Role of Histone Deacetylase 9 (HDAC9) in adipose tissue aging: mitochondrial function, oxidative stress and senescence

组蛋白脱乙酰酶 9 (HDAC9) 在脂肪组织衰老中的作用：线粒体功能、氧化应激和衰老

基本信息

批准号：
10707000
负责人：
Brandee Goo
金额：
$ 5.27万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-15 至 2025-08-14
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10707000
关键词：
1 year old Acceleration Adipocytes Adipose tissue Affect Age Aging Area Biology Blood Vessels Body Composition CCL2 gene Cardiovascular Diseases Cell Aging Cell Culture Techniques Cells Confocal Microscopy Data Development Diet Digestion Disease Down-Regulation Energy Metabolism Epigenetic Process Female Fluorescence Fostering Gene Deletion Genes Genus Hippocampus HDAC9 gene Harvest Health High Fat Diet Histone Deacetylase Human Image Immunofluorescence Immunologic Immunohistochemistry Impairment In Vitro Inflammation Knock-out Knockout Mice Knowledge Laboratories Link LoxP-flanked allele Measurement Measures Mediator Mentorship Metabolic Metabolic Diseases Metabolic dysfunction Mitochondria Monitor Mus Obesity Oxidative Stress Physicians Play Predisposition Primary Cell Cultures Proteins Quantitative Reverse Transcriptase PCR Reactive Oxygen Species Recording of previous events Repression Research Role Scientist Stains Sterility Technical Expertise Testing Therapeutic Tissue Stains Tissue imaging Tissues Training Transgenic Mice Transgenic Organisms Transmission Electron Microscopy UV induced Ultraviolet Rays Universities Western Blotting adiponectin adipose derived stem cell aged beta-Galactosidase career collagenase confocal imaging detection assay diacetyldichlorofluorescein global health glucose tolerance improved insight insulin tolerance male medical schools microscopic imaging mitochondrial dysfunction mouse model novel overexpression post-doctoral training pre-doctoral prevent protein expression senescence stress reduction systemic inflammatory response

项目摘要

PROJECT SUMMARY Adipose tissue is a major depot for senescent cell accumulation and sterile inflammation in aging. While adipose tissue senescence in aging is causally linked to mitochondrial dysfunction and oxidative stress, the underlying mechanisms are undefined. Here, we propose the novel hypothesis that histone deacetylase 9 (HDAC9), a class II histone deacetylase, plays a key role in promoting adipose tissue senescence in aging by promoting mitochondrial dysfunction. Our preliminary data demonstrate that HDAC9 expression is increased in adipose tissues of aged mice and humans. Moreover, HDAC9 gene deletion improves adipose tissue mitochondrial energy expenditure and reduces adipose stem cell (ASC) senescence in 1-year-old chow diet fed mice, while protecting ASCs against senescence in vitro. Our hypothesis will be tested with two specific aims. Aim 1 will test the hypothesis that increased HDAC9 expression in aged adipose tissues contributes to mitochondrial dysfunction and oxidative stress by disrupting mitochondrial dynamics. Our preliminary data suggest that HDAC9 is strongly upregulated in the mature adipocytes of aged mice. Therefore, we will employ two novel mouse models to test our hypothesis: adipocyte-specific HDAC9 knockout (A-KO; HDAC9flox/flox adiponectin-Cre) and adipocyte-specific transgenic (A-Tg, HDAC9Tg-flox-STOP-flox adiponectin-Cre) mice. Primary ASCs will be cultured and differentiated to mature adipocytes. Mitochondrial function and dynamics will be measured in adipose tissue explants and mature adipocytes using the Seahorse analyzer, Western blot, immunofluorescence, transmission electron microscopy and confocal imaging. Aim 2 will test the hypothesis that HDAC9 gene deletion represses the development of adipose tissue senescence and promotes healthy adipose tissue aging, while overexpression of HDAC9 accelerates adipose tissue aging and augments senescence. We will quantify senescent cell accumulation in adipose tissue and metabolic health through glucose and insulin tolerance testing. ASC cultures from global HDAC9 knockout mice will be used to assess susceptibility to UV-induced senescence. Additionally, senescent cell accumulation in A-KO and A-Tg mice will be assessed by senescence-associated β-galactosidase staining, qRT-PCR and Western blot. This project will allow me to acquire deep knowledge of mitochondrial biology while developing new technical skills, including primary cell culture, tissue staining and imaging. Most importantly, it will allow me to gain expertise in conducting rigorous, hypothesis-driven research, thus setting the stage for a career as a physician-scientist. The project will be conducted under the mentorship of Dr. Neal Weintraub and co-mentorship of Dr. Masuko Ushio-Fukai in the Vascular Biology Center at the Medical College of Georgia at Augusta University, which has a rich history of successful pre- and post-doctoral training. We anticipate that findings from this proposal will identify elevated HDAC9 expression in adipose tissue aging as a key mediator of mitochondrial dysfunction and senescence and will provide insight into potential therapeutic approaches to improve adipose tissue health in aging.

项目概要脂肪组织是衰老细胞积累和衰老过程中无菌炎症的主要仓库。衰老过程中的组织衰老与线粒体功能障碍和氧化应激有因果关系，这是潜在的在此，我们提出了一个新的假设：组蛋白脱乙酰酶 9 (HDAC9)，一类。 II组蛋白脱乙酰酶，通过促进衰老，在促进脂肪组织衰老中发挥关键作用我们的初步数据表明 HDAC9 表达在脂肪中增加。此外，HDAC9 基因缺失可改善脂肪组织线粒体。 1 岁饲料喂养的小鼠的能量消耗并减少脂肪干细胞 (ASC) 衰老，同时我们的假设将通过两个具体目标进行测试。假设衰老脂肪组织中 HDAC9 表达增加有助于线粒体我们的初步数据表明 HDAC9 通过破坏线粒体动力学来抑制功能障碍和氧化应激。在老年小鼠的成熟脂肪细胞中强烈上调，因此，我们将采用两只新小鼠。检验我们假设的模型：脂肪细胞特异性 HDAC9 敲除（A-KO；HDAC9flox/flox 脂联素-Cre）和将培养脂肪细胞特异性转基因（A-Tg、HDAC9Tg-flox-STOP-flox 脂联素-Cre）小鼠。并在脂肪组织中测量分化为成熟脂肪细胞的线粒体功能和动态。使用 Seahorse 分析仪、蛋白质印迹、免疫荧光、透射法分析外植体和成熟脂肪细胞电子显微镜和共聚焦成像将检验 HDAC9 基因缺失抑制的假设。脂肪组织衰老的发展并促进健康脂肪组织衰老，而过度表达 HDAC9 加速脂肪组织老化并增强衰老我们将量化衰老细胞。通过葡萄糖和胰岛素耐量测试来了解脂肪组织的积累和代谢健康。来自全球 HDAC9 敲除小鼠的细胞将用于评估对紫外线诱导的衰老的易感性。 A-KO 和 A-Tg 小鼠中衰老细胞的积累将通过衰老相关的 β-半乳糖苷酶进行评估染色、qRT-PCR 和蛋白质印迹这个项目将使我深入了解线粒体。生物学，同时开发新的技术技能，包括原代细胞培养、组织染色和成像。重要的是，它将使我获得进行严格的、假设驱动的研究的专业知识，从而设定该项目将在尼尔博士的指导下进行。 Weintraub 和医学院血管生物学中心 Masuko Ushio-Fukai 博士的共同指导乔治亚州奥古斯塔大学拥有丰富的博士前和博士后培训成功历史。预计该提案的结果将确定脂肪组织衰老中 HDAC9 表达升高是一个线粒体功能障碍和衰老的关键介质，将为潜在的治疗提供见解改善衰老过程中脂肪组织健康的方法。