scholarly journals Caveolin-1 and caveolin-3 regulate Ca2+ homeostasis of single smooth muscle cells from rat cerebral resistance arteries

2007 ◽  
Vol 293 (1) ◽  
pp. H204-H214 ◽  
Author(s):  
T. Kamishima ◽  
T. Burdyga ◽  
J. A. Gallagher ◽  
J. M. Quayle
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Removal Rate ◽  
Muscle Cells ◽  
Amino Acid Residues ◽  
Resistance Arteries ◽  
Inhibitory Peptide ◽  
Caveolin 1 ◽  
Domain Peptide ◽  
Cerebral Resistance

The role of caveolins, signature proteins of caveolae, in arterial Ca2+ regulation is unknown. We investigated modulation of Ca2+ homeostasis by caveolin-1 and caveolin-3 using smooth muscle cells from rat cerebral resistance arteries. Membrane current and Ca2+ transients were simultaneously measured with voltage-clamped single cells. Membrane depolarization triggered Ca2+ current and increased intracellular Ca2+ concentration ([Ca2+]i). After repolarization, elevated [Ca2+]i returned to the resting level. Ca2+ removal rate was determined from the declining phase of the Ca2+ transient. Application of caveolin-1 antibody or caveolin-1 scaffolding domain peptide, corresponding to amino acid residues 82–101 of caveolin-1, significantly slowed Ca2+ removal rate at a measured [Ca2+]i of 250 nM, with little effect at a measured [Ca2+]i of 600 nM. Application of caveolin-3 antibody or caveolin-3 scaffolding domain peptide, corresponding to amino acid residues 55–74 of caveolin-3, also significantly slowed Ca2+ removal rate at a measured [Ca2+]i of 250 nM, with little effect at a measured [Ca2+]i of 600 nM. Likewise, application of calmodulin inhibitory peptide, autocamtide-2-related inhibitory peptide, and cyclosporine A, inhibitors for calmodulin, Ca2+/calmodulin-dependent protein kinase II, and calcineurin, also significantly inhibited Ca2+ removal rate at a measured [Ca2+]i of 250 nM but not at 600 nM. Application of cyclopiazonic acid, a sarcoplasmic reticulum Ca2+ ATPase inhibitor, also significantly inhibited Ca2+ removal rate at a measured [Ca2+]i of 250 nM but not at 600 nM. Our results suggest that caveolin-1 and caveolin-3 are important in Ca2+ removal of resistance artery smooth muscle cells.

scholarly journals Inhibitory effect of caveolin-1 in vascular endothelial cells, pericytes and smooth muscle cells

Oncotarget ◽  
2017 ◽  
Vol 8 (44) ◽  
pp. 76165-76173 ◽  
Author(s):  
Hongping Xu ◽  
Liwei Zhang ◽  
Wei Chen ◽  
Jiazhou Xu ◽  
Ruting Zhang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Endothelial Cells ◽  
Muscle Cells ◽  
Inhibitory Effect ◽  
Vascular Endothelial ◽  
Caveolin 1

Urokinase-receptor-mediated phenotypic changes in vascular smooth muscle cells require the involvement of membrane rafts

2009 ◽  
Vol 423 (3) ◽  
pp. 343-351 ◽  
Author(s):  
Julia Kiyan ◽  
Graham Smith ◽  
Hermann Haller ◽  
Inna Dumler
Keyword(s):  
Smooth Muscle ◽  
Cell Migration ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Lipid Rafts ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Caveolin 1 ◽  
Phenotypic Changes ◽  
Dependent Cell

The cholesterol-enriched membrane microdomains lipid rafts play a key role in cell activation by recruiting and excluding specific signalling components of cell-surface receptors upon receptor engagement. Our previous studies have demonstrated that the GPI (glycosylphosphatidylinositol)-linked uPAR [uPA (urokinase-type plasminogen activator) receptor], which can be found in lipid rafts and in non-raft fractions, can mediate the differentiation of VSMCs (vascular smooth muscle cells) towards a pathophysiological de-differentiated phenotype. However, the mechanism by which uPAR and its ligand uPA regulate VSMC phenotypic changes is not known. In the present study, we provide evidence that the molecular machinery of uPAR-mediated VSMC differentiation employs lipid rafts. We show that the disruption of rafts in VSMCs by membrane cholesterol depletion using MCD (methyl-β-cyclodextrin) or filipin leads to the up-regulation of uPAR and cell de-differentiation. uPAR silencing by means of interfering RNA resulted in an increased expression of contractile proteins. Consequently, disruption of lipid rafts impaired the expression of these proteins and transcriptional activity of related genes. We provide evidence that this effect was mediated by uPAR. Similar effects were observed in VSMCs isolated from Cav1−/− (caveolin-1-deficient) mice. Despite the level of uPAR being significantly higher after the disruption of the rafts, uPA/uPAR-dependent cell migration was impaired. However, caveolin-1 deficiency impaired only uPAR-dependent cell proliferation, whereas cell migration was strongly up-regulated in these cells. Our results provide evidence that rafts are required in the regulation of uPAR-mediated VSMC phenotypic modulations. These findings suggest further that, in the context of uPA/uPAR-dependent processes, caveolae-associated and non-associated rafts represent different signalling membrane domains.

Abstract 507: G Proteins are Required for Lipoxygenase EDHF Activity of Rabbit Arterial Smooth Muscle Cells

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Kathryn M Gauthier ◽  
J. R Falck ◽  
William B Campbell
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
G Proteins ◽  
Muscle Cells ◽  
Specific Structure ◽  
Inhibitory Peptide ◽  
Receptor Binding Site ◽  
Channel Activation ◽  
Sk Channel ◽  
Vascular Activity

Arachidonic acid 15-lipoxygenase (15-LO) metabolites function as endothelium-derived hyperpolarizing factors in rabbit and human arteries. In rabbit arteries, LO metabolites mediate nitric-oxide and prostaglandin-independent relaxations to acetylcholine and AA. Previously, we characterized 11,12,15-trihydroxyeicosatrienoic acid (11,12,15-THETA) as a major vasoactive 15-LO metabolite in rabbit arteries. 11,12,15-THETA requires a specific structure for vascular activity. 11(R),12(S),15(S)-THETA causes concentration-related relaxation whereas 11(R),12(R),15(S)-THETA is without activity. The specific structure requirement suggests a role for a receptor. Therefore, we examined the role of G proteins in 11(R),12(S),15(S)-THETA vascular activity. Western immunoblot verified protein expression of Gαs, Gαi and a Gαo in rabbit endothelial and smooth muscle cells. 11(R),12(S),15(S)-THETA increased GTPγ35S binding to rabbit arterial membranes 280±25% while 11(R),12(S),15(S)-THETA was without effect. In cell-attached patches of rabbit smooth muscle, 11(R),12(S),15(S)-THETA (100 nM) increased mean open time of apamin-sensitive, calcium-activated, small conductance potassium (SK) channels from 0.0001±0.0001 to 0.0015±0.0006. In inside-out patches, 11(R),12(S),15(S)-THETA did not increase channel opening (0.0001±0.0001) unless GTP was present (0.0051±0.0023). In the presence of GTP, an antibody against Gαs and a Gαs inhibitory peptide inhibited 11(R),12(S),15(S)-THETA SK channel activation (0.0007±0.0005, 0.0013±0.0012, respectively) whereas an antibody against Gαi was without effect (0.0042±0.0018). A cell-permeant, penetratin-linked Gαs inhibitory peptide also inhibited 11(R),12(S),15(S)-THETA SK channel activation in cell-attached patches (0.0005±0.0002) and blocked 11(R),12(S),15(S)-THETA relaxations in rabbit aorta (max relaxations = 74±6%, 23±7% for control and permeant peptide, respectively). These studies indicate that 11,12,15-THETA-induced SK channel activation and vascular relaxation are mediated by a Gs-coupled mechanism and that 11,12,15-THETA acts via a stereo-specific G protein coupled receptor/binding site.

scholarly journals TRPV4-dependent dilation of peripheral resistance arteries influences arterial pressure

2009 ◽  
Vol 297 (3) ◽  
pp. H1096-H1102 ◽  
Author(s):  
Scott Earley ◽  
Thierry Pauyo ◽  
Rebecca Drapp ◽  
Matthew J. Tavares ◽  
Wolfgang Liedtke ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Peripheral Resistance ◽  
Muscle Cells ◽  
Mesenteric Arteries ◽  
Transient Receptor Potential Vanilloid ◽  
Resistance Arteries

Transient receptor potential vanilloid 4 (TRPV4) channels have been implicated as mediators of calcium influx in both endothelial and vascular smooth muscle cells and are potentially important modulators of vascular tone. However, very little is known about the functional roles of TRPV4 in the resistance vasculature or how these channels influence hemodynamic properties. In the present study, we examined arterial vasomotor activity in vitro and recorded blood pressure dynamics in vivo using TRPV4 knockout (KO) mice. Acetylcholine-induced hyperpolarization and vasodilation were reduced by ∼75% in mesenteric resistance arteries from TRPV4 KO versus wild-type (WT) mice. Furthermore, 11,12-epoxyeicosatrienoic acid (EET), a putative endothelium-derived hyperpolarizing factor, activated a TRPV4-like cation current and hyperpolarized the membrane of vascular smooth muscle cells, resulting in the dilation of mesenteric arteries from WT mice. In contrast, 11,12-EET had no effect on membrane potential, diameter, or ionic currents in the mesenteric arteries from TRPV4 KO mice. A disruption of the endothelium reduced 11,12-EET-induced hyperpolarization and vasodilatation by ∼50%. A similar inhibition of these responses was observed following the block of endothelial (small and intermediate conductance) or smooth muscle (large conductance) K+ channels, suggesting a link between 11,12-EET activity, TRPV4, and K+ channels in endothelial and smooth muscle cells. Finally, we found that hypertension induced by the inhibition of nitric oxide synthase was greater in TRPV4 KO compared with WT mice. These results support the conclusion that both endothelial and smooth muscle TRPV4 channels are critically involved in the vasodilation of mesenteric arteries in response to endothelial-derived factors and suggest that in vivo this mechanism opposes the effects of hypertensive stimuli.

scholarly journals Peripheral Coupling Sites Formed by STIM1 Govern the Contractility of Vascular Smooth Muscle Cells

2021 ◽  
Author(s):  
Vivek Krishnan ◽  
Sher Ali ◽  
Albert L. Gonzales ◽  
Pratish Thakore ◽  
Caoimhin S. Griffin ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Transmembrane Domain ◽  
Muscle Cells ◽  
Channel Activity ◽  
Resistance Arteries ◽  
Store Depletion ◽  
Domain Protein

Peripheral coupling between the sarcoplasmic reticulum (SR) and plasma membrane (PM) forms signaling complexes that regulate the membrane potential and contractility of vascular smooth muscle cells (VSMCs), although the mechanisms responsible for these membrane interactions are poorly understood. In many cells, STIM1 (stromal interaction molecule 1), a single transmembrane-domain protein that resides in the endoplasmic reticulum (ER), transiently moves to ER-PM junctions in response to depletion of ER Ca2+ stores and initiates store-operated Ca2+ entry (SOCE). Fully differentiated VSMCs express STIM1 but exhibit only marginal SOCE activity. We hypothesized that STIM1 is constitutively active in contractile VSMCs and maintains peripheral coupling. In support of this concept, we found that the number and size of SR-PM interacting sites were decreased and SR-dependent Ca2+ signaling processes were disrupted in freshly isolated cerebral artery SMCs from tamoxifen-inducible, SMC specific STIM1-knockout (Stim1-smKO) mice. VSMCs from Stim1-smKO mice also exhibited a reduction in nanoscale colocalization between Ca2+-release sites on the SR and Ca2+-activated ion channels on the PM, accompanied by diminished channel activity. Stim1-smKO mice were hypotensive and resistance arteries isolated from them displayed blunted contractility. These data suggest that STIM1 – independent of SR Ca2+ store depletion – is critically important for stable peripheral coupling in contractile VSMCs.

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