scholarly journals Differential regulation of muscarinic M2 and M3 receptor signaling in gastrointestinal smooth muscle by caveolin-1

2013 ◽  
Vol 305 (3) ◽  
pp. C334-C347 ◽  
Author(s):  
Sayak Bhattacharya ◽  
Sunila Mahavadi ◽  
Othman Al-Shboul ◽  
Senthilkumar Rajagopal ◽  
John R. Grider ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Kinase Activity ◽  
Rho Kinase ◽  
Receptor Signaling ◽  
Caveolin 1 ◽  
Pi Hydrolysis ◽  
G Protein Coupled ◽  
Stimulation Of

Caveolae act as scaffolding proteins for several G protein-coupled receptor signaling molecules to regulate their activity. Caveolin-1, the predominant isoform in smooth muscle, drives the formation of caveolae. The precise role of caveolin-1 and caveolae as scaffolds for G protein-coupled receptor signaling and contraction in gastrointestinal muscle is unclear. Thus the aim of this study was to examine the role of caveolin-1 in the regulation of Gq- and Gi-coupled receptor signaling. RT-PCR, Western blot, and radioligand-binding studies demonstrated the selective expression of M2 and M3 receptors in gastric smooth muscle cells. Carbachol (CCh) stimulated phosphatidylinositol (PI) hydrolysis, Rho kinase and zipper-interacting protein (ZIP) kinase activity, induced myosin phosphatase 1 (MYPT1) phosphorylation (at Thr696) and 20-kDa myosin light chain (MLC20) phosphorylation (at Ser19) and muscle contraction, and inhibited cAMP formation. Stimulation of PI hydrolysis, Rho kinase, and ZIP kinase activity, phosphorylation of MYPT1 and MLC20, and muscle contraction in response to CCh were attenuated by methyl β-cyclodextrin (MβCD) or caveolin-1 small interfering RNA (siRNA). Similar inhibition of PI hydrolysis, Rho kinase, and ZIP kinase activity and muscle contraction in response to CCh and gastric emptying in vivo was obtained in caveolin-1-knockout mice compared with wild-type mice. Agonist-induced internalization of M2, but not M3, receptors was blocked by MβCD or caveolin-1 siRNA. Stimulation of PI hydrolysis, Rho kinase, and ZIP kinase activities in response to other Gq-coupled receptor agonists such as histamine and substance P was also attenuated by MβCD or caveolin-1 siRNA. Taken together, these results suggest that caveolin-1 facilitates signaling by Gq-coupled receptors and contributes to enhanced smooth muscle function.

Inhibition of p42 and p44 MAP kinase does not alter smooth muscle contraction in swine carotid artery

1998 ◽  
Vol 275 (1) ◽  
pp. H131-H138 ◽  
Author(s):  
Isabelle Gorenne ◽  
Xiaoling Su ◽  
Robert S. Moreland
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Map Kinase ◽  
Map Kinases ◽  
Kinase Activity ◽  
Smooth Muscle Contraction ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation

Caldesmon inhibits myosin ATPase activity; phosphorylation of caldesmon reverses the inhibition. The caldesmon kinase is believed to be mitogen-activated protein (MAP) kinase. MAP kinases are activated during vascular stimulation, but a cause-and-effect relationship between kinase activity and contraction has not been established. We examined the role of MAP kinase in contraction using PD-098059, an inhibitor of MAP kinase kinase (MEK). MAP kinase activity was assessed using an anti-active MAP kinase antibody and direct measurement of MAP kinase catalyzed phosphorylation of myelin basic protein, MBP-(95—98). MAP kinase phosphorylation, stimulated by histamine (50 μM) or phorbol 12,13-dibutyrate (PDBu, 0.1 μM), was inhibited by PD-098059 (100 μM). PD-098059 did not alter the sensitivity or the maximal level of force in smooth muscle stimulated by histamine or PDBu, nor did PD-098059 affect contraction of β-escin-permeabilized tissue. Our data suggest that p44 and p42 MAP kinases are not involved in regulation of vascular smooth muscle contraction. These results do not, however, preclude a role for other isoforms of the MAP kinase family.

Role of Rho-kinase in guinea-pig gallbladder smooth muscle contraction

2006 ◽  
Vol 534 (1-3) ◽  
pp. 210-217 ◽  
Author(s):  
Teresa Quinn ◽  
Ronan Feighery ◽  
Alan William Baird
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Muscle Contraction ◽  
Rho Kinase ◽  
Smooth Muscle Contraction

Extraction of membrane cholesterol disrupts caveolae and impairs serotonergic (5-HT2A) and histaminergic (H1) responses in bovine airway smooth muscle: role of Rho-kinase

2009 ◽  
Vol 87 (3) ◽  
pp. 180-195 ◽  
Author(s):  
Bettina Sommer ◽  
Luis M. Montaño ◽  
Verónica Carbajal ◽  
Edgar Flores-Soto ◽  
Alicia Ortega ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Serotonin Receptors ◽  
Rho Kinase ◽  
Membrane Cholesterol ◽  
Histamine Stimulation ◽  
Caveolin 1 ◽  
Intracellular Ca ◽  
Rock Inhibition ◽  
Rock Activity

Some receptors and signaling molecules, such as Rho-kinase (ROCK), localize in caveolae. We asked whether the function of histamine receptors (H1) and 5-hydroxytryptamine (serotonin) receptors (5-HT2A) in bovine tracheal smooth muscle are modified after caveolae disruption and if so, whether the altered ROCK activity plays a role in this modification. Methyl-β-cyclodextrin (MβCD), used to deplete membrane cholesterol, was shown to disrupt caveolae and diminish sustained contractions to histamine (∼80%), 5-HT (100%), α-methyl-5-HT (100%), and KCl (∼30%). Cholesterol-loaded MβCD (CL-MβCD) restored the responses to KCl and partially restored the responses to agonists. ROCK inhibition by Y-27632 diminished contractions to histamine (∼85%) and 5-HT (∼59%). 5-HT or histamine stimulation augmented ROCK activity. These increases were reduced by MβCD and partially reestablished by CL-MβCD. The increase in intracellular Ca2+ that was induced by both agonists was reduced by MβCD. The presence of caveolin-1 (Cav-1), H1, 5-HT2A, and ROCK1 was corroborated by immunoblotting of membrane fractions from sucrose gradients and by confocal microscopy. H1 receptors coimmunoprecipitated with Cav-1 in caveolar and noncaveolar membrane fractions, whereas 5-HT2A receptors appeared to be restricted to noncaveolar membrane fractions. We conclude that caveolar and cholesterol integrity are indispensable for the proper functionality of the H1 and 5-HT2A receptors through their Rho/ROCK signaling.

scholarly journals Role of rho-kinase activity in angiotensin II-induced contraction of rabbit clitoral cavernosum smooth muscle

2002 ◽  
Vol 14 (6) ◽  
pp. 472-477 ◽  
Author(s):  
J K Park ◽  
S O Lee ◽  
Y G Kim ◽  
S H Kim ◽  
G Y Koh ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Kinase Activity ◽  
Rho Kinase

Role of the RhoA/Rho-kinase pathway in the regulation of pulmonary vasoconstrictor function

2010 ◽  
Vol 88 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Bobby D. Nossaman ◽  
Vaughn E. Nossaman ◽  
Subramanyam N. Murthy ◽  
Philip J. Kadowitz
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Calcium Binding ◽  
Rho Kinase ◽  
Smooth Muscle Contraction ◽  
Downstream Effector ◽  
Downstream Effectors ◽  
Vascular Beds ◽  
Kinase Pathway

Calcium is the major intracellular messenger that triggers smooth muscle contraction. The study of calcium-binding proteins, such as calmodulin and its downstream effectors, reveals critical regulation of smooth muscle contraction by protein kinases and phosphatases. Moreover, the small GTP-binding protein RhoA and its downstream effector protein, Rho-kinase, have been shown to play a novel role in the regulation of smooth muscle contraction. Studies have shown that the activation of Rho-kinase is involved in the development of endothelial dysfunction, inflammation, restenosis, and increased vascular tone in a number of cardiovascular disorders. Because inhibitors of this pathway promote vasodilation independent of the mechanism that increases vasoconstrictor tone, it is our hypothesis that Rho-kinase is constitutively active in regulating vasoconstrictor tone in the pulmonary and systemic vascular beds. Studies in the literature suggest that the RhoA/Rho-kinase pathway has an important role in the pathogenesis of pulmonary hypertension.

scholarly journals Role of contractile prostaglandins and Rho-kinase in growth factor-induced airway smooth muscle contraction

2005 ◽  
Vol 6 (1) ◽  
Author(s):  
Dedmer Schaafsma ◽  
Reinoud Gosens ◽  
I Sophie T Bos ◽  
Herman Meurs ◽  
Johan Zaagsma ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Rho Kinase ◽  
Smooth Muscle Contraction

Ozone-induced airway hyperresponsiveness: roles of ROCK isoforms

2015 ◽  
Vol 309 (12) ◽  
pp. L1394-L1397 ◽  
Author(s):  
James A. Lambert ◽  
Weifeng Song
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Rho Kinase ◽  
Smooth Muscle Contraction ◽  
Wild Type ◽  
Epithelial Injury ◽  
Robust Evidence

Acute ozone (O3) inhalation has been shown to cause airway and pulmonary epithelial injury with accompanying inflammation responses. Robust evidence exists that O3 induces airway hyperresponsiveness (AHR) in humans and in animal models. Several pathways exist that culminate in airway smooth muscle contraction, but the mechanism(s) by which O3 elicits AHR are unclear. Here, we review the recent report by Kasahara et al. (Kasahara DI, Mathews JA, Park CY, Cho Y, Hunt G, Wurmbrand AP, Liao JK, Shore SA. Am J Physiol Lung Cell Mol Physiol 309: L736–L746, 2015.) describing the role of two Rho kinase (ROCK) isoforms in O3-induced AHR utilizing a murine haploinsufficiency model. Compared with wild-type (WT) mice, the authors report that ROCK1+/− and ROCK2+/− mice exhibited significantly reduced AHR following acute exposure to O3. Additionally, WT mice treated with fasudil, an FDA-approved ROCK1/2 inhibitor, recapitulated reduction in AHR as seen in ROCK haplotypes. It was suggested that, although the two ROCK isoforms are both induced by Rho, they have different mechanisms by which they mediate O3-induced AHR: ROCK1 via hyaluronan signaling vs. ROCK2 acting downstream of inflammation at the level of airway smooth muscle contraction. These observations provide an important framework to develop novel ROCK-targeting therapies for acute O3-induced AHR.

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