骨髓间充质干细胞移植对自然衰老小鼠免疫功能的调节作用研究OA

Objective To investigate the regulatory effect of bone marrow mesenchymal stem cells(BM-MSCs)transplantation on immune function in naturally aged mice.Methods BM-MSCs were isolated and cultured from the bone marrow of young C57BL/6N mice.Cell morphology was observed,and the cells were characterized by alizarin red staining after osteogenic induction and flow cytometry.Naturally aged mice were randomly divided into a control group and a BM-MSCs transplantation group,with 5 mice in each group.The treatment group received BM-MSCs via tail vein injection,while the control group received an equal volume of normal saline.Some BM-MSCs were labeled with green fluorescent protein(GFP)for homing analysis in vivo.After treatment,histopathological changes in spleen tissue were observed by hematoxylin-eosin(HE)staining.The expression levels of interleukin-2(IL-2)and interleukin-10(IL-10)in spleen tissues were deter-mined by ELISA.The proportions of CD3+CD4+and CD3+CD8+T cells in spleen tissues were detected by flow cytometry.Results Primary BM-MSCs showed adherent growth.After passage,the cells exhibited spindle-shaped or polygonal morphology and grew in a confluent pattern.Alizarin red staining showed positive calcified nodules after osteogenic induction.Flow cytometry demonstrated that the cultured cells were positive for CD44 and negative for CD34 and CD45,consistent with the phenotypic characteristics of BM-MSCs.GFP-labeled BM-MSCs showed strong green fluorescence and were able to home to spleen tissue after tail vein transplantation.Compared with the control group,the BM-MSCs transplantation group showed improved splenic architecture with clearer red pulp and white pulp,more intact splenic corpuscles,and fewer macrophages.In addition,IL-2 expres-sion in spleen tissues increased,whereas IL-10 expression decreased.The proportions of CD3+CD4+and CD3+CD8+T cells also significantly increased in the BM-MSCs transplantation group(P<0.05).Conclusion BM-MSCs transplantation can home to the spleen of naturally aged mice and enhance immune function by impro-ving splenic histological structure,regulating cytokine expression,and increasing the proportions of CD3+CD4+and CD3+CD8+T cells,suggesting a potential intervention effect on immunosenescence.