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: 9206882
• 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/9206882
• 关键词: Alternative Splicing; Apoptosis; Astrocytes; Benign; Binding Sites; Biology; Brain; CREB1 gene; Cells; Child; Chronic; Clinical; 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; Genetic Transcription; Genetic screening method; Genomics; Gulf War; HLA Antigens; High Prevalence; Human; In Vitro; Induction of Apoptosis; Inflammation; Inflammatory; Inflammatory Response; Inherited; 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; 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）： 在招募多发性硬化症患者进行 PBMC 研究的过程中，发现一个有 5 个兄弟姐妹被诊断患有多发性硬化症的家庭。在美国，多发性硬化症的患病率约为 1:1000，有 5 个兄弟姐妹患有多发性硬化症的几率极低。某些罕见肿瘤存在合并症导致对肿瘤抑制基因 STK11 进行测序分析，并在内含子 V 中发现了突变。STK11 编码 LKB1 激酶，该激酶与 LKB1 激酶有关。 T 细胞的细胞代谢和炎症反应、神经胶质细胞的炎症反应以及少突胶质细胞成熟的调节这导致我们的假设：STK11 基因突变导致 LKB1 表达减少，导致 MS 患者 T 细胞活化增加。由于LKB1在MS中的作用尚未被表征，我们进一步探究了在EAE（MS的小鼠模型）过程中发生了LKB1表达或活性的变化。在这个项目中，我们将确定指标家族的其他成员是否具有相同或相似的 STK11 基因突变，并检验从这些家族成员中分离的 PBMC 表达减少或改变的假设。由于仅 STK11 突变不足以诱导 MS 型表型，我们将进行完整的外显子组和基因组测序，以鉴定与 STK11 突变一起可能导致 MS 的相关变异。将要通过对 3,000 名 MS 患者（包括复发缓解型和原发进展型）和匹配对照（包括从在海湾服役的不同种族退伍军人获得的样本）的 DNA 样本进行 PCR 分析，确定 MS 人群中任何新发疾病的患病率是否有所增加战争时代。我们将使用人类 T 细胞确定 STK11 突变如何影响 T 细胞激活；然后通过实验操纵 LKB1 表达来确定对 T 细胞激活的影响。在初步研究中，我们发现减少星形胶质细胞中的 LKB1 会增加其激活。因此，我们将在体外表征星形胶质细胞中的 LKB1，并确定操纵 LKB1 是否会改变小鼠中的星形胶质细胞反应，我们将确定 LKB1 的表达在 EAE 过程中在大脑、脊髓和外周 T 细胞中是否发生变化。在一只 LKB1 floxed 小鼠中，我们将测试从 T 细胞或星形胶质细胞中条件性敲除 LKB1 是否会导致或恶化 EAE 疾病。最后，我们将测试二甲双胍（FDA 批准的治疗药物）是否会导致 EAE 疾病恶化。糖尿病，可以在体外选择性诱导 LKB1 缺陷的 T 细胞凋亡。阳性结果将证明 LKB1 在 MS 疾病发展中的新作用，并表明二甲双胍或相关药物可用于减少 MS 患者的活化 T 细胞。 T 细胞 LKB1 表达存在缺陷。