Physiologic Profiling of sGC Genetic Variants

描述(由申请人提供)：高血压是心血管、脑血管和肾脏疾病的强烈危险因素。尽管具有高度的遗传性，但普通人群中血压变异的遗传基础一直没有得到很好的界定。在初步工作中，在GUCY1A3/GUCY1B3基因座上发现了一个与血压相关的常见遗传变异，该基因座编码可溶性鸟苷环化酶的α1和β1亚单位，该酶在一氧化氮激活时合成cGMP，并在血管中大量表达。在多达20万名欧洲血统的个体中，58%的人拥有两个BP升高等位基因的副本。拟议研究计划的总体目标是确定与血压相关的GUCY1A3/GUCY1B3基因变异(或紧密连锁的变异)是否调节可溶性鸟苷环化酶α1和/或β1亚单位的表达。在目标1中，我们试图确定BP与GUCY1A3/GUCY1B3基因座上的SNP之间的关联是否可能由sGC活性的差异决定。吸入性一氧化氮将被给予具有0或2个BP升高等位基因拷贝的个体，并将确定基因对吸入NO提高血浆cGMP水平的能力的影响。在平行实验中，将比较不同基因型之间的血小板可溶性鸟苷环化酶亚单位mRNA和蛋白水平，以及酶活性和不可抑制的聚集性。在目标2中，基因变异将被引入到含有人类GUCY1A3/GUCY1B3基因座的细菌人工染色体中。含有主、次等位基因的克隆将被引入血管平滑肌细胞，并比较可溶性鸟苷环化酶α1和β1亚基的表达。研究人员提议使用详细的生理表型和DNA序列变异的分子特征，有望对GUCY1A3和GUCY1B3基因的调控产生基本的见解，并开始更好地理解一氧化氮可溶性鸟苷环化酶-cGMP信号在普通人群血压调节中的作用。

DESCRIPTION (provided by applicant): High blood pressure is a strong risk factor for cardiovascular, cerebrovascular, and kidney disease. Although highly heritable, the genetic basis of blood pressure variation in the general population has been poorly-defined. In preliminary work, a common genetic variant associated with blood pressure was identified at the GUCY1A3/GUCY1B3 locus, which encodes the alpha1 and beta1 subunit of soluble guanylate cyclase, an enzyme which synthesizes cGMP when activated by nitric oxide and which is abundantly expressed in the vasculature. Among up to 200,000 individuals of European ancestry, 58% of the population has two copies of a BP-raising allele. The overall goal of the proposed research program is to ascertain whether the GUCY1A3/GUCY1B3 genetic variant associated with blood pressure (or a closely linked variant) modulates expression of soluble guanylate cyclase alpha1 and/or beta1 subunits. In Aim 1, we seek to establish whether the association of BP with the SNP at the GUCY1A3/GUCY1B3 locus is likely to be determined by a difference in sGC activity. Inhaled nitric oxide will be administered to individuals with 0 or 2 copies of the BP-raising allele, and the impact of genotype on the ability of NO inhalation to increase plasma cGMP levels will be determined. In parallel experiments, platelet soluble guanylate cyclase subunit mRNA and protein levels, as well as enzyme activity and NO- inhabitable aggregation will be compared between genotypes. In Aim 2, genetic variants will be introduced into bacterial artificial chromosomes containing the human GUCY1A3/GUCY1B3 locus. Clones containing major and minor alleles will be introduced in vascular smooth muscle cells, and expression of the soluble guanylate cyclase alpha1 and beta1 subunits will be compared. The investigators' proposed use of detailed physiologic phenotyping and molecular characterization of the DNA sequence variation promises to yield fundamental insights into regulation of the GUCY1A3 and GUCY1B3 genes and to begin to better understand the role of nitric oxide-soluble guanylate cyclase-cGMP signaling in blood pressure regulation in the general population.