CHANNEL-MEDIATED RBC DEHYDRATION IN SICKLE CELL DISEASE

镰状细胞病中通道介导的红细胞脱水

基本信息

批准号：
6651976
负责人：
ALICIA RIVERA
金额：
$ 13.89万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-09-01 至 2005-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6651976
关键词：
biological signal transduction body water dehydration calcium flux cell morphology cell water clinical research endothelin erythrocytes hemoglobin As hemoglobin Ss hormone receptor human subject laboratory mouse potassium channel protein kinase C receptor expression sickle cell anemia sickle cell crisis

项目摘要

DESCRIPTION (Applicant's abstract) The objective of this application is to provide the applicant with an in-depth training experience that will result in her becoming an independent and funded investigator at the end of this work. Our long-range goal is to study ion transport modulation in red cells and other tissues in an over-stimulated environment that may lead to additional pathology. Dehydration of hemoglobin S-containing erythrocytes favors the formation of dense cells due to increased hemoglobin S polymerization in sickle cell disease. The preliminary results indicate that the potent vasoactive peptide endothelin-1 induces dehydration of sickle erythrocytes. In addition, it was found that endothelin-1 induced activation of Ca(2+)- activated K(+) channel (Gardos channel) via an endothelin receptor type B- mediated process in normal and sickle erythrocytes. The central hypothesis of this application is that the elevated systemic and local concentrations of endothelin-1 contributes to the pathogenesis of vaso-occlusive episodes by induced dehydration via the Gardos channel. This hypothesis will be tested by defining the regulatory mechanism(s) by which endothelin-1 induces Gardos channel activation and red cell dehydration in sickle cell disease. To this end, the functional properties of the Gardos channel will be evaluated in mouse and human erythrocytes containing Hb A and S by following these specific aims: 1) Establish the mechanism(s) by which endothelin-1 activates Gardos channel in sickle erythrocytes: to test the hypothesis that endothelin-1 induced a signaling pathway that changes the Ca(2+) affinity constant of the Gardos channel via a protein kinase C-mediated mechanism(s) in normal and sickle erythrocytes. 2) Identify the mechanism(s) by which endothelin-1 induces dehydration in sickle erythrocytes: to define the physiological pathway(s) of endothelin-1 induced dense red cell formation in normal and sickle cells and its regulatory mechanism(s) by specific blockers of endothelin-1 receptors. Erythrocytes from mice transgenic for hemoglobin S will be studied in vitro and in vivo to assess the role of endothelin receptors in sickle cell dehydration by using endothelin-1 selective receptor antagonists. It is the expectation that this work will determine the mechanism(s) identified are expected to provide critical information on pathological activation of the Gardos channel in sickle erythrocytes. Finally, it is expected that these data will provide preliminary results for the subsequent planned submission of an R01 application. The research proposed in the application is significant because it will provide us with a more comprehensive knowledge of erythrocyte volume regulatory mechanism(s). These, in turn, will help to develop a novel therapeutic strategy to reduce sickle cell formation, and decrease the occurrence of vaso-occlusive episodes. It is additionally significant, because it will provide the means for the applicant to establish an independent research career and to become competitive for a tenure-track assistant professional position.

描述（申请人的摘要）本申请的目的是提供具有深入培训经验的申请人将导致她在这项工作结束时成为独立和资助的研究者。我们的远程目标是研究红细胞中的离子传输调制和在过度刺激的环境中的其他组织可能导致额外病理。血红蛋白S的红细胞脱水有利于由于血红蛋白S的聚合增加而形成致密细胞的形成镰状细胞性贫血症。初步结果表明有效血管活性肽内皮素-1诱导镰状红细胞脱水。此外，发现内皮素-1诱导Ca（2+） - 通过内皮素受体型B-激活的K（+）通道（GARDOS通道）正常和镰状红细胞的介导过程。中心假设该应用是升高的全身和局部浓度内皮素-1有助于通过通过Gardos通道诱导脱水。该假设将通过定义内皮素-1诱导gardos的调节机制镰状细胞疾病中的通道激活和红细胞脱水。对此最后，将评估Gardos通道的功能特性通过遵循这些特异性目的：1）建立内皮素-1激活gardos的机制镰状红细胞中的渠道：测试内皮素-1的假设诱导了改变CA（2+）亲和力常数的信号通路加德斯通道通过正常和镰状红细胞。 2）确定内皮素-1的机制诱导镰状红细胞脱水：定义生理内皮素-1的途径在正常和镰状细胞及其调节机制通过特定的阻滞剂内皮素-1受体。小鼠的红细胞转基因的血红蛋白S 将在体外和体内研究以评估内皮素的作用通过使用内皮素-1选择性受体，镰状细胞中的受体脱水对手。期望这项工作将决定预计确定的机制将提供有关的关键信息镰状红细胞中加尔多斯通道的病理激活。最后，预计这些数据将为随后计划提交R01申请。研究应用程序中提出的意义很大，因为它将为我们提供对红细胞体积调节机制的更全面了解。反过来，这些将有助于制定一种新颖的治疗策略来减少镰状细胞的形成，并减少血管占地发作的发生。它的另外很重要，因为它将为申请人建立独立的研究职业并成为具有终身助理专业职位的竞争力。