title: Activin-A and FGF-2 mimic the inductive effects of anterior endoderm on terminal cardiac myogenesis in vitro.
abstract: We recently reported that the differentiation of cultured embryonic precardiac myocytes is specifically promoted by anterior lateral plate endoderm from Hamburger-Hamilton stage 6 chick embryos. Polypeptide growth factors are probable mediators of cardiogenesis during embryonic development. It was previously noted that activin-A is a major secretory product of endoderm cultured from chicken embryos. Also, fibroblast growth factor-like proteins are present in anterior endoderm of stage 6 chick embryos. Therefore, we have examined the cardiogenic effects of these growth factors on cultured precardiac mesoderm cells explanted from stage 6 embryos. Similar to the effects of anterior endoderm, low concentrations of activin-A, FGF-2 (bFGF), or insulin significantly increased the incidence of explants that exhibited synchronous contractions and expressed cardiac alpha-actin mRNA. By contrast, explants treated with transferrin, bovine serum albumin, or nerve growth factor never contracted and contained only cytoplasmic beta-actin transcripts. These results provide additional evidence that endoderm-secreted activin-A, FGF-2, and perhaps insulin participate in regulating terminal cardiac differentiation in the embryo.
authors.affiliation: Department of Cellular Biology and Anatomy, Medical College of Wisconsin, Milwaukee 53226, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Sugi
authors.forename: J
authors.initials: J
authors.lastname: Lough
mesh_terms: D000199:Actins / Q000096:biosynthesis; D028341:Activins; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D002642:Chick Embryo; D004707:Endoderm / Q000166:cytology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D007265:Inhibins / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D008648:Mesoderm / Q000166:cytology; D009206:Myocardium / Q000166:cytology*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D000199:Actins; D007328:Insulin; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; D028341:Activins; D007265:Inhibins