Does Necroptosis Play a Role in Inflammation and Aging

坏死性凋亡在炎症和衰老中起作用吗

• 批准号: 10454859
• 负责人: ARLAN G. RICHARDSON
• 金额: --
• 依托单位: OKLAHOMA CITY VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10454859
• 关键词: Affect; Age; Age-Years; Aging; Alzheimer' s Disease; Alzheimer' s disease model; Amyotrophic Lateral Sclerosis; Animals; Apoptosis; Atherosclerosis; Attenuated; Autopsy; Binding; Brain; Cardiovascular Diseases; Cell Death; Cell membrane; Cells; Chronic; Cognition; Cytolysis; Data; Disease; Dwarfism; Elderly; FRAP1 gene; Feedback; Generations; Hand Strength; Human; Immune; Individual; Inflammaging; Inflammasome; Inflammation; Intervention; Knock-out; Knockout Mice; Link; Longevity; MAP Kinase Gene; Malignant Neoplasms; Measures; Mediating; Mitochondrial DNA; Molecular; Morbidity - disease rate; Mus; Necrosis; Neurodegenerative Disorders; Non-Insulin-Dependent Diabetes Mellitus; Oxidative Stress; Pathology; Pathway interactions; Pattern; Performance; Persons; Pharmacology; Phosphorylation; Phosphotransferases; Play; Production; Protein Kinase; Proteins; RIPK1 gene; RIPK3 gene; Research; Risk Factors; Role; Signal Transduction; Stimulus; TNF gene; Testing; Tissues; Transcription Factor AP-1; United States Department of Veterans Affairs; Up-Regulation; Veterans; Wild Type Mouse; age effect; age related; anti aging; base; cell type; cytokine; demographics; dietary restriction; frailty; healthspan; improved; inhibitor; insulin sensitivity; military veteran; mortality; mouse model; neuron loss; novel; prevent

Chronic, low-grade inflammation (inflammaging) is a hallmark of aging and is a major risk factor for both morbidity and mortality in the elderly humans. In addition, inflammation is a major risk factor for a variety of age-related diseases, e.g. type 2 diabetes, cardiovascular disease, cancer, neurodegenerative diseases, frailty, etc. Despite the link between inflammation, aging, and age-associated diseases, we do not know the molecular mechanism(s)/pathway(s) responsible for the chronic, low-grade inflammation seen in old animals and whether the increase in chronic inflammation is a causative factor in aging and age-related diseases. Necroptosis is a recently identified pathway of programmed necrosis that induces cell death through the lysis of cells, resulting in the release of damage-associated molecular patterns (DAMPs) from the dead cells. DAMPs are potent inducers of inflammation, and circulating DAMPs have been shown to increase with age in humans and to be strongly correlated to the level of inflammation in the individual. We hypothesize that necroptosis plays a role in chronic, low-grade inflammation, which occurs with age, and preventing necroptosis will attenuate inflammation, leading to increased lifespan, improved healthspan, and reduced age-related pathology. We will use genetically modified mouse models and a pharmacological intervention to block/reduce apoptosis by targeting the receptor-interacting protein kinases (RIPK) 1 or 2 and mixed lineage kinase domain like (MLKL) protein, which are involved in the initiation of necroptosis. Aim1. Determine the role of necroptosis in chronic inflammation that occurs with age and the types of cells undergoing necroptosis. We will determine the effect of reducing necroptosis either genetically (using Ripk3+/-, Ripk3-/-, Mlkl+/-, and Mlkl-/- mice) or pharmacologically (treating with necrostatin-1s, a RIPK1 inhibitor) on inflammation. We will also identify the cell type(s) that undergo necroptosis in selected tissues of old mice. Based on our hypothesis, we predict that those tissues showing an up-regulation in necroptosis with age will show an increase in production of proinflammatory cytokines and reducing/blocking necroptosis will decrease inflammation in these tissues as well as circulating levels of proinflammatory cytokines. Aim2. Identify the pathways that increase necroptosis with age and determine the mechanism(s) that mediates the age-related increase in inflammation arising from necroptosis. TNFα, oxidative stress, and mTOR signaling have been proposed to initiate necroptosis, and these pathways increase with age. In Aim 2, we determine the role of these pathways play in the age-related increase in necroptosis using specific inhibitors to each of the pathways. DAMPs released by necroptotic cells induce inflammation through activation of three pathways: the IKK-NF-κB, MAPK-AP1 and inflammasome pathways. In Aim 2, we will also assess the effect of age on the activation of these pathways in various tissues of WT mice and determine which of the pathways are reduced when necroptosis is reduced/blocked in Ripk3 and Mlkl knockout mice or by necrostatin-1s treatment. Aim3. Determine the role of necroptosis in aging. In Aim 3, two groups of mice in which necroptosis has been blocked/reduced will be compared to wildtype mice. Mouse models (e.g., Ripk3 and/or Mlkl knockout mice) will be used that we find block inflammaging in Aim 1. The lifespan, healthspan (e.g., activity, rotarod performance, grip strength, insulin sensitivity, cognition, etc.), and age-associated pathology of these mice will be compared to WT mice. Based on our hypothesis, we predict that reducing/blocking necroptosis will retard aging as shown by improved healthspan, reduced pathology, and increased lifespan. These data would provide the first direct evidence that necroptosis induced inflammation is directly involved in aging and that chronic, low-grade inflammation plays a role in aging and the increase in pathology and age-related diseases.

慢性低度炎症（炎症）是衰老的标志，也是两者的主要危险因素 老年人的发病率和死亡率。此外，炎症是多种疾病的主要危险因素。 与年龄相关的疾病，例如2型糖尿病、心血管疾病、癌症、神经变性疾病， 尽管炎症，衰老和年龄相关疾病之间存在联系，但我们不知道 在老年动物中观察到的慢性、低度炎症的分子机制/途径 以及慢性炎症的增加是否是衰老和与年龄有关的疾病的致病因素。 坏死性凋亡是最近发现的一种程序性坏死途径，其通过裂解诱导细胞死亡， 导致死亡细胞释放损伤相关分子模式（DAMP）。 DAMPs是炎症的有效诱导物，并且循环DAMPs已被证明随着年龄的增长而增加。 并且与个体中的炎症水平强烈相关。我们假设 坏死性凋亡在慢性低度炎症中起作用，这种炎症随着年龄的增长而发生， 坏死性凋亡将减轻炎症，从而延长寿命，改善健康状况， 减少与年龄相关的病理学。我们将使用转基因小鼠模型和药理学方法， 通过靶向受体相互作用蛋白激酶（RIPK）1或2进行干预以阻断/减少细胞凋亡， 混合谱系激酶结构域样（MLKL）蛋白，其参与坏死性凋亡的起始。 目标1.确定坏死性凋亡在随着年龄增长而发生的慢性炎症中的作用， 细胞坏死我们将确定减少坏死性凋亡的影响，无论是遗传（使用 Ripk 3 +/-、Ripk 3-/-、Mlkl+/-和Mlkl-/-小鼠）或RIPK（用坏死抑素-1s（一种RIPK 1抑制剂）治疗） 关于炎症我们还将鉴定在老年小鼠的选定组织中经历坏死性凋亡的细胞类型。 基于我们的假设，我们预测随着年龄的增长，坏死性凋亡的组织表达上调， 显示促炎细胞因子产生的增加和减少/阻断坏死性凋亡将减少 这些组织中的炎症以及促炎细胞因子的循环水平。 目标2。确定随着年龄增长而增加坏死性凋亡的途径，并确定 介导由坏死性凋亡引起的与年龄相关的炎症增加。TNFα、氧化应激和 已经提出mTOR信号传导启动坏死性凋亡，并且这些途径随着年龄增加而增加。在目标2中， 我们确定这些途径在与年龄相关的坏死性凋亡增加中的作用， 抑制剂的每一个途径。坏死性凋亡细胞释放的DAMP通过以下途径诱导炎症： IKK-NF-κB、MAPK-AP 1和炎性小体通路。在目标2中，我们还将 评估年龄对WT小鼠各种组织中这些途径活化的影响，并确定 当在Ripk 3和Mlkl敲除小鼠中减少/阻断坏死性凋亡时，哪些途径减少，或者 necrostatin-1 s治疗。 目标3。确定坏死性凋亡在衰老中的作用。在目标3中，两组小鼠中， 将被阻断/减少的小鼠与野生型小鼠进行比较。小鼠模型（例如，Ripk 3和/或Mlkl敲除 小鼠）将被使用，我们发现在Aim 1中阻断炎症。寿命、健康寿命（例如，活动，旋转棒 性能、握力、胰岛素敏感性、认知等），这些小鼠的年龄相关病理学将 与WT小鼠相比。基于我们的假设，我们预测减少/阻断坏死性凋亡将延缓 衰老，表现为改善的健康寿命、减少的病理和增加的寿命。这些数据将 提供了第一个直接证据，即坏死性凋亡诱导的炎症直接参与衰老， 慢性、低度炎症在衰老和病理学和年龄相关疾病的增加中起作用。