The activation effect of Sr and/or Si ions on autophagy in OA chondrocytes. (A) P62 gene, (B) Atg5 gene, (C) Atg12 gene, (D) Atg16L1 gene. In OA model, Sr or Si ions protected chondrocytes by inducing autophagy within the concentration range of Sr 0.25-4 mg/L or Si 0.5-8 mg/L. Furthermore, Sr and Si ions together promoted the expression of P62 gene at the concentration of Sr 4 mg/L and Si 8 mg/L, as well as enhanced Atg5 gene expression at the concentration of Sr 1 mg/L and Si 2 mg/L. In addition, Sr and Si ions cooperatively promoted the expression of Atg12 gene within the concentration range of Sr 0.25-4 mg/L and Si 0.5-8 mg/L. Sr and/or Si ions protected chondrocytes form OA by increasing autophagy. IL-1β plays a key role in OA pathogenesis, SANT-1 is a hedgehog signaling inhibitor. The relative gene amount of CTR groups was set as 1, the value of expression gene was the fold change relative to CTR. Repeat number: n=3. (*p<0.05, **p<0.01, ***p<0.001).