Inhibition of Histone Deacetylase 8 (HDAC8) as a Therapy for Pulmonary Fibrosis

项目总结/摘要：特发性肺纤维化（IPF）是一种进行性致死性肺部疾病 不太理想的治疗方法成纤维细胞增殖、迁移和成纤维细胞向肌成纤维细胞分化 (FMD)已被认为是纤维化进展的主要动力。然而，最近的研究已经开始， 揭示纤维化肺中成纤维细胞和肌成纤维细胞的巨大异质性， 促纤维化/病理性成纤维细胞和抗纤维化/修复性/再生性成纤维细胞。因此，有一个关键的 需要更好地表征成纤维细胞群体，并开发特异性靶向促纤维化的治疗剂， 在一些实施方案中，纤维化细胞可以促进成纤维细胞的增殖，同时伴随促进抗纤维化成纤维细胞的扩增。 Saito博士最近的数据表明，抑制组蛋白去乙酰化酶8（HDAC 8）代表了这样一种作用。 战略他发现：1）肺成纤维细胞中HDAC 8的敲低下调了基因的表达， 编码促增殖/促纤维化蛋白，同时上调编码抗增殖/促纤维化蛋白的基因的表达。 迁移/抗纤维化蛋白;和2）用HDAC 8选择性抑制剂治疗改善博来霉素- 诱导小鼠肺纤维化，可能是通过激活抗纤维化信号通路。 基于这些数据，Saito博士假设：1）抑制HDAC 8改善成纤维细胞 增殖，迁移和FMD通过修饰染色质结构，然后激活转录的抗- 2）HDAC 8的抑制通过扩大抗纤维化基因的表达而减少体内肺纤维化 成纤维细胞亚群。齐藤博士将以三个具体目标来检验这些假设。在第一个目标中，他将 使用功能测定确定HDAC 8抑制对成纤维细胞表型和基因调控的影响 (i.e.,增殖测定，迁移测定）和测序技术（即，RNA-seq、ATAC-seq、ChIP-seq）。 在第二个目标中，他将确定HDAC 8选择性抑制剂在细胞中的内在转录效应。 采用单细胞RNA-seq建立博莱霉素诱导的小鼠肺纤维化模型，并确定其作用 HDAC 8在细胞中促进体内纤维化消退。在第三个目标中，他将评估间充质细胞- 特异性HDAC 8基因敲除小鼠被保护免受博来霉素诱导的肺纤维化并探索类型 HDAC 8介导肺纤维化的细胞。 这项工作将在杜兰大学进行，由杰伊·科尔斯博士（主要负责人）指导。 导师），基因组学和肺生物学方面的公认专家，以及约瑟夫·拉斯基博士（共同导师），公认的 肺纤维化方面的专家，沿着有基因组学和表观遗传学方面的专家顾问。与 在指导委员会的指导下，齐藤博士制定了一个为期四年的综合培训计划， 培养成为一名具有基因组学和表观遗传学专业知识的独立研究者所需的技能 肺纤维化他对研究的承诺，强大的指导，以及杜兰大学对培训的奉献精神 下一代的科学家，将使他建立一个成功的职业生涯作为一个物理学家，科学家。

PROJECT SUMMARY/ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is a progressive fatal lung disease with suboptimal therapeutics. Fibroblast proliferation, migration, and fibroblast-to-myofibroblast differentiation (FMD) have been proposed as the major impetus for fibrosis progression. However, recent studies have begun to reveal great heterogeneity of fibroblasts and myofibroblasts in fibrotic lungs, which appear to contain both pro-fibrotic/pathologic fibroblasts and anti-fibrotic/reparative/regenerative fibroblasts. Thus, there is a critical need to better characterize fibroblast populations and to develop therapeutics specifically targeting pro-fibrotic fibroblasts while concomitantly promoting the expansion of anti-fibrotic fibroblasts. Dr. Saito’s recent data suggest that inhibition of histone deacetylase 8 (HDAC8) represents such a strategy. He discovered that: 1) HDAC8 knockdown in lung fibroblasts downregulates expression of genes encoding pro-proliferative/pro-fibrotic proteins while upregulating expression of genes encoding anti- migratory/anti-fibrotic proteins; and 2) treatment with an HDAC8-selective inhibitor ameliorates bleomycin- induced pulmonary fibrosis in mice, likely by activating anti-fibrotic signaling pathways. Based on these data, Dr. Saito hypothesizes that: 1) inhibition of HDAC8 ameliorates fibroblast proliferation, migration, and FMD by modifying chromatin structure and then activating transcription of anti- fibrotic genes; and 2) inhibition of HDAC8 reduces pulmonary fibrosis in vivo by expanding anti-fibrotic fibroblast subpopulations. Dr. Saito will test these hypotheses with three specific aims. In the first aim, he will define the effects of HDAC8 inhibition on fibroblast phenotype and gene regulation, using functional assays (i.e., proliferation assay, migration assay) and sequencing technologies (i.e., RNA-seq, ATAC-seq, ChIP-seq). In the second aim, he will identify cell intrinsic transcriptional effects of the HDAC8-selective inhibitor in a bleomycin-induced pulmonary fibrosis mouse model using single-cell RNA-seq, and determine the role of HDAC8 in cells promoting fibrosis resolution in vivo. In the third aim, he will assess whether mesenchymal cell- specific HDAC8 knockout mice are protected against bleomycin-induced pulmonary fibrosis and explore types of cells through which HDAC8 mediates pulmonary fibrosis. This work will be conducted at Tulane University, under the mentorship of Dr. Jay Kolls (the primary mentor), a recognized expert in genomics and lung biology, and Dr. Joseph Lasky (co-mentor), a recognized expert in pulmonary fibrosis, along with advisors who have expertise in genomics and epigenetics. With the guidance of his mentoring committee, Dr. Saito has developed a comprehensive four-year training program to develop the skills needed to become an independent investigator with expertise in genomics and epigenetics of pulmonary fibrosis. His commitment to research, strong mentorship, and the dedication of Tulane to training the next generation of scientists, will allow him to build a successful career as a physician-scientist.