Intracellular calcium in the treatment of polycystic kidney and liver diseases

细胞内钙治疗多囊肾和肝病

• 批准号: 7737679
• 负责人: Sergio A Gradilone
• 金额: $ 7.56万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7737679
• 关键词: Affect; Age; Agonist; Animal Model; Autosomal Dominant Polycystic Kidney; Autosomal Recessive Polycystic Kidney; Calcium; Cell Line; Cell Proliferation; Cells; Chemicals; Childhood; Cilia; Code; Cyclic AMP; Cyst; Disease; Ductal; Epithelial Cells; Figs - dietary; Fluids and Secretions; Foundations; Genes; Genetic; Goals; Growth; Hepatic; Hepatic Cyst; Hereditary Disease; Infant; Kidney; Lesion; Liver; Liver diseases; Mechanics; Mediating; Morbidity - disease rate; Mutate; Mutation; Organelles; Patients; Perinatal; Phenotype; Polycystic Kidney Diseases; Process; Proprotein Convertase 1; Proprotein Convertase 2; Proteins; Rattus; Reporting; Rodent Model; Role; Sensory; Signal Pathway; Signal Transduction; Stimulus; Testing; Therapeutic; apical membrane; biliary tract; cholangiocyte; in utero; kidney epithelial cell; mortality; neonate; novel; novel therapeutics; polycystic liver disease; research study; restoration; therapeutic target

DESCRIPTION (Provided by Applicant): Autosomal recessive polycystic kidney disease (ARPKD) is an important genetic disorder in pediatric practice. ARPKD is a renal and hepatic disease in neonates and infants, and <30% of affected neonates die because of greatly enlarged kidneys detected in utero or in the perinatal period. In surviving ARPKD patients, hepatic lesions become progressively more severe with age, and liver disease is a major cause of morbidity and mortality. In ARPKD, as well as in all the polycystic liver diseases, well described genetic defects initiate formation of hepatic cysts, which arise from cholangiocytes, the epithelial cells lining the biliary tree. Cysts further expand due to disturbances in at least three processes: cell proliferation, cell-matrix interaction, and fluid secretion. Different factors, individually or in combination, could impact cholangiocyte proliferation and promote cyst growth. One of these potential factors is intracellular calcium, level of which is known to be decreased in cyst-derived kidney epithelial cells, leading to cellular dedifferentiation and hyperproliferation. The overall goal of this application is to test the hypothesis that cholangiocytes lining liver cysts have dysfunctional ciliary sensory machinery, which results in decreased levels of intracellular calcium, leading to a cAMP-mediated hyperproliferative phenotype; and that pharmacological restoration of normal intracellular calcium levels could reverse the hyperproliferative phenotype. To test this hypothesis, Specific Aim 1 is to characterize the dysregulation of intracellular calcium and its downstream effects on liver cystogenesis, using an animal model of ARPKD, the PCK rat. Specific Aim 2 is to evaluate the potential role of TRPV4, a calcium entry channel, as therapeutic target. The experimental results from the present application will provide novel information regarding the mechanisms controlling the proliferation of cyst cholangiocytes, and will produce the foundation for a plausible alternative or complementary therapeutic treatment of polycystic liver diseases. PROJECT NARRATIVE: This application will both examine the cellular mechanisms by which cysts form in the liver as well as test a new pharmacological approach to inhibit cholangiocyte hyperproliferation and cyst growth in rodent models of ARPKD and ADPKD, the two most important, incurable, genetic liver diseases. These diseases are associated with mutations in known genes, which protein products are expressed in cilia, antenna-like organelles that extend from the apical membrane into the ductal lumen. It is hypothesized that abnormalities in the sensory machinery of cholangiocyte cilia are central to hepatic cyst formation.

描述（由申请人提供）：常染色体隐性多囊肾病（ARPKD）是儿科实践中的一种重要遗传性疾病。 ARPKD 是新生儿和婴儿的一种肾脏和肝脏疾病，<30% 的受影响新生儿因在子宫内或围产期检测到肾脏大幅增大而死亡。 在幸存的 ARPKD 患者中，肝脏病变随着年龄的增长而变得越来越严重，肝脏疾病是发病和死亡的主要原因。 在 ARPKD 以及所有多囊肝病中，明确的遗传缺陷会引发肝囊肿的形成，肝囊肿由胆管细胞（胆管树内衬的上皮细胞）产生。 由于至少三个过程的干扰，囊肿进一步扩大：细胞增殖、细胞-基质相互作用和液体分泌。 不同的因素，单独或组合，可能会影响胆管细胞增殖并促进囊肿生长。 这些潜在因素之一是细胞内钙，已知囊肿来源的肾上皮细胞中的细胞内钙水平降低，导致细胞去分化和过度增殖。 本申请的总体目标是检验以下假设：肝囊肿内壁胆管细胞的纤毛感觉机制功能失调，导致细胞内钙水平下降，从而导致 cAMP 介导的过度增殖表型；正常细胞内钙水平的药理学恢复可以逆转过度增殖表型。 为了检验这一假设，具体目标 1 是使用 ARPKD 动物模型（PCK 大鼠）来表征细胞内钙的失调及其对肝囊肿发生的下游影响。 具体目标 2 是评估钙进入通道 TRPV4 作为治疗靶点的潜在作用。 本申请的实验结果将提供关于控制囊肿胆管细胞增殖的机制的新信息，并将为多囊肝病的合理替代或补充治疗奠定基础。 项目叙述：该应用将检查肝脏中囊肿形成的细胞机制，并测试一种新的药理学方法，以在 ARPKD 和 ADPKD（两种最重要的、无法治愈的遗传性肝病）啮齿动物模型中抑制胆管细胞过度增殖和囊肿生长。 这些疾病与已知基因的突变有关，这些基因的蛋白质产物在纤毛中表达，纤毛是从顶膜延伸到导管腔的天线状细胞器。 据推测，胆管细胞纤毛感觉机制的异常是肝囊肿形成的核心。