The Role of Trypsin in Pancreatitis

该提案的中心目标是建立和表征急性和慢性炎症的新模型， 胰腺炎通过直接腺泡内细胞胰蛋白酶原激活。胰蛋白酶原的最新发现， 遗传性胰腺炎患者中胰蛋白酶抑制剂突变支持以下假设： 胰腺酶原对胰腺内活性酶的不适当激活启动了 炎症过程。因此，胰蛋白酶的过早活化被认为是胰蛋白酶活性的初始步骤。 胰腺炎的发展。然而，目前的急性胰腺炎动物模型涉及治疗 它具有许多非特异性作用，除了激活细胞外， 胰蛋白酶慢性胰腺炎的情况更不清楚，因为没有可靠的动物模型 这种疾病。具体目标#1是通过在胰腺内直接激活胰蛋白酶来诱导急性胰腺炎。 大鼠胰腺腺泡细胞。我们将首先使用腺病毒介导的基因转移到大鼠 胰腺的突变胰蛋白酶原（AdPACE-TRY），我们开发，并已证明成为 在腺泡细胞内被激活。我们假设，这种病毒在体内传递到胰腺， 激活胰蛋白酶从而引发胰腺炎。具体目标#2是确定细胞内是否 胰蛋白酶诱导NF-κ B活化以及NF-κ B在胰蛋白酶诱导的急性胰腺炎中的作用。 先前已经证明NF-κ B活化不引起胰蛋白酶原活化。在这里，我们将测试，如果 腺泡细胞内的胰蛋白酶活性可以使用AdPACE-TRY激活胰蛋白酶来激活NF-κ B 并研究相关机制。我们将进一步研究 胰蛋白酶激活NF-κ B在炎症级联反应的启动中的作用 表达kB-cc的腺病毒，其将阻断NF-κ B活化。具体目标#3是建立一个 通过直接调节腺泡内胰蛋白酶活性，建立慢性胰腺炎模型。我们将创建一个 通过直接调节腺泡内胰蛋白酶活性，建立慢性胰腺炎模型。为此， 弹性蛋白酶启动子驱动的他莫昔芬可调控的Cre-Er转基因小鼠将与loxP- GFP侧翼的PACE-TRY转基因小鼠。他莫昔芬激活Cre， 允许活性胰蛋白酶表达的序列。我们认为大剂量的他莫昔芬 诱导高胰蛋白酶活性并因此引起严重急性胰腺炎，而低剂量他莫昔芬将 引起部分胰腺损伤和长期胰腺损伤， 胰腺炎

The central goal of this proposal is to establish and characterize novel models of acute and chronic pancreatitis by direct intra-acinar cell trypsinogen activation. Recent discoveries of trypsinogen and trypsin inhibitor mutations in patients with hereditary pancreatitis support the hypothesis that an inappropriate activation of pancreatic zymogens to active enzymes within the pancreas starts the inflammatory process. Thus premature activation of trypsin is believed to be the initial step in the development of pancreatitis. However, current animal models of acute pancreatitis involve treatments that have many non-specific effects and trigger numerous signaling pathways in addition to activating trypsin. The situation for chronic pancreatitis is even less clear, as there are no reliable animal models of this disease. Specific aim #1 is to induce acute pancreatitis by direct trypsin activation within pancreatic acinar cells in rats. We will initially use adenoviral mediated gene transfer into the rat pancreas of a mutant trypsinogen (AdPACE-TRY) which we developed and have shown to become activated within the acinar cells. We hypothesize that delivery of this virus to the pancreas in vivo will active trypsin and thereby initiate pancreatitis. Specific aim #2 is to determine whether intracellular trypsin induces NF-KB activation and the role of NF-KB in trypsin induced acute pancreatitis.We have previously shown that NF-KB activation does not cause trypsinogen activation. Here we will test if trypsin activity within the acinar cell can activate NF-KB using AdPACE-TRY to activate trypsin intracellularly and investigate the mechanisms involved. We will further examine the importance of trypsin activation of NF-KB in the initiation of the inflammatory cascade by co-administering an adenovirus expressing kB-cc which will block NF-KB activation. Specific aim #3 is to establish a chronic pancreatitis model by directly regulating intra-acinar trypsin activity. Wewill create a chronic pancreatitis model by directly regulating intra-acinar trypsin activity. For this purpose, an elastase promoter driven tamoxifen regulatable Cre-Er transgenic mouse will be crossed with a loxP- GFP flanked PACE-TRY transgenic mouse. Tamoxifen activation of Cre will then remove a stop sequence allowing the expression of the active trypsin. We expect that a high dose tamoxifen will induce high trypsin activity and thus cause severe acute pancreatitis and that a low dose tamoxifen will induce partially pancreatic injury and prolonged pancreatic damage that will result in chronic pancreatitis.