Proteomics of Pancreatic Fluid and Urine in Chronic Pancreatitis

描述(申请人提供)：慢性胰腺炎(CP)是一种渐进性衰弱的疾病，只有中等到高级的诊断是可能的。此外，在CP的怀疑下对慢性腹痛进行评估，每年导致数百万美元的医疗费用和工资损失。慢性胰腺炎的特征是慢性炎症和进行性瘢痕形成，导致胰腺不可逆转的损害，导致外分泌和内分泌功能丧失，在某些情况下还会导致胰腺癌。由于我们对疾病缺乏了解，早期和轻度疾病的影像研究中很少有形态学改变，所以在治疗窗口内诊断CP仍然是难以捉摸的。对CP发病机制的认识是早期诊断的关键。此外，以炎症为重点的基于病理生理学的治疗可以改变或延缓疾病的进展。我在这项研究提案中提出的与健康相关的主题是：(1)CP的发病机制目前尚不清楚，(2)CP的临床诊断只能检测到中到高度的疾病。我假设CP特异的蛋白质可以通过全面的、定量的胰液蛋白质组图谱(PF)来识别，并且胰腺蛋白质分泌组的这种扰动反映在排泄的尿液中。在特定目标1(SA1)中，我将确定PF中的炎性蛋白是否具有病因学特异性。使用定量质谱仪，我们将评估6种不同病因的晚期CP和一个非疾病对照组的PF，并比较炎性蛋白谱，以生成用于特定目的2(SA2)的包含列表。这份蛋白质清单将在SA2中使用两个大的队列进行验证：(1)非胰腺疾病和(2)有不同程度胰腺功能缺陷的CP。这些结果对评估在SA1中发现的蛋白质用于诊断应用的价值将是重要的。在特定目标3(SA3)中，我将使用直接定量质谱法研究CP受试者尿中的炎症相关蛋白。我推测，在SA1中发现并在SA2中验证的蛋白质也可以在SA3的尿中识别出来。使用本文概述的策略确定的CP特异性炎症相关蛋白将来自：(1)胰液--一种近端体液，非常适合研究胰腺功能障碍的生理途径；(2)尿液--一种非常适合临床诊断的非侵入性收集体液。虽然在PF中有许多种类的蛋白质可以用蛋白质组学来研究，但我选择专注于炎性蛋白质，因为表征它们的表达可能具有诊断和治疗意义。为了符合NIDDK的使命，我的目标是确定不同组CP特异性炎症蛋白的身份、相对数量、细胞来源和分子功能，长期目标是(1)了解CP与病因学相关的炎症蛋白反应，(2)识别候选诊断标记物，以及(3)发现定向治疗的靶点。

DESCRIPTION (provided by applicant): Chronic pancreatitis (CP) is a progressively debilitating disease for which only moderate to advanced diagnosis is possible. In addition, the evaluation of chronic abdominal pain under the suspicion of CP results in millions of dollars in healthcare costs and lost wages annually. CP is characterized by chronic inflammation and progressive scarring leading to irreversible damage to the pancreas, resulting in loss of exocrine and endocrine function and in some cases pancreas carcinoma. The diagnosis of CP within a "therapeutic window" has remained elusive due to our poor understanding of the disease and scarce morphological changes on imaging studies in early and mild disease. The understanding of CP pathogenesis is paramount in early diagnosis. Furthermore, pathophysiology based therapy focused on inflammation could modify or retard disease progression. The health-related topics that I address in this research proposal are: (1) CP pathogenesis is currently poorly understood and (2) clinical diagnosis of CP detects only moderate to advanced disease. I hypothesize that CP-specific proteins can be identified by comprehensive, quantitative proteomic profiling of pancreatic fluid (PF) and that such perturbations of the pancreatic protein secretome is reflected in excreted urine. In Specific Aim 1 (SA1), I will determine if inflammatory proteins in PF are etiology-specific. Using quantitative mass spectrometry, we will evaluate the PF from 6 different etiologies of advanced CP, plus a non-diseased control group and compare the inflammatory protein profile to generate an inclusion list to be used in Specific Aim 2 (SA2). This list of proteins will be validated in SA2 using two large cohorts (1) non-pancreatic disease and (2) CP with varying degrees of pancreatic deficiency. These results will be important in assessing the value of the proteins discovered in SA1 for diagnostic applications. In Specific Aim 3 (SA3), I will investigate inflammation-related proteins in the urine of CP subjects using directed quantitative mass spectrometry. I hypothesize that proteins discovered in SA1 and validated in SA2 can also be identified in urine in SA3. CP- specific, inflammatory-related proteins identified using the strategy outlined herein will originate from: (1) Pancreatic fluid-a proximal body fluid which is ideal for investigation of physiological pathways of pancreatic dysfunction and (2) Urine-a noninvasively collected fluid that is well-suited for clinical diagnostics. While there are many classes of proteins that can be investigated with proteomics in PF, I chose to focus on inflammatory proteins because characterization of their expression may have both diagnostic and therapeutic implications. In conforming with the mission of the NIDDK, I aim to determine the identity, relative quantity, cellular origin, and molecular function of distinct sets of CP-specific, inflammatory proteins with the long-term goals of (1) understanding the inflammatory protein response of CP with respect to etiology, (2) identifying candidate diagnostic markers, and (3) discovering targets for directed therapy.