LncRNA HCG18 promotes inflammation and apoptosis in intervertebral disc degeneration via the miR-495-3p/FSTL1 axis

Intervertebral disc degeneration (IDD) causes pain in the back and neck. This study investigated the role of long non-coding RNA HLA complex group 18 (HCG18) in a cell model of IDD. An IDD model was established by stimulating nucleus pulposus (NP) cells with interleukin (IL)-1 beta. MTT assay was performed to evaluate NP cell viability. The apoptosis was detected by flow cytometry. The expressions of HCG18, microRNA (miR)-495-3p, and follistatin-like protein-1 (FSTL1) were measured by RT-qPCR. The interactions of miR-495-3p with HCG18 and FSTL1 were analyzed by luciferase reporter assay. IL-1 beta stimulation upregulated HCG18 and FSTL1, but downregulated miR-495-3p in NP cells. Silencing of HCG18 or FSTL1, as well as miR-495-3p overexpression in NP cells alleviated IL-1 beta-induced apoptosis and inflammation of NP cells. Both HCG18 and FSTL1 had binding sites for miR-495-3p. Overexpression of FSTL1 abolished the effects of HCG18 silencing on IL-1 beta-induced apoptosis and inflammation. The HCG18/miR-495-3p/FSTL1 axis is essential for IDD development. Therapeutic strategies targeting this axis may be used for IDD treatment.