Effect of miR-202-5p-mediated ATG7 on autophagy and apoptosis of degenerative nucleus pulposus cells

J. Chen, Q. Sun, G.-Z. Liu, F. Zhang, C.-Y. Liu, Q.-M. Yuan, X.-S. Di, S.-W. Long, Y.-S. Jia, Y.-J. Wang

Department of Orthopedics, Dongzhimen Hospital of Beijing University of Chinese Medicine, Beijing, P.R. China. 13466584110@163.com

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• Orthopedics

OBJECTIVE: This study aimed to research the effect of miR-202-5p-mediated ATG7 on autophagy and apoptosis of degenerative nucleus pulposus cells.

PATIENTS AND METHODS: The intervertebral disc nucleus pulposus (NP) tissue of patients with intervertebral disc degenerative disease and normal intervertebral disc nucleus pulposus (NP) tissue of patients with spinal fractures was collected as the research object. Normal NP cells and degenerative NP cells were isolated. Low expression of miR-202-5p and overexpression of ATG7 were carried out in degenerative NP cells. The expression of miR-202-5p and ATG7 mRNA was detected by RT-PCR. The expression of ATG7, LC3-II, Bax, and Bcl-2 proteins was detected by Western blot. The autophagy of cells was detected by MDC staining. The apoptosis of NP cells was detected by flow cytometry. The targeting relationship between miR-202-5p and ATG7 was detected by Dual-Luciferase reporter.

RESULTS: In the degenerative NP tissues, miR-202-5p was highly expressed and ATG7 was low expressed. The inhibition of miR-202-5p expression can effectively promote autophagy of NP cells, increase the expression of ATG7 and LC3-II, inhibit the apoptosis of NP cells, inhibit the expression of pro-apoptotic proteins Bax, and promote the expression of pro-apoptotic proteins Bcl-2 proteins. The upregulation of ATG7 expression in degenerative NP cells alone had the same effect as the downregulation of miR-202-5p. The assay of the Dual-Luciferase reporter confirmed the targeting relationship between miR-202-5p and ATG7.

CONCLUSIONS: MiR-202-5p can affect the autophagy and apoptosis of degenerative nucleus pulposus cells through targeted adjustment of ATG7, which may be a new therapeutic target for intervertebral disc degenerative diseases.

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