Epigenetic gene repression in pulmonary fibrosis

项目总结 肺纤维化是全球范围内日益增加的死亡原因，尽管有数十年的研究， 随着这种疾病如何开始和发展，存在着相当大的不确定性。而多发性纤维化 分子已被发现驱动异常基质沉积，这种机制负责维持 持续性和自持性纤维化在很大程度上是未知的。目标确定机制，使 成纤维细胞在疾病进展过程中的病理状态可能是一种有吸引力的治疗策略 阻止肺纤维化。目前的建议涉及表观基因抑制在调节成纤维细胞中的作用。 活化与肺纤维化的发展。我们将研究组蛋白3赖氨酸9甲基化的作用 (H3K9Me)是一种重要的表观遗传修饰，它抑制了关键基因的转录 使肺成纤维细胞保持或恢复到抗纤维化或静止的不活跃状态。我们的初步数据 证明通过靶向H3K9甲基转移酶G9a或表观遗传学来抑制H3K9甲基化 阅读器CBX5有效地抑制成纤维细胞的激活。从机制上讲，我们的数据表明 G9a和Cbx5都直接参与抑制线粒体的主要调节因子pGc1 病变肺成纤维细胞代谢显著下调。前列腺素C_1表达缺失促进 成纤维细胞的激活，同时通过表观遗传机制恢复Pgc1逆转成纤维细胞的激活。我们会 使用功能丧失策略靶向表观遗传调控基因CBX5和G9a来研究它们的 成纤维细胞在激活和静止状态之间切换的机械作用。利用小鼠遗传学 我们将研究抑制H3K9甲基化在阻止疾病进展方面的好处 博莱霉素性肺纤维化模型。因为我们的初步数据有力地支持了抗肝纤维化的作用。 Pgc1在肺成纤维细胞体外活化过程中的作用，在本研究中，我们将进一步研究其抗纤维化作用。 功能和评估上游和下游的转录网络，介导其抗纤维化功能。 综上所述，拟议的研究将揭示治疗的关键表观遗传学靶点。 旨在阻止或逆转肺纤维化进展的干预措施。

PROJECT SUMMARY Pulmonary fibrosis represents an increasing cause of mortality worldwide and despite decades of investigation, considerable uncertainty exists as how this disease initiates and progresses. While multiple fibrogenic molecules have been found to drive aberrant matrix deposition, the mechanisms responsible for maintaining persistent and self-sustaining fibrogenesis are largely unknown. Targeting mechanisms that perpetuate the pathological state of fibroblasts during disease progression may serve as an attractive therapeutic strategy to halt lung fibrosis. The current proposal addresses the role of epigenetic gene repression in regulating fibroblast activation and lung fibrosis development. We will investigate the role of histone 3 lysine 9 methylation (H3K9me) as an important epigenetic modification that represses the transcription of genes essential to maintaining or returning lung fibroblasts to an anti-fibrotic or quiescent inactive state. Our preliminary data demonstrate that inhibition of H3K9 methylation by targeting the H3K9 methyltransferase G9a or the epigenetic reader CBX5 potently inhibits fibroblast activation by fibrogenic stimuli. Mechanistically, our data demonstrate that both G9a and CBX5 are directly involved in repressing PGC1, a master regulator of mitochondria metabolism significantly downregulated in diseased lung fibroblasts. Loss of PGC1 expression promotes fibroblast activation, while restoring PGC1 via epigenetic mechanisms reverses fibroblast activation. We will use loss of function strategies to target the epigenetic regulators CBX5 and G9a to investigate their mechanistic roles in switching fibroblasts between activated and quiescence states. Using mouse genetics approaches we will investigate the benefits of inhibiting H3K9 methylation in halting disease progression in bleomycin-induced lung fibrosis models. As our preliminary data strongly support an anti-fibrotic function for PGC1 during lung fibroblast activation in vitro, in this proposal we will further characterize its anti-fibrotic function and evaluate upstream and downstream transcriptional network that mediate its anti-fibrotic functions. Taken together, the proposed research studies will reveal critical epigenetic targets for therapeutic interventions aimed at halting or reversing the progression of pulmonary fibrosis.