Involvement of proteasome in endothelin-1 production in cultured vascular endothelial cells.
We examined whether the proteasome could regulate endothelin (ET)-1 production in vascular endothelial cells (ECs). A proteasome inhibitor N-benzyloxycarbonyl-Ile-Glu (O-t-Bu)-Ala-leucinal (PSI) significantly decreased ET-1 release from ECs by about 25% of the basal release. PSI also suppressed tumor necrosis factor (TNF)-alpha-induced ET-1 release from ECs in a dose-dependent manner. Similar inhibitory effects were observed using another proteasome inhibitor lactacystin, whereas a calpain inhibitor calpeptin had no apparent effect on ET-1 release. Furthermore, PSI significantly attenuated prepro ET-1 mRNA expression under basal and TNF-alpha-stimulated conditions. Electrophoretic mobility shift assay showed that proteasome inhibitors diminished TNF-alpha-stimulated nuclear factor-kappa B (NF-kappaB) activation in ECs. Pretreatment with antioxidants, pyrrolidine dithiocarbamate and alpha-lipoic acid, both of which are known to be suppressors of NF-kappaB activation, effectively attenuated basal and TNF-alpha-induced ET-1 release. Thus, a proteasome-dependent proteolytic pathway is at least partly involved in ET-1 production under basal conditions, and this proteolytic pathway seems to have a crucial role in ET-1 production enhanced by TNF-alpha. The reduction of NF-kappaB activation may be involved in the mechanisms for suppressive effects of proteasome inhibitors on ET-1 gene transcription and the consequent decrease in ET-1 mRNA expression and ET-1 release.
Ohkita
Mamoru
M
Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, Japan.
Takaoka
Masanori
M
Kobayashi
Yutaka
Y
Itoh
Eriko
E
Uemachi
Hiroko
H
Matsumura
Yasuo
Y
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics; D016232:Endothelins / Q000187:drug effects / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006023:Glycoproteins / Q000494:pharmacology; D006801:Humans; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D009842:Oligopeptides / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex; D011498:Protein Precursors / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
D000975:Antioxidants; D015853:Cysteine Proteinase Inhibitors; D019332:Endothelin-1; D016232:Endothelins; D006023:Glycoproteins; D009097:Multienzyme Complexes; D016328:NF-kappa B; D009842:Oligopeptides; D011498:Protein Precursors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C090535:benzyloxycarbonyl-isoleucyl-glutamyl(O-tert-butyl)-alanyl-leucinal; C039304:calpain inhibitors; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex