Suppression of miR-301a alleviates LPS-induced inflammatory injury in ATDC5 chondrogenic cells by targeting Sirt1.

Osteoarthritis is one of the most common joint diseases and is characterized by joint inflammation. MicroRNAs (miRNA) play an important role in osteoarthritis. In this study, we examined the role of miR-301a in lipopolysaccharide (LPS)-treated murine chondrogenic ATDC5 cells. LPS at 10 µg/mL concentration was used to induce inflammatory injury in chondrogenic cells. Cell Counting Kit-8 assay was used to measure cell viability and flow cytometry was used to measure cell apoptosis. Effect of miR-301a on concentrations of inflammatory cytokines was measured using ELISA, and on mRNA expressions was measured using qRT-PCR. The miR-301 target was identified by luciferase reporter assay. Western blot analysis was used to measure the expressions of apoptotic proteins, Sirt1, and PI3K/AKT and NF-κB pathways proteins. Treatment with LPS decreased cell viability, and increased apoptosis, inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF-α) level, and miR-301a expression. Overexpression of miR-301a aggravated the effects of LPS on the chondrogenic cells and the inflammatory cytokines by negatively regulating Sirt1 expression. Sirt1 was identified as a target of miR-301. Suppression of miR-301a showed the opposite effects. Western blot showed that suppression of miR-301a increased the expression of PI3K/AKT and NF-κB pathways proteins. Suppression of miR-301a expression alleviated LPS-induced chondrogenic cell injury by upregulating Sirt1 and activating the PI3K/AKT and NF-κB signal pathways.