Human placental endothelin: expression of endothelin-1 mRNA by human placental fibroblasts in culture.
Endothelin-1 (ET-1) mRNA is expressed by the human placenta in a developmentally regulated manner and has been shown to stimulate the growth of placental mesenchymal cells. The ability of placental fibroblasts to express preproET-1 mRNA was studied to determine if ET-1 could potentially participate via autocrine mechanisms in the proliferation of placental fibroblasts. Fibroblasts were isolated from normal placentae at various gestational ages (7-19 weeks and term) and their abilities to express preproET-1 mRNA in culture evaluated by Northern analysis. Sparse, rapidly growing cultures of placental fibroblasts expressed preproET-1 mRNA at each gestational age in the presence of 10% FBS. The regulation of preproET-1 expression in placental fibroblasts was studied by exposing cells to known mitogenic stimuli. Quiescent, confluent monolayers of placental fibroblasts expressed no detectable levels of preproET-1 mRNA under basal conditions. Epidermal growth factor (EGF, 10 mg/ml), transforming growth factor-beta 1 (TGF-beta 1, 5 ng/ml), or interleukin 1 beta (IL-1 beta) alone, had no significant effect on steady state preproET-1 mRNA levels. Cycloheximide, an inhibitor of protein synthesis, increased the steady state levels of preproET-1 mRNA at a concentration of 10 micrograms/ml. In the presence cycloheximide, IL-1 beta markedly stimulated preproET-1 mRNA expression, whereas EGF was less effective. TGF-beta 1 had no effect in the presence or absence of cycloheximide. In contrast, 12-O-tetradecanoylphorbol 13-acetate (TPA, 20 nM) exerted a small stimulatory effect on preproET-1 mRNA expression which was not influenced by cycloheximide.(ABSTRACT TRUNCATED AT 250 WORDS)
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Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, MO 63110, USA.
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D015152:Blotting, Northern; D002478:Cells, Cultured; D019332:Endothelin-1; D016232:Endothelins / Q000235:genetics*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014327:Trophoblasts / Q000378:metabolism
D019332:Endothelin-1; D016232:Endothelins; D007375:Interleukin-1; D011498:Protein Precursors; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor; D013755:Tetradecanoylphorbol Acetate