重度支气管肺发育不良的遗传学研究和相关通路基因的功能分析

Bronchopulmonary dysplasia (BPD) is the most common complication of premature birth, among which severe BPD is of high mortality and poor prognosis. Multiple twin studies showed genetic factor is involved in the pathogenesis of BPD. Based on previous reports in literatures and our recent research findings, there exist different kinds of rare mutations in the genomes of severe BPD infants， and the highly heterogeneity of mutations in individual BPD patient suggests the possibility of multiple gene involvement. Therefore in-depth investigation of the whole genome of BPD cases is crucial for the identification of key candidate genes and pathways involved in BPD. In this study, we plan to perform the whole exome sequencing on severe BPD family with larger sample size in search for candidate genes and pathways participating in BPD pathogenesis along with RNA-Seq. Function studies of novel variations will be performed in vitro. The role of PI3K-AKT-mTOR pathway in BPD pathogenesis will be investigated with the high oxygen exposed BPD rat model and NGFR targeted mutant rat model. This study will help to elucidate the genetic mechanism of severe BPD and provide new ideas for the development of novel interventional methods of BPD.

支气管肺发育不良（BPD）是早产儿最常见的呼吸系统并发症，其中重度BPD的死亡率高，远期预后差。多项双胎研究显示，遗传因素参与了BPD的发生。文献报道和我们的前期研究提示，重度BPD患儿的基因组存在各种罕见变异，且个例BPD存在明显的基因变异的异质性和多基因参与的可能，针对BPD病例进行全基因组层面的深入研究有利于更全面地识别BPD的关键候选基因和信号通路。本课题拟扩大重度BPD核心家系量行全外显子组测序，结合转录组测序，寻找影响BPD发生的关键基因和信号通路；体外细胞水平对基因突变进行功能学验证；通过建立高氧暴露BPD大鼠模型和NGFR定点突变大鼠模型，研究PI3K-AKT-mTOR通路在BPD中的作用。本研究有助于识别出影响BPD发生发展的重要基因和通路，明确PI3K-AKT-mTOR通路在BPD中的作用，阐明重度BPD的遗传机制，为新防治手段的研发提供全新的思路。

通过建立245例早产儿出生队列，跟踪支气管肺发育不良（BPD）的发生及严重程度，同时进行外显子测序，使用课题组开发的NetBID算法结合公共数据库肺组织表达谱数据挖掘BPD发生相关遗传易感基因及失调信号通路，发现30个高可信度候选BPD风险基因，主要在ECM/integrin和PI3K-Akt相关通路上富集。并利用BPD高氧大鼠模型对候选基因及信号通路进行机制研究证实遗传病因的作用，同时结合候选BPD风险基因和临床危险因素建立BPD早期风险预测模型，结果显示有很好的预测BPD及重度BPD的效果。本研究为BPD的遗传作用提供了新的证据并首次证实了遗传因素对BPD及其严重程度的早期预测的贡献。