EFFECTS OF RHO-KINASE INHIBITION ON ADRENERGIC AND CALCIUM SENSITIVITY IN VASCULAR SMOOTH MUSCLE ASSOCIATED WITH DIABETES MELLITUS: PP.17.135

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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Force maintenance and myosin filament assembly regulated by Rho-kinase in airway smooth muscle

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00222.2014 ◽

2015 ◽

Vol 308 (1) ◽

pp. L1-L10 ◽

Cited By ~ 24

Author(s):

Bo Lan ◽

Linhong Deng ◽

Graham M. Donovan ◽

Leslie Y. M. Chin ◽

Harley T. Syyong ◽

...

Keyword(s):

Smooth Muscle ◽

Airway Smooth Muscle ◽

Initial Phase ◽

Rho Kinase ◽

Myosin Filament ◽

Second Phase ◽

Minimal Effect ◽

Kinase Inhibition ◽

Myosin Filaments ◽

Force Maintenance

Smooth muscle contraction can be divided into two phases: the initial contraction determines the amount of developed force and the second phase determines how well the force is maintained. The initial phase is primarily due to activation of actomyosin interaction and is relatively well understood, whereas the second phase remains poorly understood. Force maintenance in the sustained phase can be disrupted by strains applied to the muscle; the strain causes actomyosin cross-bridges to detach and also the cytoskeletal structure to disassemble in a process known as fluidization, for which the underlying mechanism is largely unknown. In the present study we investigated the ability of airway smooth muscle to maintain force after the initial phase of contraction. Specifically, we examined the roles of Rho-kinase and protein kinase C (PKC) in force maintenance. We found that for the same degree of initial force inhibition, Rho-kinase substantially reduced the muscle's ability to sustain force under static conditions, whereas inhibition of PKC had a minimal effect on sustaining force. Under oscillatory strain, Rho-kinase inhibition caused further decline in force, but again, PKC inhibition had a minimal effect. We also found that Rho-kinase inhibition led to a decrease in the myosin filament mass in the muscle cells, suggesting that one of the functions of Rho-kinase is to stabilize myosin filaments. The results also suggest that dissolution of myosin filaments may be one of the mechanisms underlying the phenomenon of fluidization. These findings can shed light on the mechanism underlying deep inspiration induced bronchodilation.

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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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Resveratrol’s Impact on Vascular Smooth Muscle Cells Hyporeactivity: The Role of Rho-Kinase Inhibition

BioMed Research International ◽

10.1155/2020/9012071 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Michał Wiciński ◽

Bartosz Malinowski ◽

Paweł Rajewski ◽

Paweł Szychta ◽

Eryk Wódkiewicz ◽

...

Keyword(s):

Smooth Muscle ◽

Protein Kinases ◽

Vascular Smooth Muscle Cells ◽

Kinase Inhibitor ◽

Rho Kinase ◽

Pressure Effects ◽

Kinase Inhibition ◽

Rho Kinase Inhibitor ◽

Dependent Protein

Resveratrol (3,5,4′-trihydroxystilbene) is a chemical compound belonging to the group of polyphenols and flavonoids. The aim of the present study was to determine the influence of resveratrol application along with certain modulating factors, such as 8Br-cGMP-activator of cGMP-dependent protein kinases, HA-1077-Rho-kinase inhibitor, and Bay K8644-calcium channel agonist, on VMSCs constriction triggered by phenylephrine. Resveratrol at a dose of 10 mg/kg/24 h administered for 4 weeks reduced the reactivity of the arteries to the pressure action of catecholamines. Tests performed after four weeks of resveratrol administration showed that 8Br-cGMP at the concentrations of 0.01 mM/l and 0.1 mM/l intensifies this effect. Simultaneous resveratrol and Bay K8644 administration led to a significant decrease in contractility compared to the vessels collected from animals (Res−). This effect was dependent on the concentration of Bay K8644. Resveratrol seems to be counteractive against Bay K8644 by blocking L-type calcium channels. As the concentration of HA-1077 increased, there was a marked hyporeactivity of the vessels to the pressure effects of phenylephrine. The results indicate synergy between resveratrol and Rho-kinase inhibition.

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