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The effect of chronic high insulin exposure upon metabolic and myogenic markers in C2C12 skeletal muscle cells and myotubes
Author(s) -
Turner Mark C.,
Player Darren J.,
Martin Neil R.W.,
Akam Elizabeth C.,
Lewis Mark P.
Publication year - 2018
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.26748
Subject(s) - glut4 , myogenesis , medicine , insulin , endocrinology , skeletal muscle , protein kinase b , glucose uptake , myocyte , insulin receptor , biology , insulin resistance , phosphorylation , microbiology and biotechnology
Skeletal muscle is an insulin sensitive tissue and accounts for approximately 80% of post‐prandial glucose disposal. This study describes the effects of insulin, delivered for 72 h, to skeletal muscle myoblasts during differentiation or to skeletal muscle myotubes. After chronic treatment, cultures were acutely stimulated with insulin and analyzed for total and phosphorylated Akt (Ser 473 ), mRNA expression of metabolic and myogenic markers and insulin‐stimulated glucose uptake. Skeletal muscle cells differentiated in the presence of insulin chronically, reduced acute insulin stimulated phosphorylation of Akt Ser 473 . In addition, there was a reduction in mRNA expression of Hexokinase II (HKII), GLUT4 and PGC‐1α. Insulin‐stimulated glucose uptake was attenuated when cells were differentiated in the presence of insulin. In contrast, myotubes exposed to chronic insulin showed no alterations in phosphorylation of Akt Ser 473 . Both HKII and GLUT4 mRNA expression were reduced by chronic exposure to insulin; while PGC‐1α was not different between culture conditions and was increased by acute insulin stimulation. These data suggest that there are differential responses in insulin signalling, transcription, and glucose uptake of skeletal muscle cells when cultured in either the presence of insulin during differentiation or in myotube cultures.