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Published on: September 18, 2019
miR-221 modulates skeletal muscle satellite cells proliferation and differentiation
Buwei Liu1, Yu Shi1, Hongbing He1
1Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China.
Abstract:
MicroRNAs (miRNAs) are a class of small non-coding RNA molecules, which play important roles in animals by targeting mRNA transcripts for translational repression. Many recent studies have shown that miRNAs are involved in the control of muscle development. In this study, the expression levels of miR-221 in different tissues and during rabbit skeletal muscle satellite cells (SMSCs) differentiation were detected. Gene ontology term enrichment was used to predict the potential biological roles of miR-221. A synthetic miR-221 mimic and a miR-221 inhibitor were used to investigate the functions of miR-221 during SMSCs proliferation and differentiation to further verify the functions of miR-221 in muscle development. In this report, we compared the expression levels of miR-221 in different tissues. The expression levels of miR-221 were upregulated after the induction of differentiation, and then were gradually downregulated during SMSCs differentiation. Overexpression of miR-221 promoted SMSCs proliferation, whereas inhibiting expression restrained proliferation in the EdU and CCK-8 assays. In addition, overexpression of miR-221 led to a decline in the expression levels of the differentiation marker genes MyoG and MHC. miR-221 overexpression suppressed SMSCs myotube formation. On the contrary, inhibition of miR-221 promoted myotube formation. Our data showed that miR-221 increased SMSCs proliferation and decreased differentiation.
Insights
MicroRNAs (miRNAs) regulate muscle growth. This study found that miR-221 promotes skeletal muscle satellite cell proliferation while inhibiting their differentiation into muscle fibers.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- MicroRNAs (miRNAs) are small non-coding RNAs crucial for post-transcriptional gene regulation.
- miRNAs play significant roles in various biological processes, including animal muscle development.
- Specific miRNAs are implicated in controlling skeletal muscle satellite cell (SMSC) functions.
Purpose of the Study:
- To investigate the expression patterns of miR-221 in different rabbit tissues.
- To determine the role of miR-221 in regulating rabbit skeletal muscle satellite cell (SMSC) proliferation and differentiation.
- To elucidate the function of miR-221 in muscle development.
Main Methods:
- Quantification of miR-221 expression levels in various tissues and during SMSC differentiation.
- Gene Ontology (GO) term enrichment analysis to predict miR-221 functions.
- Experimental manipulation of miR-221 levels using mimics and inhibitors in SMSCs, followed by EdU, CCK-8, and myogenesis marker assays.
Main Results:
- miR-221 expression was detected in different tissues and dynamically changed during SMSC differentiation, initially upregulating then downregulating.
- Overexpression of miR-221 enhanced SMSC proliferation, while inhibition suppressed it.
- miR-221 overexpression reduced the expression of muscle differentiation markers (MyoG, MHC) and inhibited myotube formation, whereas inhibition promoted these processes.
Conclusions:
- miR-221 acts as a positive regulator of SMSC proliferation.
- miR-221 functions as a negative regulator of SMSC differentiation.
- These findings highlight miR-221's critical role in controlling muscle development by balancing proliferation and differentiation.
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