Elucidating the epigenetic regulation of extracellular matrix and virus-induced fibroblast activation

阐明细胞外基质和病毒诱导的成纤维细胞活化的表观遗传调控

• 批准号: 10572863
• 负责人: Jaye C Gardiner
• 金额: $ 12.5万
• 依托单位: RESEARCH INST OF FOX CHASE CAN CTR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10572863
• 关键词: 2019-nCoV; ATAC-seq; Affect; Applied Skills; Bacterial Infections; Binding; Binding Proteins; Biological Markers; Categories; Cells; Cellular biology; ChIP-seq; Chemicals; Chromatin; Chronic Obstructive Pulmonary Disease; Communication; Complex; Connective Tissue; Coxsackie B Viruses; Cues; DNA-Directed RNA Polymerase; Data; Deposition; Development; Disease; Environment; Epigenetic Process; Excision; Extracellular Matrix; Failure; Fibroblasts; Fibrosis; Future; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Goals; Grant; Growth Factor; Hepatitis B Virus; Histone Acetylation; Human; In Vitro; Infection; Inflammatory Response; Influenza A virus; Knockout Mice; Lead; Link; Liver Fibrosis; Malignant Neoplasms; Mediating; Mesenchymal; Molecular; Myofibroblast; Nucleosomes; Organ; Organ failure; Pancreas; Pancreatitis; Pathologic; Patient Isolation; Phenotype; Play; Predisposition; Process; Pulmonary Fibrosis; Regulation; Reporting; Research; Resolution; Respiratory Tract Infections; Respiratory syncytial virus; Role; Signal Transduction; Simplexvirus; Specificity; Stimulus; Testing; Time; Tissue Sample; Tissues; Transcription Coactivator; Transcription Initiation; Transforming Growth Factor beta; Tropism; Viral; Virus; Virus Diseases; Work; brahma; chromatin remodeling; clinically relevant; cytokine; epigenetic memory; epigenetic regulation; experimental study; extracellular; falls; human pathogen; idiopathic pulmonary fibrosis; in vivo; innovation; insight; interstitial; memory acquisition; mouse model; netrin-G1; novel; pancreatic cancer patients; programs; recruit; repaired; response; skill acquisition; small molecule inhibitor; therapeutic target; tissue repair; transcriptome sequencing; virology; wound healing

PROJECT SUMMARY While wound healing processes are vital for successful organismal tissue repair, failure to turn off these mechanisms lead to the excessive accumulation of the extracellular matrix (ECM) and the development of fibrosis. Although recent research is beginning to illuminate the circumstances that allow for fibrosis resolution, most fibrotic conditions remain unresolved; resulting in organ failure or a predisposition to cancer. While the triggers for fibrotic diseases fall within a handful of categories, including viral/bacterial infection, tissue damage, and chemical insults, all induce the sustained activation of mesenchymal cells into myofibroblasts. Besides transforming growth factor β (TGF-β), which is a major activator of fibroblasts, the ECM also has the ability to alter a fibroblast’s activation state. We and others have demonstrated that this activated phenotype can persist despite the cell’s removal from fibrotic tissues, suggesting that fibroblasts have an “epigenetic memory” acquired during activation and retained thereafter. However, the molecular details underlying epigenetic regulation during myofibroblastic activation and whether these details are universal despite the activation trigger is unknown. One potential mechanism of myofibroblast regulation is through the ECM-dependent expression of pro- fibrotic genes. Gene expression is a tightly regulated process that requires chromatin remodeling, binding of transcriptional activators, and recruitment of RNA polymerase to initiate transcription. As such, the structural reorganization of the chromatin plays a large role in the temporal regulation and tissue specificity of gene expression. Brahma-related gene 1 (BRG1) is a central catalytic ATP-subunit of the BAF (BRG1/BRM1- associated factor) complex which works to drive chromatin accessibility via nucleosome eviction. BRG1 has also been shown to regulate ECM gene expression in both healthy and virally-induced fibrotic contexts. Moreover, preliminary data found that BRG1-deficient pancreatic fibroblasts lost the expression of a key functional regulator, Netrin G1. Taken together, this suggests a role of BRG1 in regulating myofibroblast pro-fibrotic genes. The overarching goal of this proposal is to test the hypothesis that the ECM and fibrosis-inducing viruses alter fibroblasts’ chromatin landscape in a BRG1-dependent manner and contribute to the epigenetic memory that underlies myofibroblastic function. To test this hypothesis, Aim 1 will first investigate BRG1’s involvement in pancreatic fibroblast activation in vitro and whether this is regulated by ECM-mediated signaling. In Aim 2, experiments will focus on the role of BRG1 in regulating disease formation by using an in vivo pancreatitis mouse model. Finally, Aim 3 will build on these lessons and investigate the mechanisms by which fibrosis-inducing viruses cause myofibroblast activation, beginning with the frequent human pathogen, Influenza A virus. By using a novel perspective to understanding fibrosis, this research provides insights that will advance cell biology, epigenetics, and virology, as well as reveal how the ECM/viruses create a pro-fibrotic state.

项目摘要 虽然伤口愈合过程对于成功的有机组织修复至关重要，但如果不能关闭这些功能， 机制导致细胞外基质（ECM）的过度积累和 纤维化虽然最近的研究开始阐明允许纤维化解决的情况， 大多数纤维化病症仍未得到解决;导致器官衰竭或易患癌症。而 纤维化疾病的触发因素属于少数几类，包括病毒/细菌感染，组织损伤， 和化学损伤都诱导间充质细胞持续活化为肌成纤维细胞。除了 除了转化生长因子β（TGF-β），其是成纤维细胞的主要活化剂之外，ECM还具有以下能力： 改变成纤维细胞的活化状态我们和其他人已经证明，这种激活的表型可以持续存在， 尽管细胞从纤维化组织中移除，这表明成纤维细胞具有获得的“表观遗传记忆”， 在激活期间并在其后保持。然而，在哺乳动物发育过程中，表观遗传调控的分子细节 成肌纤维细胞活化，以及这些细节是否是普遍的，尽管激活触发是未知的。 肌成纤维细胞调节的一个潜在机制是通过ECM依赖性的前胶原蛋白表达， 纤维化基因基因表达是一个严格调控的过程，需要染色质重塑， 转录激活因子，以及募集RNA聚合酶以启动转录。因此，结构 染色质的重组在基因表达的时间调控和组织特异性中起着重要作用。 表情Brahma相关基因1（BRG 1）是BAF的一个中心催化ATP亚基（BRG 1/BRM 1 - 1）。 相关因子）复合物，其通过核小体驱逐来驱动染色质可接近性。BRG 1还 在健康和病毒诱导的纤维化背景下，都显示出调节ECM基因表达。此外，委员会认为， 初步数据发现，BRG 1缺陷的胰腺成纤维细胞失去了一个关键的功能表达， 调节剂，Netrin G1。总之，这表明BRG 1在调节肌成纤维细胞促纤维化基因中的作用。 该提案的首要目标是测试ECM和纤维化诱导病毒改变细胞增殖的假设。 成纤维细胞的染色质景观在BRG 1依赖的方式，并有助于表观遗传记忆， 是肌纤维母细胞功能的基础。 为了验证这一假设，Aim 1将首先研究BRG 1参与胰腺成纤维细胞活化， 体外以及这是否受ECM介导的信号传导调节。在目标2中，实验将侧重于 BRG 1在使用体内胰腺炎小鼠模型调节疾病形成中的作用最后，目标3将建立在 这些教训和研究纤维化诱导病毒引起肌成纤维细胞活化的机制， 首先是常见的人类病原体，甲型流感病毒。用一种新颖的视角去理解 纤维化，这项研究提供的见解，将推进细胞生物学，表观遗传学和病毒学，以及揭示 ECM/病毒如何产生促纤维化状态。