p38 MAPK Participates in Muscle-Specific RING Finger 1-Mediated Atrophy in Cast-Immobilized Rat Gastrocnemius Muscle.
10.4196/kjpp.2009.13.6.491
- Author:
Junghwan KIM
1
;
Kyung Jong WON
;
Hwan Myung LEE
;
Byong Yong HWANG
;
Young Min BAE
;
Whan Soo CHOI
;
Hyuk SONG
;
Ki Won LIM
;
Chang Kwon LEE
;
Bokyung KIM
Author Information
1. Department of Physical Therapy, College of Public Health & Welfare, Yongin University, Yongin 449-714, Korea.
- Publication Type:Original Article
- Keywords:
Cast immobilization;
MuRF1;
p38 MAPK;
Skeletal muscle atrophy;
Starvation
- MeSH:
Aging;
Animals;
Atrophy;
Bed Rest;
Fingers;
Imidazoles;
Immobilization;
Muscle, Skeletal;
Muscles;
Myoblasts;
Myoblasts, Skeletal;
p38 Mitogen-Activated Protein Kinases;
Phosphorylation;
Protein Kinases;
Pyridines;
Rats;
RNA, Small Interfering;
Space Flight;
Starvation;
Transfection
- From:The Korean Journal of Physiology and Pharmacology
2009;13(6):491-496
- CountryRepublic of Korea
- Language:English
-
Abstract:
Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles.
