Functional analyses of mutations in transcription factors associated to chronic pancreatitis

慢性胰腺炎(CP)是一种以反复发作的疼痛、不可逆的形态改变和胰腺内外分泌功能受损为特征的胰腺炎症性疾病。因此，患者会出现消化不良、脂肪泻和糖尿病。然而，长期CP患者最严重的并发症是胰腺癌的发展。到目前为止，与CP相关的11个基因或遗传位点的遗传缺陷已被确定。到目前为止，所有已知的易感基因在我们的儿科队列中只占遗传性的50%。因此，必须存在几个进一步的致病基因。为了识别这些基因，我们在德国发现的550名CP患者和600名欧洲复制队列的CP患者中进行了完整的外显子组测序(WES)。除了已知的易感基因外，我们还发现了几个潜在的CP风险基因，其中三个代表(胰腺)转录因子。我们推测，编码RBPJL、HNF1A和NR5A2基因的WES变异会削弱蛋白质-DNA结合能力、转录因子复合体的蛋白质-蛋白质相互作用、核定位或转录活性，从而最终损害内源性靶基因的表达。在这个项目中，我们将详细描述所发现的突变的功能影响。鉴于所有三种转录因子对胰腺细胞的识别、完整性和许多腺泡细胞特异性基因的调节的重要性，这些突变可能会对胰腺的动态平衡产生巨大的影响。除了有助于深入揭示胰腺炎的遗传遗传性外，我们的结果还可能进一步指导人们对胰腺炎甚至胰腺癌的确切病理条件的理解。

Chronic pancreatitis (CP) is an inflammatory disease of the pancreas characterized by recurrent agonizing pain, irreversible morphological changes, and impairment of exocrine and endocrine pancreatic function. As a consequence, patients develop maldigestion, steatorrhea and diabetes mellitus. The most serious complication in patients with long-lasting CP, however, is the development of pancreatic cancer.So far, genetic defects in eleven genes or genetic loci, respectively, associated to CP have been identified. All known susceptibility genes to date account for only 50% of hereditability in our paediatric cohort. Thus, several further disease causing genes have to exist. To identify these genes, we performed whole exome sequencing (WES) in a German discovery cohort of 550 CP patients and in a European replication cohort of 600 CP patients.Besides known susceptibility genes, we found several potential CP risk genes, three of them represent (pancreatic) transcription factors. We hypothesize that variants identified by WES in the genes encoding RBPJL, HNF1A and NR5A2 impair protein-DNA binding capacity, protein-protein interaction of transcription factor complexes, nuclear localization or transcriptional activity, and thus finally endogenous target gene expression. In this project, we will characterize the functional effects of the mutations found in detail.Given the importance of all three transcription factors for pancreatic cell identity, integrity and regulation of numerous acinar cell specific genes, these mutations might have a huge impact on pancreas homeostasis. Besides contributing to in-depth uncovering genetic heritability of pancreatitis, our results may additionally guide further understanding of the precise pathological conditions of pancreatitis and even pancreatic cancer.