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Exercise‐induced PGC‐1α mRNA increase is independent on calcineurin activation in skeletal muscle of rats
Author(s) -
KOULMANN Nathalie,
BANZET Sébastien,
SANCHEZ Hervé,
CHAPOT Rachel,
SERRURIER Bernard,
SIMLER Nadine,
PEINNEQUIN André,
BIGARD Xavier
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb116
Subject(s) - calcineurin , messenger rna , medicine , endocrinology , activator (genetics) , skeletal muscle , chemistry , biology , receptor , biochemistry , gene , transplantation
This study aimed to examine the relationship between calcineurin activation and enhanced PGC‐1α mRNA during endurance exercise in skeletal muscles of rats. We first determined whether PGC‐1α mRNA varies after exercise in parallel with calcineurin activation estimated by MCIP‐1 mRNA, within single myofibers. Secondly, we measured PGC‐1α mRNA after exercise in muscles of rats treated or not by Cyclosporin A (CsA) or FK506, two inhibitors of calcineurin activity. In single fibers after exercise, PGC‐1α mRNA had a tendency to increase in type I and increased in type IIA and IIX fibers ( P< 0.05), while MCIP‐1 mRNA increased in type I, IIA and IIX fibers ( P< 0.05). Exercise induced no changes in both transcript levels in type IIB fibers. A strong correlation ( P< 0.001) was found between PGC‐1α and MCIP‐1 mRNA within individual fibers. Pharmacological inhibition of calcineurin activity totally inhibited the exercise‐induced increase in MCIP‐1 mRNA. The exercise‐induced increase in PGC‐1α mRNA remained unchanged in CsA‐treated rats, whereas it was abolished in FK506‐treated rats. Interestingly, FK506‐treatment also abolished the exercise‐induced increase in the phosphorylated state of p38, a well‐known activator of PGC‐1α expression, whereas CsA‐treatment had no effect. Present results provide definitive evidence that the exercise‐induced increase in PGC‐1α mRNA occurs independently on calcineurin activation.