Combined therapies with exercise, ozone and mesenchymal stem cells improve the expression of HIF1 and SOX9 in the cartilage tissue of rats with knee osteoarthritis.

Purpose: Knee osteoarthritis (OA) is a common type of degenerative joint disease which decreases the quality of life. Sex-determining region Y box 9 (SOX9) and hypoxia-inducible factor-1 (HIF1) are considered as the key regulators of OA. We investigated the effect of combined therapies with mesenchymal stem cells (MSCs), ozone (O3) and exercise training on SOX9 and HIF1 expression in the cartilage of rats with knee OA.

Methods: Knee OA was induced by surgical method. OA rats were divided into model, MSCs, ozone, exercise, MSCs + ozone, MSCs + exercise, ozone + exercise and MSCs + ozone + exercise groups. Rats in the MSCs group received intraarticular injection of 1 × 106 cells/kg. Rats in the ozone group received O3 at the concentration of 20 μg/mL, once weekly for 3 weeks. Rats in the exercise group were trained on rodent treadmill three times per week. 48 hours after the programs, cartilage tissues were isolated and the expression of SOX9 and HIF1 was determined using Real-Time PCR.

Results: Significant differences were found in the expression of SOX9 and HIF1 between groups (P < 0.0001). Although combined therapies with exercise, MSCs and O3 significantly increased the expression of SOX9 and HIF1 in the cartilage tissue of rats with knee OA, combination of exercise with O3 was significantly more effective compared to the other combined therapies (P < 0.001).

Conclusions: Combined therapy with exercise, MSCs and O3 significantly increased the expression of SOX9 and HIF1 genes in the cartilage of rats with knee OA; however, exercise + O3 was significantly more effective.