胎盘生物钟蛋白BHLHE41通过非泛素化依赖的蛋白酶体降解途径调控HIF-1α在子痫前期发病中的机制研究

最新证据提示子痫前期（PE）是一种胎盘生物节律紊乱性疾病，但分子机制不明。申请人前期发现生物钟基因BHLHE41全身性敲除孕鼠出现PE样征状，并伴随胎盘HIF-1α水平升高；分子机制实验提示BHLHE41不影响HIF-1α泛素化修饰。故提出科学假说：胎盘生物钟蛋白BHLHE41通过非泛素化依赖的蛋白酶体降解途径调控HIF-1α表达，参与PE发病过程。本项目拟①采用病例对照研究及分析公共数据库，阐明BHLHE41与子痫前期发病、严重程度及血压昼夜节律的相关性；②利用条件性基因敲除鼠阐明胎盘BHLHE41下调是PE发病及血压节律紊乱的重要因素；③在类器官及细胞水平上阐明BHLHE41对滋养细胞抗/促血管生成因子及自噬水平的影响；④在分子水平上证明BHLHE41通过非泛素化依赖的蛋白酶体降解途径调控HIF-1α。本项目首次从生物节律角度阐释PE发病机制，以期为该病精准诊疗提供新理论和新靶点。

Recent evidence suggests preeclampsia (PE) is a placental disorder of circadian rhythm; however, the molecular mechanism remains unknown. We have found that the pregnant BHLHE41-/- mice showed PE-like symptoms with the increased level of hypoxia inducing factor 1 alpha (HIF-1α) in placentae. Molecular experiments suggested that BHLHE41 did not affect HIF-1α ubiquitination. We hypothesize that placental clock protein BHLHE41 promoting degradation of HIF-1α by a ubiquitin-independent pathway, which is involved in the pathogenesis of PE. This study includes four parts: ① Analysis of the correlation between BHLHE41 and the severity of PE, and circadian rhythm of blood pressure using a case-control study; ② Elucidating that down-regulation of BHLHE41 in placenta is an important mechanism of PE pathogenesis using conditional BHLHE41 knockout mice; ③ Investigating the effects of BHLHE41 on autophagic regulation and placental angiogenic balance of trophoblast at cellular/organoid-level; ④Uncovering the mechanism that BHLHE41 down-regulates HIF-1α in a ubiquitin-independent proteasome manner. To the best of our knowledge, this project was the first to explain the pathogenesis of PE from the perspective of circadian clock, which will provide a new idea for the etiology of preeclampsia.