[Gene expression profiling analysis of stress-sensitive genes and their potential functions in myoblasts]

To screen the stress-sensitive genes in myoblasts and reveal the potential target genes and their regulatory mechanisms of facial muscle remodeling induced by functional orthopaedic force.

The procedure involved the use of gene microarray technology to identify the differentially expressed genes(DEGs) in myoblasts. DEGs were then categorized by Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses. Furthermore, real-time quantitative PCR(qRT-PCR) was used to verify the DEGs. Western blot, transmission electron microscopy(TEM), and confocal laser scanning microscope(CLSM) were employed to detect the effect of stress on autophagy in myoblasts. The data were analyzed by SPSS 17.0 software package.

A total of 1 410 DEGs were identified in stretched myoblasts, with 788 up-regulated and 622 down-regulated genes. GO enrichment analysis indicated that DEGs were primarily involved in signal transduction, biopolymer metabolic process, and protein metabolic process. KEGG analysis revealed that DEGs were primarily associated with ECM-receptor interaction, pathway in cancer, MAPK signaling pathway, focal adhesion and lysosome. Both TEM and CLSM showed that stress could promote the formation of autophagosomes, and Western blot demonstrated that stress could promote the expression of autophagy-related molecules Beclin-1 and LC3-II. Rapamycin could enhance all the above processes, while 3-MA could inhibit them.

Autophagy may play an important role in the regulation of myoblast fate induced by cyclic tensile stress.