Biological Basis of Phenotypes and Clinical Outcomes in Biliary Atresia

描述（由申请人提供）：这是一个竞争性的更新申请，建议对NIDDK-儿童肝病研究和教育网络（ChiLDREN）进行辅助研究。胆道闭锁是新生儿胆汁淤积症最常见的原因，由肝外胆管的纤维炎性阻塞引起。尽管几乎一致进展为终末期肝硬化，但对手术/药物治疗的可变反应和疾病进展速度表明存在未被识别的生物过程，这些生物过程驱动不同的疾病表型或阶段。在该奖项的第一个任期内，我们发现了树突状细胞和自然杀伤细胞在疾病致病机制中的证据，确定了ADD 3基因在疾病易感性中的作用，并产生了肝病炎症和纤维化阶段的基因表达特征，即使使用标准组织学标准，这些阶段也与临床结果有关。在这项应用的发现型初步研究中，我们定量了血清中的炎症生物标志物，并鉴定了对胆道闭锁高度特异性的蛋白质谱，并预测了对手术治疗的充分反应。这些数据构成了总体假设的基础，即与胆道损伤发病机制相关的肝脏和循环生物标志物是肝病诊断、分期和临床结局的预测因子。为了验证这个假设，我们 将创建一个数据集成平台，其中包含关键的临床、实验室和组织学数据，以及胆道闭锁患者以及患病和健康对照的基因（肝脏中）和蛋白质（血清中）的综合表达谱。我们将挖掘该平台以追求三个目标：1）定义诊断胆道闭锁时与临床结果相关的疾病阶段，2）确定生物学预测因子和对治疗的有利反应，以及3）发现组织纤维化的血清生物标志物和肝硬化的临床终点。目标1的实验将使用RNAseq生成全基因组表达数据集，以验证炎症和纤维化特征，并在诊断时对肝脏疾病进行分期，确定对类固醇治疗反应的分子预测因子，并研究疾病的新转录机制。目标2和3的实验将使用蛋白质多重技术来量化炎症和纤维化的血清生物标志物，并使用高度严格的统计模型来定义先前未识别的基于其生物组成（疾病阶段）的患者亚组，这些亚组可预测对标准手术、新药物治疗和门静脉高压进展的反应。通过应用高度互补的方法来研究来自已被ChiLDREN前瞻性表型化的足够大小的队列的组织，我们的实验将提供对未来临床试验和受影响儿童的护理如何基于疾病生物标志物进行个性化的见解。

DESCRIPTION (provided by applicant): This is a competing renewal application proposing ancillary studies to the NIDDK-Childhood Liver Disease Research and Education Network (ChiLDREN). Biliary atresia, the most common cause of neonatal cholestasis, results from a fibro-inflammatory obstruction of extrahepatic bile ducts. Despite nearly uniform progression to end-stage cirrhosis, the variable response to surgical/medical treatment and rate of progression of disease suggest the existence of unrecognized biological processes that are driving different phenotypes or stages of disease. In the first tenure of the award, we found evidence for dendritic and natural killer cells in pathogenic mechanisms of disease, identified a role for the ADD3 gene in susceptibility of disease, and generated a gene expression signature of inflammatory and fibrotic stages of liver disease at presentation, which have relationship to clinical outcome even when these stages are not present using standard histological criteria. In discovery-type preliminary studies for this application, we quantified inflammatory biomarkers in the serum and identified protein profiles that are highly specific for biliary atresia and predict adequate response to surgical treatment. These data form the foundation for the overall hypothesis that hepatic and circulating biomarkers linked to pathogenesis of biliary injury are predictors of diagnosis, stages of liver disease, and clinical outcome. To test this hypothesis, we will create a Data Integration Platform with key clinical, laboratory and histological data combined with comprehensive expression profiles for genes (in the liver) and protein (in the serum) of patients with biliary atresia and diseased- and healthy-controls. We will mine the platform to pursue three aims: 1) To define disease stages at diagnosis of biliary atresia with relevance to clinical outcome, 2) To identify biological predictors and favorable response to treatment, and 3) To discover serum biomarkers of tissue fibrosis and clinical end-points of cirrhosis. Experiments for Aim 1 will use RNAseq to generate whole-genome expression datasets to validate inflammatory and fibrotic signatures and stage the liver disease at diagnosis, identify molecular predictors of response to steroid treatment, and investigate new transcriptional mechanisms of disease. Experiments for Aims 2 and 3 will use protein-multiplexing technologies to quantify serum biomarkers of inflammation and fibrosis and highly stringent statistical models to define previously unrecognized subgroups of patients based on their biological makeup (stages of disease) that are predictive of response to standard surgery, new medical therapies, and progression of portal hypertension. By applying highly complementary approaches to study tissues from adequately sized cohorts that have been prospectively phenotyped by ChiLDREN, our experiments will provide insight into how future clinical trials and the care of affected children can be personalized based on biomarkers of disease.