骨髓间充质干细胞移植对实验性自身免疫性葡萄膜炎的抑制作用

Transplantation of bone marrow mesenchymal stem cells inhibits rat experimental autoimmune uveitis

目的 观察骨髓间充质干细胞对实验性自身免疫性葡萄膜炎（EAU）的抑制作用,探讨其对活体内免疫机制的调节机制.方法 将18只Lewis大鼠采用随机数字表随机分为模型对照组、骨髓间充质干细胞干预组和正常对照组,每组6只.将浓度为1 mg/ml的人视网膜可溶性抗原第35号抗原决定簇多肽片段（HS-AgP35）溶液与完全福氏佐剂等体积混合,取0.2 ml分别注射至Lewis大鼠双侧后足垫内进行免疫.7 d后相同抗原剂量行第二次免疫制作模型组.造模当日将1 ml细胞数为2×106/ml骨髓间充质干细胞悬液经尾静脉注射干预组大鼠体内,观察时间为2周.正常对照组不做任何处理.比较3组大鼠的眼部表现、组织病理学分级和血清内干扰素γ（IFN-γ）水平.结果 正常对照组大鼠的眼前节及眼底检查未见异常.模型对照组大鼠的眼部表现分级为1级1只、2级1只、3级3只、4级1只;干预组大鼠的眼部表现分级为0级2只、0.5级3只、1级1只.与模型对照组相比,干预组大鼠眼部表现分级显著降低（P=0.015）.正常对照组大鼠视网膜各层细胞排列整齐,细胞形态正常.模型对照组大鼠组织病理学分级为3级4只、4级2只;干预组大鼠组织病理学分级为0级1只、0.5级4只、1级1只.两组大鼠组织病理学分级比较,差异有统计学意义（P＜0.01）.干预组大鼠外周血中IFN-γ水平下降,与模型对照组相比,差异有统计学意义（t=9.057 4,P=0.01）.结论 骨髓间充质干细胞对EAU有明显抑制作用.其机制可能是通过降低大鼠血清内炎性因子INF-γ水平.

Objective To investigate the impact of bone marrow mesenchymal stem cell transplantation on a rat model of experimental autoimmune uveitis （EAU） and analyze its immune regulatory mechanisms in vivo. Methods Eighteen Lewis rats were randomly divided into three groups： model control group, intervention group and normal control group, six animals in each group. Human retinal S-antigen peptide （HS-AgP35, 1 mg/ml） was mixed and emulsified with complete Freund＇s adjuvant and injected into hind foot pad of rats on the first and eighth day to establish the animal model of EAU. For bone marrow mesenchymal stem cell transplantation, 1 ml of cell suspension （2 × 106 cells/ml） was injected into tail vein of the intervention group rats on the first day when the emulsified S-antigen was injected. EAU manifestation, pathological change and IFN-γ level were evaluated and compared among those three groups after two weeks. Results No abnormal signs were found in the eyes of rats in normal control group. The manifestation grading of the intervention group （two rats at grade 0, three rats at grade 0.5, one rat at grade one） was significantly different from the model control group （one rat at grade one, one rat at grade two, three rats at grade three, one rat at grade four） （P=0. 015）. The retina of rats in normal control group was ordinary under light microscope. The histopathological grading of the intervention group （one rat at grade 0, four rats at grade 0.5, one rat at grade one） and the model control group （four rats at grade three, two rats at grade four） was also statistically different （P〈0. 01）. Furthermore, the IFN-γ level in peripheral blood of the intervention group rats declined significantly compared to the model control group （t=9. 057 4, P=0. 01）. Conclusions Bone marrow mesenchymal stem cells can inhibit EAU significantly,possibly by lowering the level of IFN-γ, thereby reduce the severity of uveitis and improve the condition of uveitis in rats.