Circular RNA, CDR1as, modulates spinal fibrosis via the miR-7a-5p/TGF-βR2 axis and the Smads signaling pathway

Abstract Damage to the spinal cord is the most serious complication of spinal injury. The method to reduce fibrogenesis after spinal cord injury, to facilitate repair, is an ongoing hurdle despite advancements in research. Non-coding RNA plays an important role in the progression of many diseases, but the study of its role in the progression of spinal fibrosis is still emerging. Here, we investigated the function of circular RNAs, specifically CDR1as, in spinal fibrosis and characterized its molecular mechanism and pathophysiology. The presence of CDR1as in the spinal cord was verified by sequencing and polymerase chain reaction assays. Further, gene and protein expression of miR-7a-5p and TGF-βR2 were measured to evaluate their predicted interactions. The combination miR-7a-5p/TGF-βR2 was predicted by bioinformatics and validated using a luciferase reporter assay. The regulatory effects and activation pathways of miR-7a-5p and CDR1as on spinal fibrosis were subsequently verified by Western blot. miR-7a-5p inhibitor and siCDR1as were transfected and inhibited the effect of siCDR1as. These results indicate that CDR1as/miR-7a-5p/TGF-βR2 interactions may exert important functions and suggest potential therapeutic targets for treating spinal fibrotic diseases.