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 虽然失去愈合过程对于成功的有机组织修复至关重要，但未能关闭这些问题 机制导致细胞外基质（ECM）的过量积累和发展 纤维化。尽管最近的研究开始阐明允许解决纤维化的情况，但 大多数纤维化条件仍未解决；导致器官衰竭或癌症的易感性。而 纤维化疾病的触发因素属于少数类别，包括病毒/细菌感染，组织损伤， 和化学侮辱，都诱导间充质细胞持续激活成肌纤维细胞。除了 转化生长因子β（TGF-β）是成纤维细胞的主要激活剂，ECM也具有能力 改变成纤维细胞的激活状态。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取出，但表明成纤维细胞获得了“表观遗传记忆” 在激活过程中保留并在此之后保留。但是，在表观调节的基础分子细节 肌纤维细胞激活以及这些细节是否是通用目的地，激活触发尚不清楚。 肌纤维细胞调节的一种潜在机制是通过ECM依赖性表达 纤维化基因。基因表达是一个严格调节的过程，需要染色质重塑，结合 转录激活剂和RNA聚合酶募集以启动转录。因此，结构 染色质的重组在基因的临时调节和组织特异性中起着重要作用 表达。梵天相关的基因1（BRG1）是BAF的中心催化ATP亚基（BRG1/BRM1-- 相关因子）复合物，可通过核小体驱逐来驱动染色质访问性。 BRG1也有 我们被证明可以调节健康和虚拟诱导的纤维化环境中的ECM基因表达。而且， 初步数据发现BRG1缺陷胰腺成纤维细胞失去了关键功能的表达 调节器Netrin G1。综上所述，这表明BRG1在控制肌纤维细胞促纤维纤维基因中的作用。 该提案的总体目标是检验ECM和纤维化诱导的病毒改变的假设 成纤维细胞的染色质景观以BRG1依赖性方式，并有助于表观遗传记忆 基础肌纤维细胞功能。 为了检验这一假设，AIM 1将首先研究BRG1参与胰腺成纤维细胞激活 体外以及是否受ECM介导的信号传导调节。在AIM 2中，实验将集中在 通过使用体内胰腺炎小鼠模型来调节疾病形成的BRG1。最后，AIM 3将基础 这些课程并研究了纤维化诱导的病毒引起肌纤维细胞激活的机制， 从经常人类病原体开始，流感病毒。通过使用新颖的观点来理解 纤维化，这项研究提供了可以推进细胞生物学，表观遗传学和病毒学的见解，并揭示了 ECM/病毒如何创建促纤维化状态。