Epigenetics, dysbiosis and inflammation in epithelial cells

上皮细胞的表观遗传学、生态失调和炎症

• 批准号: 8816932
• 负责人: DENIS F KINANE
• 金额: $ 40万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8816932
• 关键词: Address; Alveolar Bone Loss; Animal Model; Animals; Anti-Inflammatory Agents; Anti-inflammatory; Azacitidine; Biological Assay; Biopsy; Bone Resorption; Candidate Disease Gene; Cells; Chronic; Clinical; Clinical Research; Complex; Crown Lengthening; Cytokine Network Pathway; DNA; DNA Methylation; DNA Methyltransferase Inhibitor; DNA Modification Methylases; DNA analysis; Data; Decitabine; Diagnostic; Disease; Disease Progression; Disease susceptibility; Effectiveness; Engineering; Epigenetic Process; Epithelial; Epithelial Cells; Etiology; Excision; Exhibits; Functional disorder; Gene Expression; Gene Expression Profiling; Gene Silencing; Genes; Genetic; Gingiva; Gingivitis; Goals; Health; Homeostasis; Human; Hypermethylation; Immune; Immune response; Immunoprecipitation; In Vitro; Individual; Infection; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Response; Knock-out; Lead; Link; Literature; Measures; Methylation; Methyltransferase; Microbial Biofilms; Modification; Natural History; Natural Immunity; Oral; Pathogenesis; Pathology; Patients; Periodontal Diseases; Periodontitis; Pharmaceutical Preparations; Phenotype; Population; Porphyromonas gingivalis; Predisposition; Promoter Regions; Publishing; Regulation; Rodent Model; Role; Sampling; Signal Pathway; Signal Transduction; Signaling Molecule; Source; Specificity; TLR2 gene; Testing; Therapeutic; Therapeutic Agents; Tissues; Variant; Work; alveolar bone; antimicrobial; bone loss; cytokine; demethylation; epigenetic variation; in vivo; in vivo Model; inhibitor/antagonist; innovation; methylation pattern; mouse model; novel; novel therapeutic intervention; oncology; oral bacteria; pathogen; promoter; public health relevance; receptor; response; tool; transcriptome sequencing

DESCRIPTION (provided by applicant): Periodontitis is a common complex chronic inflammatory disease initiated by a microbial biofilm and is a significant health burden for the population. This competing renewal investigates variation in human gingival epithelial cells' inflammatory responses that may elucidate human susceptibility to periodontal disease and other chronic inflammatory conditions in general and provide diagnostic and therapeutic tools to treat these complex diseases. TLR deficiencies and altered downstream signaling is now being appreciated in many disease pathologies. Our long-term goal is to unravel human inflammatory dysfunctions that render patients susceptible to periodontal disease. We aim to define the mechanism whereby genetic factors modify the inflammatory response. A major advance in understanding variation comes from our recent observation that there is a hypermethylated TLR2 promoter region in cells with dysfunctional inflammatory responses that exhibited a blunted cytokine response which could hampers anti-inflammatory signaling. Thus inflammatory responses are prolonged and contribute to the inflammatory burden. Our central question in this continuation is "Does epigenetic dysregulation creates dysbiosis?" Our preliminary data suggest that hyper-methylation of promoter regions in epithelial cells causes a diminished host response by silencing pivotal innate immune genes. The present proposal aims to characterize epithelial cells in vitro by challenging Porphyromonas gingivalis, to test the in vivo model to reverse epigenetic modifications and a clinical study to unravel epigenetic modifications in disease susceptibility. Inhibition of de novo DNA methylation using DNA methyltransferase inhibitors has been regarded as a new therapeutic approach in oncology. Nonetheless, their mechanism of action and specificity of these drugs are not clearly understood. The proposed in vivo model will test the specificity and utility of DNA methyltransferase in restoring the epigenetically silenced TLR related genes. This innovative proposal involves in vitro, in vivo animal and human clinical samples to elucidate disease susceptibility, and introduces DNA methyltransferase inhibitor as a potential therapeutic agent for periodontal disease. Specifically, Aim 1 will determine and engineer the altered methylation pattern of the TLR2 promoter DNA in dysfunctional epithelial cells following P. gingivalis infection. This will utilize DNA methyltransferase inhibitor 5-azacytidine (decitabine) to reverse the methylation of the TLR2 gene promoter to restore the normal TLR2 inflammatory response to P. gingivalis. This aim will test whether TLR2 hypermethylation influences innate immune dysregulation and whether active demethylation restores TLR2 functionality in dysregulated cells. In Aim 2, we will use the oral gavage mouse model to study the ability of P. gingivalis to induce epigenetic changes. The chronic inflammation induced alveolar bone loss will be studied and the consequence of bacterial induced methylation will be investigated. This aim will also test the utility of Decitabine as a therapeutic drug against periodontitis, and in Aim 3, Clinical studies are proposed to investigate epigenetic changes in epithelial cells of individuals with periodontitis. This will address cross-sectionally whether TLR2 promoter hypermethylation is relevant in the natural history of periodontal disease and if it influences a subjects' susceptibility to disease and whether an experimental gingivitis induce epigenetic alteration in the gingiva.

描述（由申请人提供）：牙周炎是一种常见的由微生物生物膜引发的复杂慢性炎症性疾病，是人群的重要健康负担。这种竞争性更新研究了人类牙龈上皮细胞炎症反应的变化，可能阐明人类对牙周病和其他慢性炎症的易感性，并为治疗这些复杂疾病提供诊断和治疗工具。TLR缺陷和下游信号的改变现在在许多疾病病理中得到重视。我们的长期目标是解开人类炎症功能障碍，使患者易患牙周病。我们的目标是确定遗传因素改变炎症反应的机制。在理解变异方面的一个重大进展来自于我们最近的观察，即在炎症反应功能失调的细胞中存在一个高甲基化的TLR2启动子区域，该区域表现出迟钝的细胞因子反应，可能阻碍抗炎信号传导。因此，炎症反应被延长，并导致炎症负担。我们这节课的中心问题是“表观遗传失调会造成生态失调吗？”我们的初步数据表明，上皮细胞启动子区域的超甲基化通过沉默关键的先天免疫基因导致宿主反应减弱。本研究旨在通过挑战牙龈卟啉单胞菌在体外表征上皮细胞，测试体内模型以逆转表观遗传修饰，并开展临床研究以揭示表观遗传修饰在疾病易感性中的作用。利用DNA甲基转移酶抑制剂抑制新生DNA甲基化已被认为是肿瘤治疗的新途径。然而，这些药物的作用机制和特异性尚不清楚。提出的体内模型将测试DNA甲基转移酶在恢复表观遗传沉默的TLR相关基因中的特异性和实用性。这一创新的建议涉及体外、体内动物和人类临床样本来阐明疾病易感性，并介绍了DNA甲基转移酶抑制剂作为牙周病的潜在治疗剂。具体来说，Aim 1将确定和设计功能失调上皮细胞在牙龈假单胞菌感染后TLR2启动子DNA甲基化模式的改变。这将利用DNA甲基转移酶抑制剂5-氮杂胞苷（地西他滨）来逆转TLR2基因启动子的甲基化，以恢复正常的TLR2对牙龈卟啉菌的炎症反应。本研究旨在测试TLR2超甲基化是否会影响先天免疫失调，以及活性去甲基化是否会恢复失调细胞中的TLR2功能。在Aim 2中，我们将使用灌胃小鼠模型来研究牙龈假单胞菌诱导表观遗传改变的能力。慢性炎症诱导的牙槽骨丢失将被研究，细菌诱导的甲基化的后果将被调查。该目标还将测试地西他滨作为治疗牙周炎药物的效用，在目标3中，提出临床研究以调查牙周炎患者上皮细胞的表观遗传变化。这将横断面探讨TLR2启动子高甲基化是否与牙周病的自然史相关，是否影响受试者对疾病的易感性，以及实验性牙龈炎是否会诱导牙龈的表观遗传改变。