Hormonal regulation of IGF-binding protein-2 expression in proliferating C2C12 myoblasts

Publisher Website
Google Scholar
Abstract
No studies have investigated the hormonal regulation of IGF-binding protein-2 (IGFBP-2) secretion and mRNA expression in myoblasts. In this study, cells of the C2C12 mouse myoblast cell line were used to examine the effects of various agents on the hormonal regulation of IGFBP-2. Conditioned medium (CM) was collected and cells were harvested at 2, 4, 6, 15 and 24 h after exposure to treatment media containing porcine insulin (pINS) or recombinant human IGF-I (rhIGF-I), and at 6, 15 and 24 h after exposure to treatment media containing dexamethasone (DEX) or prostaglandin E2 (PGE2). Relative abundance of a single 1·8 kb IGFBP-2 mRNA transcript was determined by Northern analysis using total cellular RNA and a labeled cDNA specific for rat IGFBP-2. IGFBP-2 was detected in CM by probing Western blots with 125I-IGF-I (ligand blot analysis). We have previously shown by immunoblot analysis that the predominant 32 000 Mr protein on ligand blots is IGFBP-2. Treatment with 10−9 or 10−6 m pINS led to a rapid reduction (P−10 or 7 × 10−9 m (5 or 50 ng/ml) rhIGF-I increased IGFBP-2 mRNA abundance and protein secretion (P−8 m DEX exhibited significantly increased (P−6 m PGE2 but mRNA levels were higher than controls at 24 h (P2C12 myoblasts. Journal of Endocrinology (1996) 149, 417–429

This publication has 0 references indexed in Scilit: