Artículo de revista
Contraction-related stimuli regulate GLUT4 traffic in C2C12-GLUT4myc skeletal muscle cells
Fecha
2010Registro en:
Am J Physiol Endocrinol Metab 298: E1058–E1071, 2010.
doi:10.1152/ajpendo.00773.2009
Autor
Niu, Wenyan
Bilan, Philip J.
Ishikura, Shuhei
Schertzer, Jonathan D.
Contreras Ferrat, Ariel Eduardo
Fu, Zhengxiang
Liu, Jie
Boguslavsky, Shlomit
Foley, Kevin P.
Liu, Zhi
Li, Jinru
Chu, Guilan
Panakkezhum, Thomas
Lopaschuk, Gary D.
Lavandero González, Sergio
Yao, Zhi
Klip, Amira
Institución
Resumen
Contraction-related stimuli regulate GLUT4 traffic in C2C12-
GLUT4myc skeletal muscle cells. Am J Physiol Endocrinol Metab
298: E1058 –E1071, 2010. First published February 16, 2010;
doi:10.1152/ajpendo.00773.2009.—Muscle contraction stimulates
glucose uptake acutely to increase energy supply, but suitable cellular
models that faithfully reproduce this complex phenomenon are lacking.
To this end, we have developed a cellular model of contracting
C2C12 myotubes overexpressing GLUT4 with an exofacial mycepitope
tag (GLUT4myc) and explored stimulation of GLUT4 traffic by
physiologically relevant agents. Carbachol (an acetylcholine receptor
agonist) induced a gain in cell surface GLUT4myc that was mediated by
nicotinic acetylcholine receptors. Carbachol also activated AMPK, and
this response was sensitive to the contractile myosin ATPase inhibitor
N-benzyl-p-toluenesulfonamide. The gain in surface GLUT4myc elicited
by carbachol or by the AMPK activator 5-amino-4-carboxamide-1 -ribose
was sensitive to chemical inhibition of AMPK activity by compound
C and partially reduced by siRNA-mediated knockdown of
AMPK catalytic subunits or LKB1. In addition, the carbachol-induced
gain in cell surface GLUT4myc was partially sensitive to chelation of
intracellular calcium with BAPTA-AM. However, the carbachol-induced
gain in cell surface GLUT4myc was not sensitive to the CaMKK inhibitor
STO-609 despite expression of both isoforms of this enzyme and a rise in
cytosolic calcium by carbachol. Therefore, separate AMPK- and calciumdependent
signals contribute to mobilizing GLUT4 in response to carbachol,
providing an in vitro cell model that recapitulates the two major
signals whereby acute contraction regulates glucose uptake in skeletal
muscle. This system will be ideal to further analyze the underlying
molecular events of contraction-regulated GLUT4 traffic.