New insights into the relationship between mIGF-1-induced hypertrophy and Ca2+ handling in differentiated satellite cells

• Published in: PloS one Vol. 9; no. 9; p. e107753
• Main Authors: Guarnieri, Simone, Morabito, Caterina, Belia, Silvia, Barberi, Laura, Musarò, Antonio, Fanò-Illic, Giorgio, Mariggiò, Maria A
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17.09.2014; Public Library of Science (PLoS)
• Subjects: Acetylcholine; Activation; Animals; Biology and Life Sciences; Caffeine; Calcium (extracellular); Calcium (intracellular); Calcium - metabolism; Calcium channels; Calcium channels (voltage-gated); Calcium mobilization; Cell culture; Cell Differentiation; Cells (biology); Chlorides; Chronic fatigue syndrome; Differentiation (biology); Dihydropyridine; Electrophysiological Phenomena; Embryology; Environmental conditions; Extracellular Space - metabolism; Gene expression; GTP; Guanosine triphosphate; Handling; Histology; Homeostasis; Hypertrophy; Hypertrophy - metabolism; Insulin-Like Growth Factor I - genetics; Insulin-Like Growth Factor I - metabolism; Insulin-like growth factors; Intracellular; Kinases; Laboratories; Lipid peroxidation; Membrane Fluidity; Mice; Mice, Transgenic; Muscle Fibers, Skeletal - pathology; Muscle Fibers, Skeletal - physiology; Muscles; Musculoskeletal system; Myogenesis; Myosin Light Chains - genetics; Myotubes; Neurosciences; Oxidation; Oxidative Stress; Potassium chloride; Potentiation; Regeneration; Rodents; Sarcolemma; Satellite cells; Satellite Cells, Skeletal Muscle - metabolism; Satellite Cells, Skeletal Muscle - pathology; Satellites; Signal transduction; Stem cells; Transgenic animals; Transgenic mice
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0107753

Muscle regeneration involves the activation of satellite cells, is regulated at the genetic and epigenetic levels, and is strongly influenced by gene activation and environmental conditions. The aim of this study was to determine whether the overexpression of mIGF-1 can modify functional features of satellite cells during the differentiation process, particularly in relation to modifications of intracellular Ca2+ handling. Satellite cells were isolated from wild-type and MLC/mIGF-1 transgenic mice. The cells were differentiated in vitro, and morphological analyses, intracellular Ca2+ measurements, and ionic current recordings were performed. mIGF-1 overexpression accelerates satellite cell differentiation and promotes myotube hypertrophy. In addition, mIGF-1 overexpression-induced potentiation of myogenesis triggers both quantitative and qualitative changes to the control of intracellular Ca2+ handling. In particular, the differentiated MLC/mIGF-1 transgenic myotubes have reduced velocity and amplitude of intracellular Ca2+ increases after stimulation with caffeine, KCl and acetylcholine. This appears to be due, at least in part, to changes in the physico-chemical state of the sarcolemma (increased membrane lipid oxidation, increased output currents) and to increased expression of dihydropyridine voltage-operated Ca2+ channels. Interestingly, extracellular ATP and GTP evoke intracellular Ca2+ mobilization to greater extents in the MLC/mIGF-1 transgenic satellite cells, compared to the wild-type cells. These data suggest that these MLC/mIGF-1 transgenic satellite cells are more sensitive to trophic stimuli, which can potentiate the effects of mIGF-1 on the myogenic programme.