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Preparation of Primary Myogenic Precursor Cell/Myoblast Cultures from Basal Vertebrate Lineages
Published on: April 30, 2014
The decrease in mature myostatin protein in male skeletal muscle is developmentally regulated by growth hormone.
Jenny M Oldham1, Claire C Osepchook, Ferenc Jeanplong
1Growth Physiology Group, AgResearch Ltd., Hamilton, New Zealand.
The Journal of Physiology
|December 3, 2008
Summary
Mature myostatin protein decreases in male mice after six weeks, a process regulated by growth hormone (GH) via Stat5b. This finding sheds light on sexually dimorphic skeletal muscle growth.
Area of Science:
- Muscle physiology
- Endocrinology
- Developmental biology
Background:
- Myostatin is a key inhibitor of muscle growth.
- Mature myostatin protein is less abundant in adult male mice compared to females.
- This difference may contribute to sexually dimorphic skeletal muscle growth.
Purpose of the Study:
- To investigate the developmental timing of mature myostatin protein decrease in male mice.
- To determine if growth hormone (GH) influences mature myostatin protein levels.
- To elucidate the role of Stat5b in mediating GH's effect on myostatin.
Main Methods:
- Quantification of myostatin mRNA and mature protein in mouse gastrocnemius muscle across development (2-32 weeks).
- Experiments involving hypophysectomized mice treated with GH.
- Analysis of myostatin levels in Stat5b knockout mice.
Main Results:
- Myostatin mRNA levels increased with age and were higher in males than females.
- Mature myostatin protein decreased in males after 6 weeks.
- GH administration decreased mature myostatin protein and increased mRNA in hypophysectomized mice.
- Stat5b knockout males did not show reduced mature myostatin protein compared to females, despite higher mRNA.
Conclusions:
- The reduction in mature myostatin protein is developmentally regulated.
- Growth hormone, acting through Stat5b, regulates mature myostatin protein abundance.
- GH also influences myostatin mRNA via a non-Stat5b pathway.
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