MECHANISMS OF BILE PIGMENT EXCRETION

胆色素排泄机制

• 批准号: 2139615
• 负责人: IRWIN Monroe ARIAS
• 金额: $ 43.64万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-12-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2139615
• 关键词: bile pigments; biological transport; cholanate compound; cholestasis; fluorescent dye /probe; fungal genetics; immunocytochemistry; in situ hybridization; laboratory rat; lipid transport; liver cells; liver metabolism; membrane transport proteins; molecular cloning; phospholipids; protein purification; protein sequence; protein structure function; purines; transfection; yeasts

Using molecular, cell biologic, biochemical and immunomorphologic methods, we request to continue long range studies of mechanisms involved in the transfer of various organic molecules (i.e., bile acids, pigments, drugs, metabolites and others) from blood to bile and back. In particular, we seek to determine the structure, function and regulation of four bile canalicular transporters and, ultimately, their dysfunction in developmental, acquired and inheritable cholestasis: (a) Cloning, sequencing and purification of the ATP-dependent transporters for bile acids and nonbile acid organic anions in mutant budding and fisson yeast in order to generate probes for identifying and studying structure and regulation of the mammalian homologues (which, due to low abundance, have frustrated efforts at purification and cloning). (b) Preliminary evidence suggests that mdr2, the major multidrug resistance gene product in the canaliculus, has ATP-dependent phospholipid translocase activity and increases phospholipid release from cell plasma membranes. Therefore, we seek to determine how these processes are related with respect to canalicular phospholipid transport, and the possible role of mdr2 in the "vanishing bile duct syndrome". (c) Cloning, sequencing and study of the regulation of the canalicular Na+ dependent purine transporter which conserves nucleosides in hepatocytes.

使用分子、细胞生物学、生化和免疫形态学方法， 我们要求继续对涉及的机制进行长期研究 各种有机分子（即胆汁酸、色素、药物、 代谢物和其他）从血液到胆汁再返回。 特别是，我们寻求确定结构、功能和监管 四种胆小管转运蛋白及其最终功能障碍 在发育性、获得性和遗传性胆汁淤积中： (a) ATP依赖性转运蛋白的克隆、测序和纯化 对于突变体出芽中的胆汁酸和非胆汁酸有机阴离子 裂殖酵母以产生用于识别和研究的探针 哺乳动物同源物的结构和调节（由于低 丰富，挫败了纯化和克隆的努力）。 (b) 初步证据表明，主要的多药耐药性 MDR2 小管中的抗性基因产物，具有 ATP 依赖性磷脂 转位酶活性并增加细胞浆中磷脂的释放 膜。 因此，我们试图确定这些过程是如何进行的 与小管磷脂运输有关，以及 mdr2 在“胆管消失综合征”中可能发挥的作用。 (c) 小管Na+调控的克隆、测序和研究 依赖嘌呤转运蛋白，在肝细胞中保存核苷。