15-LO/15-HETE通路参与子痫前期内皮细胞损伤机制研究

Preeclampsia (PE), a syndrome of pregnant women, endothelial dysfunction is a major hallmark of PE, while the exact mechanism has not been explained. In our previous study, we have found 15-lipoxygenase (15-LO) was upregulated in endothelial cells from PE patients, the level of 15-hydroxyeicosatetraenoic acid (15-HETE) was also increased in venous blood form PE patients, hypoxia induced facor-1α (HIF-1α) was also upregulated in PE placenta, Meanwhile the inhibitors of 15-LO and p38 MAPK protected endothelial cells from dysfunction induced by hypoxia, so we suggest a hypothesis that HIF-1α can regulate the expression of 15-LO/15-HETE which participate the process of endothelial cell injury through p38 MAPK in PE. Then we will adopt the clinical samples, clinical pathological parameters, hypoxia induced preeclampsia mice model, 15-LO gene knocked out mice to ensure the relationship between 15-LO/15-HETE and endothelial dysfunction and the clinical parameters. We also will use hypoxia-induced human umbilical endothelial cells dysfunction model to confirm the molecular mechanism and mediated signaling pathway of 15-LO/15-HETE involved in endothelial dysfunction. Finally, we will provide an important experimental data for illustrate the pathological mechanism and intervention strategy of PE.

子痫前期（PE）是孕期特有的并发症，全身血管内皮损伤是其病理生理基础，但其具体机制尚未阐明。在前期研究发现PE患者内皮细胞15-脂氧合酶（15-LO）表达增加，静脉血15-羟基二十碳四烯酸（15-HETE，15-LO代谢产物）水平上升，PE患者胎盘中缺氧诱导因子-1α(HIF-1α）表达明显上调，15-LO抑制剂、p38MAPK通路抑制剂具有减少内皮细胞损伤的基础上，我们提出HIF-1α-15-LO/15-HETE-p38MAPK通路参与了PE血管内皮损伤机制的假说。本项目将利用临床人标本、缺氧诱导子痫前期小鼠模型、15-LO基因敲除鼠以明确15-LO/15-HETE与内皮损伤、临床病理参数的相关性；通过缺氧诱导人脐静脉内皮细胞损伤模型，采用siRNA技术及信号转导通路阻断以确定15-LO/15-HETE的上下游调控通路。研究结果将为PE机制深入阐明及干预策略寻找提供重要实验依据。

子痫前期（Preeclampsia, PE）病理生理机制仍未阐明，全身血管内皮细胞损伤为其主要病理过程。在前期研究发现PE患者内皮细胞中15-LOX表达增加，静脉血中15-HETE水平上调，PE患者胎盘中缺氧诱导因子-1α(HIF-1α）表达增加，以及15-LO抑制剂、p38MAPK抑制剂参与内皮细胞损伤过程，但具体的机制需进一步深入探讨。在本项目资助下，继续深入探讨15-LOX/15-HETE通路参与子痫前期内皮细胞损伤的病理机制。研究发现：1.胎盘样本中PE组15-LOX和sVCAM-1含量明显上升，sEng明显下降；血液样本中PE组15-LOX、15-HETE、p-p38MAPK、sICAM-1、sVCAM-1和sFlt-1含量明显上升，提示15-HETE主要通过血液循环发挥作用；2.从目前的统计分析示15-LOX/15-HETE与收缩压、舒张压、尿蛋白间无相关性；而胎盘组织中p38MAPK与sEng表达量与收缩压存在明显的负相关；血液样本中sFlt-1与舒张压存在明显的正相关关系，sICAM-1与舒张压存在明显的负相关。但胎盘组织和血液样本中测定的8个指标均与尿蛋白无明确的相关性；3.缺氧诱导HUVECs中 15-LOX表达增加，细胞活力降低和凋亡增加，而给予15-LOX-siRNA后，细胞活力增加和凋亡减少，p38MAPK与p-p38MAPK表达减少。缺氧诱导的sFlt-1、sEng、sVCAM-1和sICAM-1表达增加可被15-LOX-siRNA抑制和15-HETE诱导。同时p38MAPK抑制剂(SB)可抑制缺氧诱导的相关因子的表达，而15-HETE不能逆转SB对sFlt-1、sEng、sVCAM-1表达的影响，揭示缺氧通过15-LOX/15-HETE调控p38MAPK通路，调节sFlt-1、sEng、sVCAM-1的表达，参与缺氧诱导内皮细胞损伤的过程；4.子痫前期PE模型鼠中胎盘组织中15-LOX/15-HETE表达显著增加，从动物水平揭示了15-LOX/15-HETE参与子痫前期的病理机制中。因此，本项目系统阐明了15-LOX/15-HETE通路参与缺氧诱导子痫前期内皮细胞损伤的病理机制，将为PE机制深入阐明及干预策略寻找提供重要的实验依据。