Cyclooxygenase is regulated by ET-1 and MAPKs in peripheral lung microvascular smooth muscle cells

Abstract

-We examined the hypothesis that the potent vasoconstrictor endothelin (ET)-1 regulates both its own production and production of the vasodilator prostaglandins PGE 2 and prostacyclin in sheep peripheral lung vascular smooth muscle cells (PLVSMC). Confluent layers of PLVSMC were exposed to 10 nM ET-1; expression of the prepro (pp)-ET-1, cyclooxygenase (COX)-1, and COX-2 genes was examined by RT-PCR and Western analysis. Intracellular levels of ET-1 were measured by ELISA with and without addition of the protein synthesis inhibitor brefeldin A (50 g/ml). Prostaglandin levels were measured by gas chromatography-mass spectrometry. Through use of ET A and ETB antagonists (BQ-610 and BQ-788, respectively), the contribution of the ET receptors to COX-1 and -2 expression and ppET-1 gene expression was examined. The contribution of phosphorylated p38 and p44/42 MAPK on COX-1 and COX-2 expression was also examined with MAPK inhibitors (p38, SB-203580 and p44/ 42, PD-98056). ET-1 resulted in transient increases in ppET-1, COX-1, and COX-2 gene and protein expression and release of 6-keto-PGF1␣ and PGE2 (P Ͻ 0.05). Both internalization of ET-1 and synthesis of new peptide contributed to an increase in intracellular ET-1 (P Ͻ 0.05). Although increased ppET-1 was regulated by both ETA and ETB, COX-2 expression was upregulated only by ETA; COX-1 expression was unaffected by either antagonist. ET-1 treatment resulted in transient phosphorylation of p38 and p44/42 MAPK; inhibitors of these MAPKs suppressed expression of COX-2 but not COX-1. Our data indicate that local production of ET-1 regulates COX-2 by activation of the ETA receptor and phosphorylation of p38 and p44/42 MAPK in PLVSMC.prostacyclin; prostaglandin E2; endothelin receptors

Effect of endothelin-1 on cyclooxygenase-2 expression in human hormone refractory prostate cancer cells

“…The activation of p38 MAPK was found to be involved in ET-1-stimulated COX-2 expression in cultured feline esophageal smooth muscle cells (25). Chen et al reported that ET-1 treatment results in an increase in the phosphorylation of both p38 and p42/44 MAPKs in peripheral lung microvascular smooth muscle cells (13). Our study demonstrated that the MEK pathway inhibitor, PD98059, as well as the p38 MAPK inhibitor, SB203580, block the ET-1-induced COX-2 expression, indicating that ET-1-mediated effects are likely to be dependent on the MAPK pathway.…”

“…ET-1 regulates COX-2 expression through p38 and p42/44 MAPK in vascular smooth muscle cells (13) and through p42/44 MAPK in osteoblast-like cells (11). The activation of p38 MAPK was found to be involved in ET-1-stimulated COX-2 expression in cultured feline esophageal smooth muscle cells (25).…”

“…ET-1 plays an important role in modulating COX-2 expression in various types of normal cells (10)(11)(12)(13), but the precise molecular mechanisms controlling these effects remain undefined. Spinella et al reported that ET-1 appears to lead to an increased COX-2 expression in human ovarian carcinoma cells (14).…”

Endothelin and endothelin converting enzyme-1 in the fish gill:evolutionary and physiological perspectives

“…Medullary interstitial cells also contain EDNRs but do not produce EDN1 (Dean et al, 1996). Endothelin has been shown to stimulate COX-2 in a variety of mammalian tissues (Hughes et al, 1995;Chen et al, 2003), and EDN1 signaling via endothelial ENDRB results in the production of prostacyclin (Warner et al, 1989;Hirata et al., 1993). Taken together, our findings suggest that during rapid changes in environmental salinity, gill cell survival during this osmotic stress may be accomplished by increased EDN1 production and subsequent stimulation of COX production of prostaglandins.…”

Upregulation of rhoA mRNA in Bronchial Smooth Muscle of Antigen-induced Airway Hyperresponsive Rats.

“…The level of rhoA mRNA was examined by RT-PCR, a simple method that is widely used for semi-quantitative measurement of mRNA levels (e.g., Niiro et al, 1997;Ma et al, 2002;Murray et al, 2002;Chen et al, 2003;Medina et al, 2003;Zhu et al, 2003). Briefly, cDNAs were prepared from the total RNA (0.5 µg) by using a Takara RNA PCR Kit (Ver.…”