CircRNA_02540 alleviated the migration and ligament differentiation capacities of SM-MSCs suppressed by chronic inflammation via regulating miR-203a-3p/ZIC1 pathway

Implant of mesenchymal stem cells (MSCs) is a promising therapy for the reconstruction of anterior cruciate ligament (ACL), but the chronic inflammation environment impairs the capacity of MSCs. This study aimed to alleviate the function of synovial membrane-derived MSCs (SM-MSCs) by regulating circRNA and its downstream molecules. In the present study, chronic inflammatory stimulation (TNF-α treatment) weakened the migration and ligament differentiation abilities of SM-MSCs, and reduced the expression level of circRNA_02540, screened from candidates dysregulated in relevant pathological tissues (Jiang et al. in Ann Transl Med 9:1685, 2021; Xiang et al. in J Cell Biochem 120:18031-18040, 2019). Upregulating circRNA_02540 alleviated the functions of SM-MSCs under inflammatory milieu. RNA-sequencing identified 348 differentially expressed genes (DEGs) in circRNA_02540 overexpression group. Bioinformatics analyses screened 23 upregulated DEGs involved in migration and differentiation relevant processes, and used to construct the ceRNA network of circRNA_02540. Next, ZIC1 and miR-203a-3p were screened out. Overexpression of miR-203a-3p or knockdown of ZIC1 inhibited the positive effects of circRNA_02540 on the function of SM-MSCs. Knockdown of ZIC1 inhibited the positive effects exerted by silencing miR-203a-3p on SM-MSC, and overexpression of ZIC1 alleviated the inhibitory effects of miR-203a-3p on the function of SM-MSCs. In conclusion, circRNA_02540 promoted the migration and ligament differentiation abilities of SM-MSCs by sponging miR-203a-3p and enhancing ZIC1 expression, providing a potential solution to enhance the function decline of MSCs used for ACL reconstruction.

Chronic inflammation; CircRNA; Ligament differentiation; ZIC1; miR-203a-3p.