[Effect of allogenic mesenchymal stem cells transplantation on the expression of interleukin-22 and matrix metalloproteinase-3 in rats with collagen induced arthritis].

To study the effect of allogeneic bone marrow mesenchymal stem cells transplantation on the expression of interleukin -22 (IL-22), matrix metalloproteinase -3 (MMP-3) in serum and synovial of rats with collagen induced arthritis. Type Ⅱ collagen were injected twice to establish the collagen induced arthritis (CIA) rat model. Forty-eight rats were randomly divided into 3 groups: control group, CIA control group, CIA experiment group. Rat bone marrow mesenchymal stem cells were cultured by bone marrow method combined with adherent culture method. After identify, the remaining cells were injected in the CIA experimental group. Enzyme linked immunosorbent assay (ELISA) and immunohistochemistry were used to detect the expression of IL-22 and MMP-3 in serum and anklebone joint's synovium of rats, respectively. Synovial cells were isolated and cultured, and were treated with different concentrations of IL-22. MMP-3 protein and mRNA were detected before and after stimulation by Western blot and real-time quantitative polymerase chain reaction (RT-qPCR). After MSC transplantation, arthritis index, X-ray, HE staining of CIA rat showed that joint damage significantly reduced compared with the control group. The ELISA results showed that the expression of MMP-3 and IL-22 in CIA control group was higher than those in the control group (125.79±9.12 vs 102.00±7.63 ng/ml, <0.05), (292.35±31.23 vs 257.27±13.99 ng/ml, <0.05) and CIA experiment group (125.79±9.12 vs 97.94±9.50 ng/ml, <0.05), (292.35±31.23 vs 262.16±22.02 ng/ml, <0.05) with statistically significant difference (<0.05). There was no significant difference between the control group and CIA experimental group. Immunohistochemical showed similar results with ELISA. Western blotting and RT-qPCR showed that MMP-3 protein and mRNA expression was increased after IL-22 stimulation in a dose-dependent manner. IL-22 and MMP-3 play an important role in the pathogenesis of rheumatoid arthritis. IL-22 could regulate the expression of MMP-3, and bone marrow mesenchymal stem cells could reduce the expression of MMP-3 in the treatment of rheumatoid arthritis by reducing the expression of IL-22.