胎盘组织中尿皮素和促肾上腺皮质激素释放激素2β受体表达变化与先兆子痫发病的关系

Study on the level of placental urocortin and corticotropin-releasing hormone receptor 2β of preeclampsia

目的探讨先兆子痫患者胎盘组织中尿皮素(UCN)和促肾上腺皮质激素释放激素2β受体(CRH R2β)表达与先兆子痫发病的关系。方法应用半定量RT PCR技术测定20例先兆子痫患者(先兆子痫组)和20例正常妊娠妇女(对照组)胎盘组织中UCNmRNA和CRH R2βmRNA的水平;采用免疫组化方法对UCN进行蛋白定位和半定量分析。结果(1)先兆子痫组胎盘组织中UCNmRNA的表达水平为1 14±0 26,高于对照组的0 78±0 46,两组比较,差异有统计学意义(P<0 05)。(2)先兆子痫组胎盘组织中CRH R2βmRNA的表达水平为0 89±0 33,与对照组的0 93±0 50比较,差异无统计学意义(P>0 05)。(3)免疫组化定位结果显示,两组产妇的UCN蛋白表达主要位于合体滋养细胞,少量表达于细胞滋养细胞和血管内皮细胞。蛋白半定量结果显示,UCN在先兆子痫组胎盘合体滋养细胞中的表达强度高于对照组,两组比较,差异有统计学意义(P<0 05 )。结论先兆子痫患者胎盘组织中UCN表达水平升高,而CRH R2β水平则无明显变化,因此UCN的作用加强。这可能是胎盘组织对母体和胎儿应激状态的一种继发性代偿反应,并参与先兆子痫的病理生理过程。

Objective To determine the relation between the expression of urocortin and corticotropin-releasing hormone receptor 2β (CRH-R2β) in the placenta and pathogenesis of preeclampsia. Methods Placentas were collected from 20 pregnant women with preeclampsia as study group and 20 normal pregnant women as control group. Urocortin mRNA and CRH-R2β mRNA were measured by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Urocortin peptide was measured by immunohistochemistry. Results (1) The mRNA expression of urocortin was significantly higher (P<0.05) in preeclampsia (1.14±0.26) compared with normal pregnancies (0.78±0.46). (2) There was no significant difference between the expression of CRH-R2β mRNA of preeclampsia (0.89±0.33) and of normal pregnancies (0.93±0.50). (3) The result of immunohistochemistry demonstrated that urocortin was predominantly localized in syntrophoblast with weak staining in cyntrophoblast and capillaries. Urocortin in syntrophoblast of preeclampsia was significantly higher than that of normal pregnancy (P<0.05). Conclusions Our study demonstrates that urocortin peptide and mRNA is increased in women with preeclampsia. This may be a kind of stress-responsive compensatory mechanism in human placenta. Urocortin may play a role in the pathology of the disease.