Tanshinone IIA protects murine chondrogenic ATDC5 cells from lipopolysaccharide-induced inflammatory injury by down-regulating microRNA-203a.

Osteoarthritis is the most common bone-joint disease in middle and older people all over the world. Tanshinone IIA (Tan IIA) is the main lipophilic diterpenoid isolated from the root of Salvia miltiorrhiza Bunge (Lamiaceae). This study analyzed the protective effects of Tan IIA on lipopolysaccharide (LPS)-induced murine chondrogenic ATDC5 cell inflammatory injury model. Cell viability was assessed using cell counting kit-8 (CCK-8) assay. Cell apoptosis was detected using Annexin V-FITC/PI staining. Enzyme-linked immunosorbent assay (ELISA) was conducted to measure the concentrations of interleukin 6 (IL-6), IL-8 and tumor necrosis factor α (TNF-α) in the culture supernatant of ATDC5 cells. qRT-PCR was performed to determine the expression of IL-6, IL-8, TNF-α and microRNA-203a (miR-203a) in ATDC5 cells. Cell transfection was used to enhance the expression of miR-203a. Protein expression of key factors involved in apoptosis, pro-inflammatory reaction, Janus kinase/signal transducers and activators of transcription (JAK/STAT) and c-Jun-N-terminal kinase (JNK) pathways were evaluated using western blotting. LPS significantly induced ATDC5 cell inflammatory injury, as evidenced by the loss of cell viability, enhancement of cell apoptosis and increases of pro-inflammatory factors expression. Tan IIA obviously alleviated LPS-induced ATDC5 cell inflammatory injury and down-regulated the expression of miR-203a. Overexpression of miR-203a obviously promoted ATDC5 cell inflammatory injury and remarkably reversed the protective effects of Tan IIA on LPS-induced ATDC5 cell inflammatory injury by influencing JAK/STAT and JNK pathways. Our research verified that Tan IIA protected ATDC5 cells from LPS-induced inflammatory injury by down-regulating miR-203a and suppressing JAK/STAT and JNK pathways.