title: IGF-I- and EGF-dependent DNA synthesis of porcine myoblasts is influenced by the dietary isoflavones genistein and daidzein.
abstract: Soy-derived isoflavones have been reported to be specific inhibitors of protein tyrosine kinases like the type 1 insulin-like growth factor receptor (IGF-1R) and the epidermal growth factor receptor (EGFR). This study was conducted to investigate, whether IGF-I and EGF stimulate porcine myoblast growth and whether the responses are influenced by isoflavones. Satellite cell-born myoblasts derived from the semimembranosus muscle of newborn piglets were treated for 26 h with IGF-I or EGF alone and in combination with genistein or daidzein. The DNA amount was measured and DNA synthesis was recorded as 6 h-[(3)H]thymidine incorporation during exponential growth in serum-free basal medium. IGF-I and EGF synergistically stimulated DNA synthesis of porcine myoblast with EGF causing a greater response. Genistein (100 micromol/l) effectively reduced the growth factor-mediated DNA synthesis, which was associated with an inhibition of growth factor receptor protein expression. In response to daidzein no reduction in growth factor-mediated DNA synthesis was found. Daidzein (1; 10 micromol/l) combined with IGF-I caused even a slight increase in DNA amount compared with the untreated control. The expression of the IGF-1R precursor protein was reduced with 10 and 100 micromol/l daidzein, whereas the EGFR expression remained unchanged with daidzein. The results suggest that dietary isoflavones may interact with growth factor-induced stimulation of pig skeletal muscle growth.
authors.affiliation: Research Unit Muscle Biology and Growth, Research Institute for the Biology of Farm Animals, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Mau
authors.forename: Claudia
authors.initials: C
authors.lastname: Kalbe
authors.forename: Karin
authors.initials: K
authors.lastname: Wollenhaupt
authors.forename: Gerd
authors.initials: G
authors.lastname: Nürnberg
authors.forename: Charlotte
authors.initials: C
authors.lastname: Rehfeldt
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004247:DNA / Q000096:biosynthesis*; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D007150:Immunohistochemistry / Q000662:veterinary; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007529:Isoflavones / Q000494:pharmacology*; D008297:Male; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013552:Swine / Q000502:physiology*; D013936:Thymidine / Q000378:metabolism
chemical_list: D007529:Isoflavones; D004815:Epidermal Growth Factor; C004742:daidzein; D007334:Insulin-Like Growth Factor I; D004247:DNA; D019833:Genistein; D066246:ErbB Receptors; D017526:Receptor, IGF Type 1; D013936:Thymidine