p38丝裂原活化蛋白激酶信号分子在子痫前期患者血管内皮细胞损伤中的作用

摘要

目的 探讨p38丝裂原活化蛋白激酶(MAPK)信号分子在子痫前期患者血管内皮细胞损伤中的作用.方法选择2009年9月至2010年3月在重庆医科大学附属第一医院住院分娩的足月产妇54例为研究对象,其中36例为子痫前期患者,按病情分为子痫前期轻度组(20例)、子痫前期重度组(16例);同期足月择期剖宫产孕妇为对照组(18例).采用CD34标记血管内皮细胞,计数各组胎盘微血管密度(MVD);SP法检测磷酸化的p38 MAPK(p-p38 MAPK)在胎盘组织中的定位;蛋白印迹法检测各组胎盘p38 MAPK及p-p38 MAPK的蛋白表达差异;双抗体夹心ELISA法检测各组血清中可溶性血管内皮生长因子受体1(sFlt-1)及可溶性内皮糖蛋白(soluble endoglin,sEng)的水平.结果 (1)MVD:对照组、子痫前期轻度组及子痫前期重度组患者胎盘MVD分别为103±3、81±5、63±4,各组间两两比较,差异均有统计学意义(P＜0.05).(2)p38 MAPK和p-p38 MAPK蛋白表达水平:对照组、子痫前期轻度组及子痫前期重度组患者胎盘组织p38 MAPK蛋白表达水平分别为0.84±0.05、0.90±0.14、0.86±0.18,各组间两两比较,差异均无统计学意义(P＞0.05);p-p38 MAPK蛋白的表达水平分别为0.13±0.05、0.59±0.12和1.16±0.18,各组间两两比较差异均有统计学意义(P＜0.05).(3)p-p38 MAPK蛋白的表达部位:p-p38 MAPK蛋白主要表达于胎盘滋养层细胞的胞质及胞核、血管内皮细胞及少量间质细胞的胞核.(4)sFlt-1及sEng的水平:①对照组孕妇血清sFlt-1、sEng水平分别为(5.2±0.3)、(10.9-±0.4)μg/L;子痫前期轻度组分别为(12.5±1.2)、(20.4±5.3)μg/L;子痫前期重度组分别为(19.3±3.0)、(29.5±3.7)μg/L;各组sFlt-1、sEng水平两两比较,差异均有统计学意义(P＜0.05);②p-p38 MAPK蛋白表达水平与血清sFlt-1、sEng水平的相关性:子痫前期重度组和子痫前期轻度组p-p38 MAPK蛋白表达水平与血清sFlt-1、sEng水平均呈明显正相关(r=0.68,P＜0.05;r=0.87,P＜0.05).结论 子痫前期患者胎盘组织中p38 MAPK信号分子的显著活化,使血清中sFlt-l、sEng水平升高,损伤胎盘血管内皮细胞,导致胎盘MVD降低;p38 MAPK信号分子可能是子痫前期患者血管内皮细胞损伤的关键信号传导通路之一.%Objective To study expression and activation of p38 mitogen activated protein kinase (MAPK) in vascular endothelial cells dysfunction in preeclampsia. Methods From Sept. 2009 to Mar.2010, 54 pregnant women underwent deliveries in the First Affiliated Hospital of Chongqing Medical University were enrolled in this study, including 20 patients in mild preeclampsia group, 16 patients in severe preeclampsia group and 18 women with term cesarean section without perinatal complications as control group. Placental endothelial cells were labeled by CD34 to assay microvessel density (MVD) of each group. Immunohistochemical SP and western blot were used to detect localization and expression of p-p38 MAPK protein, respectively. The levels of sera soluble fms-like tyrosine kinase-1 (sFlt-1)and soluble endoglin(sEng) were measured by ELISA. Results ①The MVD of placenta were 103 ± 3 in control group, 81 ±5 in mild preeclampsia group and 63±4 in severe group, respectively, which showed statistical difference among each group (P＜0.05).②The expression of p38 MAPK protein were 0.84±0.05 in control group,0.90±0.14 in mild group and 0. 86 ±0.18 in severe group, which did not reach remarkable difference among each group (P＞0.05). The expression of p-p38 MAPK protein were 0.13±0.05 in control group,0.59±0.12 in mild group and 1.16±0.18 in severe group, which show statistical difference among each group(P＜0.05).(3) The localization of p-p38 was in trophoblast, endothelial cells and a few (5.2±0.3)and(10.9±0.4)μg/L in control group,(12.5±1.2) and (20.4±5.3)μg/L in mild group and (19.3±3.0) and (29. 5 ±3.7) μg/L in severe group. When drawing paired comparison in those p-p38 MAPK protein levels and the concentrations of serum sFlt-1, sEng in preeclampsia groups (r=0.68,P＜0.05;r=0.87,P＜0.05). Conclusions The remarkable activation of the p38 MAPK in the placenta of patients with preeclampsia induced the increased levels of sFlt-1 and sEng in maternal serum, which confer the injury of vascular endothelial cells that caused the significant decline of MVD in placentas. p38 MAPK signaling might be one of the key pathways in vascular endothelial cell dysfunction in preeclampsia.