Tanshinone IIA alleviates IL-1ß-induced chondrocyte apoptosis and inflammation by regulating FBXO11 expression.

OBJECTIVE: This study explored the pharmacological mechanism of Tanshinone IIA (TAN IIA) in the treatment of Osteoarthritis (OA), which provided a certain reference for further research and clinical application of Tan IIA in OA. METHODS: CHON-001 cells were stimulated with 10 µg/mL IL-1ß for 48 h and treated with 10 µM TAN IIA for 48 h. Cellular viability and apoptosis were evaluated by CCK-8 assay and flow cytometry, and Cleaved caspase-3 was measured by Immunoblot assay and RT-qPCR. TNF-α, IL-6, and iNOS in CHON-001 cells were determined by RT-qPCR and ELISA. To further verify the effect of TAN IIA on OA, a rat model of OA in vivo was established by right anterior cruciate ligament transection. TAN IIA was administered at 50 mg/kg or 150 mg/kg for 7 weeks. The degree of cartilage destruction in OA rats was observed by TUNEL and HE staining. Cleaved caspase-3 and FBXO11 were measured by immunohistochemical staining, RT-qPCR, and Immunoblot. TNF-α, IL-6, and iNOS in chondrocytes of OA rats were detected by ELISA. RESULTS: IL-1ß stimulated CHON-001 cell apoptosis and inflammation, and TAN IIA had anti-apoptosis and anti-inflammatory effects on IL-1ß-regulated CHON-001 cells. TAN IIA down-regulated FBXO11 and inhibited PI3K/AKT and NF-κB pathways, thereby alleviating apoptotic and inflammatory reactions in CHON-001 cells under IL-1ß treatment. Moreover, TAN IIA treatment improved chondrocyte apoptosis and inflammations in OA rats. CONCLUSION: TAN IIA inhibits PI3K/Akt and NF-κB pathways by down-regulating FBXO11 expression, alleviates chondrocyte apoptosis and inflammation, and delays the progression of OA.

Tanshinone IIA alleviates chondrocyte apoptosis and extracellular matrix degeneration by inhibiting ferroptosis.

Articular cartilage degeneration caused by chondrocyte damage is the primary pathological mechanism of osteoarthritis (OA). Oxidative stress is correlated with chondrocyte injury by potentiating ferroptosis, a newly identified form of cell death. Given the effects of Tanshinone IIA (Tan IIA) on alleviating oxidative stress, we further explored whether Tan IIA inhibited chondrocyte death and cartilage degeneration by decreasing ferroptosis. ATDC5 chondrocytes were treated with lipopolysaccharides (LPS) and Tan IIA, and cell viability was assessed using cell counting kit-8 (CCK-8) assays. Matrix metalloproteinase-13 (MMP13), a disintegrin and metalloproteinase with thrombospondin motif-5 (ADAMTS5), and type II collagen (Col II) levels were measured using quantitative real-time polymerase chain reaction (qRT‒PCR), western blotting, and immunofluorescence (IF) analysis. We demonstrated that Tan IIA treatment prominently increased ATDC5 cell viability and decreased cell apoptosis in the presence of LPS-induced stress. MMP13 and ADAMTS5 expression was increased, and Col II expression was decreased in ATDC5 cells after LPS stimulation, whereas these changes were reversed by Tan IIA. Mechanistically, Tan IIA inhibited LPS-induced ferroptosis in ATDC5 cells, as indicated by decreased levels of iron, reactive oxygen species, and malondialdehyde and increased GSH levels. Importantly, a ferroptosis agonist partially abrogated the effect of Tan IIA on alleviating chondrocyte damage and death. Taken together, these results suggest that Tan IIA ameliorates chondrocyte apoptosis and cartilage degeneration by inhibiting ferroptosis and may be a potential therapeutic agent for OA.