【作者】 余俊；

【导师】 冯玲；

【作者基本信息】 华中科技大学 ， 妇产科学， 2013， 博士

【摘要】 【目的】先兆子痫（Preeclampsia, PE）是造成胎儿生长受限及围产儿死亡的重要原因。氧化应激和血管扩张调控系统紊乱是PE的主要发病机制。S烯丙基L半胱氨酸（S allyl L cysteine, SAC）是大蒜提取物中最丰富的化合物之一，具有多种生物活性。本研究主要探讨SAC对胎盘组织中重要的内源性血管舒张调控信号通路——NO/cGMP信号通路的影响，及氧化应激状态下SAC对该信号通路的作用。【方法】采用体外培养人早孕绒毛滋养细胞株（TEV1细胞）和胎盘绒毛组织的方法检测SAC的作用。TEV1细胞和人胎盘绒毛组织分成以下各组：SAC干预组，H2O2干预组，H2O2+SAC联合干预组。通过流式细胞仪检测细胞内ROS水平，并采用硝酸还原酶法检测NO分泌量，放射免疫分析法测定cGMP水平，免疫组化和Western blot法检测TEV1细胞中eNOS的表达。【结果】研究结果显示，H2O2干预增加TEV1细胞中ROS的产生，且显著降低TEV1细胞和胎盘绒毛组织中的NO和cGMP水平，与对照组相比差异具有统计学意义（p<0.05）。H2O2干预组相比对照组，TEV1细胞eNOS表达也显著下降（p<0.05）。H2O2+SAC联合干预组相比H2O2干预组，ROS的量明显减少，且NO、cGMP和eNOS的水平明显高于H2O2干预组（p<0.05），与对照组水平无显著差异。此外，在非氧化应激状态下，SAC干预可呈剂量依赖性的增加TEV1细胞和胎盘绒毛组织中的NO和cGMP水平（p<0.05），而eNOS表达水平无显著改变。当TEV1细胞在eNOS抑制剂（L NAME）和NO供体（Sodium nitroprusside，SNP）共同存在的条件下培养时，SAC干预仍然能增加NO水平，且差异有统计学意义（p<0.05）。【结论】本研究结果表明在非氧化应激状态下SAC能增加TEV1细胞和胎盘绒毛组织中NO和cGMP水平；且SAC可抵御H2O2诱导产生的氧化应激对NO/cGMP信号通路的损害作用；提示SAC具有治疗PE的潜在作用。更多还原

【Abstract】 ObjectivePreeclampsia (PE) is a major cause of fetal growth restriction and perinatal mortality,which involves oxidative stress and vasodilator signaling disorder. S allyl L cysteine (SAC)is one of the most abundant compounds in garlic extracts, and possesses several biologicalactivities. This research was designed to investigate the effects of SAC on the NO/cGMPsignaling pathway in placenta, as well as the protective effects of SAC againstH2O2induced oxidative insults to the pathway.MethodTEV1cells and placental explants were used to detect the effects of SAC. TEV1cells and human placental explants were separately exposed to SAC, H2O2, or acombination of H2O2and SAC. Intracellular ROS was detected by flow cytometry; the NOlevel was detected, and the cGMP level was simultaneously measured by the method ofradioimmunoassay; the expression of eNOS in TEV1cells was measured byimmunochemistry and Western blot.ResultThe results showed that H2O2treatment increased ROS production in TEV1cells andsignificantly decreased NO and cGMP levels either in TEV1cells or placental explantscompared to the control groups (p<0.05). The expression of eNOS in TEV1cells alsosignificantly decreased in H2O2treated group compared to the control group (p<0.05).Co treatment of H2O2and SAC significantly decreased ROS productions, and increasedNO, cGMP and eNOS levels compared to the H2O2treated alone groups (p<0.05), whichwere all reverted back to near control levels. Further more, SAC treatment increased NOand cGMP levels of TEV1cells and placental explants in a dose dependent manner even atnon oxidative stress status (p<0.05). However, when the TEV1cells were cultured in thepresence of eNOS inhibitor (L NAME) and NO donor (SNP), additional SAC treatmentstill significantly increased the NO level in comparison with SAC non treated group(p<0.05). ConclusionIn conclusion, these results demonstrate that oxidative stress (H2O2mediated) caninduce insults to NO/cGMP pathway, while SAC could antagonize these insults. And SACalso possesses the ability to increase NO and cGMP levels at non oxidative stress status inTEV1cells and placenta explants. SAC is therefore hypothesized to be a potential drug forPE treatment.更多还原