Lymphocytic Targets and Behavior in Fragile X

描述(申请人提供)：脆性X综合征(FRAX)是遗传性智力低下最常见的形式，与FMRP的缺乏有关，FMRP是一种参与蛋白质合成调节的蛋白质。最近的微阵列研究发现，FMRP基因敲除小鼠的大脑和患有FRAX的男性淋巴母细胞中的转录本都受到异常调控。这些FMRP靶点包括参与突触发育和可塑性的结构和功能蛋白。此外，利用蛋白质组学技术，我们在FRAX淋巴细胞中证明了几种蛋白质的异常乙酰化，包括小胶质细胞调节蛋白Annexin-1(ANX-1)和神经元细胞骨架蛋白a-tuBulin。ANX-1的异常表达也预示着FRAX的自闭症特征。我们假设FRAX神经行为表型的特定方面(如自闭症、巨脑症)和变异性是一个或多个神经蛋白异常表达的结果，这些贡献可以通过表征淋巴细胞中异常神经蛋白表达的模式及其与FRAX男性神经行为的相关性来识别。我们建议研究12个选定的FMRP靶点在具有FRAX特征的男性样本淋巴细胞中的表达模式，这些样本代表了神经行为表型表现的光谱。针对L，我们将结合免疫化学技术对100例男性FRAX患者和20例正常对照的淋巴细胞蛋白表达模式和水平进行研究。在目标2中，我们将研究这些分子变量与FRAX受试者神经行为表型的选择性方面(例如，α-微管蛋白和智商)之间的关系。由于有50名FRAX受试者和10名对照受试者的血液样本和行为数据，两年内只有一半的样本将被招募。初步数据也显示了研究其中4种蛋白质的可行性。由于他们在检查基因-表型关系方面的创新方法，我们相信拟议的研究符合探索/发展资助(R21)计划的目的。

DESCRIPTION (provided by applicant): Fragile X syndrome (FraX), the most prevalent form of inherited mental retardation, is associated with the absence of FMRP, a protein involved in regulation of protein synthesis. Recent microarray studies have identified transcripts that are abnormally regulated in both brains from FMRP knockout mice and lymphoblasts from males with FraX. These FMRP targets include structural and functional proteins that participate in synaptic development and plasticity. In addition, using proteomics techniques, we have demonstrated in FraX lymphocytes abnormal acetylation of several proteins that include the microglial regulatory protein annexin-1 (Anx-1) and the neuronal cytoskeletal protein a-tubulin. Abnormal Anx-1 expression is also predictive of autistic features in FraX. We hypothesize that specific aspects (e.g, autism, megalencephaly), and variability, of the FraX neurobehavioral phenotype are the consequence of abnormal expression of one or more neural proteins, and that these contributions can be identified by characterizing patterns of abnormal neural protein expression in lymphocytes and their neurobehavioral correlates in males with FraX. We propose to study the patterns of expression of 12 selected FMRP targets in lymphocytes from a well-characterized sample of males with FraX, representing the spectrum of neurobehavioral phenotypic manifestations. In Aim l, we will use a combination of immunochemical techniques to characterize patterns and levels of lymphocytic protein expression in 100 males with FraX and 20 controls. In Aim 2, we will examine the relationships between these molecular variables and selective aspects of the neurobehavioral phenotype (e.g., a-tubulin and IQ) of the FraX subjects. Since blood samples and behavioral data are available on 50 FraX and 10 control subjects, only half of the sample will be recruited over two years. Preliminary data also show the feasibility of studying 4 of the proposed proteins. Because of their innovative approach to examining genotype-phenotype relationships, we believe that the proposed studies are in accordance with the purposes of the Exploratory/Developmental Grant (R21) Program.