脐带间充质干细胞对小胶质细胞增殖及活化的影响

目的 观察人脐带来源的间充质干细胞(hUC-MSCs)在正常环境和炎症环境下对小胶质细胞活化的调节作用,探讨hUC-MSCs对中枢神经系统炎症反应的免疫调节作用。 方法 将BV2细胞与人脐带间充质干细胞来源的条件培养基(hUC-MSCs-CM)和(或)脂多糖(LPS)共培养24或48 h后利用MTT比色法分析BV2增殖活力的变化,ELISA试剂盒分析BV2细胞上清中TNF-α和IL-6的变化,免疫印迹法检测精氨酸酶1(Arg1)的表达, Real-time PCR分析TNF-α、IL-6、ARG1基因的表达水平。 结果 (1)BV2在LPS长程刺激下表现出明显的增殖效应,而hUC-MSCs-CM可以抑制这种增殖反应;(2)炎症刺激诱导BV2表达TNF-α和IL-6明显增多,而在hUC-MSCs-CM和LPS共刺激时TNF-α和IL-6表达明显低于LPS单刺激组;(3)hUC-MSCs-CM共培养组BV2细胞高表达M2型小胶质细胞标志物Arg1。 结论 脐带间充质干细胞抑制炎症所致的小胶质细胞增殖;脐带间充质干细胞通过旁分泌机制调节小胶质细胞向M2型活化,降低促炎因子表达,这可能是其最终发挥神经保护作用的机制之一。

Effect of umbilical cord mesenchymal stem cells on microglial polarization and proliferation

Objective To observe the effect of umbilical cord mesenchymal stem cells(hUC-MSCs)on the microglia proliferation and activation in normal or inflammatory conditions, in order to explore their immunomodulation effect on the central nervous system. Methods After BV2 cells were co-cultured with hUC-MSCs-CM and/or lipopolysaccharide(LPS)for 24 or 48 h, the proliferation was analyzed by MTT colorimetric method, TNF-α and IL-6 in the supernatant were measured by ELISA kit, Arginase 1(Arg1)protein and mRNA levels were examined by Western blotting, TNF-α and IL-6 mRNA expression level were tested by real-time PCR. Results (1) After long-time LPS stimulation, BV2 cells obviously proliferated, while hUC-MSCs-CM inhibited the proliferation. (2) BV2 cultured with LPS expressed high levels of TNF-α and IL-6, while in both hUC-MSCs-CM and LPS conditions, the TNF-α and IL-6 levels were lower than in LPS stimulation. (3) The level of Arg1 was increased in BV2 cells co-cultured with hUC-MSCs-CM for 48 h. Conclusions Human UC-MSCs inhibit microglia proliferation caused by inflammatory stimulation. Human UC-MSCs induce microglial cells to M2 polarization and reduce the expression of proinflammatory factors via paracrine mechanism, and this may be the mechanism for its neuroprotective effect.