哺乳动物雷帕霉素靶蛋白、核转录因子-κB、固醇调节元件结合蛋白2在子痫前期患者中的表达及意义

Expression of mammalian target of rapamycin(mTOR),nuclear factor-κ B(NF-κB) and sterol regulatory element binding protein 2 (SREBP2) in serum and placentas among gravidas with preeclampsia

目的探讨子痫前期患者外周血及胎盘组织中哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin, mTOR)、核转录因子-κB(nuclear factor-κ B, NF-κB)、固醇调节元件结合蛋白2(sterol regulatory element binding protein 2, SREBP2)的表达意义。方法选择2015年8月至2017年8月在中南大学湘雅二医院进行规律产前检查并剖宫产分娩的60例子痫前期患者,根据子痫前期分度标准分为重度子痫前期(severe preeclampsia, SPE)组(40例)和轻度子痫前期(mild preeclampsia, MPE)组(20例),并按照2∶1比例选择同期因头盆不称、胎位异常及社会因素行剖宫产终止妊娠的30例孕妇作为对照组。所有孕妇均采用酶联免疫吸附试验(enzyme linked immunosorbent assay, ELISA)法检测外周血mTOR、高密度脂蛋白-胆固醇(high density lipoprotein-cholesterol, HDL-C)、低密度脂蛋白-胆固醇(low density lipoprotein-cholesterol, LDL-C)、甘油三酯、总胆固醇浓度;采用蛋白质印迹法检测胎盘mTOR、磷酸化mTOR (phospho- mTOR, p-mTOR)、NF-κB、SREBP2蛋白表达。采用单因素方差分析、Bonferroni法或Dunnett's T3检验,以及Pearson相关分析进行统计分析。结果(1)SPE组和MPE组孕妇外周血mTOR[分别为(11 765.56±1 698.95)、(8 278.56±1 106.59)与(4 366.19±716.43) pg/ml]、LDL-C[分别为(7.81±1.90)、(4.11±0.75)与(2.42±0.45) mmol/L]水平均高于对照组(P值均<0.05),且SPE组均高于MPE组(P值均<0.05);SPE组和MPE组孕妇外周血HDL-C水平低于对照组[分别为(0.36±0.12)、(0.85±0.11)与(1.33±0.16) mmol/L],且SPE组低于MPE组(P值均<0.05)。SPE组孕妇外周血甘油三酯水平均高于MPE组及对照组[分别为(46.19±18.92)、(35.55±6.54)与(33.24±9.78) nmol/L,P值均<0.05],SPE组和MPE组孕妇外周血胆固醇水平均高于对照组[分别为(24.72±7.17)、(21.83±4.19)与(16.32±3.88)nmol/L,P值均<0.05 ]。(2)SPE组和MPE组孕妇胎盘mTOR(分别为0.52±0.09、0.38±0.08与0.24±0.05)、p-mTOR(分别为0.42±0.08、0.26±0.05与0.14±0.03)、NF-κB(分别为0.58±0.10、0.36±0.05与0.21±0.03)、SREBP2(分别为0.52±0.08、0.33±0.05与0.20±0.05)蛋白表达及p-mTOR/mTOR(分别为0.75±0.10、0.69±0.14与0.59±0.13)水平均高于对照组,且SPE组mTOR、p-mTOR、NF-κB p65、SREBP2蛋白表达均高于MPE组(P值均<0.05)。(3)经Pearson相关分析,SPE组外周血mTOR及胎盘mTOR、p-mTOR蛋白水平分别与外周血LDL-C(相关系数分别为0.682、0.584、0.504)、甘油三酯(相关系数分别为0.612、0.658、0.422),以及外周血mTOR、胎盘mTOR与总胆固醇水平(相关系数分别为0.598、0.452)均呈正相关(P值均<0.05),分别与外周血HDL-C水平呈负相关(相关系数分别为-0.375、-0.442、-0.390,P值均<0.05)。SPE组胎盘NF-κB分别与胎盘mTOR、外周血LDL-C呈正相关(相关系数分别为0.375、0.391,P值均<0.05),胎盘SREBP2分别与胎盘mTOR、外周血总胆固醇呈正相关(相关系数分别为0.364、0.392,P值均<0.05)。(4)MPE组外周血mTOR、胎盘mTOR及p-mTOR水平分别与外周血LDL-C(相关系数分别为0.813、0.641、0.465)、甘油三酯(相关系数分别为0.646、0.529、0.502)及总胆固醇(相关系数分别为0.558、0.482、0.483)均呈正相关(P值均<0.05);外周血mTOR水平与外周血HDL-C水平呈负相关(相关系数为-0.606,P<0.05);MPE组胎盘NF-κB分别与胎盘mTOR、外周血LDL-C呈正相关(相关系数分别为0.458、0.595,P值均<0.05),胎盘SREBP2分别与胎盘mTOR、外周血总胆固醇呈正相关(相关系数分别为0.580、0.560,P值均<0.05)。结论mTOR、NF-κB、SREBP2可能通过介导脂代谢紊乱参与子痫前期的发生、发展。

Objective To investigate the level of mammalian target of rapamycin (mTOR) in serum and the expression of mTOR, nuclear factor-κ B (NF-κB) and sterol regulatory element binding protein 2 (SREBP2) in placenta among gravidas with preeclampsia. Methods From August 2015 to August 2017, 60 gravidas including 40 with severe preeclampsia (SPE) and 20 with mild preeclampsia (MPE) who underwent regular prenatal care and delivered by caesarean section were selected from the Second Xiangya Hospital of Central South University. According to the ratio of 2∶1, 30 gravidas who delivered through caesarean section due to cephalopelvic disproportion, abnormal fetal position or social factors during the same period were enrolled as the control group. Peripheral blood samples were obtained to determine the concentrations of serum mTOR, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), triglyceride (TG) and total cholesterol (TC) by enzyme linked immunosorbent assay (ELISA). The expression of mTOR, phospho-mTOR (p-mTOR), NF-κB and SREBP2 in placenta were measured by Western blot. Clinical datas were statistically analyzed using one-way ANOVA, Bonferroni or Dunnett's T3 test, and Pearson's correlation analysis. Results (1) The serum levels of mTOR and LDL-C in the SPE and MPE group were both higher than that in the control group [mTOR:(11 765.56±1 698.95) and (8 278.56±1 106.59) vs (4 366.19±716.43) pg/ml;LDL-C:(7.81±1.90) and (4.11±0.75) vs (2.42±0.45) mmol/L, all P<0.05].Furthermore the serum levels of mTOR and LDL-C in the SPE group were both higher than those in the MPE group (both P<0.05). The serum level of HDL-C in the SPE and MPE group were lower than that in the control group [(0.36±0.12) and (0.85±0.11) vs (1.33±0.16) mmol/L, both P<0.05], and that in the SPE group was lower than that in the MPE group (P<0.05). Women in the SPE group showed higher TG level when comparing with the MPE and control group [(46.19±18.92) vs (35.55±6.54) and (33.24±9.78) nmol/L, both P<0.05], while the TC levels in the SPE and MPE group were higher than that in the control group[(24.72±7.17) and (21.83±4.19) vs (16.32±3.88) nmol/L, both P<0.05].(2) The placental expressions of mTOR, p-mTOR, NF-κB and SREBP2 protein in the SPE and MPE group were higher compared with that in the control group [mTOR:(0.52±0.09) and (0.38±0.08) vs (0.24±0.05);p-mTOR:(0.42±0.08) and (0.26±0.05) vs (0.14±0.03);NF-κB:(0.58±0.10) and (0.36±0.05) vs (0.21±0.03);SREBP2:(0.52±0.08) and (0.33±0.05) vs (0.20±0.05);all P<0.05], and those expressions of the SPE group also higher comparing with the MPE group. Otherwise the p-mTOR/mTOR ratios in the SPE group and MPE group were higher than that in the control group [(0.75±0.10) and (0.69±0.14) vs (0.59±0.13), both P<0.05].(3) Pearson's correlation analysis showed that serum level of mTOR and placental expressions of mTOR and p-mTOR in the SPE group were positively correlated with serum LDL-C (r=0.682, 0.584 and 0.504, all P<0.05), TG (r=0.612, 0.658 and 0.422, all P<0.05), while serum level of mTOR and placental expressions of mTOR in the SPE group were positively correlated with TC (r=0.598 and 0.452, all P<0.05), but were negatively correlated with serum HDL-C (r=-0.375,-0.442 and -0.390, all P<0.05). The NF-κB expression in placenta of the SPE group was significantly positively correlated with the mTOR expression in placenta and serum LDL-C (r=0.375 and 0.391, both P<0.05). Moreover, in the SPE group, the SREBP2 level in placenta was significantly positively correlated with placental expression of mTOR and serum TC level (r=0.364 and 0.392, both P<0.05).(4) In the MPE group, mTOR level in serum and levels of mTOR and p-mTOR in placenta were significantly positively correlated with serum LDL-C (r=0.813, 0.641 and 0.465, all P<0.05), TG (r=0.646, 0.529 and 0.502, all P<0.05) and TC (r=0.558, 0.482 and 0.483, all P<0.05), while the level of serum mTOR was negatively correlated with the level of serum HDL-C (r=-0.606, P<0.05). The NF-κB level in placenta in MPE group was positively correlated with the mTOR in placenta and the serum LDL-C (r=0.458 and 0.595, both P<0.05), while the SREBP2 level in placenta was significantly positively correlated with mTOR in placenta and serum TC (r=0.580, 0.560, respectively;both P<0.05) in the MPE group. Conclusionsm TOR, NF-κB and SREBP2 may play important roles in the onset and development of preeclampsia by interfering lipid metabolism.