scholarly journals Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization

2014 ◽  
Vol 307 (7) ◽  
pp. H945-H957 ◽  
Author(s):  
Srinivasa Raju Datla ◽  
Daniel J. McGrail ◽  
Sasa Vukelic ◽  
Lauren P. Huff ◽  
Alicia N. Lyle ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Traction Force ◽  
Force Generation ◽  
Dependent Manner ◽  
Interacting Protein ◽  
Nadph Oxidase 4 ◽  
Focal Adhesion Turnover

Polymerase-δ-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner.

scholarly journals Homocysteine promotes vascular smooth muscle cell migration by induction of the adipokine resistin

2009 ◽  
Vol 297 (6) ◽  
pp. C1466-C1476 ◽  
Author(s):  
Changtao Jiang ◽  
Heng Zhang ◽  
Weizhen Zhang ◽  
Wei Kong ◽  
Yi Zhu ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Focal Adhesions ◽  
Diabetic Patients ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Adipokines may represent a mechanism linking insulin resistance to cardiovascular disease. We showed previously that homocysteine (Hcy), an independent risk factor for cardiovascular disease, can induce the expression and secretion of resistin, a novel adipokine, in vivo and in vitro. Since vascular smooth muscle cell (VSMC) migration is a key event in vascular disease, we hypothesized that adipocyte-derived resistin is involved in Hcy-induced VSMC migration. To confirm our hypothesis, Sprague-Dawley rat aortic SMCs were cocultured with Hcy-stimulated primary rat epididymal adipocytes or treated directly with increasing concentrations of resistin for up to 24 h. Migration of VSMCs was investigated. Cytoskeletal structure and cytoskeleton-related proteins were also detected. The results showed that Hcy (300–500 μM) increased migration significantly in VSMCs cocultured with adipocytes but not in VSMC cultured alone. Resistin alone also significantly increased VSMC migration in a time- and concentration-dependent manner. Resistin small interfering RNA (siRNA) significantly attenuated VSMC migration in the coculture system, which indicated that adipocyte-derived resistin mediates Hcy-induced VSMC migration. On cell spreading assay, resistin induced the formation of focal adhesions near the plasma membrane, which suggests cytoskeletal rearrangement via an α5β1-integrin-focal adhesion kinase/paxillin-Ras-related C3 botulinum toxin substrate 1 (Rac1) pathway. Our data demonstrate that Hcy promotes VSMC migration through a paracrine or endocrine effect of adipocyte-derived resistin, which provides further evidence of the adipose-vascular interaction in metabolic disorders. The migratory action exerted by resistin on VSMCs may account in part for the increased incidence of restenosis in diabetic patients.

scholarly journals EBP50 promotes focal adhesion turnover and vascular smooth muscle cells migration

2012 ◽  
Vol 53 (6) ◽  
pp. 809-819 ◽  
Author(s):  
Gyun Jee Song ◽  
Kristen L. Leslie ◽  
Stacey Barrick ◽  
Sylvain Bougoin ◽  
Juan M. Taboas ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Focal Adhesion ◽  
Muscle Cells ◽  
Focal Adhesion Turnover

scholarly journals Extracellular matrix-specific focal adhesions in vascular smooth muscle produce mechanically active adhesion sites

2008 ◽  
Vol 295 (1) ◽  
pp. C268-C278 ◽  
Author(s):  
Zhe Sun ◽  
Luis A. Martinez-Lemus ◽  
Michael A. Hill ◽  
Gerald A. Meininger
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Focal Adhesion ◽  
Focal Adhesions ◽  
Mechanical Activity ◽  
Tissue Blood Flow ◽  
Cell Contact ◽  
Type I ◽  
Adhesion Sites

Integrin-mediated mechanotransduction in vascular smooth muscle cells (VSMCs) plays an important role in the physiological control of tissue blood flow and vascular resistance. To test whether force applied to specific extracellular matrix (ECM)-integrin interactions could induce myogenic-like mechanical activity at focal adhesion sites, we used atomic force microscopy (AFM) to apply controlled forces to specific ECM adhesion sites on arteriolar VSMCs. The tip of AFM probes were fused with a borosilicate bead (2∼5 μm) coated with fibronectin (FN), collagen type I (CNI), laminin (LN), or vitronectin (VN). ECM-coated beads induced clustering of α5- and β3-integrins and actin filaments at sites of bead-cell contact indicative of focal adhesion formation. Step increases of an upward ( z-axis) pulling force (800∼1,600 pN) applied to the bead-cell contact site for FN-specific focal adhesions induced a myogenic-like, force-generating response from the VSMC, resulting in a counteracting downward pull by the cell. This micromechanical event was blocked by cytochalasin D but was enhanced by jasplakinolide. Function-blocking antibodies to α5β1- and αvβ3-integrins also blocked the micromechanical cell event in a concentration-dependent manner. Similar pulling experiments with CNI, VN, or LN failed to induce myogenic-like micromechanical events. Collectively, these results demonstrate that mechanical force applied to integrin-FN adhesion sites induces an actin-dependent, myogenic-like, micromechanical event. Focal adhesions formed by different ECM proteins exhibit different mechanical characteristics, and FN appears of particular relevance in its ability to strongly attach to VSMCs and to induce myogenic-like, force-generating reactions from sites of focal adhesion in response to externally applied forces.

PAK1 induces podosome formation in A7r5 vascular smooth muscle cells in a PAK-interacting exchange factor-dependent manner

2005 ◽  
Vol 289 (4) ◽  
pp. C898-C907 ◽  
Author(s):  
Bradley A. Webb ◽  
Robert Eves ◽  
Scott W. Crawley ◽  
Shutang Zhou ◽  
Graham P. Côté ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Cell Motility ◽  
Vascular Smooth Muscle Cells ◽  
Focal Adhesions ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Turnover Rates ◽  
Exchange Factor

Remodeling of the vascular smooth muscle cytoskeleton is essential for cell motility involved in the development of diseases such as arteriosclerosis and restenosis. The p21-activated kinase (PAK), which is an effector of the Rho GTPases Rac and Cdc42, has been shown to be involved in cytoskeletal remodeling and cell motility. We show herein that expression of cytoskeletally active constructs of PAK1 is able to induce the formation of dynamic, podosome-like F-actin columns in the A7r5 vascular smooth muscle cell line. Most of these actin columns appear at the junctions between stress fibers and focal adhesions and contain several known podosomal protein markers, such as cortactin, Arp2/3, α-actinin, and vinculin. The kinase activity of PAK plays a role in the regulation of the turnover rates of these actin columns but is not essential for their formation. The ability of PAK to interact with the PAK-interacting exchange factor (PIX) but not with Rac or Cdc42, however, is required for the formation of the actin columns as well as for the translocation of PIX and G protein-coupled receptor kinase-interacting protein (GIT) to focal adhesions adjacent to the actin columns. These findings suggest that interaction between PAK and PIX, as well as the recruitment of PIX and GIT to focal adhesions, plays an important role in the formation of actin columns that resemble podosomes induced by phorbol ester in vascular smooth muscle cells.

scholarly journals ATP allosterically stabilizes Integrin-linked kinase for efficient force generation

2021 ◽  
Author(s):  
Isabel M. Martin ◽  
Michele M. Nava ◽  
Sara A. Wickstroem ◽  
Frauke Graeter
Keyword(s):  
Focal Adhesion ◽  
Protein Unfolding ◽  
Focal Adhesions ◽  
Traction Force ◽  
Force Generation ◽  
Force Microscopy ◽  
Integrin Linked Kinase ◽  
And Migration ◽  
Dynamics Simulations ◽  
Propagation Network

Focal adhesions link the actomyosin cytoskeleton to the extracellular matrix regulating cell adhesion, shape, and migration. Adhesions are dynamically assembled and disassembled in response to extrinsic and intrinsic forces, but how the essential adhesion component intergrin-linked kinase (ILK) dynamically responds to mechanical force and what role ATP bound to this pseudokinase plays remains elusive. Here, we apply force-probe molecular dynamics simulations of ILK:alpha-parvin coupled to traction force microscopy to explore ILK mechanotransducing functions. We identify two key saltbridge-forming arginines within the allosteric, ATP-dependent force-propagation network of ILK. Disrupting this network by mutation impedes parvin binding, focal adhesion stabilization, force generation, and thus migration. Under tension, ATP shifts the balance from rupture of the complex to protein unfolding, indicating that ATP increases the force threshold required for focal adhesion disassembly. Our study proposes a new role of ATP as an obligatory binding partner for structural and mechanical integrity of the pseudokinase ILK, ensuring efficient cellular force generation and migration.

Resveratrol inhibits glucose‐induced migration of vascular smooth muscle cells mediated by focal adhesion kinase

2014 ◽  
Vol 58 (7) ◽  
pp. 1389-1401 ◽  
Author(s):  
Yi‐Chiao Lin ◽  
Li‐Hsuen Chen ◽  
T. Varadharajan ◽  
May‐Jywan Tsai ◽  
Yi‐Chen Chia ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Focal Adhesion Kinase ◽  
Vascular Smooth Muscle Cells ◽  
Focal Adhesion ◽  
Muscle Cells

Docosahexaenoic Acid, a Peroxisome Proliferator-Activated Receptor-α Activator, Induces Apoptosis in Vascular Smooth Muscle Cells by Activation of P38 Mitogen-Activated Protein Kinase

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 679-679
Author(s):  
Quy N Diep ◽  
Rhian M Touyz ◽  
Ernesto L Schiffrin
Keyword(s):  
Smooth Muscle ◽  
Cytochrome C ◽  
Docosahexaenoic Acid ◽  
Vascular Smooth Muscle ◽  
Morphological Changes ◽  
Mitogen Activated Protein Kinase ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Mitogen Activated Protein ◽  
P38 Mapks

9 Omega-3 fatty acids (n-3 FAs) exert a blood pressure-lowering effect in hypertension, possibly by influencing vascular structure. We previously demonstrated that n-3 FAs might induce vascular smooth muscle cell (VSMC) apoptosis, which could exert an effect on structure of blood vessels. This study investigated signaling pathways through which n-3 FAs mediate apoptosis in VSMCs. Cultured Mesenteric VSMCs from Sprague Dawley rats were stimulated with docosahexaenoic acid (DHA), a representative n-3 FA. Morphological changes of apoptosis and DNA fragmentation were examined by phase-contrast microscopy and fluorescence microscopy with Hoechst 33342 staining. To clarify possible pathways of apoptosis, expression of phosphorylated p38 mitogen-activated protein kinases (p38 MAPKs), bax, bcl-2, cytochrome C and peroxisome proliferator-activated receptors-α (PPARs-α) was evaluated by Western blot analysis. DHA treatment induced cell shrinkage, cell membrane blebbing and apoptotic bodies in VSMCs. DHA increased apoptosis (%) in a time-dependent manner to 1.5±0.1, 3.6±0.5, 7.1±0.4, 22.5±0.6, 50.8±1.8 and 61.4±0.9 after 0, 1, 3, 6, 17, and 24 h, respectively. DHA time-dependently activated p38 MAPKs, bax, PPARs-α and cytochrome C with maximal effects obtained after 5, 30 min, 1 h and 3 h, respectively to 551±42, 245±55, 310±12 and 407±14.7 % of controls, respectively. SB-203580 (10 -5 M) and SB-202190 (10 -5 M), selective p38 inhibitors, reduced DHA-elicited apoptosis and expression of PPARs-α, but had no effect on expression of bax or cytochrome C. The present results indicate that DHA induces apoptosis in VSMCs through at least two distinct mechanisms: (i) a p38-dependent pathway that regulates PPAR-α and (ii) a p38-independent pathway via dissipation of mitochondrial transmembrane potential. The death-signaling pathway mediated by DHA may involve an integration of these multiple pathways. By triggering VSMC apoptosis, DHA could play a pathophysiological role in vascular remodeling in cardiovascular disease.

Abstract 126: Differential Effects of Respectively Blocking Two BET Bromodomains on Vascular Smooth Muscle Cell Phenotype Transformation

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Mengxue Zhang ◽  
Bowen Wang ◽  
Craig Kent ◽  
Lian-Wang Guo
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Molecular Mechanisms ◽  
Cell Phenotype ◽  
Dependent Manner ◽  
Stat3 Phosphorylation ◽  
Phenotype Transformation

Introduction: Intimal hyperplasia (IH) occurs primarily due to vascular smooth muscle cell (SMC) transformation from quiescent to pathogenic phenotypes (e.g. proliferation and inflammation). Identification and effective targeting of key epigenetic factors governing SMC pathogenic transformation may lead to novel therapeutic methods for prevention of IH. We previously found that globally blocking the bromo- and extra-terminal (BET) epigenetic “reader” family abrogated SMC phenotype transformation and IH. We further investigated the functions of the two BET bromodomains (Bromo1 and Bromo2). Hypothesis: Bromo1 and Bromo2 play different roles in SMC pathogenic transformation. Methods and Results: We pre-treated rat primary aortic SMCs (for 2h) with Olinone or RVX208, inhibitors specific for Bromo1 and Bromo2 respectively, and then stimulated SMC phenotype transformation. Whereas RVX208 abrogated PDGF-BB-stimulated SMC proliferation (BrdU assay) in a dose dependent manner, Olinone enhanced SMC proliferation at high concentrations (>20 μM). RVX208 at 50 μM reduced TNFα-induced SMC inflammation (MCP-1 ELISA) by 80%,but Olinone at the same concentration slightly increased MCP-1. Furthermore, whereas RVX208 abolished PDGF-BB or TNFα-induced STAT3 phosphorylation (Western blotting), Olinone slightly increased phospho-STAT3. Conclusions: Our results reveal that blocking two BET bromodomains respectively produces distinct effects on SMC phenotype transformation, suggesting their differential epigenetic functions. Further elucidation of the underlying molecular mechanisms should contribute to precise targeting of the BET family for optimal mitigation of IH.

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