Dietary Regulation of Pancreatic Digestive Enzymes

胰腺消化酶的饮食调节

• 批准号: 7760631
• 负责人: JOHN A WILLIAMS
• 金额: $ 36.09万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-21 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7760631
• 关键词: Acinar Cell; Acinus organ component; Acute; Address; Adenovirus Vector; Adherent Culture; Adult; Attention; Caerulein; Calcineurin; Calcium; Cell Cycle; Cell Cycle Regulation; Cell Lineage; Cell division; Cells; Cholecystokinin; Chronic; Collagen; Cyclin D1; Diet; ERG gene; Ensure; Enzymes; Ethionine; Exocrine pancreas; Extracellular Signal Regulated Kinases; FOS gene; Family member; Feedback; Gene Expression; Gene Proteins; Gene Targeting; Genes; Growth; Growth Factor; Hormonal; Hormones; Human; In Vitro; Individual; Injury; JUN gene; Knowledge; Lead; MAPK8 gene; MEKs; Malignant neoplasm of pancreas; Mediating; Mitogen-Activated Protein Kinases; Modeling; Mus; Natural regeneration; Pancreas; Pancreatic Diseases; Pancreatitis; Pathway interactions; Pattern; Plasma; Protease Inhibitor; Proteins; Regulation; Regulatory Pathway; Role; Signal Pathway; Small Interfering RNA; Stimulation of Cell Proliferation; Techniques; Tissues; Transcription Factor AP-1; Transgenic Mice; Work; camostate; chronic pancreatitis; design; extracellular; feeding; human FRAP1 protein; in vitro Model; in vivo; inhibitor/antagonist; inorganic phosphate; loss of function; protein expression; public health relevance; response

DESCRIPTION (provided by applicant): The overall aim of this work is to understand how the growth of the adult pancreas is regulated to provide an adequate supply of digestive enzymes. We hypothesize that growth can occur by two mechanisms. The first occurs in response to diet and hormones and involves stimulation of differentiated acinar cells to enter the cell cycle and divide. The second form of growth that occurs following tissue injury such as pancreatitis involves dedifferentiation, cell division and dedifferentiation and will be referred to as regeneration. Our primary model for hormonal stimulation of growth involves feeding the synthetic protease inhibitor, camostat to mice to increase plasma CCK. We have shown this growth requires the calcium activated phosphates calcineurin and the mTOR pathway, and is accompanied by the activation of the MAP kinases, ERK and JNK, and the expression of a number of early response genes including multiple c-Jun and c-Fos family members. In Specific Aim 1 we will study the mechanisms mediating mitogenesis and growth of differentiated cells driven by chronic CCK elevation. a) We will identify the cell cycle regulators activated by CCK. b) We will study target genes regulated by NFATs (regulated by calcineurin) and AP-1 (activated by MAP kinases) with particular attention to regulation of cell-cycle regulating genes such as cyclin D1 and PCNA and to endogenous feedback inhibitors such as MClP1 for calcineurin. In Specific Aim 2 we will determine the mechanisms mediating regeneration after tissue injury. We will study regeneration following two models of pancreatitis induced by ethionine and caerulein over-stimulation. a) We will determine how the pattern of gene expression is altered in regeneration in the presence and absence of CCK using CCK deficient mice. b) We will determine the importance of calcineurin and mTOR for regeneration using both pharmacological inhibitors and gene targeted mice. In Specific Aim 3 we will determine the regulatory mechanisms for CCK and Growth Factor stimulated growth of acinar cells in primary monolayer culture which serves as a model for growth similar to regeneration and in which proteins and siRNA can be expressed with adenoviral vectors. We will first characterize the dedifferentiation and establish the acinar cell origin of dividing cells by lineage tracing. We will then evaluate the importance of different signaling pathways and cell cycle components with a focus on the key role of c-jun and AP1. Overall, the project will lead to better understanding of pancreatic growth and assist in designing approaches to regulating pancreatic growth in humans. PUBLIC HEALTH RELEVANCE: A number of pancreatic diseases including acute and chronic pancreatitis and pancreatic cancer lead to a loss of functioning pancreatic tissue. Knowledge from this project should allow designing approaches to assist the human pancreas to regenerate and ensure an adequate supply of pancreatic digestive enzymes.

描述（由申请人提供）：这项工作的总体目的是了解如何调节成年胰腺的生长以提供足够的消化酶供应。我们假设可以通过两种机制发生增长。第一次发生是响应饮食和激素，涉及分化腺泡细胞进入细胞周期和分裂的刺激。胰腺炎等组织损伤后发生的第二种生长形式涉及去分化，细胞分裂和去分化，并将其称为再生。我们的激素刺激生长的主要模型涉及喂食合成蛋白酶抑制剂，camostat至小鼠增加血浆CCK。我们已经表明，这种生长需要钙激活的磷酸盐钙调神经酶和MTOR途径，并伴随着MAP激酶，ERK和JNK的激活，以及许多早期反应基因的表达，包括多个C-JUN和C-FOS家族成员。在特定目的1中，我们将研究介导由慢性CCK升高驱动的分化细胞的介导的机制。 a）我们将确定由CCK激活的细胞周期调节剂。 b）我们将研究由NFAT（由钙调蛋白调节）和AP-1（由MAP激酶激活）调节的靶基因，特别注意调节细胞周期调节基因（例如Cyclin d1 and PCNA）和内源性反馈抑制剂（例如MCLP1）的钙调蛋白。在特定目标2中，我们将确定组织损伤后介导再生的机制。我们将在乙氨氨酸和塞林蛋白过度刺激引起的两个模型遵循两个模型的胰腺炎模型之后研究再生。 a）我们将确定使用CCK缺乏小鼠在CCK存在和不存在CCK的情况下，基因表达的模式如何改变。 b）我们将使用药理学抑制剂和基因靶向小鼠来确定钙调神经酶和mTOR对再生的重要性。在特定目标3中，我们将确定CCK和生长因子的调节机制刺激了原代单层培养物中腺泡细胞的生长，这是类似于再生的生长模型，其中蛋白质和siRNA可以用腺病毒载体表达。我们将首先表征去分化，并通过谱系跟踪来建立分裂细胞的腺泡细胞起源。然后，我们将评估不同信号通路和细胞周期成分的重要性，重点是C-JUN和AP1的关键作用。总体而言，该项目将使人们更好地了解胰腺生长，并有助于设计调节人类胰腺生长的方法。公共卫生相关性：许多胰腺疾病，包括急性和慢性胰腺炎以及胰腺癌，导致胰腺组织功能丧失。该项目的知识应允许设计方法来帮助人类胰腺再生并确保足够的胰腺消化酶供应。