Microtubule depolymerization facilitates contraction of vascular smooth muscle via increased activation of RhoA/Rho-kinase

Expression of GLUT4 is decreased in arterial smooth muscle of hypertensive rats and mice, and total body overexpression of GLUT4 in mice prevents enhanced arterial reactivity. To demonstrate that the effect on vascular response to GLUT4 overexpression is vascular rather than systemic in origin we utilized smooth muscle-specific GLUT4 transgenic mice (SMG4). GLUT4 expression in aortae of SMG4 compared to WT mice was increased 2-3 fold. Adult wild-type (WT) and SMG4 mice were made hypertensive or not through implantation of angiotensin II (AngII; 1.4mg/kg/d for 2 wks) or vehicle containing osmotic mini-pumps. Both WT and SMG4 mice AngII-treated mice exhibited significantly increased systolic blood pressure. In AngII-treated WT mice (WT-AngII) aortic GLUT4 expression was significantly decreased, whereas GLUT4 expression in aortae of AngII-treated SMG4 mice (SMG4-AngII) was maintained. The phosphorylation of ERM and MYPT1(Thr850) were significantly increased in aortae of WT-AngII compared to WT-Sham and SMG4-AngII mice. Responsiveness to the contractile agonists, phenylephrine, 5-HT, and PGF 2 was significantly increased in endothelium-intact aortic rings from WT-AngII mice, but remained normal in aortae of SMG4-AngII mice. Following pretreatment with Rho-kinase inhibitor Y-27632, relative inhibition of contractility to 5-HT was equal in aortae from WT-AngII and SMG4-AngII-treated mice. With endothelial denudation, contractility to 5-HT was equally enhanced in aortae of WT-AngII and SMG4-AngII-treated mice. Interestingly, whereas acetylcholine stimulated relaxation was significantly decreased in aortic rings of WT-AngII mice, relaxation in rings from SMG4-AngII mice was not significantly different from WT or SMG4. These results demonstrate an interesting phenomenon whereby decreased expression of GLUT4 in vascular smooth muscle leads to an endothelial dysfunction that not only impairs relaxation, but also enhances contractility.

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Urokinase-induced migration of human vascular smooth muscle cells requires coupling of the small GTPases RhoA and Rac1 to the Tyk2/PI3-K signalling pathway

Thrombosis and Haemostasis ◽

10.1055/s-0037-1613478 ◽

2003 ◽

Vol 89 (05) ◽

pp. 904-914 ◽

Cited By ~ 35

Author(s):

Natalia Tkachuk ◽

Hermann Haller ◽

Inna Dumler ◽

Ioulia Kiian

Keyword(s):

Smooth Muscle ◽

Cell Migration ◽

Vascular Smooth Muscle ◽

Kinase Inhibitor ◽

Rho Kinase ◽

Small Gtpases ◽

Janus Kinase ◽

Immunocytochemical Staining ◽

Boyden Chamber ◽

Dependent Manner

SummaryUrokinase-type plasminogen activator (uPA) facilitates cell migration by localizing proteolisys on the cell surface and by inducing intracellular signalling pathways. In human vascular smooth muscle cell (VSMC) uPA stimulates migration via the uPA receptor (uPAR) signalling complex containing the Janus kinase Tyk2 and phosphatidylinositol 3-kinase (PI3-K). We report that active GTP-bound forms of small GTPases RhoA and Rac1, but not Cdc42, are directly associated with Tyk2 and PI3-K in an uPA/uPAR-dependent fashion. Endogenous RhoA, but not Rac1 or Cdc42, was significantly activated in response to uPA. RhoA activation was abolished by cell treatment with two unrelated, structurally distinct, specific inhibitors of PI3-K, wortmannin, and LY294002. Downstream of RhoA, phosphorylation of myosin light chain (MLC) was dramatically upregulated by uPA in a Rho kinase- and PI3-K-dependent manner. Thus, selective Rho kinase inhibitor Y27632 and PI3-K inhibitors wortmannin and LY294002 prevented the uPA-induced stimulation of MLC phosphorylation. Rho kinase inhibition also decreased uPA-stimulated VSMC migration as observed in a Boyden chamber. VSMC immunocytochemical staining demonstrated redistribution of RhoA and Rac1 active forms to the newly formed leading edge of migrating cell. VSMC microinjection with antibodies to either Rho or Rac1 decreased uPA-stimulated cell migration, indicating the involvement of both GTPases in the migration process. Our results provide evidence that the small GTPases RhoA and Rac1, together with Rho kinase, are necessary to mediate the uPA/uPAR-directed migration via the Tyk2/PI3-K signalling complex in human VSMC.

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Inflammatory stimuli upregulate Rho-kinase in human coronary vascular smooth muscle cells

Journal of Molecular and Cellular Cardiology ◽

10.1016/j.yjmcc.2004.05.008 ◽

2004 ◽

Vol 37 (2) ◽

pp. 537-546 ◽

Cited By ~ 120

Author(s):

J HIROKI

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Rho Kinase ◽

Muscle Cells ◽

Inflammatory Stimuli

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Up-Regulation of Rhoa/Rho Kinase Pathway by Translationally Controlled Tumor Protein in Vascular Smooth Muscle Cells

International Journal of Molecular Sciences ◽

10.3390/ijms150610365 ◽

2014 ◽

Vol 15 (6) ◽

pp. 10365-10376 ◽

Cited By ~ 4

Author(s):

Jeehye Maeng ◽

Vadim Sheverdin ◽

Hyekyoung Shin ◽

Insu Ha ◽

Sun Bae ◽

...

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Rho Kinase ◽

Muscle Cells ◽

Translationally Controlled Tumor Protein ◽

Kinase Pathway

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Airway smooth muscle excitation-contraction coupling and airway hyperresponsiveness

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y05-070 ◽

2005 ◽

Vol 83 (8-9) ◽

pp. 725-732 ◽

Cited By ~ 15

Author(s):

Simon Hirota ◽

Peter B Helli ◽

Adriana Catalli ◽

Allyson Chew ◽

Luke J Janssen

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Signaling Pathways ◽

Airway Smooth Muscle ◽

Airway Hyperresponsiveness ◽

Rho Kinase ◽

Shortness Of Breath ◽

Excitation Contraction Coupling ◽

Contraction Coupling ◽

Hallmark Feature

The primary complaints from patients with asthma pertain to function of airway smooth muscle (ASM) function including shortness of breath, wheezing, and coughing. Thus, it is imperative to better understand the mechanisms underlying excitation-contraction coupling in ASM. Here, we review the various signaling pathways underlying contraction in ASM, and then examine how these are altered in asthma and airway hyperresponsiveness (a hallmark feature of asthma). Throughout, we highlight how studies of vascular smooth muscle have helped or hindered progress in understanding ASM physiology and pathophysiology.Key words: airway smooth muscle, vascular smooth muscle, excitation-contraction coupling, calcium, Rho-kinase.

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