circ_0000389 inhibits intervertebral disc degeneration by targeting the miR-346/KLF7 axis.

Intervertebral disc degeneration (IVDD) is a major cause of low back pain. An increasing number of studies have demonstrated that circRNAs regulate the progression of IVDD. However, the specific role of circ_0000389 in the progression of IVDD is not clear. In this study, circ_0000389 is selected by bioinformatics analysis of the GSE67566 dataset. RT-qPCR is performed to detect the expressions of circ_0000389, miR-346 and KLF7 in nucleus pulposus (NP) tissues. The proliferative capacity of nucleus pulposus cells (NPCs) is examined via CCK-8 assay. Western blot analysis of extracellular matrix (ECM) catabolism is performed in NPCs. Dual-luciferase reporter gene assays and RNA immunoprecipitation (RIP) confirm the interaction of circ_0000389 with miR-346 and KLF7. The expression of circ_0000389 is significantly downregulated in degenerating NP tissues. Functionally, circ_0000389 inhibits ECM catabolism. Mechanistically, we identify miR-346 and KLF7 as downstream target genes of circ_0000389 and miR-346, respectively. miR-346 overexpression reverses the effect of circ_0000389 on NPCs, and KLF7 overexpression reverses the effect of miR-346 on NPCs, indicating that circ_0000389 alleviates IVDD progression by regulating the miR-346/KLF7 axis. This study may provide a new therapeutic target for the treatment of IVDD.