPCs demonstrated more pronounced senescence markers and lower Skp2 levels in comparison with those of their younger counterparts. Depletion of Skp2 induced increases in senescence-associated β-galactosidase (SA-βGal) activity and a reduction of telomere length and generated a senescent bioenergetics profile, whereas adenoviral-mediated Skp2 expression reversed the relevant senescence. EPCs isolated from older rats displayed a reduced proliferation rate and increased SA-βGal activity, both of which were significantly reversed by Skp2 ectopic expression. In addition to reversing senescence, Skp2 also rescued the angiogenic activity of senescent EPCs in the ischemic hind limbs of nude mice. The results revealed that ectopic expression of Skp2 has the potential to rejuvenate senescent EPCs and rescue their angiogenic activity and thus may be pivotal in the development of novel strategies to manage aging-related vascular disease.
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15
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Smith SA, Newby AC, Bond M. Ending Restenosis: Inhibition of Vascular Smooth Muscle Cell Proliferation by cAMP. Cells 2019; 8:cells8111447. [PMID: 31744111 PMCID: PMC6912325 DOI: 10.3390/cells8111447] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/14/2019] [Accepted: 11/14/2019] [Indexed: 12/17/2022] Open
Abstract
Increased vascular smooth muscle cell (VSMC) proliferation contributes towards restenosis after angioplasty, vein graft intimal thickening and atherogenesis. The second messenger 3′ 5′ cyclic adenosine monophosphate (cAMP) plays an important role in maintaining VSMC quiescence in healthy vessels and repressing VSMC proliferation during resolution of vascular injury. Although the anti-mitogenic properties of cAMP in VSMC have been recognised for many years, it is only recently that we gained a detailed understanding of the underlying signalling mechanisms. Stimuli that elevate cAMP in VSMC inhibit G1-S phase cell cycle progression by inhibiting expression of cyclins and preventing S-Phase Kinase Associated Protein-2 (Skp2-mediated degradation of cyclin-dependent kinase inhibitors. Early studies implicated inhibition of MAPK signalling, although this does not fully explain the anti-mitogenic effects of cAMP. The cAMP effectors, Protein Kinase A (PKA) and Exchange Protein Activated by cAMP (EPAC) act together to inhibit VSMC proliferation by inducing Cyclic-AMP Response Element Binding protein (CREB) activity and inhibiting members of the RhoGTPases, which results in remodelling of the actin cytoskeleton. Cyclic-AMP induced actin remodelling controls proliferation by modulating the activity of Serum Response Factor (SRF) and TEA Domain Transcription Factors (TEAD), which regulate expression of genes required for proliferation. Here we review recent research characterising these mechanisms, highlighting novel drug targets that may allow the anti-mitogenic properties of cAMP to be harnessed therapeutically to limit restenosis.
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Affiliation(s)
| | | | - Mark Bond
- Correspondence: ; Tel.: +44-117-3423586
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16
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Ebrahimighaei R, McNeill MC, Smith SA, Wray JP, Ford KL, Newby AC, Bond M. Elevated cyclic-AMP represses expression of exchange protein activated by cAMP (EPAC1) by inhibiting YAP-TEAD activity and HDAC-mediated histone deacetylation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:1634-1649. [PMID: 31255721 DOI: 10.1016/j.bbamcr.2019.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/19/2019] [Accepted: 06/26/2019] [Indexed: 02/05/2023]
Abstract
Ligand-induced activation of Exchange Protein Activated by cAMP-1 (EPAC1) is implicated in numerous physiological and pathological processes, including cardiac fibrosis where changes in EPAC1 expression have been detected. However, little is known about how EPAC1 expression is regulated. Therefore, we investigated regulation of EPAC1 expression by cAMP in cardiac fibroblasts. Elevation of cAMP using forskolin, cAMP-analogues or adenosine A2B-receptor activation significantly reduced EPAC1 mRNA and protein levels and inhibited formation of F-actin stress fibres. Inhibition of actin polymerisation with cytochalasin-D, latrunculin-B or the ROCK inhibitor, Y-27632, mimicked effects of cAMP on EPAC1 mRNA and protein levels. Elevated cAMP also inhibited activity of an EPAC1 promoter-reporter gene, which contained a consensus binding element for TEAD, which is a target for inhibition by cAMP. Inhibition of TEAD activity using siRNA-silencing of its co-factors YAP and TAZ, expression of dominant-negative TEAD or treatment with YAP-TEAD inhibitors, significantly inhibited EPAC1 expression. However, whereas expression of constitutively-active YAP completely reversed forskolin inhibition of EPAC1-promoter activity it did not rescue EPAC1 mRNA levels. Chromatin-immunoprecipitation detected a significant reduction in histone3-lysine27-acetylation at the EPAC1 proximal promoter in response to forskolin stimulation. HDAC1/3 inhibition partially reversed forskolin inhibition of EPAC1 expression, which was completely rescued by simultaneously expressing constitutively active YAP. Taken together, these data demonstrate that cAMP downregulates EPAC1 gene expression via disrupting the actin cytoskeleton, which inhibits YAP/TAZ-TEAD activity in concert with HDAC-mediated histone deacetylation at the EPAC1 proximal promoter. This represents a novel negative feedback mechanism controlling EPAC1 levels in response to cAMP elevation.
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Affiliation(s)
- Reza Ebrahimighaei
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Madeleine C McNeill
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Sarah A Smith
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Jason P Wray
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Kerrie L Ford
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Andrew C Newby
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Mark Bond
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK.
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17
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Yu Q, Gratzke C, Wang R, Li B, Kuppermann P, Herlemann A, Tamalunas A, Wang Y, Rutz B, Ciotkowska A, Wang X, Strittmatter F, Waidelich R, Stief CG, Hennenberg M. A NAV2729-sensitive mechanism promotes adrenergic smooth muscle contraction and growth of stromal cells in the human prostate. J Biol Chem 2019; 294:12231-12249. [PMID: 31243101 DOI: 10.1074/jbc.ra119.007958] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/19/2019] [Indexed: 12/25/2022] Open
Abstract
Voiding symptoms in benign prostatic hyperplasia (BPH) are driven by prostate smooth muscle contraction and prostate growth. Smooth muscle contraction in the prostate and other organs critically depends on activation of the small monomeric GTPase RhoA and probably Rac1. A role of another GTPase, ADP-ribosylation factor 6 (ARF6), for smooth muscle contraction has been recently suggested by indirect evidence but remains to be proven for any organ. Here, we report effects of NAV2729, an inhibitor with assumed specificity for ARF6, in human prostate tissues and cultured prostate stromal cells (WPMY-1). NAV2729 (5 μm) inhibited neurogenic and α1-adrenergic contractions of human prostate tissues. Contractions induced by endothelin-1, by the thromboxane A2 agonist U46619, or by high molar KCl were not inhibited. Correlation analyses suggested up-regulation of prostatic ARF6 expression with increasing degree of BPH, as ARF6 expression increased with the content of prostate-specific antigen (PSA) of prostate tissues. NAV2729 inhibited ARF6 activity but not other GTPases (ARF1, RhoA, Rac1) in prostate tissues and in WPMY-1 cells. Proliferation of WPMY-1 cells was inhibited concentration-dependently by NAV2726, as reflected by decreased viability, 5-ethynyl-2'-deoxyuridine (EdU) assay, colony formation assay, and expression of Ki-67. Silencing of ARF6 expression mimicked effects of NAV2729 on viability and in the EdU assay. Effects of NAV2729 on viability and proliferation were attenuated in cells with silenced ARF6 expression. Our findings suggest that a NAV2729-sensitive mechanism promotes adrenergic contraction and stromal cell growth in the human prostate, which is probably ARF6-mediated. Similar actions in other organs and urodynamic effects of NAV2729 appear possible.
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Affiliation(s)
- Qingfeng Yu
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany; Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510230, China
| | - Christian Gratzke
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany; Department of Urology, University of Freiburg, Freiburg 79106, Germany
| | - Ruixiao Wang
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Bingsheng Li
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Paul Kuppermann
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Annika Herlemann
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Alexander Tamalunas
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Yiming Wang
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Beata Rutz
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Anna Ciotkowska
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Xiaolong Wang
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Frank Strittmatter
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Raphaela Waidelich
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Christian G Stief
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Martin Hennenberg
- Department of Urology, University Hospital, LMU Munich, 81377 Munich, Germany.
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18
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Ruffoni A, Ferri N, Pinto A, Pellegrino S, Contini A, Clerici F. Identification of the first enantiopure Rac1-Tiam1 protein-protein interaction inhibitor and its optimized synthesis via phosphine free remote group directed hydroarylation. MEDCHEMCOMM 2018; 10:310-314. [PMID: 30931091 DOI: 10.1039/c8md00477c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/21/2018] [Indexed: 01/24/2023]
Abstract
A phospine free hydroarylation reaction applied to norbornene derivatives is described for the first time and was exploited for the regioselective gram scale synthesis of AR-148, a known Rac1-Tiam1 PPI inhibitor. Umpolung conversion of the nitro group into free amine allowed the regiocontrol of the key arylation step via a long range effect. The effect of AR-148 in comparison with its enantiomers on Rac1 activation of has been evaluated and (-)AR-148 has been identified as the first enantiomerically pure inhibitor of Rac1-Tiam1 PPI.
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Affiliation(s)
- Alessandro Ruffoni
- School of Chemistry , University of Manchester , Manchester , M13 9PL , UK .
| | - Nicola Ferri
- Department of Pharmaceutical and Pharmacological Sciences , Via Marzolo 5 , 35131 Padua , Italy
| | - Andrea Pinto
- Department of Food, Environmental and Nutritional Sciences (DeFENS) , Via Mangiagalli 25 , 20133 Milano , Italy
| | - Sara Pellegrino
- Department of Pharmaceutical Sciences , General and Organic Chemistry Section "Alessandro Marchesini" , Via Venezian 21 , 20133 Milano , Italy .
| | - Alessandro Contini
- Department of Pharmaceutical Sciences , General and Organic Chemistry Section "Alessandro Marchesini" , Via Venezian 21 , 20133 Milano , Italy .
| | - Francesca Clerici
- Department of Pharmaceutical Sciences , General and Organic Chemistry Section "Alessandro Marchesini" , Via Venezian 21 , 20133 Milano , Italy .
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19
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Chen MC, Tsai YC, Tseng JH, Liou JJ, Horng S, Wen HC, Fan YC, Zhong WB, Hsu SP. Simvastatin Inhibits Cell Proliferation and Migration in Human Anaplastic Thyroid Cancer. Int J Mol Sci 2017; 18:ijms18122690. [PMID: 29236027 PMCID: PMC5751292 DOI: 10.3390/ijms18122690] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 11/29/2017] [Accepted: 12/09/2017] [Indexed: 12/12/2022] Open
Abstract
Malignant human anaplastic thyroid cancer (ATC) is pertinacious to conventional therapies. The present study investigated the anti-cancer activity of simvastatin and its underlying regulatory mechanism in cultured ATC cells. Simvastatin (0–20 μM) concentration-dependently reduced cell viability and relative colony formation. Depletions of mevalonate (MEV) and geranylgeranyl pyrophosphate (GGpp) by simvastatin induced G1 arrest and increased apoptotic cell populations at the sub-G1 phase. Adding MEV and GGpp prevented the simvastatin-inhibited cell proliferation. Immunoblotting analysis illustrated that simvastatin diminished the activation of RhoA and Rac1 protein, and this effect was prevented by pre-treatment with MEV and GGpp. Simvastatin increased the levels of p21cip and p27kip proteins and reduced the levels of hyperphosphorylated-Rb, E2F1 and CCND1 proteins. Adding GGpp abolished the simvastatin-increased levels of p27kip protein, and the GGpp-caused effect was abolished by Skp2 inhibition. Introduction of Cyr61 siRNA into ATC cells prevented the epidermal growth factor (EGF)-enhanced cell migration. The EGF-induced increases of Cyr61 protein expression and cell migration were prevented by simvastatin. Taken together, these results suggest that simvastatin induced ATC proliferation inhibition through the deactivation of RhoA/Rac1 protein and overexpression of p21cip and p27kip, and migration inhibition through the abrogation of Cyr61 protein expression.
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Affiliation(s)
- Mei-Chieh Chen
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
| | - Yuan-Chin Tsai
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan.
| | - Jen-Ho Tseng
- Department of Neurosurgery, Taipei City Hospital, Renai Branch, Taipei 106, Taiwan.
| | - Jr-Jiun Liou
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
| | - Steve Horng
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan.
| | - Heng-Ching Wen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
| | - Yu-Ching Fan
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan.
| | - Wen-Bin Zhong
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
| | - Sung-Po Hsu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
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Contini A, Ferri N, Bucci R, Lupo MG, Erba E, Gelmi ML, Pellegrino S. Peptide modulators of Rac1/Tiam1 protein-protein interaction: An alternative approach for cardiovascular diseases. Biopolymers 2017; 110. [PMID: 29178143 DOI: 10.1002/bip.23089] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/25/2017] [Accepted: 10/30/2017] [Indexed: 01/01/2023]
Abstract
Rac1 GTPase interaction with guanine nucleotide exchange factor Tiam1 is involved in several cancer types and cardiovascular diseases. Although small molecules interfering with their protein-protein interaction (PPI) were identified and studied, the ability of small peptides and peptide mimics acting as Rac1/Tiam1 PPI inhibitors has not been yet explored. Using computational alanine scanning (CAS), the "hot" interfacial residues have been determined allowing the design of a small library of putative PPI inhibitors. In particular, the insertion of an unnatural alpha, alpha disubstituted amino acid, that is norbornane amino acid, and the side chain stapling have been evaluated regarding both conformational stability and biological activity. REMD calculations and CD studies have indicated that one single norbornane amino acid at the N-terminus is not sufficient to stabilize the helix structure, while the side-chain stapling is a more efficient strategy. Furthermore, both engineered peptides have been found able to reduce Rac1-GTP levels in cultured human smooth muscle cells, while wild type sequence is not active.
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Affiliation(s)
- Alessandro Contini
- Department of Pharmaceutical Sciences, University of Milano, Milano, Italy
| | - Nicola Ferri
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padua, Italy
| | - Raffaella Bucci
- Department of Pharmaceutical Sciences, University of Milano, Milano, Italy
| | - Maria Giovanna Lupo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padua, Italy
| | - Emanuela Erba
- Department of Pharmaceutical Sciences, University of Milano, Milano, Italy
| | - Maria Luisa Gelmi
- Department of Pharmaceutical Sciences, University of Milano, Milano, Italy
| | - Sara Pellegrino
- Department of Pharmaceutical Sciences, University of Milano, Milano, Italy
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21
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Abstract
Smooth muscle contraction requires both myosin activation and actin cytoskeletal remodeling. Actin cytoskeletal reorganization facilitates smooth muscle contraction by promoting force transmission between the contractile unit and the extracellular matrix (ECM), and by enhancing intercellular mechanical transduction. Myosin may be viewed to serve as an "engine" for smooth muscle contraction whereas the actin cytoskeleton may function as a "transmission system" in smooth muscle. The actin cytoskeleton in smooth muscle also undergoes restructuring upon activation with growth factors or the ECM, which controls smooth muscle cell proliferation and migration. Abnormal smooth muscle contraction, cell proliferation, and motility contribute to the development of vascular and pulmonary diseases. A number of actin-regulatory proteins including protein kinases have been discovered to orchestrate actin dynamics in smooth muscle. In particular, Abelson tyrosine kinase (c-Abl) is an important molecule that controls actin dynamics, contraction, growth, and motility in smooth muscle. Moreover, c-Abl coordinates the regulation of blood pressure and contributes to the pathogenesis of airway hyperresponsiveness and vascular/airway remodeling in vivo. Thus, c-Abl may be a novel pharmacological target for the development of new therapy to treat smooth muscle diseases such as hypertension and asthma.
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Affiliation(s)
- Dale D Tang
- Albany Medical College, Albany, NY, United States.
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22
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YAP determines the cell fate of injured mouse hepatocytes in vivo. Nat Commun 2017; 8:16017. [PMID: 28681838 PMCID: PMC5504293 DOI: 10.1038/ncomms16017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 05/22/2017] [Indexed: 01/05/2023] Open
Abstract
The presence of senescent, transformed or damaged cells can impair tissue function or lead to tumorigenesis; therefore, organisms have evolved quality control mechanisms to eliminate them. Here, we show that YAP activation induced by inactivation of the Hippo pathway specifically in damaged hepatocytes promotes their selective elimination by using in vivo mosaic analysis in mouse liver. These damaged hepatocytes migrate into the hepatic sinusoids, undergo apoptosis and are engulfed by Kupffer cells. In contrast, YAP activation in undamaged hepatocytes leads to proliferation. Cellular stresses such as ethanol that damage both liver sinusoidal endothelial cells and hepatocytes switch cell fate from proliferation to migration/apoptosis in the presence of activated YAP. This involves the activation of CDC42 and Rac that regulate cell migration. Thus, we suggest that YAP acts as a stress sensor that induces elimination of injured cells to maintain tissue and organ homeostasis. Senescent and injured cells affect tissue functions and can drive tumorigenesis. Thus, efficient elimination of these cells is pivotal for tissue integrity. Here Miyamura et al. show that YAP acts as a cellular stress sensor and promotes the elimination of damaged cells to maintain tissue homeostasis.
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Divergent Regulation of Actin Dynamics and Megakaryoblastic Leukemia-1 and -2 (Mkl1/2) by cAMP in Endothelial and Smooth Muscle Cells. Sci Rep 2017. [PMID: 28623279 PMCID: PMC5473867 DOI: 10.1038/s41598-017-03337-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Proliferation and migration of vascular smooth muscle cells (VSMCs) or endothelial cell (ECs) promote or inhibit, respectively, restenosis after angioplasty, vein graft intimal thickening and atherogenesis. Here we investigated the effects of cAMP-induced cytoskeletal remodelling on the serum response factor (SRF) co-factors Megakaryoblastic Leukemia-1 and -2 (MKL1 and MKL2) and their role in controlling VSMC and EC proliferation and migration. Elevation of cAMP using forskolin, dibutyryl-cAMP (db-cAMP), BAY60-6583 or Cicaprost induced rapid cytoskeleton remodelling and inhibited proliferation and migration in VSMCs but not EC. Furthermore, elevated cAMP inhibited mitogen-induced nuclear-translocation of MKL1 and MKL2 in VSMCs but not ECs. Forskolin also significantly inhibited serum response factor (SRF)-dependent reporter gene (SRE-LUC) activity and mRNA expression of pro-proliferative and pro-migratory MKL1/2 target genes in VSMCs but not in ECs. In ECs, MKL1 was constitutively nuclear and MKL2 cytoplasmic, irrespective of mitogens or cAMP. Pharmacological or siRNA inhibition of MKL1 significantly inhibited the proliferation and migration of VSMC and EC. Our new data identifies and important contribution of MKL1/2 to explaining the strikingly different response of VSMCs and ECs to cAMP elevation. Elucidation of these pathways promises to identify targets for specific inhibition of VSMC migration and proliferation.
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Kimura TE, Duggirala A, Smith MC, White S, Sala-Newby GB, Newby AC, Bond M. The Hippo pathway mediates inhibition of vascular smooth muscle cell proliferation by cAMP. J Mol Cell Cardiol 2016; 90:1-10. [PMID: 26625714 PMCID: PMC4727789 DOI: 10.1016/j.yjmcc.2015.11.024] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/05/2015] [Accepted: 11/20/2015] [Indexed: 12/30/2022]
Abstract
AIMS Inhibition of vascular smooth muscle cell (VSMC) proliferation by intracellular cAMP prevents excessive neointima formation and hence angioplasty restenosis and vein-graft failure. These protective effects are mediated via actin-cytoskeleton remodelling and subsequent regulation of gene expression by mechanisms that are incompletely understood. Here we investigated the role of components of the growth-regulatory Hippo pathway, specifically the transcription factor TEAD and its co-factors YAP and TAZ in VSMC. METHODS AND RESULTS Elevation of cAMP using forskolin, dibutyryl-cAMP or the physiological agonists, Cicaprost or adenosine, significantly increased phosphorylation and nuclear export YAP and TAZ and inhibited TEAD-luciferase report gene activity. Similar effects were obtained by inhibiting RhoA activity with C3-transferase, its downstream kinase, ROCK, with Y27632, or actin-polymerisation with Latrunculin-B. Conversely, expression of constitutively-active RhoA reversed the inhibitory effects of forskolin on TEAD-luciferase. Forskolin significantly inhibited the mRNA expression of the pro-mitogenic genes, CCN1, CTGF, c-MYC and TGFB2 and this was reversed by expression of constitutively-active YAP or TAZ phospho-mutants. Inhibition of YAP and TAZ function with RNAi or Verteporfin significantly reduced VSMC proliferation. Furthermore, the anti-mitogenic effects of forskolin were reversed by overexpression of constitutively-active YAP or TAZ. CONCLUSION Taken together, these data demonstrate that cAMP-induced actin-cytoskeleton remodelling inhibits YAP/TAZ-TEAD dependent expression of pro-mitogenic genes in VSMC. This mechanism contributes novel insight into the anti-mitogenic effects of cAMP in VSMC and suggests a new target for intervention.
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Affiliation(s)
- Tomomi E Kimura
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol BS2 8HW, UK
| | - Aparna Duggirala
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol BS2 8HW, UK
| | - Madeleine C Smith
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol BS2 8HW, UK
| | - Stephen White
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol BS2 8HW, UK
| | - Graciela B Sala-Newby
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol BS2 8HW, UK
| | - Andrew C Newby
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol BS2 8HW, UK
| | - Mark Bond
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol BS2 8HW, UK.
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25
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Vosper J, Masuccio A, Kullmann M, Ploner C, Geley S, Hengst L. Statin-induced depletion of geranylgeranyl pyrophosphate inhibits cell proliferation by a novel pathway of Skp2 degradation. Oncotarget 2015; 6:2889-902. [PMID: 25605247 PMCID: PMC4413625 DOI: 10.18632/oncotarget.3068] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/21/2014] [Indexed: 12/18/2022] Open
Abstract
Statins, such as lovastatin, can induce a cell cycle arrest in the G1 phase. This robust antiproliferative activity remains intact in many cancer cells that are deficient in cell cycle checkpoints and leads to an increased expression of CDK inhibitor proteins p27Kip1 and p21Cip1. The molecular details of this statin-induced growth arrest remains unclear. Here we present evidence that lovastatin can induce the degradation of Skp2, a subunit of the SCFSkp2 ubiquitin ligase that targets p27Kip1 and p21Cip1 for proteasomal destruction. The statin-induced degradation of Skp2 is cell cycle phase independent and does not require its well characterised degradation pathway mediated by APC/CCdh1- or Skp2 autoubiquitination. An N-terminal domain preceding the F-box of Skp2 is both necessary and sufficient for its statin mediated degradation. The degradation of Skp2 results from statin induced depletion of geranylgeranyl isoprenoid intermediates of cholesterol biosynthesis. Inhibition of geranylgeranyl-transferase-I also promotes APC/CCdh1- independent degradation of Skp2, indicating that de-modification of a geranylgeranylated protein triggers this novel pathway of Skp2 degradation.
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Affiliation(s)
- Jonathan Vosper
- Division of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Alessia Masuccio
- Division of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael Kullmann
- Division of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Christian Ploner
- Division of Molecular Pathophysiology, Biocenter/Clinic of Plastic and Reconstructive Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Stephan Geley
- Division of Molecular Pathophysiology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Ludger Hengst
- Division of Medical Biochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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26
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Parnell E, Palmer TM, Yarwood SJ. The future of EPAC-targeted therapies: agonism versus antagonism. Trends Pharmacol Sci 2015; 36:203-14. [PMID: 25744542 PMCID: PMC4392396 DOI: 10.1016/j.tips.2015.02.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/03/2015] [Accepted: 02/05/2015] [Indexed: 02/06/2023]
Abstract
Although tractable to drug development, targeting of cAMP signalling has side effects. Selectively targeting EPAC1 and EPAC2 cAMP sensor enzymes may limit some of these off-target effects. EPAC agonists could be used to treat vascular inflammation (EPAC1) or type 2 diabetes (EPAC2). EPAC1 and EPAC2 antagonists could be used to treat heart disease.
Pharmaceutical manipulation of cAMP levels exerts beneficial effects through the regulation of the exchange protein activated by cAMP (EPAC) and protein kinase A (PKA) signalling routes. Recent attention has turned to the specific regulation of EPAC isoforms (EPAC1 and EPAC2) as a more targeted approach to cAMP-based therapies. For example, EPAC2-selective agonists could promote insulin secretion from pancreatic β cells, whereas EPAC1-selective agonists may be useful in the treatment of vascular inflammation. By contrast, EPAC1 and EPAC2 antagonists could both be useful in the treatment of heart failure. Here we discuss whether the best way forward is to design EPAC-selective agonists or antagonists and the current strategies being used to develop isoform-selective, small-molecule regulators of EPAC1 and EPAC2 activity.
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Affiliation(s)
- Euan Parnell
- Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Timothy M Palmer
- School of Pharmacy, University of Bradford, Bradford BD7 1DP, UK
| | - Stephen J Yarwood
- Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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27
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LAN LEI, HAN YONGSHENG, REN WEI, JIANG JIELONG, WANG PENG, HU ZHAO. Advanced glycation end-products affect the cytoskeletal structure of rat glomerular endothelial cells via the Ras-related C3 botulinum toxin substrate 1 signaling pathway. Mol Med Rep 2015; 11:4321-6. [DOI: 10.3892/mmr.2015.3317] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 12/09/2014] [Indexed: 11/06/2022] Open
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28
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Duggirala A, Kimura TE, Sala-Newby GB, Johnson JL, Wu YJ, Newby AC, Bond M. cAMP-induced actin cytoskeleton remodelling inhibits MKL1-dependent expression of the chemotactic and pro-proliferative factor, CCN1. J Mol Cell Cardiol 2015; 79:157-68. [PMID: 25446180 PMCID: PMC4312355 DOI: 10.1016/j.yjmcc.2014.11.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/24/2014] [Accepted: 11/12/2014] [Indexed: 12/17/2022]
Abstract
Elevation of intracellular cAMP concentration has numerous vascular protective effects that are in part mediated via actin cytoskeleton-remodelling and subsequent regulation of gene expression. However, the mechanisms are incompletely understood. Here we investigated whether cAMP-induced actin-cytoskeleton remodelling modulates VSMC behaviour by inhibiting expression of CCN1. In cultured rat VSMC, CCN1-silencing significantly inhibited BrdU incorporation and migration in a wound healing assay. Recombinant CCN1 enhanced chemotaxis in a Boyden chamber. Adding db-cAMP, or elevating cAMP using forskolin, significantly inhibited CCN1 mRNA and protein expression in vitro; transcriptional regulation was demonstrated by measuring pre-spliced CCN1 mRNA and CCN1-promoter activity. Forskolin also inhibited CCN1 expression in balloon injured rat carotid arteries in vivo. Inhibiting RhoA activity, which regulates actin-polymerisation, by cAMP-elevation or pharmacologically with C3-transferase, or inhibiting its downstream kinase, ROCK, with Y27632, significantly inhibited CCN1 expression. Conversely, expression of constitutively active RhoA reversed the inhibitory effects of forskolin on CCN1 mRNA. Furthermore, CCN1 mRNA levels were significantly decreased by inhibiting actin-polymerisation with latrunculin B or increased by stimulating actin-polymerisation with Jasplakinolide. We next tested the role of the actin-dependent SRF co-factor, MKL1, in CCN1 expression. Forskolin inhibited nuclear translocation of MKL1 and binding of MKL1 to the CCN1 promoter. Constitutively-active MKL1 enhanced basal promoter activity of wild-type but not SRE-mutated CCN1; and prevented forskolin inhibition. Furthermore, pharmacological MKL-inhibition with CCG-1423 significantly inhibited CCN1 promoter activity as well as mRNA and protein expression. Our data demonstrates that cAMP-induced actin-cytoskeleton remodelling regulates expression of CCN1 through MKL1: it highlights a novel cAMP-dependent mechanism controlling VSMC behaviour.
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Affiliation(s)
- Aparna Duggirala
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol, BS2 8HW, UK
| | - Tomomi E Kimura
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol, BS2 8HW, UK
| | - Graciela B Sala-Newby
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol, BS2 8HW, UK
| | - Jason L Johnson
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol, BS2 8HW, UK
| | - Yih-Jer Wu
- Department of Medicine, MacKay Medical College, New Taipei, Taiwan; Cardiovascular Division, Department of Internal Medicine, MacKay Memorial Hospital, New Taipei, Taiwan
| | - Andrew C Newby
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol, BS2 8HW, UK
| | - Mark Bond
- Bristol Heart Institute, School of Clinical Sciences, University of Bristol, Bristol, BS2 8HW, UK.
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29
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Dirat B, Ader I, Golzio M, Massa F, Mettouchi A, Laurent K, Larbret F, Malavaud B, Cormont M, Lemichez E, Cuvillier O, Tanti JF, Bost F. Inhibition of the GTPase Rac1 mediates the antimigratory effects of metformin in prostate cancer cells. Mol Cancer Ther 2014; 14:586-96. [PMID: 25527635 DOI: 10.1158/1535-7163.mct-14-0102] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cell migration is a critical step in the progression of prostate cancer to the metastatic state, the lethal form of the disease. The antidiabetic drug metformin has been shown to display antitumoral properties in prostate cancer cell and animal models; however, its role in the formation of metastases remains poorly documented. Here, we show that metformin reduces the formation of metastases to fewer solid organs in an orthotopic metastatic prostate cancer cell model established in nude mice. As predicted, metformin hampers cell motility in PC3 and DU145 prostate cancer cells and triggers a radical reorganization of the cell cytoskeleton. The small GTPase Rac1 is a master regulator of cytoskeleton organization and cell migration. We report that metformin leads to a major inhibition of Rac1 GTPase activity by interfering with some of its multiple upstream signaling pathways, namely P-Rex1 (a Guanine nucleotide exchange factor and activator of Rac1), cAMP, and CXCL12/CXCR4, resulting in decreased migration of prostate cancer cells. Importantly, overexpression of a constitutively active form of Rac1, or P-Rex, as well as the inhibition of the adenylate cyclase, was able to reverse the antimigratory effects of metformin. These results establish a novel mechanism of action for metformin and highlight its potential antimetastatic properties in prostate cancer.
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Affiliation(s)
- Béatrice Dirat
- INSERM, C3M, U1065, Team Cellular and Molecular Physiopathology of Obesity and Diabetes, Nice, France. Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France
| | - Isabelle Ader
- CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France. Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Muriel Golzio
- CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France. Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Fabienne Massa
- INSERM, C3M, U1065, Team Cellular and Molecular Physiopathology of Obesity and Diabetes, Nice, France. Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France
| | - Amel Mettouchi
- Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France. INSERM, C3M, U1065, Equipe Labellisée Ligue Contre le Cancer, Team Microtoxins in Host Pathogens Interactions, Nice, France
| | - Kathiane Laurent
- INSERM, C3M, U1065, Team Cellular and Molecular Physiopathology of Obesity and Diabetes, Nice, France. Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France
| | - Frédéric Larbret
- University of Nice Sophia Antipolis, EA6302, Flow Cytometry Facility, Hôpital l'Archet 1, Nice, France
| | - Bernard Malavaud
- CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France. Université de Toulouse, UPS, IPBS, Toulouse, France. Hôpital Rangueil, Service d'Urologie et de Transplantation Rénale, Toulouse, France
| | - Mireille Cormont
- INSERM, C3M, U1065, Team Cellular and Molecular Physiopathology of Obesity and Diabetes, Nice, France. Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France
| | - Emmanuel Lemichez
- Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France. INSERM, C3M, U1065, Equipe Labellisée Ligue Contre le Cancer, Team Microtoxins in Host Pathogens Interactions, Nice, France
| | - Olivier Cuvillier
- CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France. Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Jean François Tanti
- INSERM, C3M, U1065, Team Cellular and Molecular Physiopathology of Obesity and Diabetes, Nice, France. Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France
| | - Frédéric Bost
- INSERM, C3M, U1065, Team Cellular and Molecular Physiopathology of Obesity and Diabetes, Nice, France. Univ. Nice Sophia Antipolis, C3M, U1065, Nice, France.
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30
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Genetic dissection of the vav2-rac1 signaling axis in vascular smooth muscle cells. Mol Cell Biol 2014; 34:4404-19. [PMID: 25288640 DOI: 10.1128/mcb.01066-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vascular smooth muscle cells (vSMCs) are key in the regulation of blood pressure and the engagement of vascular pathologies, such as hypertension, arterial remodeling, and neointima formation. The role of the Rac1 GTPase in these cells remains poorly characterized. To clarify this issue, we have utilized genetically engineered mice to manipulate the signaling output of Rac1 in these cells at will using inducible, Cre-loxP-mediated DNA recombination techniques. Here, we show that the expression of an active version of the Rac1 activator Vav2 exclusively in vSMCs leads to hypotension as well as the elimination of the hypertension induced by the systemic loss of wild-type Vav2. Conversely, the specific depletion of Rac1 in vSMCs causes defective nitric oxide vasodilation responses and hypertension. Rac1, but not Vav2, also is important for neointima formation but not for hypertension-driven vascular remodeling. These animals also have allowed us to dismiss etiological connections between hypertension and metabolic disease and, most importantly, identify pathophysiological programs that cooperate in the development and consolidation of hypertensive states caused by local vascular tone dysfunctions. Finally, our results suggest that the therapeutic inhibition of Rac1 will be associated with extensive cardiovascular system-related side effects and identify pharmacological avenues to circumvent them.
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31
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Kimura TE, Duggirala A, Hindmarch CCT, Hewer RC, Cui MZ, Newby AC, Bond M. Inhibition of Egr1 expression underlies the anti-mitogenic effects of cAMP in vascular smooth muscle cells. J Mol Cell Cardiol 2014; 72:9-19. [PMID: 24534707 PMCID: PMC4051994 DOI: 10.1016/j.yjmcc.2014.02.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/30/2014] [Accepted: 02/01/2014] [Indexed: 01/23/2023]
Abstract
AIMS Cyclic AMP inhibits vascular smooth muscle cell (VSMC) proliferation which is important in the aetiology of numerous vascular diseases. The anti-mitogenic properties of cAMP in VSMC are dependent on activation of protein kinase A (PKA) and exchange protein activated by cAMP (EPAC), but the mechanisms are unclear. METHODS AND RESULTS Selective agonists of PKA and EPAC synergistically inhibited Egr1 expression, which was essential for VSMC proliferation. Forskolin, adenosine, A2B receptor agonist BAY60-6583 and Cicaprost also inhibited Egr1 expression in VSMC but not in endothelial cells. Inhibition of Egr1 by cAMP was independent of cAMP response element binding protein (CREB) activity but dependent on inhibition of serum response element (SRE) activity. SRF binding to the Egr1 promoter was not modulated by cAMP stimulation. However, Egr1 expression was dependent on the SRF co-factors Elk1 and 4 but independent of MAL. Inhibition of SRE-dependent Egr1 expression was due to synergistic inhibition of Rac1 activity by PKA and EPAC, resulting in rapid cytoskeleton remodelling and nuclear export of ERK1/2. This was associated with de-phosphorylation of the SRF co-factor Elk1. CONCLUSION cAMP inhibits VSMC proliferation by rapidly inhibiting Egr1 expression. This occurs, at least in part, via inhibition of Rac1 activity leading to rapid actin-cytoskeleton remodelling, nuclear export of ERK1/2, impaired Elk1-phosphorylation and inhibition of SRE activity. This identifies one of the earliest mechanisms underlying the anti-mitogenic effects of cAMP in VSMC but not in endothelial cells, making it an attractive target for selective inhibition of VSMC proliferation.
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MESH Headings
- Adenosine/pharmacology
- Aminopyridines/pharmacology
- Animals
- Cell Proliferation/drug effects
- Colforsin/pharmacology
- Cyclic AMP/pharmacology
- Cyclic AMP Response Element-Binding Protein/genetics
- Cyclic AMP Response Element-Binding Protein/metabolism
- Cyclic AMP-Dependent Protein Kinases/genetics
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Early Growth Response Protein 1/antagonists & inhibitors
- Early Growth Response Protein 1/genetics
- Early Growth Response Protein 1/metabolism
- Epoprostenol/analogs & derivatives
- Epoprostenol/pharmacology
- Gene Expression Regulation
- Guanine Nucleotide Exchange Factors/genetics
- Guanine Nucleotide Exchange Factors/metabolism
- Human Umbilical Vein Endothelial Cells/cytology
- Human Umbilical Vein Endothelial Cells/drug effects
- Human Umbilical Vein Endothelial Cells/metabolism
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Organ Specificity
- Primary Cell Culture
- Protein Binding
- Rats
- Rats, Sprague-Dawley
- Serum Response Factor/genetics
- Serum Response Factor/metabolism
- Signal Transduction
- ets-Domain Protein Elk-1/genetics
- ets-Domain Protein Elk-1/metabolism
- rac1 GTP-Binding Protein/genetics
- rac1 GTP-Binding Protein/metabolism
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Affiliation(s)
- Tomomi E Kimura
- Bristol Heart Institute, University of Bristol, Bristol BS2 8HW, UK
| | - Aparna Duggirala
- Bristol Heart Institute, University of Bristol, Bristol BS2 8HW, UK
| | - Charles C T Hindmarch
- Laboratory for Integrative Neuroscience & Endocrinology, University of Bristol, Bristol BS2 8HW, UK; University of Malaya, Department of Physiology, Faculty of Medicine, Kuala Lumpur, Malaysia
| | - Richard C Hewer
- Bristol Heart Institute, University of Bristol, Bristol BS2 8HW, UK
| | - Mei-Zhen Cui
- Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, USA
| | - Andrew C Newby
- Bristol Heart Institute, University of Bristol, Bristol BS2 8HW, UK
| | - Mark Bond
- Bristol Heart Institute, University of Bristol, Bristol BS2 8HW, UK.
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32
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Role of small GTPase protein Rac1 in cardiovascular diseases: development of new selective pharmacological inhibitors. J Cardiovasc Pharmacol 2014; 62:425-35. [PMID: 23921306 DOI: 10.1097/fjc.0b013e3182a18bcc] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A pathway-based genome-wide association analysis has recently identified Rac1 as one of the biologically important gene in coronary heart diseases. The role of the small GTPase Rac1 in cardiac hypertrophy and atherosclerosis has also been documented in clinical studies with the HMG-CoA reductase inhibitors and in in vitro and in vivo settings using transgenic and knockout mice. Thus, Rac1 has emerged as a new pharmacological target for the treatment of cardiovascular diseases. The activation state of Rac1 depends on the release of guanosine diphosphate and the binding of guanosine triphosphate. This cycling is regulated by the guanine nucleotide exchange factors, as activators, and by the GTPase-activating proteins. Three categories of selective Rac1 inhibitors have been developed affecting different steps of this pathway: antagonists of Rac1-guanine nucleotide exchange factor interaction, allosteric inhibitors of nucleotide binding to Rac1, and antagonists of Rac1-mediated NADPH oxidase activity. These chemical compounds have shown to selectively inhibit Rac1 activation in cultured cell lines without affecting the homologous proteins RhoA and Cdc42. Moreover, pioneer studies have been conducted with Rac1 inhibitors in in vivo experimental models of cardiovascular diseases with encouraging results. The present review summarizes the current knowledge of the role of Rac1 in cardiovascular diseases and the pharmacological approaches that have been developed to selectively inhibit its function.
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Moreno-Layseca P, Streuli CH. Signalling pathways linking integrins with cell cycle progression. Matrix Biol 2014; 34:144-53. [DOI: 10.1016/j.matbio.2013.10.011] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/22/2013] [Accepted: 10/22/2013] [Indexed: 12/30/2022]
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Nakayama A, Nakayama M, Turner CJ, Höing S, Lepore JJ, Adams RH. Ephrin-B2 controls PDGFRβ internalization and signaling. Genes Dev 2014; 27:2576-89. [PMID: 24298057 PMCID: PMC3861671 DOI: 10.1101/gad.224089.113] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ephrin-B2 is essential for supporting mural cells; namely, pericytes and vascular smooth muscle cells (VSMCs). Nakayama et al. find that ephrin-B2 controls platelet-derived growth factor receptor β (PDGFRβ) distribution in the VSMC plasma membrane, endocytosis, and signaling. VSMCs lacking ephrin-B2 exhibited a redistribution of PDGFRβ from caveolin-positive to clathrin-associated membrane fractions and enhanced PDGF-B-induced PDGFRβ internalization. Mice lacking ephrin-B2 in vascular smooth muscle developed vessel wall defects and aortic aneurysms. These results suggest that ephrin-B2 is an important regulator of PDGFRβ endocytosis in mural cells. B-class ephrins, ligands for EphB receptor tyrosine kinases, are critical regulators of growth and patterning processes in many organs and species. In the endothelium of the developing vasculature, ephrin-B2 controls endothelial sprouting and proliferation, which has been linked to vascular endothelial growth factor (VEGF) receptor endocytosis and signaling. Ephrin-B2 also has essential roles in supporting mural cells (namely, pericytes and vascular smooth muscle cells [VSMCs]), but the underlying mechanism is not understood. Here, we show that ephrin-B2 controls platelet-derived growth factor receptor β (PDGFRβ) distribution in the VSMC plasma membrane, endocytosis, and signaling in a fashion that is highly distinct from its role in the endothelium. Absence of ephrin-B2 in cultured VSMCs led to the redistribution of PDGFRβ from caveolin-positive to clathrin-associated membrane fractions, enhanced PDGF-B-induced PDGFRβ internalization, and augmented downstream mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK) activation but impaired Tiam1–Rac1 signaling and proliferation. Accordingly, mutant mice lacking ephrin-B2 expression in vascular smooth muscle developed vessel wall defects and aortic aneurysms, which were associated with impaired Tiam1 expression and excessive activation of MAP kinase and JNK. Our results establish that ephrin-B2 is an important regulator of PDGFRβ endocytosis and thereby acts as a molecular switch controlling the downstream signaling activity of this receptor in mural cells.
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Affiliation(s)
- Akiko Nakayama
- Department of Tissue Morphogenesis, Max-Planck-Institute for Molecular Biomedicine, D-48149 Münster, Germany
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Loirand G, Sauzeau V, Pacaud P. Small G Proteins in the Cardiovascular System: Physiological and Pathological Aspects. Physiol Rev 2013; 93:1659-720. [DOI: 10.1152/physrev.00021.2012] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Small G proteins exist in eukaryotes from yeast to human and constitute the Ras superfamily comprising more than 100 members. This superfamily is structurally classified into five families: the Ras, Rho, Rab, Arf, and Ran families that control a wide variety of cell and biological functions through highly coordinated regulation processes. Increasing evidence has accumulated to identify small G proteins and their regulators as key players of the cardiovascular physiology that control a large panel of cardiac (heart rhythm, contraction, hypertrophy) and vascular functions (angiogenesis, vascular permeability, vasoconstriction). Indeed, basal Ras protein activity is required for homeostatic functions in physiological conditions, but sustained overactivation of Ras proteins or spatiotemporal dysregulation of Ras signaling pathways has pathological consequences in the cardiovascular system. The primary object of this review is to provide a comprehensive overview of the current progress in our understanding of the role of small G proteins and their regulators in cardiovascular physiology and pathologies.
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Affiliation(s)
- Gervaise Loirand
- INSERM, UMR S1087; University of Nantes; and CHU Nantes, l'Institut du Thorax, Nantes, France
| | - Vincent Sauzeau
- INSERM, UMR S1087; University of Nantes; and CHU Nantes, l'Institut du Thorax, Nantes, France
| | - Pierre Pacaud
- INSERM, UMR S1087; University of Nantes; and CHU Nantes, l'Institut du Thorax, Nantes, France
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Ma J, Xue Y, Liu W, Yue C, Bi F, Xu J, Zhang J, Li Y, Zhong C, Chen Y. Role of activated Rac1/Cdc42 in mediating endothelial cell proliferation and tumor angiogenesis in breast cancer. PLoS One 2013; 8:e66275. [PMID: 23750283 PMCID: PMC3672132 DOI: 10.1371/journal.pone.0066275] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 05/03/2013] [Indexed: 01/09/2023] Open
Abstract
Angiogenesis is a well-established target in anti-cancer therapy. Although vascular endothelial growth factor (VEGF)-mediated angiogenesis apparently requires the Rho GTPases Rac1 and Cdc42, the relevant mechanisms are unclear. Here, we determined that activated Rac1/Cdc42 in MCF-7 breast cancer cells could decrease p53 protein levels and increase VEGF secretion to promote proliferation and tube formation of human umbilical vein endothelial cells (HUVECs). However, these effects are reversed after ubiquitin-proteasome breakage. In exploring potential mechanisms for this relationship, we confirmed that activated Rac1/Cdc42 could enhance p53 protein ubiquitination and weaken p53 protein stability to increase VEGF expression. Furthermore, in a xenograft model using nude mice that stably express active Rac1/Cdc42 protein, active Rac1/Cdc42 decreased p53 levels and increased VEGF expression. Additionally, tumor angiogenesis was inhibited, and p53 protein levels were augmented, by intratumoral injection of the ubiquitin-proteasome inhibitor MG132. Finally in 339 human breast cancer tissues, our analyses indicated that Rac1/Cdc42 expression was related to advanced TNM staging, high proliferation index, ER status, and positive invasive features. In particular, our data suggests that high Rac1/Cdc42 expression is correlated with low wt-p53 and high VEGF expression. We conclude that activated Rac1/Cdc42 is a vascular regulator of tumor angiogenesis and that it may reduce stability of the p53 protein to promote VEGF expression by enhancing p53 protein ubiquitin.
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Affiliation(s)
- Ji Ma
- Department of Oncology, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shannxi, China
- Department of Breast Surgery, Lanzhou General Hospital of People's Liberation Army, Lanzhou, Gansu, China
| | - Yan Xue
- Department of Oncology, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shannxi, China
- * E-mail:
| | - Wenchao Liu
- Department of Oncology, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shannxi, China
| | - Caixia Yue
- Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Feng Bi
- Laboratory of Signal Transduction and Molecular Targeted Therapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Junqing Xu
- Department of Radiology, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shannxi, China
| | - Jian Zhang
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi’an, Shannxi, China
| | - Yan Li
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi’an, Shannxi, China
| | - Cuiping Zhong
- Department of Ear Nose Throat Surgery, Lanzhou General Hospital of People's Liberation Army, Lanzhou, Gansu, China
| | - Yan Chen
- Department of Oncology, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shannxi, China
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Ferri N, Bernini SK, Corsini A, Clerici F, Erba E, Stragliotto S, Contini A. 3-Aryl-N-aminoylsulfonylphenyl-1H-pyrazole-5-carboxamides: a new class of selective Rac inhibitors. MEDCHEMCOMM 2013. [DOI: 10.1039/c2md20328f] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Attenuation of Monocrotaline-induced Pulmonary Arterial Hypertension in Rats by Rosuvastatin. J Cardiovasc Pharmacol 2012; 60:219-26. [PMID: 22592772 DOI: 10.1097/fjc.0b013e31825cce63] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bryant PW, Zheng Q, Pumiglia KM. Focal adhesion kinase is a phospho-regulated repressor of Rac and proliferation in human endothelial cells. Biol Open 2012; 1:723-30. [PMID: 23213465 PMCID: PMC3507225 DOI: 10.1242/bio.20121008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 05/15/2012] [Indexed: 11/06/2022] Open
Abstract
Focal adhesion kinase (FAK) is critically positioned to integrate signals from the extracellular matrix and cellular adhesion. It is essential for normal vascular development and has been implicated in a wide range of cellular functions including the regulation of cell proliferation, migration, differentiation, and survival. It is currently being actively targeted therapeutically using different approaches. We have used human endothelial cells as a model system to compare the effects of inhibiting FAK through several different approaches including dominant negatives, kinase inhibitors and shRNA. We find that manipulations of FAK signaling that result in inhibition of FAK 397 phosphorylation inhibit proliferation and migration. However, abolition of FAK expression using stable (shRNA) or transient (siRNA) approaches does not interfere with these cellular functions. The ability to regulate cell proliferation by FAK manipulation is correlated with the activation status of Rac, an essential signal for the regulation of cyclin-dependent kinase inhibitors. The knockdown of FAK, while not affecting cellular proliferation or migration, dramatically interferes with vascular morphogenesis and survival, mirroring in vivo findings. We propose a novel model of FAK signaling whereby one of the multifunctional roles of FAK as a signaling protein includes FAK as a phospho-regulated repressor of Rac activation, with important implications on interpretation of research experiments and therapeutic development.
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Affiliation(s)
- Patrick W Bryant
- Cell Biology and Cancer Research, Albany Medical College , Albany, NY 12208 , USA
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Demasi M, Laurindo FRM. Physiological and pathological role of the ubiquitin-proteasome system in the vascular smooth muscle cell. Cardiovasc Res 2012; 95:183-93. [PMID: 22451513 DOI: 10.1093/cvr/cvs128] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Vascular smooth muscle cell (VSMC) plasticity implies a capacity for rapid change and adaptability through processes requiring protein turnover. The ubiquitin-proteasome system (UPS) is at the core of protein turnover as the main pathway for the degradation of proteins related to cell-cycle regulation, signalling, apoptosis, and differentiation. This review briefly addresses some structural UPS aspects under the perspective of VSMC (patho)biology. The UPS loss-of-function promotes direct cell effects and many indirect effects related to the adaptation to apoptosis/survival signalling, oxidative stress, and endoplasmic reticulum stress. The UPS regulates redox homeostasis and is redox-regulated. Also, the UPS closely interacts with endoplasmic reticulum (ER) homeostasis as the effector of un/misfolded protein degradation, and ER stress is strongly involved in atherosclerosis. Inhibition of cell cycle-controlling ubiquitin ligases or the proteasome reduces VSMC proliferation and prevents modulation of their synthetic phenotype. Proteasome inhibition also strongly promotes VSMC apoptosis and reduces neointima. In atherosclerosis models, proteasome inhibitors display vasculoprotective effects and reduce inflammation. However, worsening of atherosclerosis or vascular dysfunction has also been reported. Proteasome inhibitors sensitize VSMC to increased ER stress-mediated cell death and suppress unfolded protein response signalling. Taken together, these observations show that the UPS has powerful effects in the control of VSMC phenotype and survival signalling. However, more profound knowledge of mechanisms is needed in order to render the UPS an operational therapeutic target.
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Affiliation(s)
- Marilene Demasi
- Laboratory of Biochemistry and Biophysics, Butantan Institute, São Paulo, Brazil
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Sicari BM, Troxell R, Salim F, Tanwir M, Takane KK, Fiaschi-Taesch N. c-myc and skp2 coordinate p27 degradation, vascular smooth muscle proliferation, and neointima formation induced by the parathyroid hormone-related protein. Endocrinology 2012; 153:861-72. [PMID: 22210745 DOI: 10.1210/en.2011-1590] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) contains a classical bipartite nuclear localization signal. Nuclear PTHrP induces proliferation of arterial vascular smooth muscle cells (VSMC). In the arterial wall, PTHrP is markedly up-regulated in response to angioplasty and promotes arterial restenosis. PTHrP overexpression exacerbates arterial restenosis, and knockout of the PTHrP gene results in decreased VSMC proliferation in vivo. In arterial VSMC, expression of the cell cycle inhibitor, p27, rapidly decreases after angioplasty, and replacement of p27 markedly reduces neointima development. We have shown that PTHrP overexpression in VSMC leads to p27 down-regulation, mostly through increased proteosomal degradation. Here, we determined the molecular mechanisms through which PTHrP targets p27 for degradation. S-phase kinase-associated protein 2 (skp2) and c-myc, two critical regulators of p27 expression and stability, and neointima formation were up-regulated in PTHrP overexpression in VSMC. Normalization of skp2 or c-myc using small interfering RNA restores normal cell cycle and p27 expression in PTHrP overexpression in VSMC. These data indicate that skp2 and c-myc mediate p27 loss and proliferation induced by PTHrP. c-myc promoter activity was increased, and c-myc target genes involved in p27 stability were up-regulated in PTHrP overexpression in VSMC. In primary VSMC, PTHrP overexpression led to increased c-myc and decreased p27. Conversely, knockdown of PTHrP in primary VSMC from PTHrP(flox/flox) mice led to cell cycle arrest, p27 up-regulation, with c-myc and skp2 down-regulation. Collectively, these data describe for the first time the role of PTHrP in the regulation of skp2 and c-myc in VSMC. This novel PTHrP-c-myc-skp2 pathway is a potential target for therapeutic manipulation of the arterial response to injury.
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Affiliation(s)
- Brian M Sicari
- Division of Endocrinology, University of Pittsburgh School of Medicine, 3550 Terrace Street, Pittsburgh, Pennsylvania 15213, USA
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Involvement of the SKP2-p27(KIP1) pathway in suppression of cancer cell proliferation by RECK. Oncogene 2011; 31:4128-38. [PMID: 22158033 DOI: 10.1038/onc.2011.570] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The membrane-anchored matrix metalloproteinase-regulator RECK is often downregulated in cancers; in some cases, a significant correlation between the level of residual RECK in resected tumors and patient survival has been noted. Furthermore, restoration of RECK expression in certain cancer-derived cell lines results in reduced tumorigenicity. Here we report that acute RECK expression in colon carcinoma cells results in cell cycle-arrest accompanied by downregulation of a ubiquitin ligase component, S-phase kinase-associated protein 2 (SKP2), and upregulation of its substrate, p27(KIP1). Our data indicate that RECK-induced growth suppression is at least partially dependent on p27, and that RECK and type I collagen share similar effects on the SKP2-p27 pathway. Importantly, in patients with lung, colorectal and bladder cancers, the RECK/SKP2 ratio is high in normal tissues and lower in the cancer tissues. These findings reveal a novel molecular pathway linking cell-cycle progression to RECK downregulation, extracellular matrix degradation and SKP2 upregulation, and suggest that treatment regimens that induce RECK expression could be promising cancer therapies.
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Song P, Wang S, He C, Wang S, Liang B, Viollet B, Zou MH. AMPKα2 deletion exacerbates neointima formation by upregulating Skp2 in vascular smooth muscle cells. Circ Res 2011; 109:1230-9. [PMID: 21980125 DOI: 10.1161/circresaha.111.250423] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RATIONALE Adenosine monophosphate-activated protein kinase (AMPK), a metabolic and redox sensor, is reported to suppress cell proliferation of nonmalignant and tumor cells. Whether AMPKα alters vascular neointima formation induced by vascular injury is unknown. OBJECTIVE The aim of this study was to determine the roles of AMPKα in the development of vascular neointima hyperplasia and to elucidate the underlying mechanisms. METHODS AND RESULTS Vascular smooth muscle cell (VSMC) proliferation and neointimal hyperplasia were evaluated in cultured VSMCs and wire-injured mouse carotid arteries from wild-type (WT, C57BL/6J), AMPKα2(-/-), and AMPKα1(-/-) mice. Mouse VSMCs derived from aortas of AMPKα2(-/-) mice exhibited increased proliferation compared with either WT or AMPKα1(-/-) VSMCs. Further, deletion of AMPKα2 but not AMPKα1 reduced the level of p27(Kip1), a cyclin-dependent kinase inhibitor, and increased the level of S-phase kinase-associated protein 2 (Skp2), a known E3 ubiquitin ligase for p27(Kip1), through activation of p52 nuclear factor kappa B (NF-κB)-2. Moreover, either pharmacological (ie, through compound C) or genetical (ie, through AMPKα2-specific siRNA) inhibition of AMPK decreased p27(Kip1) levels but increased the abundance of Skp2 in human VSMCs. Furthermore, gene silencing of Skp2 reversed the levels of p27(Kip1) and VSMCs proliferation. Finally, neointima formation after mechanical arterial injury was increased in AMPKα2(-/-) but not AMPKα1(-/-) mice. CONCLUSIONS These findings indicate that deletion of AMPKα2 through p52-Skp2-mediated ubiquitination and degradation of p27(Kip1) accentuates neointimal hyperplasia in response to wire injury.
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Affiliation(s)
- Ping Song
- Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, 73104, USA.
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Cohen JD, Tham KY, Mastrandrea NJ, Gallegos AC, Monks TJ, Lau SS. cAMP-dependent cytosolic mislocalization of p27(kip)-cyclin D1 during quinol-thioether-induced tuberous sclerosis renal cell carcinoma. Toxicol Sci 2011; 122:361-71. [PMID: 21693435 DOI: 10.1093/toxsci/kfr118] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The loss of tuberin, the tuberous sclerosis-2 (Tsc-2) gene product, is associated with cytoplasmic mislocalization of p27 in uterine leiomyomas derived from Eker rats (Tsc-2(EK/+)) and in human metastatic renal cell carcinoma tissue. Signaling associated with cytoplasmic mislocalization of p27 in renal cancer is relatively unknown. Renal tumors derived from 2,3,5-tris-(glutathion-S-yl)hydroquinone (TGHQ)-treated Tsc-2(EK/+) rats, and null for tuberin, display elevated nuclear and cytosolic p27, with parallel increases in cytosolic cyclin D1 levels. Similar changes are observed in TGHQ-transformed renal epithelial cells derived from Tsc-2(EK/+) rats (QTRRE cells), which, in addition to the cytoplasmic mislocalization of p27 and cyclin D1, exhibit high ERK, B-Raf, and Raf-1 kinase activity. Renal tumor xenografts, derived from subcutaneous injection of QTRRE cells into nude mice, also display increases in cytosolic mislocalization of p27 and cyclin D1. Dibutyryl cAMP and/or phosphodiesterase inhibitors (PIs; pentoxifylline or theophylline) increase Rap1B activation, B-Raf kinase activity, and cytosolic p27/cyclin D1 protein levels in QTRRE cells. Inhibition of Raf kinases with either sorafenib or B-Raf small interfering RNA (siRNA) caused a mitogen-activated protein kinase-mediated downregulation of p27. Moreover, decreases in cyclin D1 were also associated with p27 siRNA knockdown in QTRRE cells. Finally, theophylline-mediated increases in p27 and cyclin D1 were attenuated by sorafenib, which modulated Raf/MEK/ERK signaling. Collectively, these data suggest that the cAMP/Rap1B/B-Raf pathway modulates the expression of p27 and the cytoplasmic mislocalization of p27-cyclin D1 in tuberous sclerosis gene-regulated-renal cancer. Therefore, the loss of tuberin and engagement of the cAMP pathway may independently direct p27-cyclin D1 cytosolic stabilization during renal tumor formation.
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Affiliation(s)
- Jennifer D Cohen
- Department of Pharmacology and Toxicology, Southwest Environmental Health Sciences Center, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, USA
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Hewer RC, Sala-Newby GB, Wu YJ, Newby AC, Bond M. PKA and Epac synergistically inhibit smooth muscle cell proliferation. J Mol Cell Cardiol 2010; 50:87-98. [PMID: 20971121 PMCID: PMC3093616 DOI: 10.1016/j.yjmcc.2010.10.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 10/08/2010] [Accepted: 10/11/2010] [Indexed: 12/14/2022]
Abstract
Cyclic AMP signalling promotes VSMC quiescence in healthy vessels and during vascular healing following injury. Cyclic AMP inhibits VSMC proliferation via mechanisms that are not fully understood. We investigated the role of PKA and Epac signalling on cAMP-induced inhibition of VSMC proliferation. cAMP-mediated growth arrest was PKA-dependent. However, selective PKA activation with 6-Benzoyl-cAMP did not inhibit VSMC proliferation, indicating a requirement for additional pathways. Epac activation using the selective cAMP analogue 8-CPT-2′-O-Me-cAMP, did not affect levels of hyperphosphorylated Retinoblastoma (Rb) protein, a marker of G1-S phase transition, or BrdU incorporation, despite activation of the Epac-effector Rap1. However, 6-Benzoyl-cAMP and 8-CPT-2′-O-Me-cAMP acted synergistically to inhibit Rb-hyperphosphorylation and BrdU incorporation, indicating that both pathways are required for growth inhibition. Consistent with this, constitutively active Epac increased Rap1 activity and synergised with 6-Benzoyl-cAMP to inhibit VSMC proliferation. PKA and Epac synergised to inhibit phosphorylation of ERK and JNK. Induction of stellate morphology, previously associated with cAMP-mediated growth arrest, was also dependent on activation of both PKA and Epac. Rap1 inhibition with Rap1GAP or siRNA silencing did not negate forskolin-induced inhibition of Rb-hyperphosphorylation, BrdU incorporation or stellate morphology. This data demonstrates for the first time that Epac synergises with PKA via a Rap1-independent mechanism to mediate cAMP-induced growth arrest in VSMC. This work highlights the role of Epac as a major player in cAMP-dependent growth arrest in VSMC.
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RhoA phosphorylation induces Rac1 release from guanine dissociation inhibitor alpha and stimulation of vascular smooth muscle cell migration. Mol Cell Biol 2010; 30:4786-96. [PMID: 20696841 DOI: 10.1128/mcb.00381-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Although overactivation of RhoA is recognized as a common component of vascular disorders, the molecular mechanisms regulating RhoA activity in vascular smooth muscle cells (VSMC) are still unclear. We have previously shown that in VSMC, RhoA is phosphorylated on Ser188 by nitric oxide (NO)-stimulated cGMP-dependent kinase (PKG), which leads to RhoA-Rho kinase pathway inhibition. In this study, we showed that expression of phosphoresistant RhoA mutants prevented the stimulation of VSMC migration and adhesion induced by NO-PKG pathway activation. In contrast, under basal conditions, phosphomimetic RhoA mutants stimulated VSMC adhesion and migration through a signaling pathway requiring Rac1 and the Rho exchange factor Vav3. RhoA phosphorylation or phosphomimetic RhoA mutants induced Rac1 activation but did not activate Vav3. Indeed, phosphorylated RhoA or phosphomimetic mutants trapped guanine dissociation inhibitor α (GDIα), leading to the release of Rac1 and its translocation to the membrane, where it was then activated by the basal Vav3 nucleotide exchange activity. In vivo, RhoA phosphorylation induced by PKG activation in the aortas of rats treated with sildenafil induced dissociation of Rac1 from GDIα and activation of the Rac1 signaling pathway. These results suggest that the phosphorylation of RhoA represents a novel potent and physiological GDIα displacement factor that leads to Rac1 activation and regulation of Rac1-dependent VSMC functions.
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Puetz S, Lubomirov LT, Pfitzer G. Regulation of smooth muscle contraction by small GTPases. Physiology (Bethesda) 2010; 24:342-56. [PMID: 19996365 DOI: 10.1152/physiol.00023.2009] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Next to changes in cytosolic [Ca(2+)], members of the Rho subfamily of small GTPases, in particular Rho and its effector Rho kinase, also known as ROK or ROCK, emerged as key regulators of smooth muscle function in health and disease. In this review, we will focus on the regulation of the contractile machinery by Rho/ROK signaling and its interaction with PKC and cyclic nucleotide signaling. We will briefly discuss the emerging evidence that remodeling of cortical actin is necessary for contraction.
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Affiliation(s)
- Sandra Puetz
- Institut für Vegetative Physiologie, Universitaet Koeln, Koeln, Germany,
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Werth D, Grassi G, Konjer N, Dapas B, Farra R, Giansante C, Kandolf R, Guarnieri G, Nordheim A, Heidenreich O. Proliferation of human primary vascular smooth muscle cells depends on serum response factor. Eur J Cell Biol 2010; 89:216-24. [PMID: 20096952 DOI: 10.1016/j.ejcb.2009.12.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Smooth muscle cells (SMCs) can switch between a differentiated/contractile and an alternative proliferative phenotype. The transcription factor serum response factor (SRF) has been implicated in the regulation of gene expression profiles determining both phenotypes. Whereas strong evidence exists for a role of SRF in SMC differentiation, the contribution of SRF to SMC proliferation is less well defined. For primary human vascular SMCs in particular, existing data are non-conclusive. To study SRF functions in primary human vascular SMCs, we used an siRNA approach. siRNA-mediated SRF suppression affected the expression of established SRF target genes such as smooth muscle alpha-actin (ACTA2) or SM22alpha (TAGLN) and decreased both F-actin formation and cell migration. Furthermore, SRF knockdown caused a cell-cycle arrest in G1 associated with reduced hyperphosphorylated pRB, cyclin A and SKP2 levels, and increased p27(kip1) (CDKN1B) protein levels. SRF-depleted cells expressed senescence-associated beta-galactosidase indicating an irreversible G1 arrest. siRNA-mediated suppression of SKP2 triggered senescence to a similar extent as SRF depletion, indicating that SRF knockdown-induced senescence may be dependent on a decrease in SKP2. Thus, SRF is an essential regulator of primary human vascular SMC proliferation and senescence. Interfering with SRF function may therefore be a promising strategy for the treatment of hyperproliferative SMC disorders such as atherosclerosis and in-stent restenosis.
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Affiliation(s)
- Daniela Werth
- Department of Molecular Biology, Interfaculty Institute for Cell Biology, Eberhard Karls University of Tübingen, Germany
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Toumaniantz G, Ferland-McCollough D, Cario-Toumaniantz C, Pacaud P, Loirand G. The Rho protein exchange factor Vav3 regulates vascular smooth muscle cell proliferation and migration. Cardiovasc Res 2009; 86:131-40. [DOI: 10.1093/cvr/cvp387] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Krajicek BJ, Kottom TJ, Villegas L, Limper AH. Characterization of the PcCdc42 small G protein from Pneumocystis carinii, which interacts with the PcSte20 life cycle regulatory kinase. Am J Physiol Lung Cell Mol Physiol 2009; 298:L252-60. [PMID: 19915161 DOI: 10.1152/ajplung.00191.2009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pneumocystis carinii (Pc) causes severe pneumonia in immunocompromised hosts. The binding of Pc trophic forms to alveolar epithelial cells is a central feature of infection, inducing the expression and activation of PcSte20, a gene participating in mating, proliferation, and pseudohyphal growth. In related fungi, Ste20 proteins are generally activated by immediate upstream small G proteins of the Cdc42-like family. PcCdc42 has not been previously described in Pneumocystis. To address the potential role of such a G protein in Pneumocystis, PcCdc42 was cloned from a Pc cDNA library. Using the full-length 576-bp PcCdc42 cDNA sequence, a CHEF blot of genomic DNA yielded a single band, providing evidence that this gene is present as a single copy within the genome. The total length of PcCdc42 cDNA was 576 bp with an estimated molecular mass of approximately 38 kDa. BLASTP analysis demonstrated greater than 80% homology with other fungal Cdc42p proteins. Northern analysis indicated equal mRNA expression in both cystic and trophic life forms. Heterologous expression of PcCdc42 in Saccharomyces cerevisiae (Sc) demonstrated that PcCdc42p was able to restore growth in an ScCdc42Delta yeast strain. Additional assays with purified PcCdc42 protein demonstrated GTP binding and intrinsic GTPase activity, which was partially but significantly suppressed by Clostridium difficile toxin B, characteristic of Cdc42 GTPases. Furthermore, PcCdc42 protein was also shown to bind to the downstream PCSte20 kinase partner in the presence (but not the absence) of GTP. These data indicate that Pc possesses a Cdc42 gene expressing an active G protein, which binds the downstream regulatory kinase PcSte20, important in Pc life cycle regulation.
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Affiliation(s)
- Bryan J Krajicek
- Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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