NSP4 stimulated ion channels and age-dependent diarrhea

NSP4 刺激离子通道和年龄依赖性腹泻

• 批准号: 6438335
• 负责人: ANDREW Paul MORRIS
• 金额: $ 23.86万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-15 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6438335
• 关键词: Rotavirus; age difference; calcium ion; cell line; chloride channels; diarrhea; gastrointestinal absorption /transport; infant animal; laboratory mouse; mature animal; molecular pathology; secretion; virulence; virus protein

DESCRIPTION (provided by applicant): Rotaviruses are a major cause of life-threatening diarrhea in infants and children worldwide. Following viral infection, diarrhea is seen associated with pathophysiological changes in mucosal fluid and electrolyte balance. My group has focused on defining a new pathophysiological component to diarrhea. We have shown that a rotaviral non-structural protein called NSP4 induces diarrhea in both normal and cystic fibrosis mouse pups accompanied by calcium-sensitive chloride secretory current generation by gastrointestinal mucosa. Neither diarrhea nor anion secretion occur in adult mice. At the sub-cellular level, NSP4 causes phospholipase C sensitive intracellular calcium (Ca2+)i mobilization and calcium-sensitive halide influx into mucosal crypts. NSP4-induced (Ca2+)i mobilization (our assay for receptor occupancy) is not age-dependent. Thus, we hypothesize that NSP4 activates and age-dependent calcium-sensitive chloride channel in pup mucosa causing chloride secretion, and secretory diarrhea. We propose studies in native cells to identify and characterize the electrophysiological and pharmacological properties of the chloride channel, and thus unequivocally demonstrate a role for this conductance in NSP4 mediated age-dependent cellular halide influx. We intend to identify the cellular signaling mechanisms coupling NSP4 mediated changes in (Ca2+)i to this conductance. These mechanistic studies may identify novel targets for pharmacological intervention with clear clinical relevance. These goals will provide the cellular basis for the age-dependent secretory diarrhea and may identify a molecular target for rotaviral-induced transepithelial anion secretion. They will also translate facts established for the biophysics of calcium-activated chloride channel expression in cultured epithelial cell-lines into the fields of clinical medicine and disease. In doing so, our results will provide an excellent possibility for development of new therapies for rotaviral gastroenteritis, and for other infectious diseases in children where altered mucosal (Ca2+)i homeostasis occurs.

描述（由申请人提供）：轮状病毒是导致 全世界婴儿和儿童都患有危及生命的腹泻。病毒式传播后 感染、腹泻与病理生理变化有关 粘膜液体和电解质平衡。我的团队致力于定义一个新的 腹泻的病理生理学成分。我们已经证明，轮状病毒 称为 NSP4 的非结构蛋白可诱导正常和囊性腹泻 纤维化幼鼠伴有钙敏感氯离子分泌电流 由胃肠粘膜产生。既不腹泻也不分泌阴离子 发生在成年小鼠身上。在亚细胞水平，NSP4 引起磷脂酶 C 敏感的细胞内钙 (Ca2+)i 动员和钙敏感 卤化物流入粘膜隐窝。 NSP4 诱导的 (Ca2+)i 动员（我们的测定 对于受体占用）不依赖于年龄。因此，我们假设 NSP4 激活幼犬粘膜中年龄依赖性钙敏感氯离子通道 引起氯化物分泌和分泌性腹泻。我们建议研究 天然细胞识别和表征电生理和 氯离子通道的药理学特性，因此明确 证明了这种电导在 NSP4 介导的年龄依赖性细胞中的作用 卤化物流入。我们打算确定细胞信号传导机制耦合 NSP4 介导 (Ca2+)i 对此电导的变化。这些机制研究 可以确定具有明确临床意义的药物干预新靶点 关联。这些目标将为年龄依赖性提供细胞基础 分泌性腹泻，并可能确定轮状病毒诱导的分子靶标 跨上皮阴离子分泌。他们还将翻译为以下目的建立的事实： 培养物中钙激活氯离子通道表达的生物物理学 上皮细胞系进入临床医学和疾病领域。在 这样做，我们的成果将为发展提供极好的可能性 轮状病毒性胃肠炎和其他传染病的新疗法 粘膜 (Ca2+)i 稳态发生改变的儿童。