Spontaneous Superimposed Preeclampsia: Chronology and Expression Unveiled by Temporal Transcriptomic Analysis

Preeclampsia (PE), a multifactorial pregnancy-specific syndrome accounting for up to 8% of pregnancy complications, is a leading cause of maternal and fetal morbidity and mortality and PE is also associated with long-term risk of hypertension and stroke for both the mother and fetus. Currently, the only “cure” is delivery of the baby and placenta, largely because the pathogenesis of preeclampsia is not yet fully understood. Preeclampsia is associated with impaired vascular remodeling at the maternal-fetal interface and placental insufficiency; however, the specific factors that contribute to this impairment have not been identified. To identify potential contributing pathways, we examined temporal transcriptomic changes occurring within the uterus, uterine implantation sites, and placentae from the Dahl salt-sensitive (Dahl S) rat model of superimposed preeclampsia compared to Sprague Dawley (SD) rats. We hypothesized that the Dahl S maternal-fetal interface would exhibit a unique temporal transcriptomic profile unveiling novel biomarkers, therapeutic targets, and mechanistic pathways regarding the development of PE. Our initial study focused on evaluation of genes previously linked to the development PE from using real time quantitative PCR (RT qPCR) and total RNA was isolated from uterus (day 0), uterine implantation sites (days 7, 10, 14), and placenta (days 14 and 20). Subsequently, an unbiased transcriptome analysis was performed at each time point using whole genome microarray to identify novel factors involved in PE. 624, 332, 185 , and 366 genes were found to be differentially expressed on days 0, 7, 10 and 14 respectively, with a Reactome Pathway enrichment for “Fatty acid metabolism, Metabolism of water-soluble vitamins and cofactors, Metabolism, Synthesis of substrates in N-glucan biosynthesis on Day 7”; ”Glycerophospholipid biosynthesis, Phospholipid metabolism, and Metabolism of lipids on Day 10”; and “Metabolism of lipids, Phospholipid metabolism, degradation of the extracellular matrix, Fatty acid metabolism, and Collagen degradation on Day 14” in the Dahl S rat vs. SD. Our data revealed numerous pathways that may play a role in the pathophysiology of spontaneous superimposed PE and allow for further investigation of novel therapeutic targets and biomarker development.子痫前期（Preeclampsia, PE）是一种多因素妊娠特异性综合征，约占妊娠并发症的8%，是孕产妇和围产儿发病与死亡的主要原因，同时还会增加母体与胎儿远期罹患高血压、脑卒中的风险。目前该病唯一的“治愈手段”为分娩娩出胎儿及胎盘，这在很大程度上是由于子痫前期的发病机制尚未完全阐明。子痫前期与母胎界面血管重塑受损及胎盘功能不全密切相关，但导致该损伤的具体诱因仍未明确。为识别潜在的致病通路，本研究以叠加型子痫前期的Dahl盐敏感（Dahl salt-sensitive, Dahl S）大鼠模型为对象，与Sprague Dawley（SD）大鼠对比，检测了子宫、子宫着床位点及胎盘组织的时序转录组变化。本研究提出如下假说：Dahl S大鼠的母胎界面将呈现独特的时序转录组特征，可为子痫前期的发病机制揭示新型生物标志物、治疗靶点及信号通路。本研究初期通过实时定量聚合酶链反应（real time quantitative PCR, RT-qPCR）对既往与子痫前期发病相关的基因进行验证，同时从子宫（第0天）、子宫着床位点（第7、10、14天）及胎盘（第14、20天）中提取总RNA。随后，在每个时间点采用全基因组微阵列开展无偏转录组分析，以识别子痫前期相关的新型致病因子。结果显示，与SD大鼠相比，Dahl S大鼠在第0、7、10、14天分别存在624、332、185及366个差异表达基因；第7天的Reactome通路富集分析显示“脂肪酸代谢、水溶性维生素及辅因子代谢、代谢过程、N-聚糖生物合成底物合成”通路富集；第10天富集于“甘油磷脂生物合成、磷脂代谢及脂质代谢”通路；第14天则富集于“脂质代谢、磷脂代谢、细胞外基质降解、脂肪酸代谢及胶原蛋白降解”通路。本研究结果揭示了多条可能参与自发性叠加型子痫前期病理生理过程的通路，可为后续新型治疗靶点开发及生物标志物筛选提供研究基础。