Fiber type-specific expression of low-density lipoprotein receptor-related protein 6 in human skeletal muscles.
OBJECTIVE
Gene expression patterns differ in the two types of skeletal muscle fiber. The Wnt signaling pathway, which includes low-density lipoprotein receptor-related protein 6 (LRP6), has been associated with cell differentiation and glucose metabolism in skeletal muscles. We examined the relationships between muscle fiber types and LRP6 expression.


METHODS
Adenosine triphosphatase was assayed histochemically, and the levels of expression of LRP6 and myosin were analyzed immunohistochemically, in frozen sections of muscle fiber obtained from 16 muscle biopsy samples. The expression pattern of LRP6 in C2C12 cells was assayed by immunocytochemistry.


RESULTS
LRP6 was expressed only in type II fibers. Type IIc fibers showed variations in LRP6 expression. Expression of LRP6 was observed at the stage of myoblast differentiation.


CONCLUSIONS
Antibody to LRP6 may be useful for identifying type II skeletal muscle fibers. LRP6 may influence glucose metabolism in type II fibers of human skeletal muscles.
Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Hiroshima, Japan.
Ikuko
I
Takeda
Tetsuya
T
Takahashi
Kazuhide
K
Ochi
Takashi
T
Kurashige
Yukari
Y
Shinozaki
Masahiro
M
Nakamori
Koji
K
Arihiro
Hirofumi
H
Maruyama
Masayasu
M
Matsumoto
D015153:Blotting, Western; D006801:Humans; D007150:Immunohistochemistry; D060488:Low Density Lipoprotein Receptor-Related Protein-6 / Q000032:analysis / Q000096:biosynthesis*; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*
C555475:LRP6 protein, human; D060488:Low Density Lipoprotein Receptor-Related Protein-6