Genetic Determinants of Erythrocyte Hydration

描述（由申请方提供）：嵌入细胞膜的转运蛋白功能变化与镰状细胞性贫血、Hb CC和SC疾病、遗传性球形红细胞增多症和干细胞症中的红细胞脱水相关。脱水的细胞最有可能镰刀状并产生血管闭塞;因此，正在开发特定的治疗方法来减少体内脱水。这些途径的生理学重要调节剂/活性决定因素尚不清楚，因此阻碍了更有可能经历细胞脱水和血管闭塞的患者亚群的鉴定。我们建议确定生理上重要的基因影响的离子转运途径和细胞水合作用在小鼠和最终人类红细胞的功能。我们将使用近交系小鼠品系，以确定数量基因座（QTL），并最终个别基因，调节红细胞水合和运输。我们已经确定了细胞水合作用差异较大的近交系小鼠品系：从适当的杂交中，将进行QTL分析，以关注与不同表型相关的基因组区域，并确定相关基因。我们还提出了一个详细的表型表征的红细胞离子含量和运输性能，集中在三个已知的途径介导脱水（Gardos通道，K-CI共运输，钠钾泵），在11个正常的近交系小鼠品系。这些菌株被广泛使用，具有丰富的遗传和表型信息。我们将建立信息杂交，以确定与运输活动有意义的差异相关的特定QTL。定义的基因影响红细胞水合作用和离子转运的小鼠将启发镰状小鼠模型的探索，并允许使用敲入/敲出实验的候选基因的测试。最终目的是在未来的研究中验证小鼠候选基因与患者适当的关联研究。我们预计，这些研究将导致新的基因相关的镰状细胞综合征和其他贫血的病理生理学，和潜在的新的治疗靶点，疾病严重程度的标志物，并对特定的治疗敏感性指标的鉴定。

DESCRIPTION (provided by applicant): Changes in the function of transporters embedded into the cell membrane have been associated with erythrocyte dehydration in sickle cell anemia, Hb CC and SC diseases, hereditary spherocytosis and xerocytosis. Dehydrated cells are the most likely to sickle and produce vaso-occlusion; thus, specific therapies are being developed to diminish dehydration in vivo. The physiologically important regulators/determinants of activity of these pathways are not known, thus impeding the identification of subsets of patients more likely to experience cell dehydration and vaso-occlusion. We propose to identify physiologically important genes affecting the function of ion transport pathways and cell hydration in mouse and eventually human erythrocytes. We will use inbred mouse strains to identify quantitative tract loci (QTLs) and ultimately individual genes that modulate red cell hydration and transport. We have already identified inbred mouse strains with large differences in cell hydration: from the appropriate crosses, QTL analysis will be performed to focus on areas of the genome associated with the different phenotype, and identify the gene(s) involved. We also propose a detailed phenotypic characterization of the erythrocyte ion content and transport properties, focused on three pathways known to mediate dehydration (Gardos channel, K-CI cotransport, and Na-K pump), in 11 normal inbred mouse strains. These strains are widely used, with abundantly available genetic and phenotypic information. We will set-up informative crosses to identify specific QTLs associated with meaningful differences in transport activities. Definition of the genes influencing erythrocyte hydration and ion transport in the mouse will enlighten explorations in the sickle mouse model, and will allow testing of candidate genes using knock in/out experiments. The ultimate intent is to validate in future studies the mouse candidate genes with appropriate association studies in patients. We anticipate that these studies will lead to identification of novel genes relevant to pathophysiology of sickle cell syndromes and other anemias, and of potential new therapeutic targets, markers of disease severity, and indicators of susceptibility to specific therapies.