Inhibition of Cyclic AMP-Dependent Kinase by Expression of a Protein Kinase Inhibitor/Enhanced Green Fluorescent Fusion Protein Attenuates Angiotensin II-Induced Type 1 AT1Receptor mRNA Down-Regulation in Vascular Smooth Muscle Cells

1998 ◽  
Vol 54 (3) ◽  
pp. 514-524 ◽  
Author(s):  
Xiaofei Wang ◽  
T. J. Murphy
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Fusion Protein ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Kinase Inhibitor ◽  
Green Fluorescent

Angiotensin II type 1 receptor-mediated activation of Ras in cultured rat vascular smooth muscle cells

1996 ◽  
Vol 271 (2) ◽  
pp. H595-H601 ◽  
Author(s):  
M. Okuda ◽  
Y. Kawahara ◽  
M. Yokoyama
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Vascular Smooth Muscle Cells ◽  
Ang Ii ◽  
Kinase Activation ◽  
Ras Activation ◽  
Fos Expression

Angiotensin II (ANG II), a potent growth-promoting factor of vascular smooth muscle cells (VSMC), induces activation of mitogen-activated protein (MAP) kinases and subsequent expression of the c-fos protooncogene in VSMC. However, it remains obscure whether ANG II induces activation of the ras protooncogene product (Ras), and if it does, whether Ras is involved in signaling from the ANG II receptor to the MAP kinase pathway in VSMC. In cultured VSMC, ANG II activated Ras comparably to epidermal growth factor. ANG II-induced Ras activation was detectable within 1 min and maximal at 2–5 min. The ANG II type 1 (AT1) receptor antagonist, CV-11974, completely inhibited this reaction. Pertussis toxin treatment of VSMC inhibited ANG II-induced Ras activation by approximately 70% but had no effect on ANG II-induced MAP kinase activation and c-fos expression. These results indicate that ANG II activates Ras via AT1 receptors, which are predominantly linked to a G protein of the Gi subfamily in VSMC1 and suggest that Ras activation may not be a prerequisite for ANG II-induced MAP kinase activation and c-fos expression in this cell type.

Regulation of SERCA Ca2+ pump expression by cytoplasmic [Ca2+] in vascular smooth muscle cells

2001 ◽  
Vol 280 (4) ◽  
pp. C843-C851 ◽  
Author(s):  
Kwan-Dun Wu ◽  
David Bungard ◽  
Jonathan Lytton
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Muscle ◽  
Protein Kinase ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Kinase Inhibitor ◽  
Muscle Cells ◽  
Endoplasmic Reticulum Stress Response ◽  
Dependent Protein

Vascular smooth muscle cells (VSMC) express three isoforms of the sarcoplasmic or endoplasmic reticulum Ca2+-ATPase (SERCA) pump; SERCA2b predominates (91%), whereas SERCA2a (6%) and SERCA3 (3%) are present in much smaller amounts. Treatment with thapsigargin (Tg) or A-23187 increased the level of mRNA encoding SERCA2b four- to fivefold; SERCA3 increased about 10-fold, whereas SERCA2a was unchanged. Ca2+ chelation prevented the Tg-induced SERCA2b increase, whereas Ca2+ elevation itself increased SERCA2b expression. These responses were discordant with those of 78-kDa glucose-regulated protein/immunoglobulin-binding protein (grp78/BiP), an endoplasmic reticulum stress-response protein. SERCA2b mRNA elevation was much larger than could be accounted for by the observed increase in message stability. The induction of SERCA2b by Tg did not require protein synthesis, nor was it affected by inhibitors of calcineurin, protein kinase C, Ca2+/calmodulin-dependent protein kinase, or tyrosine protein kinases. Treatment with the nonselective protein kinase inhibitor H-7 prevented Tg-induced SERCA2b expression from occurring, whereas another nonselective inhibitor, staurosporine, was without effect. We conclude that changes in cytosolic Ca2+ control the expression of SERCA2b in VSMC via a mechanism involving a currently uncharacterized, H-7-sensitive but staurosporine-insensitive, protein kinase.

scholarly journals Angiotensin II-induced phosphatidylcholine hydrolysis in cultured vascular smooth-muscle cells. Regulation and localization

1991 ◽  
Vol 276 (1) ◽  
pp. 19-25 ◽  
Author(s):  
B Lassègue ◽  
R W Alexander ◽  
M Clark ◽  
K K Griendling
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Angiotensin Ii ◽  
Protein Kinase ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Kinase C ◽  
Hydrolysis Of

In cultured vascular smooth-muscle cells (VSMC), angiotensin II (AngII) induces a biphasic, sustained increase in diacylglycerol (DG) of unclear origin. To determine whether hydrolysis of phosphatidylcholine (PC) is a possible source of DG, we labelled cellular PC with [3H]choline, and measured the formation of intra- and extra-cellular [3H]choline and [3H]phosphocholine after stimulation with AngII. AngII induced a concentration-dependent release of choline from VSMC that was significant at 2 min and was sustained over 20 min. In contrast, accumulation of choline inside the cells was very slight. AngII also increased the formation of [3H]myristate-labelled phosphatidic acid, and, in the presence of ethanol, of [3H]phosphatidylethanol, characteristic of a phospholipase D (PLD) activity. Extracellular release of choline was partially inhibited by removal of extracellular Ca2+ (54 +/- 9% inhibition at 10 min) or inhibition of receptor processing by phenylarsine oxide (79 +/- 8% inhibition at 20 min). The protein kinase C activator phorbol myristate acetate also stimulated a large release of choline after a 5 min lag, which was unaffected by the Ca2+ ionophore ionomycin, but was additive with AngII stimulation. Down-regulation of protein kinase C by a 24 h incubation with phorbol dibutyrate (200 nM) decreased basal choline release, but had no effect on AngII stimulation. We conclude that AngII induces a major PC hydrolysis, probably mainly via PLD activation. This reaction is partially dependent on Ca2+ and is independent of protein kinase C, and appears to be mediated by cellular processing of the receptor-agonist complex. Our results are consistent with a preferential hydrolysis of PC from the external leaflet of the plasmalemma, and raise the possibility that PC hydrolysis occurs in specialized ‘signalling domains’ in VSMC.

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