microRNA‐365 attenuated intervertebral disc degeneration through modulating nucleus pulposus cell apoptosis and extracellular matrix degradation by targeting EFNA3

Abstract

This present study is aimed to investigate the role of microRNA‐365 (miR‐365) in the development of intervertebral disc degeneration (IDD). Nucleus pulposus (NP) cells were transfected by miR‐365 mimic and miR‐365 inhibitor, respectively. Concomitantly, the transfection efficiency and the expression level of miRNA were detected by quantitative reverse transcription polymerase chain reaction (qRT‐PCR). Meanwhile, NP cells apoptosis was measured through propidium iodide (PI)‐AnnexinV‐fluorescein isothiocyanate (FITC) apoptosis detection kit. Subsequently, immunofluorescence (IF) staining was performed to assess the expression of collagen II, aggrecan and matrix metalloproteinase 13 (MMP‐13). In addition, bioinformatic prediction and Luciferase reporter assay were used to reveal the target gene of miR‐365. Finally, we isolated the primary NP cells from rats and injected NP‐miR‐365 in rat IDD models. The results showed that overexpression of miR‐365 could effectively inhibit NP cells apoptosis and MMP‐13 expression and upregulate the expression of collagen II and aggrecan. Conversely, suppression of miR‐365 enhanced NP cell apoptosis and elevated MMP‐13 expression, but decreased the expression of collagen II and aggrecan. Moreover, the further data demonstrated that miR‐365 mediated NP cell degradation through targeting ephrin‐A3 (EFNA3). In addition, the cells apoptosis and catabolic markers were increased in NP cells when EFNA3 upregulated. More importantly, the vivo data supported that miR‐365‐NP cells injection ameliorated IDD in rats models. miR‐365 could alleviate the development of IDD by regulating NP cell apoptosis and ECM degradation, which is likely mediated by targeting EFNA3. Therefore, miR‐365 may be a promising therapeutic avenue for treatment IDD through EFNA3.