SECRETORY FUNCTION OF PANCREATIC DUCT CELLS

胰管细胞的分泌功能

• 批准号: 6342547
• 负责人: TOAN D. NGUYEN
• 金额: $ 16.1万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6342547
• 关键词: adenosine triphosphate; autocrine; bicarbonates; chloride channels; cyclic AMP; dogs; exocytosis; human tissue; mast cell; mucins; pancreatic duct; paracrine; protein localization; purinergic receptor; secretion

Over the last few years, we have successfully used a model of cultured non-transformed dog pancreatic duct epithelial cells (PDEC) to study the determinants of pancreatic ductal secretion and characterize different cellular receptors on these cells. In this revised submission, we propose to characterize further the regulation of pancreatic ductal cell secretion by ATP. Hypothesis 1: ATP regulates PDEC secretion through cAMP (in addition to the Ca2+ pathway). We previously reported that ATP and UTP interact with P2Y2 receptors on PDEC to mobilize Ca2+ and stimulate secretion. We recently obtained preliminary data suggesting that ATP interacts with an additional purinergic receptor (from now referred to as P2Y[unk]) to increase intracellular cAMP and stimulate PDEC secretion. Thus, we propose to: a) further define the stimulation of cAMP increase produced by ATP and other nucleotides, b) elucidate the effect of ATP on Cl- channels mediated by the cAMP pathway, c) investigate ATP effects on HCO3- secretion, and d) examine the cAMP-mediated effect of ATP on mucin secretion and exocytosis. Hypothesis 2: ATP has a paracrine and autocrine action on PDEC secretion, through the P2Y2 and P2Y[unk] receptors. P2Y2 receptors, acting via increased [Ca2+]i, are present on both apical and basolateral surfaces of PDEC; preliminary evidence suggest that the P2Y[unk] receptor, acting via cAMP, are confined to the basolateral surface of these cells. These distinct receptors, with separate localization and coupled to different signal transduction pathways, may mediate paracrine and autocrine actions of ATP. Thus we propose to: a) characterize the subtype and confirm the localization of the P2Y[unk] receptor. b) characterize the vectorial release of ATP release from PDEC (autocrine action) c) study the effect of mast cell degranulation, resulting in ATP release, on PDEC secretion (paracrine action).

在过去的几年中，我们成功地使用了培养的非转化狗胰管上皮细胞（PDEC）的模型来研究胰管分泌的决定因素，并在这些细胞上表征了不同的细胞受体。在此修订后的提交中，我们建议进一步表征ATP对胰管细胞分泌的调节。假设1：ATP通过cAMP调节PDEC分泌（除了CA2+途径）。 我们先前报道说，ATP和UTP与PDEC上的P2Y2受体相互作用，以动员Ca2+并刺激分泌。 我们最近获得了初步数据，表明ATP与其他嘌呤能受体相互作用（从现在称为P2Y [UNK]）以增加细胞内cAMP并刺激PDEC分泌。 因此，我们建议：a）进一步定义ATP和其他核苷酸产生的CAMP刺激，b）阐明ATP对cAMP途径介导的CL-通道的影响，c）C）研究ATP对HCO3分泌的作用，d）检查ATP介导的ATP对ATP的cAMP介绍对ATP的影响对ATP的影响对ATP的效果对粘液分泌和外生细胞的影响。 假设2：ATP通过P2Y2和P2Y [UNK]受体具有对PDEC分泌的旁分泌和自分泌作用。 P2Y2受体通过增加的[Ca2+] I作用在PDEC的顶端和基底外侧表面上。初步证据表明，P2Y [UNK]受体通过CAMP作用，仅限于这些细胞的基底外侧表面。 这些不同的受体，具有单独的定位并与不同的信号转导途径结合，可以介导ATP的旁分泌和自分泌作用。 因此，我们建议：a）表征亚型并确认P2Y [UNK]受体的定位。 b）表征从PDEC释放ATP（自分泌作用）c）c）研究肥大细胞脱粒的影响，导致ATP释放，对PDEC分泌（旁分泌作用）。