Mechanical signals and IGF‐I gene splicing in vitro in relation to development of skeletal muscle

• DOI: 10.1002/jcp.20107
• Publication Date: 2004-06-07T16:06:40Z
• Authors: Umber Cheema; Robert Brown; Vivek Mudera; Shi Yu Yang; Gus McGrouther; Geoffrey Goldspink
• Keywords: 0301 basic medicine; genetics: Mechanotransduction, Cellular; Satellite Cells, Skeletal Muscle; genetics: Insulin-Like Growth Factor I; Myoblasts, Skeletal; Muscle Fibers, Skeletal; metabolism: Myoblasts, Skeletal; Mechanotransduction, Cellular; Cell Line; Weight-Bearing; genetics: Cell Differentiation; Mice; 03 medical and health sciences; Microscopy, Electron, Transmission; physiology: Weight-Bearing; Animals; Protein Isoforms; Insulin-Like Growth Factor I; Muscle, Skeletal; genetics: Protein Isoforms; Research Support, Non-U.S. Gov't; Cell Differentiation; physiology: Up-Regulation; Up-Regulation; Alternative Splicing; metabolism: Satellite Cells, Skeletal Muscle; genetics: Alternative Splicing; growth & development: Muscle, Skeletal; Stress, Mechanical; metabolism: Muscle Fibers

Abstract It has been shown that the insulin‐like growth factor (IGF‐I) gene is spliced in response to mechanical signals producing forms of IGF‐I which have different actions. In order study how influence this splicing developing muscle, C 2 12 cells were grown three‐dimensional (3D) culture and subjected regimens strain. IGF‐IEa initiates fusion myoblasts form myotubes was found be constitutively expressed (held under endogenous tension) its expression upregulated by a single ramp stretch 1‐h duration but reduced repeated cyclical stretch. contrast, mechano (MGF), involved proliferation mononucleated are required for secondary myotube formation establish muscle satellite (stem) cell pool, showed no significant constitutive static cultures, cycling loading. The latter types force simulate those generated first contractions myotubes. These data indicate importance seeking understand physiological determine ratios splice variants some factor/tissue genes early stages development skeletal muscle. © 2005 Wiley‐Liss, Inc.