Abstract
Long non-coding (lnc) RNAs have been associated with osteoarthritis (OA) progression. The aim of the present study was to investigate the regulatory mechanism of lncRNA LINC01385 in OA in vitro. The mRNA expression level of LINC01385, microRNA(miR)-140-3p, and Toll-like receptor 4 (TLR4) was detected using reverse transcription-quantitative PCR, while ELISA was used to determine the concentration of different inflammatory factors [tumor necrosis factor-α (TNF-α), IL-6, and prostaglandin E2 (PGE2)]. The viability of human articular chondrocytes (HC-a) was measured using a MTT assay and western blot analysis was performed to quantify the protein expression level of TLR4. The associations between miR-140-3p and LINC01385/TLR4 were confirmed using a dual-luciferase reporter assay. LINC01385 mRNA expression level was increased in OA tissues and IL-1β-induced HC-a. LINC01385 knockdown and miR-140-3p mimics reduced the concentration of inflammatory factors in IL-1β-induced HC-a and promoted cell survival. In addition, it was confirmed that LINC01385 targeted miR-140-3p, while TLR4 was a target gene of miR-140-3p. Negative correlations between LINC01385 and miR-140-3p, and between miR-140-3p and TLR4 were observed in OA tissues. Low mRNA expression level of miR-140-3p and high protein expression level of TLR4 reversed the inhibitory effect of LINC01385 knockdown on the inflammatory responses of IL-1β-induced HC-a and exhibited a stimulating effect on cell viability. LINC01385 knockdown reduced the progression of OA by modulating the miR-140-3p/TLR4 axis in vitro; thus, LINC01385 may be a therapeutic target for OA.