Identifying the protective effects of miR‐874‐3p/ATF3 axis in intervertebral disc degeneration by single‐cell RNA sequencing and validation.

Intervertebral disc degeneration (IVDD) severely affects the work and the quality of life of people. We previously demonstrated that silencing activation transcription factor 3 (ATF3) blocked the IVDD pathological process by regulating nucleus pulposus cell (NPC) ferroptosis, apoptosis, inflammation, and extracellular matrix (ECM) metabolism. Nevertheless, whether miR‐874‐3p mediated the IVDD pathological process by targeting ATF3 remains unclear. We performed single‐cell RNA sequencing (scRNA‐seq) and bioinformatics analysis to identify ATF3 as a key ferroptosis gene in IVDD. Then, Western blotting, flow cytometry, ELISA, and animal experiments were performed to validate the roles and regulatory mechanisms of miR‐874‐3p/ATF3 signalling axis in IVDD. ATF3 was highly expressed in IVDD patients and multiple cell types of IVDD rat, as revealed by scRNA‐seq and bioinformatics analysis. GO analysis unveiled the involvement of ATF3 in regulating cell apoptosis and ECM metabolism. Furthermore, we verified that miR‐874‐3p might protect against IVDD by inhibiting NPC ferroptosis, apoptosis, ECM degradation, and inflammatory response by targeting ATF3. In vivo experiments displayed the protective effect of miR‐874‐3p/ATF3 axis on IVDD. These findings propose the potential of miR‐874‐3p and ATF3 as biomarkers of IVDD and suggest that targeting the miR‐874‐3p/ATF3 axis may be a therapeutic target for IVDD. [ABSTRACT FROM AUTHOR]