TET1-mediated 5-hydroxymethylcytosine modification & airway hyperresponsiveness

TET1介导的5-羟甲基胞嘧啶修饰

• 批准号: 10088040
• 负责人: Wan-yee Tang
• 金额: $ 12.73万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10088040
• 关键词: TET1; mediated; hydroxymethylcytosine; modification; airway

 DESCRIPTION (provided by applicant): Asthma is a complex disease characterized by airway hyperresponsiveness (AHR) and airway inflammation, which current afflicts over 300 million people worldwide. Although genetic factors unquestionably play a role in asthma, the rapid rise in asthma prevalence suggests that environmental factors likely play an equally important role. To date, epigenetic regulation is suggested to mediate, at least partly, the complex gene-by- environment interactions that can lead to asthma. Most studies to date have focused on elucidation of DNA methylation patterns in easily accessible cells including T cells and B cells to explain the immunological mechanisms driving allergen sensitization in asthmatics. Few studies have examined the epigenetic consequences of environmental triggers on lung tissues linked to chronic alterations in lung functions. We have utilized next generation sequencing techniques and proper validation assays to identify a novel set of genes which is highly enriched for Tgfb2 signaling molecules and associated with exposure to the common allergen, house dust mite (HDM), and the development of AHR through epigenetic modulation of the airway smooth muscle (ASM) cell phenotypes. In addition, we identified a novel role of the specific 5-mC dioxygenase, TET1, in the regulation of ASM function in vitro and in the development of allergen-driven AHR in vivo. Preliminarily, we demonstrated Tet1 deficiency reduced acute HDM-driven AHR in mice. Strikingly, we were able to translate the epigenetic changes in human asthmatic ASM cells; showing Tet1-mediated hydroxymethylation may influence ASM cell proliferation and contraction. Our study represents the first demonstration that Tet1 protein is regulated in the context of allergen exposure, although the mechanisms regulating Tet1 induction by allergens are unknown. Our preliminary data supported that oxidative stress generated by HDM exposure activates Tet1 and its mediated upregulation of ASM genes. Based on these novel findings, we propose the central hypothesis "HDM activates Tet1-mediated hydroxymethylation in ASM cells through regulation of redox cycling. This epigenetic reprogramming persists in ASM over long time spans, thus likely contributes to the increased ASM cell proliferation, stiffness and contractility seen in human asthma". To address these novel hypotheses, we have assembled a multi-disciplinary team of investigators with a breadth of expertise spanning the fields of epigenetics, ASM biology, pulmonology and pathobiology. First, we will determine the role of Tet1- mediated DNA hydroxymethylation in the development of the AHR phenotype in a chronic HDM-induced AHR mouse model. Second, we will investigate how HDM alters the Tet1 activity, through redox cycling of NADH in both in vitro and in vivo mouse model. Lastly, we will confirm if TET1-mediated hydroxymethylation regulates human ASM cell phenotypes. The results of the proposed experiments should provide novel perspectives on the ASM and its contributions to the excessive airway narrowing in asthma. These insights may fuel the development of new therapeutic approaches for the treatment of this debilitating disease.

 描述（由申请人提供）：哮喘是一种以气道高反应性 (AHR) 和气道炎症为特征的复杂疾病，目前全球有 3 亿多人患有哮喘，尽管遗传因素无疑在哮喘中发挥着作用，但哮喘患病率的迅速上升表明：迄今为止，大多数研究表明，表观遗传调控至少在一定程度上介导了可能导致哮喘的复杂基因与环境相互作用。迄今为止，重点是阐明 T 细胞和 B 细胞等易于接近的细胞中的 DNA 甲基化模式，以 解释驱动哮喘患者过敏原致敏的免疫机制。很少有研究研究环境触发因素对肺组织的表观遗传影响，这些影响与肺功能的慢性改变有关。富含 Tgfb2 信号分子，与接触常见过敏原屋尘螨 (HDM) 以及通过气道平滑肌 (ASM) 细胞的表观遗传调节形成 AHR 相关此外，我们还发现了特异性 5-mC 双加氧酶 TET1 在体外调节 ASM 功能和体内过敏原驱动的 AHR 发展中的新作用，我们初步证明 Tet1 缺乏会减少急性 HDM-。令人惊讶的是，我们能够转化人类哮喘 ASM 细胞的表观遗传变化；表明 Tet1 介导的羟甲基化可能会影响 ASM 细胞的增殖和收缩。首次证明 Tet1 蛋白在过敏原暴露的情况下受到调节，尽管过敏原调节 Tet1 的机制尚不清楚。基于这些，我们的初步数据支持 HDM 暴露产生的氧化应激激活 Tet1 及其介导的 ASM 基因的上调。新颖的发现，我们提出了中心假设“HDM 通过氧化还原循环的调节激活 ASM 细胞中 Tet1 介导的羟甲基化。这种表观遗传重编程在 ASM 中持续很长时间跨度，因此可能导致人类哮喘中 ASM 细胞增殖、僵硬和收缩性增加”。为了解决这些新假设，我们组建了一个多学科研究团队，他们的专业知识涵盖表观遗传学、ASM 生物学领域首先，我们将确定 Tet1 介导的 DNA 羟甲基化在慢性 HDM 诱导的 AHR 小鼠模型中 AHR 表型发展中的作用。最后，我们将在体外和体内小鼠模型中通过 NADH 的氧化还原循环来改变 Tet1 活性。所提出的实验结果将为 ASM 和细胞表型提供新的视角。这些见解可能会推动治疗这种使人衰弱的疾病的新治疗方法的发展。

项目成果

Multigenerational Epigenetic Regulation of Allergic Diseases: Utilizing an Experimental Dust Mite-Induced Asthma Model.

过敏性疾病的多代表观遗传调控：利用实验性尘螨诱发的哮喘模型。

• 发表时间: 2021
• 作者: Pulczinski, Jairus C;Shang, Yan;Dao, Tyna;Limjunyawong, Nathachit;Sun, Qinying;Mitzner, Wayne;Cheng, Robert Ys;Tang, Wan
• 通讯作者: Tang, Wan