Guo Xijiao, Feng Ling, Jia Jing, Chen Ruibao, Yu Jun
Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China.
Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China.
Placenta. 2016 Oct;46:38-44. doi: 10.1016/j.placenta.2016.08.088. Epub 2016 Aug 28.
Preeclampsia is a severe pregnancy complication mostly due to inadequate vascular dilation and remodeling of spiral arteries. VEGF, the major factor for angiogenesis, is necessary for modulating angiogenic processes in the placenta. Hence reduction of VEGF in gestational hypertension may also lead to hypoperfusion and subsequent hypoxia of the fetus in hypertensive pregnancy.
This study aimed at elucidating the mechanism of action of VEGF in preeclampsia. Small activating RNAs (saRNA) were used to upregulate VEGF expression in human trophoblast cells (HTR-8/SVneo). The VEGF expression level was analyzed by real-time quantitative PCR and western blot, while its transfection efficiency was measured by flow cytometer assay. Cell migration was analyzed by a wound scratch assay. NO secretion was detected by determining NO metabolites. eNOS expression was analyzed by western blot. Tube formation function of cells was then analyzed by matrigel migration assay.
VEGF expression significantly increased after saRNA transfection (all p ＜ 0.05). NO secretion and eNOS expression significantly increased by saRNA in HTR-8/SVneo cells (p = 0.0003 and 0.032 respectively). The migration ability and tube formation function of HTR-8/SVneo cells were enhanced by saRNA (p = 0.024 and 0.013 respectively). TNF-α inhibited VEGF-downstream eNOS-NO pathway activity as well as cell migration and tubulogenesis, while enforcing the expression of VEGF attenuated all the insults induced by TNF-α.
Utilizing an RNA activation strategy to increase endogenous VEGF expression could be an emerging and effective approach for the treatment of preeclampsia.
子痫前期是一种严重的妊娠并发症，主要是由于螺旋动脉血管舒张和重塑不足所致。血管内皮生长因子（VEGF）是血管生成的主要因子，对调节胎盘血管生成过程至关重要。因此，妊娠期高血压患者VEGF水平降低也可能导致高血压妊娠时胎儿灌注不足及随后的缺氧。
本研究旨在阐明VEGF在子痫前期中的作用机制。使用小激活RNA（saRNA）上调人滋养层细胞（HTR-8/SVneo）中VEGF的表达。通过实时定量PCR和蛋白质免疫印迹分析VEGF表达水平，同时通过流式细胞仪检测其转染效率。采用划痕试验分析细胞迁移情况。通过测定NO代谢产物检测NO分泌。通过蛋白质免疫印迹分析内皮型一氧化氮合酶（eNOS）表达。然后通过基质胶迁移试验分析细胞的管腔形成功能。
saRNA转染后VEGF表达显著增加（所有p＜0.05）。saRNA使HTR-8/SVneo细胞中NO分泌和eNOS表达显著增加（分别为p = 0.0003和0.032）。saRNA增强了HTR-8/SVneo细胞的迁移能力和管腔形成功能（分别为p = 0.024和0.013）。肿瘤坏死因子-α（TNF-α）抑制VEGF下游的eNOS-NO通路活性以及细胞迁移和管腔形成，而增强VEGF表达可减轻TNF-α诱导的所有损伤。
利用RNA激活策略增加内源性VEGF表达可能是一种新的有效治疗子痫前期的方法。
