Lymphocytic Targets and Behavior in Fragile X

描述（由申请人提供）：脆性X综合征（FraX）是遗传性智力迟钝的最常见形式，与FMRP缺失有关，FMRP是一种参与蛋白质合成调节的蛋白质。最近的微阵列研究已经在FMRP基因敲除小鼠和雄性FraX患者的淋巴母细胞的大脑中发现了异常调节的转录本。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，我们已经在FraX淋巴细胞中证实了几种蛋白质的异常乙酰化，包括小胶质调节蛋白膜联蛋白-1 （ax -1）和神经元细胞骨架蛋白a-微管蛋白。异常的x-1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、大脑畸形）和变异性是一种或多种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男性的神经行为相关来确定。我们建议研究12个选定的FMRP靶点在淋巴细胞中的表达模式，这些靶点来自具有良好特征的FraX男性样本，代表了神经行为表型表现的频谱。在Aim 1中，我们将结合免疫化学技术来表征100名患有FraX的男性和20名对照者的淋巴细胞蛋白表达模式和水平。在目标2中，我们将研究这些分子变量与FraX受试者的神经行为表型（例如，a-微管蛋白和智商）的选择方面之间的关系。由于有50名FraX和10名对照受试者的血液样本和行为数据，因此在两年内只招募一半的样本。初步数据还显示了研究其中4种蛋白质的可行性。由于他们研究基因型-表型关系的创新方法，我们认为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.