Effects of Protein Kinase C Activation and Inhibition on Endothelin-1 Release From Human Aortic and Pulmonary Artery Endothelial Cells Comparison With Effects on Bovine Endothelin-1 and Human Prostaglandin I2 Release

Objective: We investigated the regulation of endothelin-1 (ET-1) expression in in vivo high-fat diet (HFD)-fed mice and in vitro cultured human aortic endothelial cells (HAECs). Methods: Male C57BL/6 mice were fed on standard chow, serum was prepared, and ET-1 levels were analyzed using an ELISA kit. Quantitative PCR was performed using iQ SYBR Green Supermix. Statistical significance was assessed using SPSS, with p < 0.05 considered significant. Results: The serum ET-1 content and endothelial expression of ET-1 mRNA were increased in the HFD-fed mice compared to the chow-fed control mice. Moreover, the mRNA expression of ET-1 was significantly increased in cultured HAECs in response to acute (< 24 h) and chronic (12–16 days) treatments with palmitic acid (PA), one of the most abundant saturated fatty acids in obesity. We found that the induction of ET-1 expression by PA was abolished by pretreating the cells with the endoplasmic reticulum (ER) stress inhibitor 4-phenylbutyric acid or the protein kinase C (PKC) inhibitor Gö 6850. Conclusion: Our findings demonstrate for the first time that PA increases ET-1 expression in endothelial cells through the induction of ER stress and the activation of PKC, providing novel mechanistic insights into the pathogenesis of obesity-associated hypertension and cardiovascular diseases.

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Cigarette smoke extract induces endothelin-1 via protein kinase C in pulmonary artery endothelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.2001.281.2.l403 ◽

2001 ◽

Vol 281 (2) ◽

pp. L403-L411 ◽

Cited By ~ 18

Author(s):

Sang-Do Lee ◽

Dong-Soon Lee ◽

Yong-Gam Chun ◽

Tae-Sun Shim ◽

Chae-Man Lim ◽

...

Keyword(s):

Gene Expression ◽

Endothelial Cells ◽

Protein Kinase C ◽

Protein Kinase ◽

Pulmonary Artery ◽

Cigarette Smoke ◽

De Novo ◽

Ex Vivo ◽

Cigarette Smoke Extract ◽

Kinase C

We examined the mechanism of endothelin (ET)-1 regulation by cigarette smoke extract (CSE) and the effect of platelets on CSE-induced stimulation of ET-1 gene expression in human and bovine pulmonary artery endothelial cells (PAECs). Our data show that CSE (1%) induces ET-1 gene expression (after 1 h) and ET-1 peptide synthesis (after 4 h) in bovine PAECs. The induction of preproET-1 mRNA level was due to de novo transcription, and new protein synthesis was not required for this induction. The protein kinase C inhibitors staurosporine (10−8mol/l) and calphostin C (10−7mol/l) abolished the induction of ET-1 gene expression by CSE in bovine and human PAECs. Although a lower concentration of platelets (106cells/ml in bovine PAECs; 107cells/ml in human PAECs) did not significantly alter ET-1 gene expression in PAECs, incubation of platelets with CSE (1%) and PAECs produced a significant increase in preproET-1 mRNA and ET-1 peptide compared with the values in the presence of CSE (1%) alone. CSE (1%) induced platelet aggregation and increased the expression of platelet membrane glycoproteins ex vivo. Thus our data suggest that CSE stimulates ET-1 gene expression via PKC in PAECs. CSE and platelets showed a synergistic effect on ET-1 gene expression, possibly through the activation of platelets by CSE.

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Hydroperoxide-Induced Diacylglycerol Formation and Protein Kinase C Activation in Vascular Endothelial Cells

Archives of Biochemistry and Biophysics ◽

10.1006/abbi.1993.1281 ◽

1993 ◽

Vol 303 (2) ◽

pp. 260-266 ◽

Cited By ~ 81

Author(s):

M.M. Taher ◽

J.G.N. Garcia ◽

V. Natarajan

Keyword(s):

Endothelial Cells ◽

Protein Kinase C ◽

Protein Kinase ◽

Vascular Endothelial Cells ◽

Vascular Endothelial ◽

Kinase C ◽

Protein Kinase C Activation

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Influence of vasoactive agents on cytoplasmic free calcium in vascular endothelial cells

Journal of Applied Physiology ◽

10.1152/jappl.1988.65.5.2221 ◽

1988 ◽

Vol 65 (5) ◽

pp. 2221-2227 ◽

Cited By ~ 40

Author(s):

U. S. Ryan ◽

P. V. Avdonin ◽

E. Y. Posin ◽

E. G. Popov ◽

S. M. Danilov ◽

...

Keyword(s):

Endothelial Cells ◽

Protein Kinase C ◽

Protein Kinase ◽

Pulmonary Artery ◽

Vascular Endothelial Cells ◽

Umbilical Vein ◽

Platelet Activating Factor ◽

Free Calcium ◽

Kinase C ◽

Cytoplasmic Free Calcium

The regulation of cytoplasmic free calcium concentration [( Ca2+]i) in endothelial cells (EC) derived from human umbilical vein, aorta, and pulmonary artery, or from bovine pulmonary artery, was studied by means of the fluorescent Ca2+ indicator indo-1. Histamine and thrombin caused a rapid transient elevation in [Ca2+]i in the EC of all the human blood vessels tested. In aortic EC, [Ca2+]i also rose in response to ATP and bradykinin. It was shown that in bovine pulmonary artery EC [Ca2+]i rises in response to platelet-activating factor (PAF) and thrombin. For a more detailed investigation of the receptor-mediated mechanism of [Ca2+]i increase in EC we used histamine as a stimulating agent. Histamine effects were seen at concentrations ranging from 5 X 10(-7) to 10(-4) M [50% effective dose (ED50) approximately 2-4 microM)] and were mediated by H1-receptors. The histamine-induced increase in [Ca2+]i was not markedly diminished when the extracellular calcium was bound by excess ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA). The data obtained indicate that the histamine effect is best explained by Ca2+ mobilization from intracellular stores. The histamine-induced increase in [Ca2+]i was not influenced by elevating the intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or cyclic guanylic acid (cGMP) by use of isobutylmethylxanthine and forskolin or by nitroprusside preincubation, respectively. However, the protein kinase C stimulator, phorbol myristate acetate (PMA), strongly inhibits [Ca2+]i elevation. It is assumed that a negative feedback mechanism that blocks receptor-mediated [Ca2+]i increase is triggered as a result of the activation of protein kinase C.

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Endothelin-1 stimulates DNA synthesis and proliferation of pulmonary artery smooth muscle cells

AJP Cell Physiology ◽

10.1152/ajpcell.1992.263.6.c1295 ◽

1992 ◽

Vol 263 (6) ◽

pp. C1295-C1301 ◽

Cited By ~ 120

Author(s):

K. Janakidevi ◽

M. A. Fisher ◽

P. J. Del Vecchio ◽

C. Tiruppathi ◽

J. Figge ◽

...

Keyword(s):

Smooth Muscle ◽

Protein Kinase C ◽

Growth Factor ◽

Protein Kinase ◽

Pulmonary Artery ◽

Dna Synthesis ◽

Synthetic Activity ◽

Proliferative Potential ◽

Endothelin 1 ◽

Kinase C

Endothelin-1 (ET-1), a 21-amino acid peptide released from the endothelium, elicits a variety of biological effects that include vascular smooth muscle cell (VSMC) contraction, release of secondary mediators, and cell proliferation. The present study was undertaken to examine the proliferative potential of ET-1 toward pulmonary artery VSMC in culture. In the presence of low serum and epidermal growth factor (EGF), ET-1 stimulated marked DNA synthesis and proliferation of VSMC. The contributing factor from serum appeared to be platelet-derived growth factor (PDGF) because the antibody to PDGF eliminated the stimulatory activity. The antibody to EGF also prevented the stimulation, suggesting that both PDGF and EGF are required for the full expression of the VSMC growth-promoting activity of ET-1. A paradoxical aspect of ET-1 effect on VSMC was the ability of ET-1 to inhibit the EGF-stimulated DNA synthesis when the two factors were added together to a high baseline DNA synthetic activity. The inhibition was prevented if ET-1 was added 12-18 h after the addition of EGF or if ET-1 and EGF were added to a protein kinase C-depleted VSMC. The inhibition by ET-1 may be mediated by protein kinase C activation followed by inhibition of EGF binding to its receptor. The results indicate that ET-1 under appropriate conditions can modulate the growth of pulmonary artery VSMC in both positive and negative directions.

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