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

项目摘要/摘要：特发性肺纤维化(IPF)是一种进行性致命的肺部疾病。 用次优疗法。成纤维细胞的增殖、迁移和成纤维细胞向肌成纤维细胞的分化 (FMD)已被认为是纤维化进展的主要推动力。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高度异质性，两者似乎都包含 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专门针对促纤维化的治疗药物 同时促进抗纤维化成纤维细胞的扩张。 齐藤博士最近的数据表明，抑制组蛋白脱乙酰酶8(HDAC8)代表了这样一种 策略。他发现：1)肺成纤维细胞中HDAC8基因的敲除下调了基因的表达 编码促增殖/促纤维化蛋白，同时上调编码抗癌基因的表达 迁移/抗纤维化蛋白；以及2)HDAC8选择性抑制剂的治疗改善博莱霉素。 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，齐藤博士假设：1)抑制HDAC8可以改善成纤维细胞 通过改变染色质结构进而激活反义核糖核酸的转录，促进细胞的增殖、迁移和口蹄疫 肝纤维化基因；2)抑制HDAC8通过扩大抗纤维化作用减少体内肺纤维化 成纤维细胞亚群。斋藤博士将通过三个具体目标来检验这些假说。在第一个目标中，他将 利用功能分析确定HDAC8抑制对成纤维细胞表型和基因调控的影响 (即，增殖试验、迁移试验)和测序技术(即，RNA-SEQ、ATAC-SEQ、CHIP-SEQ)。 在第二个目标中，他将确定HDAC8选择性抑制剂在细胞中的内在转录效应 应用单细胞RNA-seq法建立博莱霉素诱导的小鼠肺纤维化模型，并测定其作用 HDAC8在细胞内促进体内纤维化的消退。在第三个目标中，他将评估间充质细胞- 特异性HDAC8基因敲除小鼠对博莱霉素性肺纤维化的保护作用及类型探讨 HDAC8通过其介导肺纤维化的细胞。 这项工作将在杜兰大学进行，在Jay Kolls博士(主要 Mentor)，公认的基因组学和肺部生物学专家；Joseph Lasky博士(共同导师)，公认的 肺纤维化专家，以及在基因组学和表观遗传学方面有专长的顾问。与 在指导委员会的指导下，齐藤博士制定了一个全面的四年培训计划，以 培养成为一名拥有基因组学和表观遗传学专业知识的独立研究员所需的技能 肺纤维化的症状。他对研究的承诺，强大的指导，以及杜兰对训练的奉献 下一代科学家，将使他作为一名内科科学家建立一个成功的职业生涯。

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.