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Leptin expression in human primary skeletal muscle cells is reduced during differentiation
Author(s) -
Solberg Rigmor,
Aas Vigdis,
Thoresen G. Hege,
Kase Eili Tranheim,
Drevon Christian A.,
Rustan Arild C.,
Reseland Janne E.
Publication year - 2005
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.20521
Subject(s) - leptin , myogenesis , endocrinology , medicine , leptin receptor , myogenin , myod , myocyte , skeletal muscle , biology , chemistry , obesity
We found leptin to be strongly expressed in undifferentiated human myoblasts derived from biopsies of the thigh (Musculus vastus lateralis). Both mRNA expression and secretion of leptin were reduced during in vitro differentiation into primary myotubes. However, the expression of the leptin receptor (OB‐Rb) mRNA, was unchanged during differentiation of the muscle cells. Administration of recombinant leptin had no effect on leptin, myogenin, myoD, or GLUT4 mRNA expressions during the period of cellular differentiation. A functional leptin receptor was demonstrated by an acute leptin‐induced 1.5‐fold increase in ERK activity ( P = 0.029). Although mRNA expression of regulation of suppressor of cytokine signaling‐3 (SOCS‐3) mRNA expression was unaltered, leptin significantly stimulated fatty acid oxidation after 6 h measured as acid soluble metabolites (ASM). Palmitic acid (PA), oleic acid (OA), and eicosapentaenoic acid (EPA), known to modulate leptin expression in other tissues, had no effect on mRNA expression or secretion of leptin from human myotubes. In conclusion, we demonstrate that leptin is highly expressed in undifferentiated human myoblasts and the expression is reduced during differentiation to mature myotubes. The role of leptin in these cells needs to be further characterized. © 2005 Wiley‐Liss, Inc.