Rapid activation of the novel serine/threonine protein kinase, protein kinase D by phorbol esters, angiotensin II and PDGF-BB in vascular smooth muscle cells

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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Angiotensin II responses of vascular smooth muscle cells from hypertensive rats: enhancement at the level of p42 and p44 mitogen activated protein kinase

British Journal of Pharmacology ◽

10.1038/sj.bjp.0701366 ◽

1997 ◽

Vol 122 (2) ◽

pp. 209-216 ◽

Cited By ~ 26

Author(s):

Neil Wilkie ◽

Leong L. Ng ◽

Michael R. Boarder

Keyword(s):

Smooth Muscle ◽

Angiotensin Ii ◽

Protein Kinase ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Mitogen Activated Protein Kinase ◽

Hypertensive Rats ◽

Mitogen Activated Protein

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Angiotensin II enhancement of hormone-stimulated cAMP formation in cultured vascular smooth muscle cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.264.1.h86 ◽

1993 ◽

Vol 264 (1) ◽

pp. H86-H96 ◽

Cited By ~ 4

Author(s):

S. W. Kubalak ◽

J. G. Webb

Keyword(s):

Smooth Muscle ◽

Angiotensin Ii ◽

Protein Kinase ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Ang Ii ◽

Camp Formation ◽

Camp Stimulation

The mechanism by which angiotensin II (ANG II) potentiates hormone-induced adenosine 3',5'-cyclic monophosphate (cAMP) formation was studied in cultured rat vascular smooth muscle cells. Incubation of cells for 60 s with 100 nM ANG II produced a two- to threefold enhancement of cAMP stimulation when coupled with isoproterenol, prostaglandin I2, or adenosine. ANG II also enhanced cAMP formation when adenylyl cyclase was stimulated directly with forskolin or activated through the stimulatory guanyl nucleotide-binding protein (Gs) with cholera toxin. Forskolin stimulation was increased by only 40%, but cholera toxin-stimulated cAMP formation was doubled. Activation of protein kinase C with phorbol 12-myristate 13-acetate (PMA) enhanced isoproterenol-stimulated cAMP by 51%, but inhibitors of protein kinase activation had little effect on ANG II enhancement of cAMP production. However, use of PMA to cause feedback inhibition of D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] formation blocked the effect of ANG II on agonist-stimulated cAMP formation, and the time course for this effect of PMA paralleled its inhibitory effect on Ins(1,4,5)P3 production. Furthermore, chelation of intracellular Ca2+ or treatment with calmodulin antagonists also diminished the synergism between ANG II and isoproterenol for cAMP stimulation. The results indicate that ANG II enhances cAMP formation in vascular smooth muscle cells by facilitating the interaction between activated Gs and adenylyl cyclase. In addition, the data suggest that this effect of ANG II is directly related to Ins(1,4,5)P3 stimulation and appears to involve a Ca(2+)-calmodulin-dependent mechanism.

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Activation of Akt/protein kinase B after stimulation with angiotensin II in vascular smooth muscle cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1999.276.6.h1927 ◽

1999 ◽

Vol 276 (6) ◽

pp. H1927-H1934 ◽

Cited By ~ 15

Author(s):

Tomosaburo Takahashi ◽

Takahiro Taniguchi ◽

Hiroaki Konishi ◽

Ushio Kikkawa ◽

Yuichi Ishikawa ◽

...

Keyword(s):

Smooth Muscle ◽

Angiotensin Ii ◽

Protein Kinase ◽

Vascular Smooth Muscle ◽

Tyrosine Kinase ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Protein Kinase B ◽

Muscle Cells ◽

Ang Ii

Involvement of Akt/Protein kinase B (PKB), a serine/threonine kinase with a pleckstrin-homology domain, in angiotensin II (ANG II)-induced signal transduction was investigated in cultured vascular smooth muscle cells (VSMC). Stimulation of the cells with ANG II led to a marked increase in the kinase activity of Akt/PKB, which coincided with Ser-473 phosphorylation. ANG II-stimulated Akt/PKB activation was rapid, concentration dependent, and inhibited by the AT1-receptor antagonist CV-11974, but not by pertussis toxin. Akt/PKB activity was stimulated by the Ca2+ ionophore ionomycin, suggesting the possible involvement of Ca2+ in ANG II-stimulated Akt/PKB activation. However, blockade of Ca2+ mobilization by BAPTA-AM only partially inhibited ANG II-stimulated Akt/PKB activation. ANG II-stimulated Akt/PKB activation was inhibited by the tyrosine kinase inhibitors genistein and herbimycin A and by the phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and LY-294002. These results indicate that ANG II stimulates Akt/PKB activity via AT1 receptors in VSMC and that the activities of tyrosine kinase and PI3K are required for this activation.

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Mechanism of cellular effect of phorbol esters on action of arginine vasopressin and angiotensin II on rat vascular smooth muscle cells in culture

Biochemical Journal ◽

10.1042/bj2540625 ◽

1988 ◽

Vol 254 (3) ◽

pp. 625-629 ◽

Cited By ~ 24

Author(s):

C Caramelo ◽

P Tsai ◽

R W Schrier

Keyword(s):

Smooth Muscle ◽

Protein Kinase C ◽

Angiotensin Ii ◽

Protein Kinase ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Arginine Vasopressin ◽

Muscle Cells ◽

Kinase C

The inhibitory effect of phorbol-12-myristate-13-acetate (PMA) on the Ca2+-mobilization mechanisms by arginine vasopressin (AVP) and angiotensin II (AII) was analysed in rat vascular smooth muscle cells (VSMC) in culture. PMA inhibited the Ca2+-mobilizing effect of both AVP and AII in a dose-dependent manner, including the rise in cytosolic free Ca2+ ([Ca2+]i) and Ca2+ efflux. In addition, inositol trisphosphate (IP3) production induced by AVP or AII was more than 50% reduced by PMA. The involvement of protein kinase C was implicated by the diminution of the PMA effect by the specific protein kinase C inhibitor isoquinoline-sulphonyl-O-2-methylpiperazine (H7) and the lack of effect of an inactive phorbol. Thus, these results suggest that there is a blocking site that is common or similar for both AVP and AII signal transduction, and that it is a substrate for protein kinase C. This blocking action of protein kinase C occurred at least in part by inhibition of IP3 production and, subsequently, a reduction in cytosolic Ca2+ release. In the presence of ionomycin, which produces an increase in [Ca2+]i that is not altered by PMA, 45Ca2+ efflux was increased instead of inhibited by PMA, thus suggesting that protein kinase C activation also stimulates a Ca2+-extrusion mechanism in VSMC.

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