Androgen receptor regulates expression of skeletal muscle-specific proteins and muscle cell types.
C2C12 myoblasts expressing the androgen receptor (AR) were used to analyze the role of androgen-AR signaling pathway in skeletal muscle development. Marked up-regulation of AR expression was observed in differentiated myotubes. A nuclear run-on transcription assay demonstrated that transcription of the AR gene is increased during skeletal muscle cell differentiation. Regulation of skeletal muscle-specific protein expression by the androgen-AR signaling pathway was further analyzed using quadriceps skeletal muscle from wild-type (WT) and AR knock-out (ARKO) male mice. A histological analysis of quadriceps skeletal muscle indicates no morphological differences between ARKO and WT mice. However, the androgen-AR signaling pathway increases expression of slow-twitch-specific skeletal muscle proteins and downregulates fast-twitch-specific skeletal muscle proteins, resulting in an increase of slow-twitch muscle fiber type cells in quadriceps muscle.
Altuwaijri
Saleh
S
George Whipple Lab for Cancer Research, Department of Pathology, The Cancer Center, University of Rochester Medical Center, Rochester, New York 14642, USA.
Lee
Dong Kun
DK
Chuang
Kuang-Hsiang
KH
Ting
Huei-Ju
HJ
Yang
Zhiming
Z
Xu
Qingquan
Q
Tsai
Meng-Yin
MY
Yeh
Shuyuan
S
Hanchett
LeRoy A
LA
Chang
Hong-Chiang
HC
Chang
Chawnshang
C
D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D015536:Down-Regulation; D006614:Hindlimb; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology* / Q000378:metabolism*; D032446:Myoblasts / Q000166:cytology*; D011944:Receptors, Androgen / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D015854:Up-Regulation
D009124:Muscle Proteins; D011944:Receptors, Androgen