Lupus Association with Signal Transducer and Activator of Transcription 4

狼疮与信号转导器和转录激活器的关联 4

• 批准号: 8598799
• 负责人: John Barker Harley
• 金额: --
• 依托单位: CINCINNATI VA MEDICAL CENTER RESEARCH
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-10-01 至 2016-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8598799
• 关键词: African American; Alleles; Autoimmunity; Award; Binding; Biological; Cells; Chromosome Mapping; Crohn' s disease; Curcumin; DNA Methylation; DNA Sequence; Data; Diagnosis; Disease; Epigenetic Process; Etiology; Faculty; Gene Expression; Genes; Genetic; Genomics; Genotype; Haplotypes; Hispanics; Histones; Immune System Diseases; In Vitro; Inflammatory; Inflammatory Response; Informatics; Insulin-Dependent Diabetes Mellitus; Interferons; Intervention; Introns; Knowledge; Lentivirus Vector; Life; Linkage Disequilibrium; Literature; Lupus; Maps; Mediating; Messenger RNA; Methodology; Methods; MicroRNAs; Military Personnel; Minority; Mission; Modification; Molecular; Pathogenesis; Population; Production; Proteins; RNA analysis; Regulation; Research; Rheumatoid Arthritis; Risk; Role; STAT4 gene; STAT4 protein; Stimulus; Systemic Lupus Erythematosus; Testing; Therapeutic; Time; Variant; design; disorder risk; genetic risk factor; genetic variant; high risk; improved; inhibitor/antagonist; insight; new technology; novel; novel therapeutics; physical mapping; programs; public health relevance; research study; response; risk variant; small hairpin RNA; transcription factor

DESCRIPTION (provided by applicant): Of the many genes recently discovered to be associated with Systemic Lupus Erythematosus the haplotype in STAT4 is among the most powerful outside the HLA region. STAT4 is an important inflammatory transcription factor with the level in the cell determining the magnitude of the response to the genes that STAT4 controls. This association is curious because it is localized in the fourth intron and the biological relevance of the relationship of this piece of DN to the function or activity of STAT4 is poorly understood. Our preliminary together with recent literature show that the risk allele expresses a higher level of STAT4 mRNA and protein and leads to increased sensitivity to Interferon-¿ (IFN-¿). The variant causing the association with lupus in STAT4 is located in a 55.5kb haplotype. DNA sequencing has defined many differences between the risk and non-risk haplotype. We will incorporate new genotyping and DNA sequencing data available and now being generated into a complete map, defining the genomic boundaries containing the causal variant(s) and identifying all of the possible variants that could contribute to disease risk and reducing the interval (Aim 1). Next, since disease risk appears to be related to expression, we will explore sequence specific epigenetic alterations in histone marks and DNA methylation to identify the regions of the risk haplotype that are poised for increased STAT4 mRNA production (Aim 2). This will be a novel application of epigenetics for allele specific gene mapping and candidate causal variant identification that if successful will have general application for identifying gene variants that change disease risk by changing expression level. We will evaluate the hypothesis that the differential binding of transcription factors are responsible for the difference in STAT4 gene expression with informatic approaches to identify potential risk haplotype differences controlling gene expression and by applying in vitro methods to establish which of the identified variants is actually responsible for the change in gene expression (Aim 3). We anticipate identifying the causal variant in STAT4 and explaining some of the important details of the mechanism that generates risk for lupus. Finally, throughout the proposed program of research on STAT4 we will explore progressively more sophisticated strategies for decreasing the increased STAT4 activity in the risk haplotype (Aim 4). Initially, we will explore the potential impact on STAT4 activity with the known inhibitors (lisopfylline, curcumin, and statins). Later in the program and after we identify candidate causal transcription factors, we will deliver specific shRNA with lentivirus vectors to inhibit the actionof the candidate causal transcription factor(s), which may have the potential to reduce the increased STAT4 expression of the risk allele, returning the level of expression of the risk haplotype close to the STAT4 expression of the non-risk allele and, thereby, reducing the risk of lupus. STAT4 also is associated with rheumatoid arthritis, Crohn's disease, and type 1 diabetes, giving broad importance to any effort to understand STAT4 mechanism in autoimmunity, especially if this knowledge were to bring us closer to more effective and specific therapies for the immune dysfunction of these diseases.

描述(由申请人提供)： 在最近发现的与系统性红斑狼疮相关的许多基因中，STAT4的单倍型是人类白细胞抗原区域以外最强大的基因之一。STAT4是一种重要的炎性转录因子，其在细胞中的水平决定了 对STAT4控制的基因的反应。这种关联很奇怪，因为它位于第四内含子中，而这段DN与STAT4功能或活性之间的生物学相关性尚不清楚。我们的初步研究和最近的文献表明，风险等位基因STAT4mRNA和蛋白的表达水平较高，并导致对干扰素-β的敏感性增加。在STAT4中导致与狼疮相关的变异位于55.5kb的单倍型。DNA测序已经定义了风险单倍型和非风险单倍型之间的许多差异。我们将把现有的新的基因分型和dna测序数据合并到一个完整的图谱中，定义包含因果变异(S)的基因组边界，并识别所有可能的变异 增加疾病风险和缩短间隔时间(目标1)。下一步，由于疾病风险似乎与表达有关，我们将探索组蛋白标记和DNA甲基化中序列特定的表观遗传学变化，以确定风险单倍型的区域，这些区域有望增加STAT4 mRNA的产生(目标2)。这将是表观遗传学在等位基因定位和候选因果变异识别方面的新应用，如果成功，将在识别通过改变表达水平改变疾病风险的基因变异方面具有普遍应用。我们将用信息学的方法来评估转录因子的差异结合导致STAT4基因表达差异的假设，以确定控制基因表达的潜在风险单倍型差异，并通过应用体外方法来确定哪个已识别的变体实际上导致了基因表达的变化(目标3)。我们期待确定STAT4中的因果变量，并解释导致狼疮风险的机制的一些重要细节。最后，在整个关于STAT4的拟议研究计划中，我们将逐步探索更复杂的策略，以减少风险单倍型中STAT4活性的增加(目标4)。首先，我们将探索已知的抑制剂(利索普林、姜黄素和他汀类)对STAT4活性的潜在影响。在程序的后面，在我们确定候选的因果转录因子后，我们将用慢病毒载体传递特定的shRNA来抑制候选因果转录因子(S)的作用，这可能有可能降低风险等位基因STAT4的表达，使风险单倍型的表达水平接近非风险等位基因的STAT4表达，从而降低狼疮的风险。STAT4还与类风湿性关节炎、克罗恩病和1型糖尿病有关，这对了解STAT4在自身免疫中的机制具有广泛的重要性，特别是如果这些知识能使我们更接近于更有效和更具体的治疗这些疾病的免疫功能障碍的话。