TY - JOUR
T1 - Sarcoglycan complex. Implications for metabolic defects in muscular dystrophies
AU - Groh, Séverine
AU - Zong, Haihong
AU - Goddeeris, Matthew M.
AU - Lebakken, Connie S.
AU - Venzke, David
AU - Pessin, Jeffrey E.
AU - Campbell, Kevin P.
PY - 2009/7/17
Y1 - 2009/7/17
N2 - The sarcoglycans are known as an integral subcomplex of the dystrophin glycoprotein complex, the function of which is best characterized in skeletal muscle in relation to muscular dystrophies. Here we demonstrate that the white adipocytes, which share a common precursor with the myocytes, express a cellspecific sarcoglycan complex containing β-, δ-, and ∈-sarcoglycan. In addition, the adipose sarcoglycan complex associates with sarcospan and laminin binding dystroglycan. Using multiple sarcoglycan null mouse models, we show that loss of α-sarcoglycan has no consequence on the expression of the adipocyte sarcoglycan complex. However, loss of β- or δ-sarcoglycan leads to a concomitant loss of the sarcoglycan complex as well as sarcospan and a dramatic reduction in dystroglycan in adipocytes. We further demonstrate that β-sarcoglycan null mice, which lack the sarcoglycan complex in adipose tissue and skeletal muscle, are glucose-intolerant and exhibit whole body insulin resistance specifically due to impaired insulin-stimulated glucose uptake in skeletal muscles. Thus, our data demonstrate a novel function of the sarcoglycan complex in whole body glucose homeostasis and skeletal muscle metabolism, suggesting that the impairment of the skeletal muscle metabolism influences the pathogenesis of muscular dystrophy.
AB - The sarcoglycans are known as an integral subcomplex of the dystrophin glycoprotein complex, the function of which is best characterized in skeletal muscle in relation to muscular dystrophies. Here we demonstrate that the white adipocytes, which share a common precursor with the myocytes, express a cellspecific sarcoglycan complex containing β-, δ-, and ∈-sarcoglycan. In addition, the adipose sarcoglycan complex associates with sarcospan and laminin binding dystroglycan. Using multiple sarcoglycan null mouse models, we show that loss of α-sarcoglycan has no consequence on the expression of the adipocyte sarcoglycan complex. However, loss of β- or δ-sarcoglycan leads to a concomitant loss of the sarcoglycan complex as well as sarcospan and a dramatic reduction in dystroglycan in adipocytes. We further demonstrate that β-sarcoglycan null mice, which lack the sarcoglycan complex in adipose tissue and skeletal muscle, are glucose-intolerant and exhibit whole body insulin resistance specifically due to impaired insulin-stimulated glucose uptake in skeletal muscles. Thus, our data demonstrate a novel function of the sarcoglycan complex in whole body glucose homeostasis and skeletal muscle metabolism, suggesting that the impairment of the skeletal muscle metabolism influences the pathogenesis of muscular dystrophy.
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U2 - 10.1074/jbc.C109.010728
DO - 10.1074/jbc.C109.010728
M3 - Article
C2 - 19494113
AN - SCOPUS:67749108498
SN - 0021-9258
VL - 284
SP - 19178
EP - 19182
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 29
ER -