Variation in platelet function: the genetics of platelet gene expression

血小板功能的变异：血小板基因表达的遗传学

• 批准号: 8444437
• 负责人: PAUL F. BRAY
• 金额: $ 66.67万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-26 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8444437
• 关键词: 3' Untranslated Regions; Address; Affect; Age; Agonist; Alpha Granule; Arterial Fatty Streak; Bioinformatics; Biological Markers; Biology; Blood Clot; Blood Platelets; Blood coagulation; Cardiovascular Diseases; Collagen; Copy Number Polymorphism; Coronary artery; DNA; DNA Sequence Rearrangement; Data; Dose; Epinephrine; Ethnic Origin; Exocytosis; Exons; F2R gene; Gender; Gene Dosage; Gene Duplication; Gene Expression; Genes; Genetic; Genetic Transcription; Genomics; Genotype; Goals; Human; Individual; Internet; Introns; Leukocytes; Messenger RNA; MicroRNAs; Molecular; Molecular Genetics; Outcome; P2X-receptor; Pathway interactions; Phenotype; Physiological; Physiology; Platelet Activation; Platelet aggregation; Play; Preparation; Proteins; RNA; RNA Splicing; Race; Receptor Activation; Relative (related person); Research; Research Personnel; Reverse Transcriptase Polymerase Chain Reaction; Risk; Ristocetin; Role; Rupture; Sample Size; Signal Transduction; Stimulus; Study Subject; Testing; Thrombosis; Transcript; Translations; Variant; Vascular Diseases; Wound Healing; base; cDNA Expression; cerebral artery; clinical risk; cohort; disorder risk; drug development; gene discovery; genome wide association study; insight; mRNA Expression; mortality; novel; overexpression; public health relevance; response; secretory protein; tool

DESCRIPTION (provided by applicant): There is extreme inter-individual variation in human platelet reactivity, which likely contributes to occlusion of coronary and cerebral arteries upon atherosclerotic plaque rupture in some individuals, whereas other individuals repair the wound without occluding the vessel. However, there is a lack of understanding of the molecular and genetic mechanisms responsible for this variation in platelet function. Our previous genome wide scan and platelet RNA expression studies have elucidated mechanisms for epinephrine-induced platelet aggregation, identified mRNA expression differences, as well as unexpected evidence that microRNAs (miRNAs) regulate expression of the platelet secretory protein, VAMP8. Additional analyses suggest that alternate exon splicing and genomic copy number variation also contribute to variation in platelet gene expression. Although our platelet RNA profiling study included 29 subjects, it was limited in its ability to identify genes involved in the platelet response to agonists other than epinephrine. We now propose to recall 180 subjects for new platelet phenotyping, preparation of leukocyte-depleted platelet RNA and microarray profiling of mRNA and miRNA. Rigorous bioinformatic and statistical approaches will minimize false positives, and candidate mRNAs and miRNAs will be characterized experimentally. This approach will allow definition of genes regulating the platelet response to specific agonists (ADP, CRP, collagen, TRAP, U46619, ristocetin, CD9 and epinephrine), as well as genes common to multiple platelet stimuli, and permit assessment of the effects of gender and ethnicity (Aim 1). In Aims 2-4 we will characterize molecular mechanisms regulating mRNA levels in platelets of differing reactivity. Our analyses will identify associations between platelet reactivity and alternately spliced exons, thus serving as a screen for functional domains in the platelet protein (Aim 2). We will determine platelet miRNA profiles and characterize the function of differentially expressed miRNAs in platelets of differing reactivity (Aim 3). By correlating RNA expression data with our prior GWAS genotyping on these same subjects, we will address the role of copy number variation on platelet gene expression (Aim 4). We will also generate public web tools that provide the relative expression of platelet mRNAs and miRNAs according to gender, race and age. This research will result in new insights into platelet physiology, enhance our understanding of the genetics of platelet gene expression, facilitate the selection of gender and race-specific biomarkers for thrombosis risk, and provide useful tools for other platelet researchers.

描述（由申请人提供）：人血小板反应性存在极端个体间差异，这可能有助于某些个体在动脉粥样硬化斑块破裂上抑制冠状动脉和脑动脉，而其他个体则修复伤口而无需遮挡容器。但是，缺乏对导致这种血小板功能变化的分子和遗传机制的了解。我们以前的基因组广泛扫描和血小板RNA表达研究已经阐明了肾上腺素诱导的血小板聚集的机制，鉴定出mRNA表达差异，以及意外的证据表明microRNA（miRNA）调节了血小板分泌蛋白的表达，VAPM8。其他分析表明，替代外显子剪接和基因组拷贝数变化也有助于血小板基因表达的变化。尽管我们的血小板RNA分析研究包括29名受试者，但它的能力限制了鉴定与肾上腺素以外其他激动剂的血小板反应的基因的能力。现在，我们建议回忆180名新的血小板表型，排泄白细胞血小板RNA的制备以及mRNA和miRNA的微阵列分析。严格的生物信息学和统计方法将最大程度地减少假阳性，而候选mRNA和miRNA将在实验中进行表征。这种方法将允许定义调节血小板对特定激动剂的反应的基因（ADP，CRP，胶原蛋白，TRAP，U46619，Ristocetin，CD9和肾上腺素），以及多种血小板刺激的基因，并允许评估性别和种族的影响（AIM 1）。在目标2-4中，我们将表征调节反应性不同的血小板中mRNA水平的分子机制。我们的分析将确定血小板反应性与剪接外显子之间的关联，从而充当血小板蛋白质功能域的屏幕（AIM 2）。我们将确定血小板miRNA谱并表征不同反应性的血小板中差异表达的miRNA的功能（AIM 3）。通过将RNA表达数据与我们先前对这些相同受试者的GWAS基因分型相关联，我们将解决拷贝数变化在血小板基因表达中的作用（AIM 4）。我们还将生成公共网络工具，根据性别，种族和年龄，可提供血小板mRNA和miRNA的相对表达。这项研究将导致对血小板生理学的新见解，增强我们对血小板基因表达的遗传学的理解，促进为血栓形成风险选择性别和种族特异性生物标志物，并为其他血小板研究人员提供有用的工具。