经典Wnt/β-catenin信号通路介导子痫前期滋养细胞氧化应激损伤的机制研究

Mechanism of classical Wnt/?茁-catenin signaling pathway mediated oxidaticve stress injury of trophoblast cells in preeclampsia

摘要:

目的：研究经典Wnt/β-连环蛋白（β-catenin）信号通路参与人滋养细胞氧化应激损伤的机制，探讨其在子痫前期（preeclampsia，PE）发病中的作用。方法：（1）采用免疫组化SP法和蛋白免疫印迹法（Western blot，WB）检测胎盘组织中β-catenin信号分子的表达。（2）将HTR8/SVneo分为正常培养对照组、缺氧/复氧（hypoxia/reoxygenation，H/R）处理组、氯化锂（LiCl）+H/R处理组、LiCl+正常培养组。利用WB法和间接免疫荧光法检测β-catenin在各组细胞中的表达。（3）利用流式细胞仪检测各组细胞凋亡指数及细胞内活性氧（reactive oxygen species，ROS）水平。（4）利用Transwell小室模型和明胶酶谱法分析检测各组HTR8/SVneo的侵袭率及基质金属蛋白酶（matrix metalloproteinase，MMP）-2、9的活性。结果：（1）与正常晚孕比较，子痫前期胎盘组织中β-catenin蛋白表达降低（P<0.05）。（2）与正常培养组相比较，H/R处理组的β-catenin蛋白水平显著下降，经LiCl预处理后H/R细胞中的β-catenin蛋白表达增加（P<0.01）。（3）与正常对照组相比，H/R处理可导致HTR8/SVneo凋亡率及ROS水平增加（P<0.01）；予以LiCl预处理可有效抑制H/R导致的细胞凋亡及ROS聚集（P<0.05，P<0.01）。（4）H/R组细胞的体外侵袭能力及MMP-2、9的活性均低于正常培养组；经LiCl预处理后，H/R组细胞的体外侵袭能力及清液中MMP-2、9的活性显著上升（P<0.01）。结论：LiCl通过特异性激活Wnt/β-catenin信号通路，对滋养细胞氧化应激损伤有保护性作用。

Abstract:

Objective：To investigate the roles of classic Wnt/β-catenin signaling pathway in the oxidative stress injury of trophoblasts involved in the development of preeclampsia. Methods：（1）Immunohistochemistry and Western blot were utilized to determine the ex－pression of β-catenin in the placental tissues. （2）Cell treatment and classification of each group were as follow：normal culture group，H/R culture group，LiCl+normal culture group，LiCl+H/R culture group. The expressions and localization of β-catenin protein were detected by Western blot and immunofluorescence.（3）Flow cytometry assay was employed to verify the level of reactive oxygen species（ROS） and apoptosis index of HTR8/SVneo. （4）Changes of cell invasion rates were identified by transwell matrigel invasion assay；the activities of matrix metalloproteinase（MMP-2，9） were measured by gelatin zymography assay. Results：（1）The level of β-catenin protein decreased in placental tissues of preeclamptic compared with that in normal third trimester（P<0.05）. （2）In HTR8/SV－neo cells，β-catenin was located in both nucleus and cytoplasm. HTR8/SVneo cells exposed to H/R showed a significant decrease in β-catenin protein levels compared with the normal culture cells（P<0.01）. Pretreated with LiCl could upregulate the expression of β-catenin in H/R cells（P<0.01）. （3）Treatment with H/R could increase the level of ROS and apoptosis，and reduce the inva－sive ability of HTR8/SVneo cells in vitro（P<0.01）. Pretreated with LiCl could inhibit the accumulation of ROS and apoptosis of cells caused by oxidative stress（P<0.01，P<0.05）. （4）The enzymatic activities of MMP-2，9 and the invasion rates of cells in vitro decreased significantly in HTR8/SVneo cells exposed to H/R（P<0.01），while pretreated with LiCl could increase the enzymatic activities of MMP-2，9 and enhance the invasion rates of HTR8/SVneo cells exposed to H/R（P<0.01）. Conclusion：LiCl via activate the classical wnt/β-catenin signaling pathway to inhibit the injury of oxidative stress on trophoblast.