[Transplantation of bone marrow mesenchymal stem cell improves antioxidant capacity and immune activity of aging model rats].

Objective To investigate the impact of bone marrow mesenchymal stem cell (BMSC) transplantation on the antioxidant capacity and immune activity of aging rats induced by D-galactose. Methods Ten healthy male SD rats served as a control group (aged 2 months). To establish aging models, healthy SD rats were daily injected subcutaneously with D-galactose (400 mg/kg). Then the aging model rats were randomized into aging model group and BMSC group (ten rats in each group). The BMSC group was injected with 3×10(6) BMSCs via tail vein. And rats in the control and model groups were injected with the same amount of normal saline. Blood samples were taken from the rats of the three groups to detect the content of malonaldehyde (MDA) and the activities of superoxide dismutase (SOD). The thymic mass was weighed and the indexes of thymus were calculated; thymus lymphocyte transforming index was measured with MTT assay; the levels of IL-2 and IL-10 in the thymus were detected by ELISA; and the ultrastructural changes of the thymus in each group were observed under a transmission electron microscope. Results BMSC transplantation can increase the activity of SOD, decrease the level of MDA. Compared with the model group, the indexes of thymus as well as thymus lymphocyte transforming index significantly increased in the BMSC group. And in the BMSC group, the level of IL-2 was higher, and the level of IL-10 was distinctly lower. The thymus cells were arranged loosely, some nuclei presented with characteristic changes of pyknosis or apoptosis, and adipose tissues increased in the aging model group. BMSC could protect the ultrastructures of thymus cells, reticulo-epithelial cells, and the cell organelles were abundant and complete. Conclusion BMSC transplantation can improve antioxidant capacity and immune activity of aging rats, thus postponing immunosenescence.