ADAM17介导血管内皮损伤相关因子剪切在子痫前期发病中的机制研究

Preeclampsia is a serious pregnancy complication, Although the exact pathogenesis of this disorder remains largely elusive, it is certain that vascular endothelial dysfunction is the key event of this pregnancy-specific disease. Our preliminary studies have demonstrated that plasma sAxl can be involved in the pathogenesis of preeclampsia by mediating vascular endothelial dysfunction, just as sFlt-1. However, it is not clear that the mechanism of increased circulation factors which are related with vascular endothelial dysfunction. Furthermore, our previous studies have also found that ADAM17 is highly expressed in placenta of preeclampsia, and it has been confirmed that ADAM17 may be involved in the cleavage of Axl and Flt-1, which suggest that ADAM17 can mediate the cleavage of Axl and Flt-1 and result in the onset of preeclampsia by vascular endothelial dysfunction. Therefore, this project is designed to verify the specific role of ADAM17 during the cleavage. Firstly, a case control study is performed to identify the relationship between the ADAM17 level and some of key molecules involved in the placental vascular endothelial dysfunction. Secondly, an experiment in vitro is conducted to examine the induced the vascular endothelial dysfunction via mediating the cleavage of Axl and Flt-1. Thirdly, an animal model is established to verify the hypothesis. Overall, the results of the present project will reveal the mechanism of ADAM17 affect the pathogenesis of preeclampsia by regulating Axl and Flt-1 cleavage, and develop a new target for prevention and management of this disease.

子痫前期是严重的妊娠并发症，发病机制亟待阐明，目前公认血管内皮损伤是其发病中心环节。前期研究发现子痫前期患者血浆中sAxl与sFlt-1类似，可通过介导血管内皮细胞损伤参与子痫前期的病理过程，但目前尚不清楚此类血管内皮细胞损伤因子增多的机制。课题组前期研究还发现子痫前期患者胎盘组织中存在ADAM17高表达，且已有研究证实ADAM17可能参与了Axl和Flt-1的剪切作用，提示ADAM17可能通过介导Axl及Flt-1的剪切过程参与子痫前期的发病。本研究拟从ADAM17这一全新角度，探索其可能影响血管内皮损伤相关因子剪切的机制，通过临床研究检测相关分子的表达、细胞学实验研究滋养细胞过表达ADAM17后介导Axl及Flt-1的剪切引的起血管内皮细胞损伤过程、动物体内构建子痫前期模型验证假说，最终揭示ADAM17通过调节Axl及Flt-1的剪切从而影响子痫前期发病的机制，为其防治提供新思路。

子痫前期是严重的妊娠并发症，发病机制亟待阐明，目前公认血管内皮损伤是其发病中心环节。普遍认为其发病与循环中上调的抗血管生成因子引起的全身血管内皮细胞的活化和破坏有关，从而导致多种临床表现。.前期研究发现，sAxl作为Axl的细胞外段，在子痫前期患者中出现循环高水平，而血浆sAxl 浓度与血压、24 小时尿蛋白、母体尿液病理管型浓度和新生儿出生体重有显著相关性。但是，触发sAxl升高的机制及其是否会影响血管内皮的结构和功能尚不清楚。目前的研究表明，子痫前期的胎盘组织中ADAM17升高，并且在其他疾病中发现它通过剪切Axl胞外域来参与疾病的发生发展。因此我们推测ADAM17可能在滋养细胞中剪切Axl，将sAxl释放到母体循环中，并影响血管内皮细胞的功能。在本研究中，我们比较了ADAM17和Axl在健康妊娠胎盘和先兆子痫胎盘中的表达，然后通过PMA激活了滋养细胞细胞系中的ADAM17，以研究ADAM17和Axl之间的相互作用。随后通过间接共培养观察活化的ADAM17滋养细胞对血管内皮细胞功能的影响，最后通过蛋白质谱分析人血管生成微整列，探索可能与ADAM17诱导的血管生成作用有关的细胞因子。.我们的结果表明子痫前期患者滋养细胞的ADAM17与Axl的高表达；此外体外实验证实滋养细胞中ADAM17 与Axl存在相互作用，但单纯缺氧不能改变其表达及相互作用；同时体内实验证实缺血缺氧不会引起ADAM17 的高表达；激活ADAM17使滋养细胞Axl胞外段剪切（sAxl）增加；通过间接共培养证实激活ADAM17的Htr8细胞上清液中的细胞因子可以显着促进HUVEC的增殖、迁移及血管生成，但表达增加的sAxl表现为抗血管作用；通过蛋白质谱分析人血管生成微整列，提示MCP-1，MMP-9，GM-CSF，IL-8，IL-1β，Serpin B5等六种因子在Htr8细胞上清液和HUVEC裂解物中均显著增加，推测这些因子可能与ADAM17诱导的血管生成作用有关。