| Objective To observe the effect of bone marrow mesenchymal stem cells on knee osteoarthritis rats and to explore the possible mechanisms. Methods Forty SD rats were randomly divided into normal control group (Control, saline 0.3 mL, once a week for 4 times), knee osteoarthritis group (KOA, saline 0.3 mL, once a week for 4 times), bone marrow mesenchymal stem cells group (BMSCs, 0.3 mL, once a week for 4 times), 10 rats in each group, and the remaining 10 rats were used for the isolation of bone marrow MSCs. After 4 weeks, the joint index (AI) scores of rats were performed; the pathological changes of cartilage tissue were observed by HE staining; immunohistochemistry was performed to detect the expression of Col II, IL-6, MMP-3 and MMP-13 in cartilage tissues; the content of IL-6, TNF-α, MMP-3 and MMP-13 in serum was detected by ELISA method; and the expression of Col II, Col I, TNF- α, IL-6, MMP-13, KDM6A, SOX9 and Aggrecan mRNA in cartilage tissue was detected by qRT-PCR; Western blot to detect KDM6A, SOX9, Aggrecan protein expression in cartilage tissue. Results Compared with the control group, AI score, serum IL-6, TNF-α, MMP-3, MMP-13 content, and cartilage tissue IL-6, MMP-3, MMP-13 expression were significantly higher in the KOA group rats (P<0.05); Col II, KDM6A, Aggrecan, SOX9 mRNA and protein expression significantly decreased (P<0.05). Compared with the KOA group, the BMSCs group significantly decreased AI score, significantly decreased serum IL-6, TNF-α, MMP-3, MMP-13 levels, and IL-6 mRNA expression in cartilage tissue (P<0.05), and significantly increased KDM6A, Aggrecan mRNA and protein expression in cartilage tissue (P<0.05). Conclusion Bone marrow mesenchymal stem cells significantly improved the pathological damage of knee osteoarthritis and may exert therapeutic effects on knee osteoarthritis rats by regulating the KDM6A/SOX9 signaling pathway. |