Endothelin-1 gene expression in endothelial cells is potently inhibited by a vasodilator, dilazep.
Endothelin-1 (ET-1) is considered to be involved in various cardiovascular and renal disorders. The objective of this study was to investigate whether a vasodilator and antiplatelet agent, 1,4-bis[3-(3,4,5-trimethoxybenzoyloxy) propyl]perhydro-1,4-diazepine dihydrochloride monohydrate (dilazep, DZ), has an ET-1-inhibiting effect in vitro. Bovine aortic endothelial cells (BAEC) and human umbilical vein endothelial cells (HUVEC) pretreated with fetal calf serum were treated with DZ and preproET-1 (PpET-1) transcription was evaluated by Northern blot analysis. ET-1 peptide release in culture medium was evaluated by radioimmunoassay. The effect of DZ on the ET-1 promoter/enhancer apparatus was evaluated in transfection experiments using -5 kb ET-1 promoter/enhancer constructs. Modest inhibition of PpET-1 gene transcription was detected after 30 min of DZ treatment (0.56+/-0.19 vs. 1 , p<0.01) and more marked inhibition was seen at 24 h (0.04+/-0.04 vs. 1, p<0.0001). ET-1 peptide release was suppressed strongly after 3 h (382.5+/-2.9 vs. 673.5+/-74.5pg/ml, p< 0.001) and 24 h (38.8+/-9.8 vs. 5,075+/-52.0pg/ml, p<0.0001). DZ potently inhibited PpET-1 transcription in a concentration-dependent manner (0.42+/-0.18 vs. 1, p<0.001, at 100micromol/l). DZ suppressed PpET-1 transcription in confluent HUVEC at 3 h (0.41 +/-0.11 vs. 1, p<0.0001). DZ strongly inhibited PpET-1 transcription after 1 h of thrombin (TH) treatment (0.30+/-0.01 vs. 1.51+/-0.03, p<0.0001). Transfection experiments using the 5 kb ET-1 promoter-luciferase plasmid revealed that DZ strongly suppressed ET-1 promoter activity by 99% (p<0.01). DZ potently inhibited ET-1 gene expression at the transcription level in serum- or TH-treated endothelial cells.
Shrestha
Balaram
B
Department of Cardiology, Tokyo Women's Medical University, Japan.
Hidai
Chiaki
C
Ikeda
Hiromi
H
Okada-Ohno
Masako
M
Kasanuki
Hiroshi
H
Kawana
Masatoshi
M
D000818:Animals; D001011:Aorta / Q000166:cytology; D001798:Blood Proteins / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D004109:Dilazep / Q000494:pharmacology*; D019332:Endothelin-1 / Q000235:genetics*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects; D006490:Hemostatics / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000502:physiology; D013917:Thrombin / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects; D014471:Umbilical Veins / Q000166:cytology; D014665:Vasodilator Agents / Q000494:pharmacology*
D001798:Blood Proteins; D019332:Endothelin-1; D006490:Hemostatics; D014665:Vasodilator Agents; D013917:Thrombin; D004109:Dilazep