scholarly journals Delay in post-ovariectomy estrogen replacement negates estrogen-induced augmentation of post-exercise muscle satellite cell proliferation

2015 ◽  
Vol 93 (11) ◽  
pp. 945-951 ◽  
Author(s):  
Gary Mangan ◽  
Sobia Iqbal ◽  
Andrew Hubbard ◽  
Victoria Hamilton ◽  
Eric Bombardier ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Estrogen Replacement ◽  
Sprague Dawley ◽  
Muscle Satellite Cell ◽  
Post Exercise ◽  
Muscle Satellite Cells ◽  
Satellite Cell Proliferation ◽  
Exercise Muscle

This study examined the effects of a delay in post-ovariectomy replacement of 17β-estradiol (estrogen) on the post-exercise proliferation of muscle satellite cells. Nine-week-old, ovariectomized, female Sprague–Dawley rats (n = 64) were distributed among 8 groups based on estrogen status (0.25 mg estrogen pellet or sham), exercise status (90 min run at 17 m·min–1 and a grade of –13.5° or unexercised), and estrogen replacement (“proximal”, estrogen replacement within 2 weeks; or “delayed”, estrogen replacement at 11 weeks following ovariectomy). Significant increases in satellite cells were found in the soleus and white gastrocnemius muscle (immunofluorescent colocalization of nuclei with Pax7) 72 h following eccentric exercise (p < 0.05) in all exercised groups. Proximal E2 replacement resulted in a further augmentation of muscle satellite cells in exercised rats (p < 0.05) relative to the delayed estrogen replacement group. Expression of PI3K was unaltered and phosphorylation of Akt relative to total Akt increased following estrogen supplementation and exercise. Exercise alone did not alter the expression levels of Akt. An 11 week delay in post-ovariectomy estrogen replacement negated the augmenting influence seen with proximal (2 week delay) post-ovariectomy estrogen replacement on post-exercise muscle satellite cell proliferation. This effect appears to be independent of the PI3K–Akt signaling pathway.

Oxygen-mediated regulation of skeletal muscle satellite cell proliferation and adipogenesis in culture

2001 ◽  
Vol 189 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Marie Csete ◽  
Jean Walikonis ◽  
Nicole Slawny ◽  
Yuewang Wei ◽  
Sheryl Korsnes ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Satellite Cell ◽  
Muscle Satellite Cell ◽  
Satellite Cell Proliferation ◽  
Skeletal Muscle Satellite Cell

scholarly journals Akt1 deficiency diminishes skeletal muscle hypertrophy by reducing satellite cell proliferation

2018 ◽  
Vol 314 (5) ◽  
pp. R741-R751 ◽  
Author(s):  
Nobuki Moriya ◽  
Mitsunori Miyazaki
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Protein Synthesis ◽  
Satellite Cell ◽  
Muscle Mass ◽  
Satellite Cells ◽  
Muscle Hypertrophy ◽  
Mtor Signaling ◽  
Skeletal Muscle Hypertrophy ◽  
Satellite Cell Proliferation

Skeletal muscle mass is determined by the net dynamic balance between protein synthesis and degradation. Although the Akt/mechanistic target of rapamycin (mTOR)-dependent pathway plays an important role in promoting protein synthesis and subsequent skeletal muscle hypertrophy, the precise molecular regulation of mTOR activity by the upstream protein kinase Akt is largely unknown. In addition, the activation of satellite cells has been indicated as a key regulator of muscle mass. However, the requirement of satellite cells for load-induced skeletal muscle hypertrophy is still under intense debate. In this study, female germline Akt1 knockout (KO) mice were used to examine whether Akt1 deficiency attenuates load-induced skeletal muscle hypertrophy through suppressing mTOR-dependent signaling and satellite cell proliferation. Akt1 KO mice showed a blunted hypertrophic response of skeletal muscle, with a diminished rate of satellite cell proliferation following mechanical overload. In contrast, Akt1 deficiency did not affect the load-induced activation of mTOR signaling and the subsequent enhanced rate of protein synthesis in skeletal muscle. These observations suggest that the load-induced activation of mTOR signaling occurs independently of Akt1 regulation and that Akt1 plays a critical role in regulating satellite cell proliferation during load-induced muscle hypertrophy.

MiR-27b promotes sheep skeletal muscle satellite cell proliferation by targeting myostatin gene

2018 ◽  
Vol 97 (5) ◽  
pp. 1107-1117 ◽  
Author(s):  
Wei Zhang ◽  
Shi-Yin Wang ◽  
Shuang-Yi Deng ◽  
Li Gao ◽  
Li-Wei Yang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Satellite Cell ◽  
Muscle Satellite Cell ◽  
Myostatin Gene ◽  
Satellite Cell Proliferation ◽  
Skeletal Muscle Satellite Cell

Satellite cell proliferation and differentiation during postnatal growth of porcine skeletal muscle

2002 ◽  
Vol 282 (4) ◽  
pp. C899-C906 ◽  
Author(s):  
N. T Mesires ◽  
M. E. Doumit
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Nuclear Antigen ◽  
Positive Staining ◽  
Age Related ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Satellite Cell Proliferation

Age-related changes in satellite cell proliferation and differentiation during rapid growth of porcine skeletal muscle were examined. Satellite cells were isolated from hindlimb muscles of pigs at 1, 7, 14, and 21 wk of age (4 animals/age group). Satellite cells were separated from cellular debris by using Percoll gradient centrifugation and were adsorbed to glass coverslips for fluorescent immunostaining. Positive staining for neural cell adhesion molecule (NCAM) distinguished satellite cells from nonmyogenic cells. The proportion of NCAM-positive cells (satellite cells) in isolates decreased from 1 to 7 wk of age. Greater than 77% of NCAM-positive cells were proliferating cell nuclear antigen positive at all ages studied. Myogenin-positive satellite cells decreased from 30% at 1 wk to 14% at 7 wk of age and remained at constant levels thereafter. These data indicate that a high percentage of satellite cells remain proliferative during rapid postnatal muscle growth. The reduced proportion of myogenin-positive cells during growth may reflect a decrease in the proportion of differentiating satellite cells or accelerated incorporation of myogenin-positive cells into myofibers.

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