Journal of Cell Science & Therapy

Journal of Cell Science & Therapy
Open Access

ISSN: 2157-7013

+44 1300 500008

Continuous mild heat stress induces differentiation of human myoblasts, shifting fi bertype from fast to slow


International Conference & Exhibition on Cell Science & Stem Cell Research

29 Nov - 1 Dec 2011 Philadelphia Airport Marriott, USA

Tetsuo Yamaguchi

Scientific Tracks Abstracts: J Cell Sci Ther

Abstract :

Local hyperthermia is clinically applied in order to improve blood and lymphatic fl ow to decrease swelling of tissues (e.g., skeletal muscle). As for muscle repair following injury, the mechanisms underlying the benefi cial eff ects of hyperthermia-induced muscle repair are unknown. We examined the direct eff ects of continuous heat stress on the diff erentiation of cultured human skeletal muscle myoblasts (HSMMs). Compared to control cultures grown at 37 o C, incubation at 39 o C (continuous mild heat stress; CMHS) enhanced myotube diameter, whereas myotubes were poorly formed at 41 o C by HSMMs. In HSMMs exposed to CMHS, mRNA and protein levels of myosin heavy chain (MyHC) type I were increased compared to the control cultures. Th e mRNA level of MyHC IIx was unaltered, compared to cells that were not exposed to heat stress. Th ese results indicate a fast-to-slow fi ber-type shift in myoblasts. We also examined upstream signals which might be responsible for the fast-to-slow shift of fi ber- types. CMHS enhanced the mRNA level of peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1  , but not the activities of MAPKs (ERK1/2 and p38 MAPK) in HSMMs. Th ese data suggest that CMHS induces a fast-to-slow fi ber-type shift of HSMMs through PGC- 1  . CMHS induced diff erentiation and fast-to-slow fi ber-type shift were observed in C2C12 mouse myoblasts. Th ese observations might be a general characteristic of mammalian myoblasts.

Biography :

Tetsuo Yamaguchi has completed his Ph.D at the age of 35 years from Tokyo University. He is an orthopedic surgeon and postdoctoral researcher at Clinical Research Center, National Hospital Organization Sagamihara Hospital in Japan. He specializes in sports medicine and basic research of muscle differentiation. At present, his interest is to reveal the effect of heat stress on cell differentiation. Recent publication is ?Continuous mild heat stress induces differentiation of mammalian myoblasts, shifting fi ber-type from fast to slow? (American Journal of Physiology, Cell Physiology 2010;298:C140-148).

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