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Published on: May 17, 2016
MicroRNA-668-3p inhibits myoblast proliferation and differentiation by targeting Appl1
Haigang Cao1, Tianning Du1,2, Chenchen Li1
1Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
Background:
Skeletal muscle is the largest tissue in the body, and it affects motion, metabolism and homeostasis. Skeletal muscle development comprises myoblast proliferation, fusion and differentiation to form myotubes, which subsequently form mature muscle fibres. This process is strictly regulated by a series of molecular networks. Increasing evidence has shown that noncoding RNAs, especially microRNAs (miRNAs), play vital roles in regulating skeletal muscle growth. Here, we showed that miR-668-3p is highly expressed in skeletal muscle.
Methods:
Proliferating and differentiated C2C12 cells were transfected with miR-668-3p mimics and/or inhibitor, and the mRNA and protein levels of its target gene were evaluated by RT‒qPCR and Western blotting analysis. The targeting of Appl1 by miR-668-3p was confirmed by dual luciferase assay. The interdependence of miR-668-3p and Appl1 was verified by cotransfection of C2C12 cells.
Results:
Our data reveal that miR-668-3p can inhibit myoblast proliferation and myogenic differentiation. Phosphotyrosine interacting with PH domain and leucine zipper 1 (Appl1) is a target gene of miR-668-3p, and it can promote myoblast proliferation and differentiation by activating the p38 MAPK pathway. Furthermore, the inhibitory effect of miR-668-3p on myoblast cell proliferation and myogenic differentiation could be rescued by Appl1.
Conclusion:
Our results indicate a new mechanism by which the miR-668-3p/Appl1/p38 MAPK pathway regulates skeletal muscle development.
Insights
MicroRNA-668-3p (miR-668-3p) inhibits skeletal muscle growth by downregulating Appl1, a key promoter of myoblast proliferation and differentiation. This reveals a novel regulatory pathway in muscle development.
Area of Science:
- Molecular Biology
- Cell Biology
- Physiology
Background:
- Skeletal muscle is crucial for motion, metabolism, and homeostasis.
- Muscle development involves myoblast proliferation, fusion, and differentiation.
- MicroRNAs (miRNAs) are key regulators of skeletal muscle growth, with miR-668-3p found to be highly expressed in this tissue.
Purpose of the Study:
- To investigate the role of miR-668-3p in skeletal muscle development.
- To identify the target gene of miR-668-3p and elucidate its mechanism of action.
Main Methods:
- C2C12 myoblasts were transfected with miR-668-3p mimics/inhibitors.
- mRNA and protein levels of target genes were assessed using RT-qPCR and Western blotting.
- Dual luciferase assays confirmed the targeting of Appl1 by miR-668-3p.
Main Results:
- miR-668-3p was found to inhibit myoblast proliferation and myogenic differentiation.
- Phosphotyrosine interacting with PH domain and leucine zipper 1 (Appl1) was identified as a direct target of miR-668-3p.
- Appl1 promotes myoblast proliferation and differentiation via the p38 MAPK pathway, and its expression rescued the inhibitory effects of miR-668-3p.
Conclusions:
- A novel regulatory mechanism involving the miR-668-3p/Appl1/p38 MAPK pathway in skeletal muscle development was identified.
- This pathway provides new insights into the molecular regulation of muscle growth and differentiation.
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