Role of lncRNA XIST/microRNA-19/PTEN network in autophagy of nucleus pulposus cells in intervertebral disc degeneration via the PI3K/Akt signaling pathway.

Intervertebral disc degeneration (IVDD) is a complicated pathological condition accompanying with low back pain. This study was designed to figure out the mechanism of lncRNA XIST in IVDD. Abnormally expressed lncRNAs in IVDD patients were measured. The correlations among XIST, miR-19 and PTEN were identified. Overexpression and silencing of XIST, miR-19 and PTEN were introduced and their roles in NPC autophagy in vitro were detected. The potential signaling pathway involved in these events was identified. Consequently, high expression of XIST was found in IVDD patients. It induced NPC autophagy and reduced NPC viability. XIST could serve as a competing endogenous RNA (ceRNA) for miR-19 and upregulate PTEN expression. The overexpression of XIST reduced miR-19 expression, which was followed by enhanced PTEN expression. Upregulation of miR-19 increased NPC viability and proliferation, while decreased NPC autophagy that regulated by XIST, while overexpressed PTEN reversed the above changes. Moreover, overexpression of XIST inactivated the PI3k/Akt signaling pathway.