Effect of Tongluo recipe on CD4+ CD25+ regulatory T cells in the thymus of experimental diabetic rats / 第二军医大学学报

ABSTRACT

Objective: To observe the effect of Tongluo recipe(TLR) on CD4+ CD25+ regulatory T cell in the thymus of experimental diabetic rats. Methods: Totally 112 SD rats were randomly divided into three groups control group, diabetes mellitus (DM) group, and TLR treatment group. Rat diabetic model was induced by intraperitoneal injection of streptozotocin (60 mg/kg). The TLR treatment group was further divided into two subgroups prevention group was given intragastric TLR (0.4 g·kg-1·d-1) for 12 weeks starting from the day of streptozotocin injection (TL-1 group), and the treatment group was given intragastric TLR (0.4 g· kg -1·d-1) for 12 weeks starting from 12 weeks after streptozotocin injection (TL-2). The animals were sacrificed at different time points (The control and DM group 4, 8, 12, 16, 20, and 24 weeks; TLR group 12 and 24 weeks after administration of TLR). Flow cytometry, H-E staining, and immunochemistry were performed to investigate the change of CD4+ CD25+ regulatory T cell ratio in CD4+ T cells, the thymus morphology, and the expression of Foxp3 protein in the thymus. Results: Compared with the normal control group, diabetic group had a gradually shrunk thymus, a decreased ratio of CD4+ CD25+ regulatory T cells in CD4+ T cells, and a decreased expression of Foxp3. The ratios of CD4+ CD25+ regulatory T cells and the thymus indices in the two TLR groups were significantly higher than those in the diabetic model group(P<0.05). Conclusion: Tongluo recipe can greatly increase the ratio of CD4+ CD25+ regulatory T cells, thymus index, and Foxp3 expression in the thymus, and may protect the thymus CD4+ CD25 + regulatory T cells in experimental diabetic rats.