Protein kinase C and protein kinase A regulate the expression of angiotensin II receptor mRNA in smooth muscle cells

1994 ◽  
Vol 267 (2) ◽  
pp. 175-183 ◽  
Author(s):  
Xi Chen ◽  
Junji Nishimura ◽  
Jahan Hasna ◽  
Sei Kobayashi ◽  
Tomomi Shikasho ◽  
...  
1996 ◽  
Vol 148 (1) ◽  
pp. 175-180 ◽  
Author(s):  
J Kisielewska ◽  
A P F Flint ◽  
A J Ziecik

Abstract Although the uterus is a target tissue for LH and its homologue hCG the second messenger system responding to LH/hCG in myometrial cells is not established. In this study we investigated the involvement of protein kinase A and protein kinase C in the action of hCG on porcine myometrial smooth muscle cells in vitro. Myometrium was obtained from ovariectomized gilts given 2·5 mg oestradiol benzoate plus 50 mg progesterone for five consecutive days. Myometrial cells were cultured for 48 h and different doses of hCG were then added. Increasing doses of hCG stimulated concentration-dependent increases in [3H]inositol phosphates (IPs) accumulation in incubations lasting 24 h. The highest dose of hCG (1000 mU/ml) increased turnover of IPs by 2·4-fold as reflected in elevations in IP1, IP2 and IP3, and similar effects were observed with noradrenaline. The time- and concentration-dependent effects of hCG on IPs accumulation occurred between 16 and 24 h of incubation. Incubation of myocytes with the lowest doses of hCG (0·1 and 1 mU/ml) caused a significant increase in cAMP accumulation but the highest doses (10–1000 mU/ml) had no effect on cAMP concentrations. This is the first demonstration that LH/hCG receptor signalling leads to increased inositol phosphate turnover in myometrial cells as well as cAMP generation and it leads to the conclusion that both protein kinase A and protein kinase C signalling mechanisms are involved in gonadotrophin action in porcine myometrial smooth muscle cells. Journal of Endocrinology (1996) 148, 175–180


1996 ◽  
Vol 108 (4) ◽  
pp. 315-323 ◽  
Author(s):  
A D Bonev ◽  
M T Nelson

The effects of vasoconstrictor-receptor (neuropeptide Y, alpha-adrenergic, serotonergic, histaminergic) stimulation on currents through ATP-sensitive potassium (KATP) channels in arterial smooth muscle cells were examined. Whole-cell KATP currents, activated by the synthetic KATP channel opener pinacidil or by the endogenous vasodilator, calcitonin gene-related peptide, which acts through protein kinase A, were measured in smooth muscle cells isolated from mesenteric arteries of rabbit. Stimulation of NPY-, alpha 1-, serotonin (5-HT2)-, and histamine (H1)-receptors inhibited KATP currents by 40-56%. The signal transduction pathway that links these receptors to KATP channels was investigated. An inhibitor of phospholipase C (D609) and of protein kinase C (GF 109203X) reduced the inhibitory effect of these vasoconstrictors on KATP currents from 40-56% to 11-23%. Activators of protein kinase C, a diacylglycerol analogue and phorbol 12-myristate 13-acetate (PMA), inhibited KATP currents by 87.3 and 84.2%, respectively. KATP currents, activated by calcitonin gene-related peptide, were also inhibited (47-87%) by serotonin, phenylephrine, and PMA. We propose that KATP channels in these arterial myocytes are subject to dual modulation by protein kinase C (inhibition) and protein kinase A (activation).


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Jie Li ◽  
Lei Cao ◽  
Cang-Bao Xu ◽  
Jun-Jie Wang ◽  
Yong-Xiao Cao

Minimally modified low-density lipoprotein (mmLDL) is a risk factor for cardiovascular disease. The present study investigated the effects of mmLDL on the expression of endothelin type A () receptors in coronary arteries. Rat coronary arteries were organ-cultured for 24 h. The contractile responses were recorded using a myographic system. receptor mRNA and protein expressions were determined using real-time PCR and western blotting, respectively. The results showed that organ-culturing in the presence of mmLDL enhanced the arterial contractility mediated by the receptor in a concentration-dependent and time-dependent manner. Culturing with mmLDL (10 μg/mL) for 24 h shifted the concentration-contractile curves toward the left significantly with increased of from control of and significantly increased receptor mRNA and protein levels. Inhibition of the protein kinase C, extracellular signal-related kinases 1 and 2 (ERK1/2), or NF-κB activities significantly attenuated the effects of mmLDL. The c-Jun N-terminal kinase inhibitor or the p38 pathway inhibitor, however, had no such effects. The results indicate that mmLDL upregulates the receptors in rat coronary arterial smooth muscle cells mainlyviaactivating protein kinase C, ERK1/2, and the downstream transcriptional factor, NF-κB.


1991 ◽  
Vol 276 (1) ◽  
pp. 19-25 ◽  
Author(s):  
B Lassègue ◽  
R W Alexander ◽  
M Clark ◽  
K K Griendling

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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