Cellular mechanism of thrombin on endothelin-1 biosynthesis and release in bovine endothelial cell.
We have studied the cellular mechanism responsible for induction of preproendothelin (preproET)-1 mRNA and release of ET-1 by thrombin in cultured bovine endothelial cells (ECs). Thrombin induced an immediate and dose-dependent formation of inositol-1,4,5-trisphosphate (IP3) with a concomitant increase in intracellular Ca2+ concentration ([Ca2+]i). The thrombin-induced ET-1 release was abolished either by a phospholipase C inhibitor, a protein kinase C (PKC) inhibitor, or an intracellular Ca(2+)-chelator, whereas a Ca(2+)-channel antagonist was ineffective. A selective thrombin inhibitor (argatroban) decreased IP3 formation and the increase in [Ca2+]i and ET-1 release stimulated by thrombin. Northern blot analysis revealed that thrombin-induced expression of preproET-1 mRNA was inhibited completely by a PKC inhibitor and partially by argatroban. These data suggest that thrombin is involved in the mechanism of preproET-1 mRNA expression and subsequent ET-1 release, possibly through activation PKC and mobilization of intracellular Ca2+ resulting from the receptor-mediated phosphoinositide breakdown in ECs.
Emori
T
T
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Hirata
Y
Y
Imai
T
T
Ohta
K
K
Kanno
K
K
Eguchi
S
S
Marumo
F
F
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1; D016232:Endothelins / Q000096:biosynthesis* / Q000378:metabolism*; D004727:Endothelium / Q000378:metabolism*; D005786:Gene Expression Regulation; D015544:Inositol 1,4,5-Trisphosphate / Q000096:biosynthesis; D010875:Pipecolic Acids / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013449:Sulfonamides; D013917:Thrombin / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D019332:Endothelin-1; D016232:Endothelins; D010875:Pipecolic Acids; D011498:Protein Precursors; D012333:RNA, Messenger; D013449:Sulfonamides; D015544:Inositol 1,4,5-Trisphosphate; D001120:Arginine; D013917:Thrombin; C031942:argatroban; D002118:Calcium