Epigenetic Signaling in the Aging Hypothalamus

衰老下丘脑的表观遗传信号

• 批准号: 10056001
• 负责人: Alejandro Lomniczi
• 金额: $ 26.25万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10056001
• 关键词: 20 year old; Acute; Adrenal Glands; Adult; Affect; Age; Aging; Alzheimer' s Disease; Alzheimer' s disease pathology; Animal Model; Animals; Archives; Blood Circulation; Body fat; Brain; Circadian Rhythms; Clinical; Clinical Research; Clinical Trials; Cognitive; DNA Methylation; Data; Detection; Development; Diet; Disease; Elderly; Environment; Epigenetic Process; Estradiol; Estrogen Replacement Therapy; Estrogens; Excision; Exploratory/Developmental Grant; Exposure to; Fatty acid glycerol esters; Female; Foundations; Funding; Gene Expression; Gene-Modified; Genes; Goals; Gonadal Steroid Hormones; Hormonal; Hormonal Change; Hormone replacement therapy; Hypothalamic structure; Immune response; Impaired cognition; Individual; Inferior; Inflammation; Lead; Light; Macaca mulatta; Maintenance; Memory; Menopause; Menstrual cycle; Methylation; Modification; Molecular; Monkeys; Neuraxis; Neurosecretory Systems; Operative Surgical Procedures; Output; Ovarian; Ovary; Overweight; Pathology; Pathway interactions; Pattern; Physiological; Play; Positioning Attribute; Postmenopause; Prevention; Primates; RNA; Resolution; Rest; Sampling; Signal Transduction; Site; Sleep; Sleep Wake Cycle; Sleep disturbances; Symptoms; System; Testing; United States National Institutes of Health; Woman; Women' s Health; age related; attenuation; base; brain tissue; circadian; circadian pacemaker; cognitive benefits; cognitive performance; epigenetic profiling; experience; genome-wide; glucose metabolism; healthy aging; human model; improved; in vivo; insight; insulin sensitivity; mRNA Expression; neuropathology; neurotransmission; nonhuman primate; novel; sleep quality; spatial memory; sugar; suprachiasmatic nucleus; synaptic function; targeted treatment; transcriptome sequencing; translational model; young adult

PROJECT SUMMARY In women, aging is characterized by a marked decrease in circulating estrogen (E) levels, which negatively impacts many physiological systems including sleep-wake cycles and cognitive performance. Consequently, many postmenopausal women chose to undergo E hormone replacement therapy (HRT), with the hope of reversing or alleviating these negative symptoms. Unfortunately, the underlying neuroendocrine mechanisms associated with HRT are poorly understood and the long-term efficacy of these hormonal manipulations on the central nervous system are unclear, especially in women who are overweight. Using the rhesus macaque as a translational animal model, we previously demonstrated an age-associated increase in perturbed sleep-wake cycles, and found that individuals with the most perturbed cycles showed inferior cognitive performance in a spatial memory task, as well as compromised immune responses. We also demonstrated cognitive benefits resulting from long-term administration of E to old ovariectomized females; importantly, however, the beneficial effects of E on various physiological functions were not sustained in animals maintained on a high-fat, high- sugar Western-style diet (WSD). The goal of this R21 exploratory study is to test the hypothesis that age- related molecular changes within the suprachiasmatic nucleus (SCN) contribute to disrupted sleep-wake cycles and that these are exacerbated by the marked postmenopausal attenuation of circulating E concentrations, especially when concomitantly exposed to a WSD. Therefore, our study will examine DNA methylation developments within the SCN (Aim 1), and use RNA-seq to profile gene expression changes (Aim 2), using archived brain tissue from the following pair-groups of previously-characterized rhesus macaques: 1. Young adult ovary-intact females (on a standard diet) 2. Old ovary-intact females (on a standard diet) 3. Old ovariectomized females (on a standard diet) 4. Old ovariectomized females (on a standard diet + treated with HRT for ~3 years) 5. Old ovariectomized females (on a WSD for ~3 years) 6. Old ovariectomized females (on a WSD for ~3 years + treated with HRT for ~3 years) Using a previously-validated MethylSeq approach to provide single-base resolution DNA methylation data, we will examine differential methylation CpG (DMC) and region (DMR) in the SCN – i.e., the well-established site of the master circadian clock that plays a key role in sleep maintenance and synchronizing daily physiological functions. We predict that aging, maintenance on a WSD, and insufficient E in the circulation produce functional epigenetic modifications within the core clock mechanism of the SCN that result in perturbed circadian activity-rest pattern, and in turn predispose individuals to development of Alzheimer’s disease.

项目总结