Role of transforming growth factor-beta 1 on platelet-induced enhancement of endothelin-1 production in cultured vascular endothelial cells.
We and other investigators obtained evidence that platelets stimulate endothelin-1 (ET-1) production at both message and protein levels in vascular endothelial cells (ECs), and that platelet-derived transforming growth factor-beta 1 (TGF-beta 1) is responsible for this stimulation. In the present study, we examined the effects of acidification or heat treatment, known to activate latent TGF-beta 1, on the platelet supernatant-induced ET-1 production in cultured porcine aortic ECs. Supernatant of platelets (6.0 x 10(8) platelets/ml) aggregated by adenosine diphosphate contained large amounts of TGF-beta 1, but were almost in a latent form, and the proportion of active TGF-beta 1 in the supernatant was increased markedly in the case of acidification or heat treatment. These treatments also significantly potentiated the supernatant-induced stimulation of prepro ET-1 mRNA expression and the ET-1 release in ECs. Purified TGF-beta 1 also enhanced ET-1 release, dose-dependently, but the enhancement declined at the higher concentrations. Thus, powerful stimulation of ET-1 production by platelet supernatant after acidification or heat treatment cannot be explained only by increments in active TGF-beta 1. The supernatant-induced stimulation of ET-1 synthesis was significantly inhibited by concomitant treatment of TGF-beta 1 neutralizing antibody, but this inhibition was incomplete even at a concentration that abolished TGF-beta 1-induced maximal stimulation. These results suggest that platelet-induced stimulation and subsequent acidification and heat treatment-induced potentiation on endothelial ET-1 production depend closely on release and activation of TGF-beta 1 derived from platelets.(ABSTRACT TRUNCATED AT 250 WORDS)
Murata
S
S
Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Japan.
Matsumura
Y
Y
Takada
K
K
Asai
Y
Y
Takaoka
M
M
Morimoto
S
S
D000818:Animals; D001792:Blood Platelets / Q000502:physiology*; D002478:Cells, Cultured; D003470:Culture Media; D016232:Endothelins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009500:Neutralization Tests; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013268:Stimulation, Chemical; D013552:Swine; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000502:physiology*
D003470:Culture Media; D016232:Endothelins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta