Molecular Genetics of the Telomere Biology Disorders

端粒生物学疾病的分子遗传学

• 批准号: 10642859
• 负责人: Alison A Bertuch
• 金额: $ 60.06万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10642859
• 关键词: Affect; Age; Androgens; Attenuated; Binding; Biological Models; Biology; Blood Cells; Bone Marrow; Bone Marrow Cell Transplantation; Bone marrow failure; Cause of Death; Cell Culture Techniques; Cell Differentiation process; Cells; Child; Childhood; Chromatin; Chromosomes; Clinical; Collaborations; Complex; Danazol; Data; Defect; Disease; Disease model; Dyskeratosis Congenita; Elements; Enzymes; Epitopes; Event; Funding; Gene Expression Profile; Genes; Genetic; Goals; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Human Chromosomes; Impairment; In Vitro; Individual; Intervention; Knowledge; Lead; Length; Life; Link; Maintenance; Mediating; Medical; Missense Mutation; Molecular; Molecular Genetics; Molecular Profiling; Morbidity - disease rate; Mutation; Nature; Outcome; Pathogenicity; Pathway interactions; Patients; Persons; Phenotype; Pluripotent Stem Cells; Positioning Attribute; Pre-Clinical Model; Protein Isoforms; Proteins; Role; Structure; System; TERF1 gene; TINF2 gene; Telomerase; Telomere Length Maintenance; Telomere Shortening; Telomeric Repeat Binding Protein 1; Testing; Therapeutic; Toxic effect; Variant; body system; early childhood; early onset; fitness; gain of function; genetic approach; hematopoietic cell transplantation; humanized mouse; improved; in vivo; in vivo Model; insight; mouse model; mutant; novel; pharmacologic; pre-clinical; protein complex; response; stem cell model; stem cells; telomere; therapeutic development; therapeutic evaluation; therapeutic target

The telomere biology disorder (TBD) dyskeratosis congenita (DC) and its severe variants are childhood onset, multisystem disorders caused by impaired maintenance of the ends of chromosomes known as telomeres. Bone marrow failure (BMF) is a major threat to life, occurring in 50-80% of affected individuals by age 30. The long- term objectives of this project are to elucidate the mechanisms by which mutations in the genes associated with the TBDs lead to telomere shortening and to discover how this shortening can be slowed or, better yet, reversed. With this knowledge, we will meet our long-term goal of identifying novel treatment avenues that target telomeres for these life-threatening disorders. To date, 15 genes have been associated with the TBDs, a number that poses a challenge to developing general therapeutic targets. Mutation of the TINF2 gene, which encodes the TIN2 protein, is the second most common cause of DC in children. How mutations in TINF2, which cluster, lead to marked telomere shortening is ill-defined. Our preliminary data suggest the TIN2-DC mutant protein has a new or more robust function than the normal protein, however, many critical gaps in knowledge remain as to the molecular aspects of this gain-of-function. In addition to the complex genetics, a second major challenge in the field is the lack of preclinical model systems to develop and test interventions. Through a collaboration established in 2018, the Bertuch and Hockemeyer labs have developed pluripotent and hematopoietic stem cell culture disease models as well as a humanized mouse model that reproduce the telomere shortening associated with TINF2-DC mutations. Here we propose to use these unique stem cell-based systems to examine the impact of TINF2-DC mutations on the maintenance of telomere length and hematopoiesis, and test therapeutic approaches to treat the associated-BMF. Overall, we will undertake two complementary Aims: Aim 1 will investigate the molecular determinants by which TIN2-DC mutant protein leads to short telomeres, such as how it interacts with the telomere shelterin complex proteins TRF1 and TRF2, and telomeres. We will determine if TIN2-DC mutant protein’s toxic effect on telomere length requires interaction with TRF1 and the role of TIN2- TRF2 interaction in the telomere shortening it induces. Lastly, we will determine if critical binding events are altered by mutation of DC cluster region. In Aim 2, we will determine pharmacologic and genetic mechanisms to restore telomere length and rescue the impaired fitness of TINF2-DC mutant cells. We will establish the gene expression signature of telomere shortening in our stem cell models to derive insight into the pathways impairing fitness. We will test the effect of danazol, which is a treatment for DC BMF, to assess the relationships between impacts on telomere length, TERT, and hematopoietic potential. Lastly, we will develop a genetic strategy to elongate telomeres in TINF2-DC mutant patient hematopoietic stem cells. The two Aims build upon data developed independently by the Bertuch and Hockemeyer labs as well as through their collaborative efforts and bring to bear the complementary expertise to bring a sustained impact on the TBD field.

端粒生物学障碍(TBD)、先天性角化不良(DC)及其严重的变异体是儿童期起病， 由于染色体末端的端粒维护受损而引起的多系统疾病。骨 骨髓衰竭(BMF)是对生命的主要威胁，到30岁时，50%-80%的患者会发生骨髓衰竭。长的- 这个项目的学期目标是阐明基因突变与 TBD导致端粒缩短，并发现这种缩短如何减缓，或者更好的是，逆转这种缩短。 有了这些知识，我们将实现我们的长期目标，即寻找针对端粒的新的治疗途径 这些危及生命的疾病。到目前为止，已经有15个基因与TBD有关，这一数字构成了 开发一般治疗靶点的挑战。编码TIN2的TINF2基因突变 蛋白质，是儿童DC的第二大常见原因。TINF2的哪个簇突变是如何导致 明显的端粒缩短是不明确的。我们的初步数据表明，TIN2-DC突变蛋白具有一种新的 或比正常蛋白质更强健的功能，然而，许多关键的知识缺口仍然是关于 这一功能增益的分子方面。除了复杂的遗传学外，人类面临的第二大挑战 领域是缺乏临床前模型系统来开发和测试干预措施。通过协作 贝尔图奇和霍克迈耶实验室成立于2018年，已经开发出多能和造血干细胞 培养疾病模型以及复制端粒缩短相关的人源化小鼠模型 TINF2-DC突变。在这里，我们建议使用这些独特的基于干细胞的系统来检查影响 TINF2-DC突变对维持端粒长度和造血的影响及试验治疗 相关的BMF的治疗方法。总体而言，我们将实现两个相辅相成的目标：目标1将 研究TIN2-DC突变蛋白导致端粒缩短的分子决定因素，例如如何 它与端粒保护素复合蛋白TRF1和TRF2以及端粒相互作用。我们将确定是否 TIN2-DC突变蛋白对端粒长度的毒性作用需要与TRF1相互作用及TIN2- TRF2与端粒的相互作用导致端粒缩短。最后，我们将确定关键绑定事件是否 被DC簇区突变改变。在目标2中，我们将确定药物和遗传机制 恢复端粒长度，挽救受损的TINF2-DC突变细胞的适合性。我们将建立基因 在我们的干细胞模型中端粒缩短的表达特征，以获得对损伤途径的洞察 健身。我们将测试达那唑的效果，这是一种治疗DC BMF的方法，以评估 对端粒长度、TERT和造血潜能的影响。最后，我们将开发一种遗传策略来 TINF2-DC突变患者造血干细胞的端粒延长。这两个目标建立在数据的基础上 由贝尔图赫和霍克迈耶实验室独立开发，并通过他们的合作努力和 发挥互补的专业知识，对待定发展领域产生持续影响。

项目成果

Expansion of germline RPS20 mutation phenotype to include Diamond-Blackfan anemia.

种系RPS20突变表型的膨胀，包括钻石 - 黑色贫血。

• DOI: 10.1002/humu.24092
• 发表时间: 2020-11
• 期刊: Human mutation
• 影响因子: 3.9
• 作者: Bhar S;Zhou F;Reineke LC;Morris DK;Khincha PP;Giri N;Mirabello L;Bergstrom K;Lemon LD;Williams CL;Toh Y;Elghetany MT;Lloyd RE;Alter BP;Savage SA;Bertuch AA
• 通讯作者: Bertuch AA

Editing TINF2 as a potential therapeutic approach to restore telomere length in dyskeratosis congenita.

• DOI: 10.1182/blood.2021013750
• 发表时间: 2022-08-11
• 期刊: BLOOD
• 影响因子: 20.3
• 作者: Choo, Seunga;Lorbeer, Franziska K.;Regalado, Samuel G.;Short, Sarah B.;Wu, Shannon;Rieser, Gabrielle;Bertuch, Alison A.;Hockemeyer, Dirk
• 通讯作者: Hockemeyer, Dirk