Lifespan and healthspan regulation by hypoxic response transcription factor HIF-1

缺氧反应转录因子 HIF-1 对寿命和健康的调节

• 批准号: 8441592
• 负责人: MATT KAEBERLEIN
• 金额: $ 29.88万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8441592
• 关键词: Age; Aging; Animals; Biological Assay; Caenorhabditis elegans; Cell Nucleus; Disease; Family; Gene Expression; Gene Targeting; Genes; Goals; Growth; Health; Human; Hypoxia; Insulin; Intervention; Journals; Lead; Life; Longevity; Longevity Pathway; Malignant Neoplasms; Mammals; Mass Spectrum Analysis; Measures; Messenger RNA; Nematoda; Oxygen; Pathway interactions; Pigments; Plasmids; Play; Post-Translational Protein Processing; Proteins; Publications; Publishing; RNA Interference; Regulation; Reporting; Resistance; Role; Science; Series; Signal Transduction; Specificity; System; Temperature; Testing; Toxic effect; Transgenic Animals; Work; age related; base; cell type; chromatin immunoprecipitation; dietary restriction; fluorescent age pigment; human disease; knock-down; novel; overexpression; polyglutamine; promoter; public health relevance; response; therapeutic target; transcription factor; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): We recently identified the hypoxic response transcription factor, HIF-1, as a novel modifier of longevity and healthspan in Caenorhabditis elegans. In a study published in the journal Science, we showed that stabilization of HIF-1 by inhibiting its proteasomal degradation under normoxic conditions increases life span through a mechanism that is genetically distinct from dietary restriction and reduced insulin-like signaling, a finding that has since been independently replicated by two groups. We also showed that growth of wild type animals under hypoxia, which is sufficient to stabilize and activate HIF-1, also increases life span. Following publication of our study, the Kapahi lab reported that loss of HIF-1 increases life span under their experimental conditions. We have since determined that stabilization of HIF-1 increases life span in a temperature- independent manner, while loss of HIF-1 increases life span in a temperature-dependent manner. Unlike life span extension from activation of HIF-1 in normoxia, life span extension from deletion of HIF-1 or hypoxia requires the FOXO-family transcription factor DAF-16. Here we propose to further define the mechanisms by which HIF-1 modulates longevity and healthspan in C. elegans, both as a pro- and anti-longevity factor. In Specific Aim 1, we will (1) further define the experimental conditions under which deletion of HIF-1 can increase life span and determine whether healthspan is also extended under these conditions, (2) test the hypothesis that DAF-16 is activated by loss of HIF-1 or by hypoxia using chromatin immunoprecipitation to determine whether DAF-16 is localized to known or novel target genes, and (3) determine how DAF-16 becomes relocalized to the nucleus in response to loss of HIF-1 or hypoxia by using mass spectrometry to quantify known and novel post-translational modifications of DAF-16 in response to these interventions. In specific Aim 2, we will (1) use RNAi knock-down mRNAs that are differentially expressed in response to stabilization of HIF-1 to identify the downstream targets of HIF-1 that are involved in life span and healthspan extension when HIF-1 is stabilized under normoxic conditions and (2) determine whether these genes play a role in modulating longevity in response to other known longevity pathways. In specific Aim 3, we will determine which cell types are involved in modulating life span and healthspan extension from stabilization of HIF-1 under normoxic conditions by generating transgenic animals expressing either (1) the VHL-1 E3 ligase which targets HIF-1 for degradation or (2) a non-degradable form of HIF-1 under promoters with known cell- type specificities and quantifying the resulting effects on longevity and measures of healthspan. HIF-1 and the hypoxic response are highly conserved from nematodes to humans and have been implicated in human diseases, most notably a variety of cancers. Thus, a better understanding of the dual role that HIF-1 can play as a modifier of life span and healthspan in nematodes will lead to new hypotheses that can be directly tested in mammals, and is likely to be directly relevant to human health and age-related disease.

描述（由申请人提供）：我们最近鉴定了缺氧反应转录因子HIF-1，作为秀丽隐杆线虫中寿命和健康寿命的新修饰剂。在发表在《科学》杂志上的一项研究中，我们表明，通过在常氧条件下抑制HIF-1的蛋白酶体降解来稳定HIF-1，通过一种与饮食限制和减少胰岛素样信号传导在遗传上不同的机制来延长寿命，这一发现已经被两个小组独立复制。我们还表明，野生型动物在足以稳定和激活HIF-1的缺氧条件下的生长也延长了寿命。在我们的研究发表后，Kapahi实验室报告说，在他们的实验条件下，HIF-1的缺失增加了寿命。我们已经确定，HIF-1的稳定化以不依赖于温度的方式增加寿命，而HIF-1的损失以依赖于温度的方式增加寿命。与在常氧条件下激活HIF-1延长寿命不同，缺失HIF-1或缺氧延长寿命需要FOXO家族转录因子β-16。在这里，我们建议进一步确定HIF-1调节C. elegans，both都as a pro亲- and anti-lifetime抗长寿factor因子.在具体目标1中，我们将（1）进一步定义缺失HIF-1可以增加寿命的实验条件，并确定在这些条件下健康寿命是否也延长，（2）使用染色质免疫沉淀来测试HIF-16被HIF-1缺失或缺氧激活的假设，以确定HIF-16是否定位于已知或新的靶基因，和（3）通过使用质谱法定量响应于HIF-1丧失或缺氧的IFN-16的已知和新的翻译后修饰，确定IFN-16如何响应于HIF-1丧失或缺氧而重新定位于细胞核。在具体目标2中，我们将（1）使用响应于HIF-1的稳定而差异表达的RNAi敲低mRNA来鉴定当HIF-1在常氧条件下稳定时参与寿命和健康寿命延长的HIF-1的下游靶标，以及（2）确定这些基因是否响应于其他已知的长寿途径而在调节长寿中起作用。在具体目标3中，我们将通过产生转基因动物来确定哪种细胞类型参与调节在常氧条件下由HIF-1的稳定化引起的寿命和健康寿命延长，所述转基因动物表达（1）靶向HIF-1降解的VHL-1 E3连接酶或（2）在具有已知细胞因子的启动子下的HIF-1的不可降解形式。类型特异性和量化对寿命和健康寿命的措施产生的影响。HIF-1和缺氧反应从线虫到人类高度保守，并且与人类疾病有关，最值得注意的是各种癌症。因此，更好地理解HIF-1作为线虫寿命和健康寿命的调节剂的双重作用将导致新的假设，这些假设可以在哺乳动物中直接进行测试，并且可能与人类健康和年龄相关疾病直接相关。