Tau Isoform Expression in FTDP-17

描述(申请人提供)：丝状聚集体 过度磷酸化的tau是额颞部的标志性脑部病变 与17号染色体连锁的帕金森病痴呆(FTDP 17)，遗传性 由不同的tau基因突变引起的具有不同表型的tau病。陶氏 是一种微管(MT)结合蛋白，促进微管蛋白聚合为 MTS和稳定MTS。成人的大脑含有六种tau亚型，其中一半 有3个3R亚型)，一半有4个CTERERAL MT结合重复(4R亚型) 通过外显子10(E10)的交替剪接产生。Tau基因突变导致 FTDP 17通过损害E 10的选择性剪接或tau功能。令人费解的 FTDP 17综合征的一个方面是，不同的tau突变会对选定的 神经元和神经胶质细胞的亚型。我们的第一个假设是，这种选择性 脆弱性可能反映tau异构体的细胞类型特定的扰动 导致不同的表型。为了验证这一假设，我们将测定mrna。 Tau亚型在正常脑细胞亚群中的表达谱。 虽然正常人脑中3R和4R tau的比例为1：1，但从未 在神经元和神经胶质细胞亚群中被检测到。在目标1中，我们将 显微解剖对照石蜡包埋组织切片中的神经元和胶质细胞 大脑，对提取的RNA进行线性扩增，然后进行定量 实时逆转录聚合酶链式反应检测各tau异构体的相对水平。在AIM 2，我们将类似地研究FTDP中相同的神经元和神经胶质细胞群 17个大脑。这些数据与疾病表型的相关性将澄清 FTDP1 7的机制。由于FTDP1 7突变产生不同的表型 同样的家族，第二个假说提出了一个改变的表达 第二个基因与tau基因或蛋白相互作用，影响 FTDP 17在不同受累人群中的表型变化 家庭成员。Aim 3通过检验差异来检验这一假设 候选基因的表达(即涉及剪接、RNA稳定性、 Tau功能、其他细胞过程)在受影响和未受影响的FTDP 17之间 使用定制的cDNA微阵列的大脑区域和对照大脑。这个 完成这些目标将促进对FTDP 17及其相关内容的理解 并可能为诊断和治疗提供新的靶点。

DESCRIPTION (provided by applicant): Filamentous aggregates of hyperphosphorylated tau are the signature brain lesions of frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP 17), an inherited tauopathy with diverse, phenotypes caused by different tau gene mutations. Tau is a microtubule (MT) binding protein that promotes tubulin polymerization into MTs and stabilizes MTs. The adult human brain contains six tau isoforms, half with 3 3R isoforms) and half with 4 Cterminal MTbinding repeats (4R isoforms) generated by alternatively splicing of exon 10 (E 10). Tau gene mutations cause FTDP 17 by impairing E 10 alternative splicing or tau functions. A puzzling aspect of the FTDP 17 syndromes is that different tau mutations damage selected subtypes of neurons and glia. Our first hypothesis is that this selective vulnerability may reflect cell type specific perturbations of tau isoforms to cause varied phenotypes. To test this hypothesis, we will determine mRNA expression profiles of tau isoforms in normal brain cell subpopulations. Although the ratio of 3R to 4R tau is 1:1 in normal human brain, it has never been determined in subpopulations of neurons and glia. In, Aim 1, we will microdissect neurons and glia from paraffinembedded tissue sections of control brains, perform linear amplification on extracted RNA followed by quantitative realtime RTPCR to measure the relative levels of each tau isoform mRNA. In Aim 2, we will similarly study the same neuronal and glial cell populations in FTDP 17 brains. Correlation of these data with disease phenotypes will clarify mechanisms of FTDP1 7. Since FTDP1 7 mutations produce different phenotypes in the same kindred, a second hypothesis proposes that altered expression of a second gene, which interacts with the tau gene or protein, influences development of phenotypic manifestations of FTDP 17 in different affected family members. Aim 3 tests this hypothesis by examining the differential expression of candidate genes (i.e. those involved in splicing, RNA stability, tau function, other cellular processes) between affected and unaffected FTDP 17 brain regions and control brains using custommade cDNA macroarrays. The completion of these Aims will advance understanding of FTDP 17 and related tauopathies, and may provide new targets for diagnosis and therapeutics.