Cyclooxygenase-2 induction by bradykinin in aortic vascular smooth muscle cells

Vascular smooth muscle cell proliferation and migration play an important role in the pathophysiology of several vascular diseases, including atherosclerosis. Prostaglandins that have been implicated in this process are synthesized by two isoforms of cyclooxygenase (COX), with the expression of the regulated COX-2 isoform increased in atherosclerotic plaques. Bradykinin (BK), a vasoactive peptide increased in inflammation, induces the formation of prostaglandins through specific receptor activation. We hypothesized that BK plays an important role in the regulation of COX-2, contributing to the increase in production of prostaglandins in vascular smooth muscle cells. Herein we examined the signaling pathways that participate in the BK regulation of COX-2 protein levels in primary cultured aortic vascular smooth muscle cells. We observed an increase in COX-2 protein levels induced by BK that was maximal at 24 h. This increase was blocked by a B2 kinin receptor antagonist but not a B1 receptor antagonist, suggesting that the B2 receptor is involved in this pathway. In addition, we conclude that the activation of mitogen-activated protein kinases p42/p44, protein kinase C, and nitric oxide synthase is necessary for the increase in COX-2 levels induced by BK because either of the specific inhibitors for these enzymes blocked the effect of BK. Using a similar approach, we further demonstrated that reactive oxygen species and cAMP were not mediators on this pathway. These results suggest that BK activates several intracellular pathways that act in combination to increase COX-2 protein levels. This study suggests a role for BK on the evolution of the atheromatous plaque by virtue of controlling the levels of COX-2.

Download Full-text

Rapid desensitization of vasopressin-stimulated phosphatidylinositol 4,5-bisphosphate and phosphatidylcholine hydrolysis questions the role of these pathways in sustained diacylglycerol formation in A10 vascular-smooth-muscle cells

Biochemical Journal ◽

10.1042/bj2850759 ◽

1992 ◽

Vol 285 (3) ◽

pp. 759-766 ◽

Cited By ~ 20

Author(s):

R Plevin ◽

M J O Wakelam

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Receptor Antagonist ◽

Vascular Smooth Muscle Cells ◽

Inositol Phosphates ◽

Muscle Cells ◽

Receptor Activation ◽

V1a Receptor ◽

In Cells

The kinetics of vasopressin-stimulated PtdIns(4,5)P2 and phosphatidylcholine (PtdCho) hydrolysis in relation to sustained diacylglycerol (DAG) formation was investigated in A10 vascular-smooth-muscle cells in culture. Vasopressin stimulated a transient increase in Ins(1,4,5)P3 mass formation, which was mirrored by a decrease in PtdIns(4,5)P2 mass levels. Vasopressin stimulated sustained accumulation of total [3H]inositol phosphates ([3H]IP) in the presence of Li+; however, this was significantly decreased by adding a vasopressin-receptor antagonist at different times after initial stimulation. Vasopressin-stimulated phospholipase D (PLD) activity was found to be a transient phenomenon lasting approx. 2 min. Experiments involving agonist preincubation with subsequent addition of butanol confirmed that vasopressin-stimulated PLD activity was desensitized. Vasopressin stimulated an increase in formation of choline, but not of phosphocholine, suggesting that PLD was the major catalytic route of PtdCho hydrolysis in this cell line. The roles of choline and inositol phospholipid hydrolysis in the prolonged phase of DAG formation was examined by comparing vasopressin-stimulated changes in DAG levels in the presence of butanol, the protein kinase C inhibitor Ro-31-8220 or a V1a-receptor antagonist. Vasopressin-stimulated DAG formation was decreased by 40-50% in the presence of butanol between 1 and 10 min; however, during more prolonged stimulation butanol was without significant effect. In cells pretreated with Ro-31-8220, vasopressin-stimulated DAG formation was decreased by approx. 30% at 2 min, but was significantly potentiated at later times. This coincided with an enhancement of vasopressin-stimulated [3H]IP accumulation. In cells exposed to the V1a-receptor antagonist 5 min after addition of vasopressin, subsequent DAG formation was significantly decreased, indicating that sustained formation of DAG, like [3H]IP accumulation, was dependent on continual agonist receptor activation. The results are discussed in terms of different phospholipid-hydrolytic pathways providing DAG generation.

Download Full-text

COX-2 and cytosolic PLA2mediate IL-1β-induced cAMP production in human vascular smooth muscle cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1999.276.4.h1369 ◽

1999 ◽

Vol 276 (4) ◽

pp. H1369-H1378 ◽

Cited By ~ 4

Author(s):

Debbie Beasley

Keyword(s):

Arachidonic Acid ◽

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Mrna Levels ◽

Camp Production ◽

Protein Levels ◽

Cox 2

Interleukin (IL)-1 is a potent vasodilator that causes prolonged induction of prostacyclin (PGI2) and cAMP synthesis in human vascular smooth muscle cells (HVSMC). The present study investigated IL-1 induction of PG synthetic enzymes in HVSMC and tested their respective roles in PGI2 and cAMP production. Cyclooxygenase (COX)-1 mRNA was not detectable in either control or IL-1-treated HVSMC, as assessed by RT-PCR. In contrast, COX-2 mRNA was detectable in control HVSMC, increased markedly (16-fold) after 1 h of IL-1 exposure, and increased further (52-fold) after 24 h. COX-2 protein levels, assessed by Western analysis, were increased concomitantly. HVSMC contained mRNA encoding both the secreted and cytosolic forms of phospholipase A2(sPLA2 and cPLA2, respectively). IL-1 stimulation did not affect sPLA2mRNA levels, but cPLA2 mRNA levels increased at 8 h, after the initial induction of PG synthesis. HVSMC constitutively expressed PGI2synthase mRNA, and its levels were not affected by IL-1. A selective COX-2 inhibitor, NS-398, reversed IL-1-induced PGI2 and cAMP production, supporting a role of COX-2 in mediating increased PG synthesis. IL-1-induced cAMP was also reversed by a selective cPLA2 inhibitor, AACOCF3, but not by thioetheramide phosphorylcholine, which inhibits sPLA2 preferentially over cPLA2, supporting a requirement for cPLA2-derived arachidonic acid in IL-1-induced PG synthesis. The delayed induction of cPLA2 mRNA was also attenuated by NS-398, suggesting that it was secondary to the initial COX-2-induced PG synthesis. Together, the results support the hypothesis that IL-1 induces intracellular PG synthesis in HVSMC via rapid upregulation of COX-2, which utilizes cPLA2-derived arachidonic acid to generate PG metabolites that regulate adenylate cyclase.

Download Full-text

Abstract 465: The CB2 Cannabinoid Receptor Mediates the Anti-Proliferative Actions of Angiotensin-(1-7) in Vascular Smooth Muscle Cells

Hypertension ◽

10.1161/hyp.62.suppl_1.a465 ◽

2013 ◽

Vol 62 (suppl_1) ◽

Author(s):

E. Ann Tallant ◽

Allyn Howlett ◽

Megan Grabenauer ◽

Brian F Thomas ◽

Patricia E Gallagher

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Receptor Antagonist ◽

Vascular Smooth Muscle Cells ◽

Vascular Injury ◽

Muscle Cells ◽

Receptor Activation ◽

Cb2 Receptor ◽

Vascular Proliferation

Therapeutic interventions to reduce vascular proliferation are critical for the effective treatment of hypertension-induced end-organ damage, restenosis and atherosclerosis. We showed that angiotensin-(1-7) [Ang-(1-7)] reduces neointimal formation following vascular injury and inhibits vascular growth, through activation of the AT7 receptor mas and production of arachidonic acid derivatives. Endocannaboids (ECs) derived from membrane phospholipids also inhibit vascular proliferation and reduce growth following vascular injury, by stimulation of the CB2 receptor. The impact of CB2 receptor blockade on the anti-proliferative actions of Ang-(1-7) was investigated to assess a potential interaction between the EC and Ang-(1-7)/mas receptor systems. Rat thoracic aortic vascular smooth muscle cells (VSMCs) were treated with platelet-derived growth factor (PDGF) to stimulate growth and incubated with Ang-(1-7), the AT7 receptor antagonist [D-alanine7]-angiotensin-(1-7) [Dala], the CB2 receptor agonist HU308 and/or the CB2 receptor antagonist AM630. PDGF-stimulated VSMC growth was markedly reduced by Ang-(1-7) (74 ± 6% of control, n = 10, p<0.0001) and this effect was blocked by Dala (116 ± 14% of control, n = 4; n.s.). The Ang-(1-7)-mediated reduction in growth was abolished by the CB2 receptor antagonist AM630 (136 ± 16% of control, n = 4; n.s.); AM630 alone had no effect. In contrast, the CB1 receptor antagonist AM281 did not prevent the inhibitory actions of Ang-(1-7) on VSMC growth. CB2 receptor activation by the agonist HU308 also reduced PDGF-stimulated VSMC proliferation to a similar extent as Ang-(1-7) (67 ± 4% of control, n = 5, p<0.001); Dala did not influence the response to HU308 (50 ± 10% of control, n = 5, p<0.005). Ang-(1-7) significantly increased the endogenous cannabinoid 2-arachidonoylglycerol (2-AG) by 48% in VSMC by 24 h (p<0.05, n = 4). We conclude that the growth inhibitory properties of Ang-(1-7) involve a novel pathway culminating in the downstream formation of 2-AG and subsequent activation of the CB2 receptor in VSMC. Thus, Ang-(1-7) and/or CB2 receptor activation may constitute a new and beneficial therapeutic strategy for the prevention of vascular proliferation that is prevalent in cardiovascular disease.

Download Full-text

Angiotensin II type 2 receptor activation induces RhoA inhibition through Phosphorylation of its Serine 188 in Vascular Smooth Muscle Cells

The FASEB Journal ◽

10.1096/fasebj.20.4.a105 ◽

2006 ◽

Vol 20 (4) ◽

Author(s):

Malvyne Rolli‐Derkinderen ◽

Christophe Guilluy ◽

Laurent Loufrani ◽

Daniel Henrion ◽

Gervaise Loirand ◽

...

Keyword(s):

Smooth Muscle ◽

Angiotensin Ii ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Receptor Activation

Download Full-text

Upregulation of lysyl oxidase in vascular smooth muscle cells by cAMP: Role for adenosine receptor activation

Journal of Cellular Biochemistry ◽

10.1002/(sici)1097-4644(19991001)75:1<177::aid-jcb18>3.0.co;2-w ◽

1999 ◽

Vol 75 (1) ◽

pp. 177-185 ◽

Cited By ~ 17

Author(s):

Katya Ravid ◽

Lynda I. Smith-Mungo ◽

Zhiuhu Zhao ◽

Kathleen M. Thomas ◽

Herbert M. Kagan

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Adenosine Receptor ◽

Lysyl Oxidase ◽

Muscle Cells ◽

Receptor Activation ◽

Adenosine Receptor Activation

Download Full-text

The Apoptotic Effect of Angiotensin II in Human Vascular Smooth Muscle Cells

Microscopy and Microanalysis ◽

10.1017/s1431927600035674 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 636-637

Author(s):

E. Ou ◽

C. Wei

Keyword(s):

Smooth Muscle ◽

Angiotensin Ii ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Receptor Antagonist ◽

Vascular Smooth Muscle Cells ◽

Artery Bypass ◽

Muscle Cells ◽

Tunel Staining ◽

Apoptotic Effect

Angiotensin II is a potent vasoconstrictor and mitogenic factor. However, the effects of angiotensin II on human vascular smooth muscle cells apoptosis remain controversial. Therefore, the current study was designed to investigate the actions of angiotensin II on human vascular smooth muscle cells apoptosis.Human saphenous vein was obtained from coronary artery bypass surgery (n=6) and was minced and incubated in the special tissue culture system in the absence or presence of angiotensin II (10-6 to 10-12M) for 1, 2, 4, 8, 16, & 24 hours. These studies were repeated with losartan (10-6M, AT- 1 receptor antagonist) and PD-123319 (10-6M, AT-2 receptor antagonist). To detect the DNA fragmentation, in situ terminal deoxymucleotidyl transferase dUTP nick end labeling (TUNEL) and DNA agarose gel analyses were performed. An average of 1000 nuclei was analyzed for TUNEL studies.TUNEL staining and DNA gel analysis demonstrated that angiotensin II increased apoptosis in human vascular smooth muscle cells.

Download Full-text

Hypoxia-induced expression of VEGF is reversible in myocardial vascular smooth muscle cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1997.273.2.h628 ◽

1997 ◽

Vol 273 (2) ◽

pp. H628-H633 ◽

Cited By ~ 17

Author(s):

J. W. Gu ◽

T. H. Adair

Keyword(s):

Smooth Muscle ◽

Growth Factor ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Conditioned Media ◽

Dependent Manner ◽

Induced Expression ◽

Protein Levels

We determined whether hypoxia-induced expression of vascular endothelial growth factor (VEGF) can be reversed by a normoxic environment. Dog myocardial vascular smooth muscle cells (MVSMCs) were exposed to hypoxia (1% O2) for 24 h and then returned to normoxia (20% O2). VEGF protein levels increased by more than fivefold after 24 h of hypoxia and returned to baseline within 24 h of the return of the cells to normoxia. Northern blot analysis showed that hypoxia caused a 5.5-fold increase in VEGF mRNA, and, again, the expression was reversed after reinstitution of normoxia. Additional measurements showed that basic fibroblast growth factor and platelet-derived growth factor protein levels were not induced by hypoxia and that hypoxia caused a fourfold decrease in transforming growth factor-beta 1 protein levels. Hypoxia conditioned media from MVSMCs caused human umbilical vein endothelial cells to increase [3H]thymidine incorporation by twofold, an effect that was blocked in a dose-dependent manner by anti-human VEGF antibody. The hypoxia conditioned media had no effect on MVSMC proliferation. These findings suggest that VEGF expression can be bidirectionally controlled by tissue oxygenation, and thus support the hypothesis that VEGF is a physiological regulator of angiogenesis.

Download Full-text