Spinocerebellar ataxia type 12 iPSCs and PP2A dysregulation

脊髓小脑共济失调 12 型 iPSC 和 PP2A 失调

• 批准号: 9094716
• 负责人: RUSSELL L MARGOLIS
• 金额: $ 24.3万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9094716
• 关键词: 5q32; Alzheimer' s Disease; Biopsy; Brain; CAG repeat; Cell Line; Cells; Chromosomes; Clinical Data; Code; DNA; Data; Differentiation and Growth; Disease; Electrophysiology (science); Enzyme Kinetics; Enzymes; Fibroblasts; Gene Expression; Genes; Health; Health Benefit; Holoenzymes; Human; Human Herpesvirus 4; Huntington Disease; India; Individual; Inherited; Karyotype; Length; Leukocytes; Light; Link; Mediating; Modeling; Morbidity - disease rate; Mutation; N-terminal; Nature; Neurodegenerative Disorders; Neurons; Nucleic Acid Regulatory Sequences; Pathogenesis; Patients; Pattern; Phosphoric Monoester Hydrolases; Phosphorylation; Property; Prosencephalon; Protein Isoforms; Proteins; Proteome; Public Health; RNA; RNA Splicing; Regulation; Role; Sampling; Schizophrenia; Site; Skin; Spinocerebellar Ataxias; Staging; Substrate Specificity; System; Testing; Toxic effect; Toxin; Transcript; Trinucleotide Repeats; Type 6 Spinocerebellar Ataxia; Work; base; design; disease phenotype; experience; falls; genetic pedigree; induced pluripotent stem cell; insight; lymphoblast; mouse model; nerve stem cell; neurotoxicity; overexpression; pluripotency; polyglutamine; promoter; research study; response; subcellular targeting; targeted treatment; tau Proteins; tau phosphorylation; transcriptome; vector

 DESCRIPTION (provided by applicant): Spinocerebellar ataxia type 12 (SCA12) is a progressive, autosomal dominant, neurodegenerative disorder caused by an expansion of a CAG/CTG trinucleotide repeat on chromosome 5q32; both the disease phenotype and the causative mutation were initially described by our group (Holmes et al, 1999). While the disease is one of most common forms of SCA in India, and scattered SCA12 pedigrees have been detected around the world, perhaps the most intriguing aspect of SCA12 is that the repeat falls in a putative promoter of PPP2R2B, a gene encoding ß regulatory subunits of the trimeric enzyme phosphatase 2A (PP2A). Functional PP2A consists of a structural unit, one of two catalytic units, and one of ~30 regulatory subunits, with the N-terminal region of the regulatory subunits serving to target the holoenzyme to specific intracellular sites. Dysregulation of PP2A has been directly linked to tau hyperphosphorylation in Alzheimer's disease, and to multiple other neurodegenerative diseases. We hypothesize, based on preliminary data from cell overexpression models, that the SCA12 repeat expansion leads to increased expression of PPP2R2B isoform Bß1, and that this overexpression leads to dysregulation of PP2A activity and neurotoxicity. However, it has not been possible to confirm these observations, as human SCA12 brain material is not available and PPP2R2B Is not expressed in leukocytes or lymphoblasts. To test our hypothesis, we will use fibroblasts from skin biopsies of patients with SCA12 to generate induced pluripotent stem cells (iPSCs)(Aim 1). We will then determine the effect of the mutation on PPP2R2B expression and other cellular properties in the fibroblasts and in the IPSCs differentiated into forebrain neurons (Aim 2). The potential public health benefits of this project are three fold: 1) a better understanding of how repetitive DNA can influence gene expression, 2) a better understanding of SCA12 pathogenesis, with the potential of detecting targets for therapeutic agents, and 3) new insight into the role of PP2A in the pathogenesis of neurodegenerative disease.

 描述（由适用提供）：棘脑脑性共济失调类型12（SCA12）是一种进行性的，常染色体显性，神经退行性疾病，这是由于CAG/CTG/CTG三核苷酸在5q32染色体上重复的膨胀而引起的；疾病表型和严重的突变最初都由我们的小组描述（Holmes等，1999）。尽管该疾病是印度最常见的SCA形式之一，并且在世界范围内发现了散落的SCA12谱系，但SCA12最有趣的方面也许是，重复落在PPP2R2B的假定启动子中，PPP2R2B的基因编码基因，它是一种编码三中性酶磷酸酶2a（PPP2A）的调节性亚基的基因。功能性PP2A由一个结构单元，两个催化单元之一和约30个调节亚基之一组成，其中一个调节亚基的N末端区域将靶向全酶靶向特定的细胞内部位。 PP2A的失调与阿尔茨海默氏病中的Tau高磷酸化以及多种其他神经退行性疾病直接相关。我们根据细胞过表达模型的初步数据假设SCA12重复膨胀会导致PPP2R2B同工型Bß1的表达增加，并且这种过表达导致PP2A活性和神经毒性的失调。但是，由于人类SCA12脑物质不可用，并且在白细胞或淋巴细胞中未表达PPP2R2B，因此无法确认这些观察结果。为了检验我们的假设，我们将使用SCA12患者皮肤活检的成纤维细胞生成诱导的多能干细胞（IPSC）（AIM 1）。然后，我们将确定突变对成纤维细胞和IPSC中PPP2R2B表达和其他细胞特性的影响（AIM 2）。该项目的潜在公共卫生益处是三倍：1）更好地理解重复性DNA如何影响基因表达，2）更好地了解SCA12发病机理，具有检测治疗剂的靶标的潜力，以及3）对PP2A在神经疾病疾病的病理中的作用的新洞察力。

项目成果

Bidirectional transcription at the PPP2R2B gene locus in spinocerebellar ataxia type 12.

12 型脊髓小脑共济失调中 PPP2R2B 基因位点的双向转录。

• DOI: 10.1101/2023.04.02.535298
• 发表时间: 2023
• 期刊: bioRxiv : the preprint server for biology
• 作者: Zhou,Chengqian;Liu,HansB;Bakhsh,FatemehJ;Wu,Bin;Ying,Mingyao;Margolis,RussellL;Li,PanP
• 通讯作者: Li,PanP