Corresponding Author: Email: haolinlin@jlu.edu.cn

Received September 24, 2024;    Accepted December 30, 2024.

Objective
This study aimed to investigate the role of miRNA 21-5p in regulating the differentiation of C2C12 myoblasts and intramuscular lipid droplets accumulation in myotubes.
Methods
The role of miR-21-5p in the proliferation and differentiation of myofibroblasts and intracellular lipid accumulation was analyzed using bioinformatics, CCK-8 assay, quantitative real-time polymerase chain reaction, immunoblotting, immunofluorescence staining, and Oil Red O staining.
Results
The analysis of porcine BodyMap transcriptome data revealed differential expression of miRNA 21-5p in skeletal muscle and adipose tissue. Bioinformatics analysis combined with a dual-luciferase reporter assay demonstrated that FBXO11 serves as a direct target of miR-21-5p. Transfection experiments involving a miR-21-5p mimic, miR-21-5p inhibitor, and si-FBXO11 in C2C12 cells showed that overexpression of miR-21-5p or silencing of FBXO11 significantly enhanced the proliferation of C2C12 cells, upregulated myogenesis-related factors, and promoted myotube formation. Furthermore, oleic acid-induced lipid accumulation in myotubes was suppressed, accompanied by reduced expression of adipogenesis-related genes. Conversely, inhibition of miR-21-5p expression produced opposite effects.
Conclusion
These findings indicate that miR-21-5p promotes proliferation and differentiation while inhibiting intramyocellular lipid deposition by targeting the 3'-untranslated region of FBXO11 in myogenic cell. The results suggest that miR-21-5p could serve as a potential miRNA biomarker for regulating intramuscular adipogenesis.

Keywords : C2C12 Myoblast; Differentiation; FBXO11; Intramuscular Lipid Deposition; miR-21-5p; Proliferation