Correlation of CD4⁺ CD25⁺ Foxp3⁺ Treg with the recovery of joint function after total knee replacement in rats with osteoarthritis.

In this study, we observed changes in CD4(+) CD25(+) Foxp3(+) Treg expression in rats with osteoarthritis (OA) to explore the role that CD4(+) CD25(+) Foxp3(+) Treg plays in the decline in the condition of OA rats. Thirty rats were randomly divided into 2 groups equally and OA was induced in rats in the model group by injection of papain and l-cysteine into the right knee joint. Cartilage lesions were scored by the modified Mankin scale; pulmonary function was assessed by spirometry; interleukin (IL)-17 and IL-4 levels were evaluated by the enzyme-linked immunosorbent assay; and the levels of CD4(+) CD25(+) Foxp3(+) Treg in peripheral blood were measured by flow cytometry. The left knee joints of the model rats appeared palpable swelling and osteophytes, while the body weight, heart and lung function of these rats decreased. The serum IL-4 level was lower, whereas the serum IL-17 level was higher in the model group (P < 0.05). The peripheral blood CD4(+) CD25(+) Foxp3(+) Treg of CD4(+)T cells was significantly lower. Correlation of the changes in the levels of IL-4, IL-17, and Treg suggests that the underlying mechanism may be a reduction of the regulatory effect of Treg. The specific mechanism still requires further study.

Effects of hemarthrosis on cartilage and synovium in rabbits.

PURPOSE: To provide experimental basis for clinic treatment by observing the effects of simple acute hematoma on cartilage and synovium, and improvement of hyaluronic acid (HA) on the damage. METHODS: Twenty-four New Zealand white rabbits were randomly divided 3 groups according to killed time: hematoma group, HA group and control group. These rabbits were killed at 4 days, 2, 4 and 8 weeks, respectively. RESULTS: Knee articular cartilage and synovium were obtained to detect histology, histochemistry and chondroitin proteoglycans (PG). Morphologies of cartilage and synovium in the control group were normal, while cartilage cells were detected hyperplasia of activation and each layer was disorganized in hematoma groups with 4 days and 2 weeks. Compared to the control group, concentrations of PG in 4 days and 2 weeks groups were significantly reduced (p < 0.05), while no significant difference was detected between 4 weeks group and the control group. Morphology was recovered normal in 8 weeks. Compared to hematoma group, morphology and histochemistry were improved in HA group at each time frame. CONCLUSIONS: Simple acute hematoma can lead to temporary change of morphology and biochemistry. Application of HA can reduce damage of hemarthrosis on cartilaginous and shorten the cartilage recovery time.