Evidence of a K(+)-H(+)-ATPase in vascular smooth muscle cells

1992 ◽  
Vol 262 (6) ◽  
pp. H1955-H1958 ◽  
Author(s):  
R. D. McCabe ◽  
D. B. Young

In earlier studies Na(+)-K(+)-adenosinetriphosphatase (ATPase) and Na(+)-K(+)-2Cl- cotransport partially accounted for vascular smooth muscle cell (VSMC) K+ (Rb+) uptake. In other cells Rb+ is taken up by a K(+)-H(+)-ATPase that is sensitive to NC-1300-B, SCH28080, omeprazole, and N-ethylmaleimide (NEM). This study examines the effects of K(+)-H(+)-ATPase inhibitors on VSMC. Rubidium uptake by primary cultures of canine coronary artery (CCA) VSMC or cultured rat aortic (CRA) VSMC line A7r5 was reduced 19-37% by NC-1300-B, SCH28080, or omeprazole. N-ethylmaleimide reduced CCA VSMC K+ content from 1.55 +/- 0.02 to 1.24 +/- 0.06 mu eq/mg protein. The NC-1300-B-sensitive portion of CRA VSMC Rb+ uptake was not blocked by ouabain (0.1 mM) or bumetanide (0.1 mM), but was reduced by alkalinization with 7.5 mM NH4Cl, and increased by acidification with 7.5 mM Na-acetate. Intracellular pH (pHi) of CRA VSMC was reduced 0.14 +/- 0.03 U by NC-1300-B and 0.22 +/- 0.03 U by NEM. pHi of CCA VSMC was reduced 0.20 +/- 0.03 U by omeprazole (1 mM) and 0.20 +/- 0.03 U or 0.20 +/- 0.05 U by amiloride in the absence or presence of omeprazole, respectively. Fluorescence of 2',7'-bis(carboxyethyl)-5-(6')- carboxyethyl)-5-(6')-carboxyfluorescein due to excitation at 500:441 nm in rat aortic strips was reduced by 0.21 +/- 0.02 U by omeprazole and 0.22 +/- 0.03 U by K+ removal and increased by 0.21 +/- 0.06 U by K+ repletion. We conclude that VSMC possess a previously unknown Rb+ uptake mechanism. This newly discovered mechanism helps to maintain K+ gradient and pHi by extruding H+ in exchange for K+, and is presumably a K(+)-H(+)-ATPase similar to those described in other tissues.

1996 ◽  
Vol 78 (4) ◽  
pp. 676-688 ◽  
Author(s):  
Maik Gollasch ◽  
Christian Ried ◽  
Rostislav Bychkov ◽  
Friedrich C. Luft ◽  
Hermann Haller

1984 ◽  
Vol 246 (3) ◽  
pp. C277-C287 ◽  
Author(s):  
A. M. VanDijk ◽  
P. A. Wieringa ◽  
M. van der Meer ◽  
J. D. Laird

The viscoelastic behavior of single resting vascular smooth muscle cells from bovine coronary artery was studied. No maintained passive force could be recorded, even when the cells were stretched to two to four times their initial length; this finding suggests that the smooth muscle cells do not contribute to the parallel elastic component in arterial smooth muscle tissue. The force during stretch of resting arterial cells was proportional to the rate of stretch (which varied between 20 and 60% of the initial length per second). This linear viscous resistance was also found for toad stomach cells when similar stretches were applied. The stress-relaxation curves of the arterial cells could be fitted to the sum of two exponential components (with half-lives of 13.1 and 0.5 s, respectively). As a result of the above findings, a model consisting of two viscoelastic elements in parallel was proposed for a single resting arterial smooth muscle cell. The viscous resistance to stretch of resting cells in a Ca2+-containing solution was not significantly (P greater than 0.01) different from that in a Ca2+-free solution. The same result was obtained for bovine coronary arterial rings. It is concluded that an adequate model for resting arterial smooth muscle should include an intracellular viscous element.


2018 ◽  
Author(s):  
Thomas R. Whitesell ◽  
Paul Chrystal ◽  
Jae-Ryeon Ryu ◽  
Nicole Munsie ◽  
Ann Grosse ◽  
...  

AbstractDespite the critical role of vascular mural cells (smooth muscle cells and pericytes) in supporting the endothelium of blood vessels, we know little of their early morphogenesis and differentiation. foxc1b:EGFP expressing cells in zebrafish associate with the vascular endothelium (kdrl) and co-express a smooth muscle marker (acta2), but not a pericyte marker (pdgfrβ). The expression of foxc1b in early peri-endothelial mesenchymal cells allows us to follow the morphogenesis of mesenchyme into acta2 expressing vascular smooth muscle cells. We show that mural cells expressing different markers associate with vessels of different diameters, depending on their embryonic location and developmental timing, suggesting marker expression is predictive of functional differences. We identify gene expression signatures for an enriched vascular smooth muscle cell population (foxc1b + acta2) and all smooth muscle (acta2) using fluorescence-activated cell sorting and RNA-Seq. Finally, we demonstrate that progressive loss of foxc1a/foxc1b results in decreased smooth muscle cell coverage. Together, our data highlight the early cellular dynamics and transcriptome profiles of smooth muscle cells in vivo, using foxc1b as a unique tool to probe vascular smooth muscle cell differentiation.Summary StatementTracing the morphogenesis and transcriptome of early vascular smooth muscle cells using foxc1b


2000 ◽  
Vol 113 (11) ◽  
pp. 2055-2064
Author(s):  
E. Stringa ◽  
V. Knauper ◽  
G. Murphy ◽  
J. Gavrilovic

Cell migration is a key event in many biological processes and depends on signals from both extracellular matrix and soluble motogenic factors. During atherosclerotic plaque development, vascular smooth muscle cells migrate from the tunica media to the intima through a basement membrane and interstitial collagenous matrix and proliferate to form a neointima. Matrix metalloproteinases have previously been implicated in neointimal formation and in this study smooth muscle cell adhesion and migration on degraded collagen have been evaluated. Vascular smooth muscle cells adhered to native intact collagen type I and to its first degradation by-product, 3/4 fragment (generated by collagenase-3 cleavage), unwound at 35 degrees C to mimic physiological conditions. PDGF-BB pre-treatment induced a fourfold stimulation of smooth muscle cell motility on the collagen 3/4 fragment whereas no increase in smooth muscle cell motility on collagen type I was observed. Cell migration on collagen type I was mediated by alpha2 integrin, whereas PDGF-BB-stimulated migration on the 3/4 collagen fragment was dependent on alphavbeta3 integrin. alphavbeta3 integrin was organised in clusters concentrated at the leading and trailing edges of the cells and was only expressed when cells were exposed to the 3/4 collagen fragment. Tyrphostin A9, an inhibitor of PDGF receptor-beta tyrosine kinase activity, resulted in complete abolition of migration of PDGF-BB treated cells on collagen type I and 3/4 fragment. These results strongly support the hypothesis that the cellular migratory response to soluble motogens can be regulated by proteolytic modification of the extracellular matrix.


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