Characterization of Pancreatic Disease in a Novel Porcine Cystic Fibrosis Model

描述(申请人提供)：在大多数囊性纤维化(CF)患者中，胰腺受累很常见，损伤进展为胰腺功能不全(PI)。目前，还没有阻止胰腺疾病进展的治疗方法，导致胰腺破坏的确切机制也不是很清楚。到目前为止，两大障碍是人类无法获得胰腺，以及缺乏合适的动物模型。我们培育的猪(Sus Scrofa)具有囊性纤维化跨膜传导调节因子(CFTR)等位基因的靶向性干扰。这些动物的胰腺病变与人类CF的病变明显相似，它们的胰腺炎症细胞数量增加，促炎细胞因子IL-8水平更高。本项目的目标是充分描述CFTR-/-猪胰腺的解剖和生理特征，并利用从该模型获得的数据来阐明CFTR-/-猪胰腺疾病的病理生理机制。我们计划通过以下具体目标来实现我们的目标：(1)确定CFTR-/-猪胰腺外分泌病变的个体发生；(2)确定CFTR在体内和体外调节胰腺外分泌功能中的作用。第一个目的是验证假设，即胰腺疾病在CF开始于子宫内的腺泡堵塞，并随着时间的推移发展到腺泡细胞萎缩、导管扩张、粘液细胞化生和纤维化。将利用组织病理学、酶表达、胰腺细胞标志物和微阵列基因图谱来表征新的猪CF模型的解剖起源、疾病进展和病理生理特征。我们将探讨炎症对胰腺病变发生和发展的影响。第二个目标将检验CFTR直接参与胰腺Cl-和HCO3-分泌的假设。在体内(分析粪便脂肪和胰凝乳酶；收集胰液)和体外(原代培养的猪导管上皮细胞培养)中，将使用CFTR-/-和CFTR+/+猪来确定CFTR在调节猪的外分泌胰腺功能中的作用。本应用的目的是研究我们新建立的猪CF模型的胰腺病理生理学，并更好地了解导致胰腺参与CF的病理生理学机制。我们的长期目标是设计创新的治疗方法，以保护胰腺功能，并改善CF患者的生活质量、生长迟缓和营养不良。公共卫生相关性：在大多数囊性纤维化(CF)患者中，胰腺受累很常见，损伤进展为胰腺功能不全(PI)。目前，还没有阻止胰腺疾病进展的治疗方法，导致胰腺破坏的确切机制也不是很清楚。这项应用的目的是为了充分描述我们新的CF猪模型中胰腺受累的特征，并更好地了解导致CF中PI的病理生理学机制。

DESCRIPTION (provided by applicant): Pancreatic involvement is common and the injury progresses to pancreatic insufficiency (PI) in the majority of patients with cystic fibrosis (CF). Currently, there are no treatments to halt the progression of pancreatic disease in CF and the exact mechanisms leading to the destruction of pancreas are not well-understood. Two major obstacles until now have been inaccessibility of the pancreas in humans and lack of a suitable animal model. We produced pigs (Sus scrofa) with a targeted disruption of both cystic fibrosis transmembrane conductance regulator (CFTR) alleles. These animals had pancreatic lesions markedly similar to those found in humans with CF and their pancreas had an increased number of inflammatory cells and higher levels of a proinflammatory cytokine, IL-8. The goal of this project is to fully characterize the anatomical and physiological features of CFTR-/- pig pancreas and to utilize the data obtained from this model to shed light on the pathophysiology of pancreatic disease in humans with CF. We plan to reach our goal with the following Specific Aims: (1) determine the ontogeny of exocrine pancreatic lesions in CFTR-/- pigs; and (2) determine the role of CFTR in regulating exocrine pancreatic function in vivo and in vitro. The first aim will test the hypothesis that pancreatic disease in CF starts as acinar plugs in utero and progresses over time to acinar cell atrophy, duct dilatation, mucous cell metaplasia and fibrosis. The anatomical origins, disease progression and pathophysiological features of the novel porcine model of CF will be characterized using histopathology, enzyme expression, pancreatic cell markers and microarray gene profiling. The impact of inflammation on the development and progression of the pancreatic lesions will be explored. The second aim will test the hypothesis that CFTR is directly involved in pancreatic Cl- and HCO3- secretion. The role of CFTR in regulating the exocrine pancreatic function of pigs will be determined in vivo (analysis of fecal fat and chymotrypsin; collection of pancreatic fluid) and in vitro (primary porcine ductular epithelial cell cultures) using CFTR-/- and CFTR+/+ pigs. The objective of this application is to study the pancreatic pathophysiology in our novel swine model of CF and to better understand the pathophysiological mechanisms leading to pancreatic involvement in CF. Our long-term goal is to design innovative therapies to preserve pancreatic function and improve the quality of life, growth delay and malnutrition in CF. PUBLIC HEALTH RELEVANCE: Pancreatic involvement is common and the injury progresses to pancreatic insufficiency (PI) in the majority of patients with cystic fibrosis (CF). Currently, there are no treatments to halt the progression of pancreatic disease in CF and the exact mechanisms leading to the destruction of pancreas are not well-understood. The goal of this application is to fully characterize pancreatic involvement in our novel CF pig model and to better understand the pathophysiological mechanisms leading to PI in CF.