印迹基因H19在子痫前期孕妇胎盘组织中的印迹状态

摘要

目的 探讨印迹基因H19印迹状态在子痫前期发病中的作用.方法 2007年8月-2008年3月第三军医大学附属大坪医院、西南医院、新桥医院妇产科行剖宫产分娩的子痫前期孕妇24例为子痫前期组(其中轻度子痫前期3例、重度子痫前期21例);同期行择期剖宫产的正常足月孕妇50例为正常晚孕组.采用PCR-RFLP法检测两组孕妇胎盘组织中H19基因的印迹状态,并对子痫前期组H19基因组DNA杂合子小同印迹状态孕妇的血压进行分析.结果 (1)正常晚孕组胎盘组织中有H19基因组DNA杂合子20例(40%),纯合子30例(60%);子痫前期组胎盘组织中有H19基因组DNA杂合子11例(46%),纯合子13例(57%).两组孕妇H19基因组DNA杂合子比较,差异无统计学意义(P>0.05).(2)正常晚孕组20例H19基因组DNA杂合子孕妇全部为单等位基因表达;子痫前期组11例H19基因DNA杂合子孕妇中,有5例(45%)为双等位基因表达,单等位基因表达6例(55%),子痫前期组存在印迹丢失,两组比较,差异有统计学意义(P<0.01).(3)子痫前期组H19基因DNA杂合子中双等位基因表达孕妇的收缩压为(194±21)mm Hg(1 mm Hg=0.133 kPa),舒张压为(124±18)mm Hg;单等位基因表达孕妇的收缩压为(171±9)mm Hg,舒张压为(104±8)mm Hg,两者血压比较,差异有统计学意义(P<0.05).结论 子痫前期患者胎盘组织中H19基因存在印迹丢失,且印迹丢失与血压水平变化有关.提示H19基因印迹丢失可能参与子痫前期的发病,并与疾病的严重程度密切相关.%Objective To explore the role of H19 imprinting in etiology of pre-eclampsia. Methods Placentas of 24 women with pre-eclampsia (3 with mild pre-eclampsia and 21 with severe pre-eclampsia) and 50 healthy pregnant women at full term (control) were collected during selected cesarean delivery between August 2007 and March 2008. The statuses of H19 imprinting with placental tissues from normal pregnancy and patients with pre-eclampsia were identified upon polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The systolic and diastolic pressure were analyzed in H19 heterozygotic women. Results (1) There were 20 (40%) heterozygotes in 50 cases placenta tissues of the third trimesters, 11 (45%) heterozygotes in 24 cases placenta tissues of pre-eclampsia, There were no significant difference between two groups ( P > 0.05 ). (2) All 20 heterozygotes in placenta tissues of the third trimesters are exclusively monoallelically expressed, while 5 cases (45%) in 11 heterozygotes of pre-eclampsia are biallelically expressed (loss of imprinting, LOI). There were significant difference between two groups (P < 0. 01 ). (3) The values of systolic and diastolic pressure of patients with monoallelic expression of H19 were (171 ±9) mm Hg (1 nun Hg =0.133 kPa) and ( 104±8) mm Hg, the values of systolic and diastolic pressure with biallelic expression were ( 194±21 ) mm Hg and ( 124±18) mm Hg. There were significant difference between two groups (P<0.05 ). Conclusion LOI of H19 can be identified in pre-eclamptic placentas and is associated with maternal blood pressures, which implies the involvement of H19 gene LOI in the pathogenesis of pre-eclampsia and its potential relationship with the severity of the disease.