CXCL12/CXCR4介导少突胶质前体细胞髓鞘化的作用及调控机制

CXCL12/CXCR4 induced myelination of oligodendrocyte precursor cells in vitro

[目的]体外条件下研究CXCL12/CXCR4介导大鼠少突胶质前体细胞(oligodendrocyte precursor cells,OPCs)髓鞘化的作用及影响。[方法]振荡分离、差速贴壁和免疫细胞化学技术分离、培养、鉴定OPCs;Western blotting检测在不同浓度CXCL12(0、5、10、20 ng/ml)作用下,OPCs髓磷脂碱性蛋白(MBP)和髓鞘脂蛋白(PLP)的表达;CXCR4si RNA干扰CXCR4蛋白表达、LY294002抑制AKT通路活性、U0126抑制ERK通路活性,利用Western blotting检测在20ng/ml CXCL12作用下OPCs髓鞘形成相关蛋白MBP和PLP的表达,并用免疫荧光标记MBP和PLP。[结果]随着细胞外CXCL12的浓度升高,CXCL12能够明显促进OPCs髓鞘形成相关蛋白MBP和PLP的表达。与0 ng/ml相比,CXCL12在20 ng/ml作用后,OPCs髓鞘形成相关蛋白MBP和PLP蛋白表达增加最明显(P<0.05);干扰CXCR4蛋白表达,抑制AKT、ERK通路活性,OPCs髓鞘形成相关蛋白MBP和PLP蛋白表达受到抑制(P<0.05)。[结论]体外条件CXCL12/CXCR4对大鼠少突胶质前体细胞参与轴突髓鞘化有促进作用,并且能够通过ERK和PI3K/AKT信号通路对髓鞘形成相关蛋白MBP和PLP蛋白表达进行调控。

[Objective] To study the regulatory mechanism and the promotion effect of CXCL12/CXCR4 on the myelination of rat oligodendrocyte precursor ceils （OPCs） in vitro. [Method] OPCs were separated by the centrifuge and distinguished by morphological and immunocytochemical methods. The effect of different concentrations of CXCL12 （0, 5, 10, 20 ng/ml） on OPCs myelin basic protein （MBP） and proteolipid protein （PLP） was detected by western blotting. Additionally, CXCR4 expression inhibited by CXCR4 siRNA, AKT pathway blocked by LY294002, and the ERK1/2 pathway blocked by U0126 were assessed. Furthermore, at the condition of 20 ng/mL CXCL12, OPCs myelination correlative protein MBP and PLP were detected by western blotting and irmnunofluorescence labelling. [Result] With the increasing of concentration, CX- CL12 obviously promoted the expression of OPCs myelination correlative protein MBP and PLP. Compared with 0 ng/ml, expression of MBP and PLP increased most obviously at 20ng/ml CXCL12 condition, the difference had statistical significance （P〈0.05） . As AKT and ERK1/2 pathway was restrained after CXCR4 expression, OPCs myelination had been blocked or restrained, associated with the decreasing of MBP and PLP expression, which revealed a significant difference （P〈0.05） . [Conclusion] In vitro, CXCL12 / CXCR4 can regulate OPCs myelination via the AKT and ERK1/2 pathway, and promote the expression of MBP and PLP.