Hsa_circ_0092342 promotes the apoptosis of nucleus pulposus cells by facilitating hsa-miR-320d maturation in intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is a critical factor for spinal degeneration, leading to low back pain, intervertebral disc herniation, and even disability. It is needed to seek novel targets and strategies for IDD by elucidating the pathogenesis of IDD. Suppressing apoptosis of nucleus pulposus cells (NPCs) is a promising strategy for treating IDD. However, the mechanism regulating the apoptosis of NPCs remains unclear. This study aims to investigate whether hsa_circ_0092342 induces apoptosis of NPCs by Baculoviral IAP repeat containing 5 (BIRC5) via modulating hsa-miR-320d maturation in IDD. In this study, NPCs derived from healthy controls and IDD patients were utilized. Besides, the regulatory effect of microRNA (miRNA) was determined utilizing dual-luciferase reporter gene assay, while RNA antisense purification (RAP) was used to determine the interaction of circular RNA (circRNA) and protein. Hsa_circ_0092342 promotes the apoptosis of NPCs in IDD. Mechanistically, hsa_circ_0092342 enhances the apoptosis of NPCs by inhibiting BIRC5 expression. Besides, hsa-miR-320d suppresses BIRC5 expression of NPCs, while hsa_circ_0092342 facilitates hsa-miR-320d maturation by recruiting DiGeorge syndrome critical region gene 8 (DGCR8) in NPCs. In summary, these findings indicate the novel mechanism of hsa_circ_0092342 regulating apoptosis of NPCs, providing novel targets and strategies for IDD treatment.