BIOLOGICAL MARKERS FOR CLINICAL HETEROGENEITY IN AD

这是一项科学家发展奖(K21)的申请。候选人 建议获得分子神经科学方面的额外培训，并 遗传病和分子生物学资料与临床表现的相关性 阿尔茨海默病(AD)。职业发展计划涉及增加 应聘者对分子神经科学和临床的概念性知识 相关性。此外，应聘者将增强或获得技术支持 掌握定量信使核糖核酸，细胞表面蛋白检测， 放射免疫分析、代谢标记和免疫沉淀 蛋白质和分子遗传学。具有统计分析技能， 特别是与生物遗传相关的那些，以及 临床数据，也将得到加强。研究计划的重点是 阿尔茨海默病临床异质性的生物学标志。载脂蛋白E E)和β-淀粉样多肽(BetaAP)是目前最好的候选药物 寻找阿尔茨海默病(AD)的生物标志物。大多数研究表明， 然而，已经集中在这些标志物在诊断中的使用。几乎没有人有过 解决了载脂蛋白E基因和/或β-淀粉样蛋白表达是否代表 与临床相关的生物异质性维度 AD的异质性。阿尔茨海默病患者在许多方面存在显著差异 临床维度，但没有令人满意的生物学解释 对于这个变种。我们的中心假设是载脂蛋白E基因， 脑脊液中β-AP和淀粉样蛋白的表达 白细胞与阿尔茨海默病的临床严重程度和下降速度有关。 用放射免疫法测定脑脊液中的β-AP，这种方法可以区分不同种类的 BetaAP物种，其中一些可能比其他物种更具致病性。 用逆转录法测定白细胞淀粉样蛋白的表达 聚合酶链式反应和荧光激活的细胞分选。一个 各种神经心理学、临床和脑成像措施将被 受雇的。据推测，携带载脂蛋白epsilon4等位基因的受试者 会倾向于在临床上迅速衰退。降低总脑脊液β-AP 并上调了蛋白水解酶抑制因子(KPI)的表达。 白细胞含有形式的β-淀粉样前体蛋白(β-APP) 也应该与快速下降联系在一起。变化率将是 根据淀粉样蛋白测量确定的，这应该与 临床表现下降。因为有很好的证据表明载脂蛋白E和β-AP 在AD的病理生理学中，受试者与Apo epsilon 4相互作用 等位基因在脑脊液βAP水平上表现出比其他SAD更大的下降 研究对象。Epsilon 4/epsilon 4基因组合与显著 淀粉样蛋白表达异常应该是最严重受损的特征 研究对象。最后，AD患者和正常对照组脑脊液β-AP的定量 控制将提供关于各种BetaAP贡献的新数据 物种到总的脑脊液β-AP池，这可能给我们提供新的洞察力 生成BetaAP的基本生物过程。同样， 白细胞数据将有助于阐明β-APP 这一重要的细胞群体。

This is a request for a Scientist Development Award (K21). The candidate proposes to obtain additional training in molecular neuroscience, and the correlation of genetic and molecular data with clinical presentation in Alzheimer's disease (AD). The career development plan involves increasing the candidate's conceptual knowledge of molecular neuroscience and clinical correlation. Further, the candidate will enhance or acquire technical skills in quantification of mRNA, cell surface protein detection, radioimmunoassay (RIA), metabolic labeling and immunoprecipitation of proteins, and molecular genetics. Skills in statistical analysis, particularly those relating to correlation of biological genetic, and clinical data, will also be enhanced. The research plan focuses on biological markers for clinical heterogeneity in AD. Apolipoprotein E (Apo E) and the beta-amyloid peptide (betaAP) are currently the best candidates for biological markers for Alzheimer's disease (AD). Most studies, however, have focused on the use of these markes in diagnosis. Few have addressed whether Apo E genotype and/or beta-amyloid expression represent dimensions of biological heterogeneity which correlate with clinical heterogeneity in AD. Patients with AD vary significantly along a number of clinical dimensions, yet there is no satisfactory biological explanation for this variation. Our central hypothesis is that Apo E genotype, cerebrospinal fluid (CSF) betaAP, and amyloid protein expression by leukocytes are correlated with clinical severity and rate of decline in AD. CSF betaAP will be determined with a RIA which discriminates among various betaAP species, some of which may be more pathogenic that others. Leukocyte amyloid expression will be measured with reverse transcription and polymerase chain reaction, and fluorescence activated cell sorting. A variety of neuropsychological, clinical, and brain imaging measures will be employed. It is hypothesized that subjects with the Apo epsilon4 allele will be predisposed to rapid clinical decline. Decreased total CSF betaAP and an increase in the expression of Kunitz protease inhibitor (KPI)- containing forms of beta-amyloid precursor protein (betaAPP) by leukocytes should also be associated with rapid decline. Rates of change will be determined from the amyloid measures, which should correlate with rates of clinical decline. Because there is good evidence that Apo E and betaAP interact in the pathophysiology of AD, subjects with the Apo epsilon4 allele should show larger decreases in CSF betaAP levels than do other SAD subjects. The combination of epsilon 4/epsilon4 genotype and markedly abnormal amyloid expression should characterize the most severely impaired subjects. Finally, quantification of CSF betaAP in AD subjects and controls will provide novel data on the contribution of the various betaAP species to the total CSF betaAP pool, which may give new insight into the basic biological processes by which betaAP is generated. Likewise, leukocyte data will be valuable in clarifying the processing of betaAPP by this important population of cells.