Identification and characterization of a novel risk factor for MS

多发性硬化症新危险因素的鉴定和表征

• 批准号: 9032916
• 负责人: Douglas L. Feinstein
• 金额: --
• 依托单位: JESSE BROWN VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9032916
• 关键词: Alternative Splicing; Apoptosis; Astrocytes; Benign; Binding Sites; Biology; Brain; CREB1 gene; Cells; Child; Chronic; Code; Comorbidity; Complex; DNA; DNA analysis; Data; Development; Diabetes Mellitus; Diagnosis; Disease; Exons; Experimental Autoimmune Encephalomyelitis; FDA approved; FRAP1 gene; Family; Family member; Female; Genes; Genetic; Genomics; Gulf War; HLA Antigens; High Prevalence; Human; In Vitro; Induction of Apoptosis; Inflammation; Inflammatory; Inflammatory Response; Introns; Knock-out; Lead; LoxP-flanked allele; Messenger RNA; Metabolism; Metformin; Military Personnel; Mus; Mutation; Neuroglia; Nucleotides; Odds Ratio; Oligodendroglia; Other Genetics; Ovarian Cysts; Parents; Pathogenesis; Patients; Peripheral; Peutz-Jeghers Syndrome; Pharmaceutical Preparations; Phenotype; Phosphotransferases; Population; Prevalence; Production; Protein Biosynthesis; Protein Kinase; Protein-Serine-Threonine Kinases; Race; Recruitment Activity; Relapse; Reporting; Risk; Risk Factors; Role; STK11 gene; Sampling; Scaffolding Protein; Sequence Analysis; Siblings; Single Nucleotide Polymorphism; Spinal Cord; Syndrome; T-Cell Activation; T-Lymphocyte; Testing; Therapeutic; Tumor Suppressor Genes; Variant; Veterans; adenylate kinase; cell growth; cell growth regulation; cohort; cytokine; genetic risk factor; genome wide association study; indexing; member; mouse model; multiple sclerosis patient; novel; promoter; public health relevance; response; screening; thymocyte; transcription factor; tumor

 DESCRIPTION (provided by applicant): During the course of recruiting MS patients for a study of PBMCs, a family with 5 siblings diagnosed with MS was identified. The prevalence of MS in the US is roughly 1:1000, the odds of having 5 siblings with MS is extremely low and has not been reported. The presence of comorbidity for certain rare tumors led to sequencing analysis of tumor suppressor gene STK11, and a mutation was identified in intron V. STK11 codes for the LKB1 kinase which has been implicated in regulation of cellular metabolism and inflammatory responses in T cells, of inflammatory responses in glial cells, and in oligodendrocyte maturation. This leads to our hypothesis that mutations in STK11 gene leading to a reduction in LKB1 expression cause increased activation of T cells in MS patients which contributes to development of an MS phenotype. Since the role of LKB1 in MS has not been characterized, we further hypothesize that changes in LKB1 expression or activity occur during the course of EAE, the mouse model of MS. If so, then treatments to increase LKB1 may be of therapeutic benefit. In this project, we will determine if other members of the index family harbor the same or similar mutation in the STK11 gene; and test the hypothesis that PBMCs isolated from these family members have reduced or altered expression of LKB1 mRNA, and increased T cell activation. Since a mutation in STK11 alone is not sufficient to induce an MS type phenotype we will carry out full exomic and genomic sequencing to identify associated variants which together with the STK11 mutation could lead to MS. We will determine if the prevalence of any novel variants are increased in the MS population by PCR analysis of DNA samples from 3,000 MS patients (both relapsing remitting and primary progressive forms) and matched controls, including samples obtained from military Veterans of different races who served in the Gulf War Era. Using human T cells, we will determine how the STK11 mutation influences T cell activation; then experimentally manipulate LKB1 expression to identify effects on Tcell activation. In initial studies we found tha reducing LKB1 from astrocytes increase their inflammatory responses, we will therefore characterize LKB1 in astrocyte in vitro and determine if manipulating LKB1 alters astrocyte responses. In mice, we will determine if expression of LKB1 changes during the course of EAE in brain, spinal cord, and in peripheral T cells. Using an LKB1 floxed mouse, we will test if conditional knockout of LKB1 from T cells or astrocytes leads to or exacerbates EAE disease. Finally, we will test if metformin, an FDA approved drug to treat diabetes, can selectively induce apoptosis in the LKB1 deficient T cells in vitro. Positive findings will demonstrate a novel role fr LKB1 in the development of MS disease, and suggest that metformin or related drugs could be used to reduce activated T cells in MS patients who have deficiencies in Tcell LKB1 expression.

 描述（由申请人提供）： 在招募MS患者进行PBMC的过程中，确定了一个诊断为MS的5个兄弟姐妹的家庭。美国MS的患病率大约为1：1000，与MS有5个兄弟姐妹的几率非常低，尚未报告。某些稀有肿瘤的合并症的存在导致对肿瘤抑制基因STK11的测序分析，并且在内含子V中鉴定出突变。STK11代码LKB1激酶代码为LKB1激酶代码，这导致我们的假设是STK11基因中的突变导致LKB1表达的降低导致LKB1表达的降低会导致MS患者的T细胞的降低，从而增加了MS的发展，从而导致MS的发展促成MS的发展。由于尚未表征LKB1在MS中的作用，因此我们进一步假设LKB1表达或活动的变化发生在EAE过程中，MS的小鼠模型。如果是这样，那么增加LKB1的治疗方法可能是理论的。在这个项目中，我们将确定该指数家族的其他成员是否具有STK11基因中相同或相似的突变；并检验了从这些家族成员分离的PBMC的假设降低或改变了LKB1 mRNA的表达，并增加了T细胞激活。由于仅STK11中的突变就不足以诱导MS类型表型，因此我们将进行完整的外部和基因组测序，以鉴定与STK11突变一起的相关变体可能导致MS。我们将通过对3,000名MS患者的DNA样本（包括复发恢复和主要的进行性渐进形式）的DNA样本和匹配的对照组的PCR分析，包括从墨西哥湾战争时代服役的不同种族的军事退伍军人获得的样本，确定MS种群中任何新型变体的患病率是否增加。使用人T细胞，我们将确定STK11突变如何影响T细胞激活。然后通过实验操纵LKB1表达，以鉴定对TCEL激活的影响。在最初的研究中，我们发现从星形胶质细胞中降低LKB1会增加其炎症反应，因此，我们将在体外表征LKB1体外的LKB1，并确定操纵LKB1是否会改变星形胶质细胞反应。在小鼠中，我们将确定LKB1在脑，脊髓和外周T细胞中的EAE过程中的表达是否变化。使用lkb1 floxed小鼠，我们将测试来自T细胞或星形胶质细胞的LKB1有条件敲除导致或加剧EAE病。最后，我们将测试FDA批准的治疗糖尿病药物二甲双胍是否可以在体外有选择地诱导LKB1缺陷T细胞的凋亡。积极的发现将证明LKB1在MS疾病的发展中的新作用，并表明可以使用二甲双胍或相关药物来减少TCELL LKB1表达不足的MS患者的活化T细胞。