Hormesis/Adaptive Stress Responses and Aging

毒物兴奋/适应性应激反应和衰老

• 批准号: 8335823
• 负责人: Mark Mattson
• 金额: $ 39.29万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8335823
• 关键词: Affect; Age; Age-Months; Aging; Alkaline Phosphatase; Amyloid; Animal Model; Antioxidants; Attenuated; Biological Assay; Body Weight decreased; Botanicals; Brain; Brain Injuries; Brain-Derived Neurotrophic Factor; Calmodulin; Capillary Electrophoresis; Cell membrane; Cell model; Cells; Cellular Stress; Cellular Stress Response; Cerebral cortex; Cerebrovascular Disorders; Cerebrum; Cessation of life; Characteristics; Chemical Agents; Chemicals; Chloride Ion; Chlorides; Cognitive; Corpus striatum structure; Cyclic AMP-Responsive DNA-Binding Protein; DNA Damage; DNA Repair; DNA lesion; DNA-(apurinic or apyrimidinic site) lyase; Diet; Disease; Dose; Elderly; Electroconvulsive Shock; Electroconvulsive Therapy; Electrons; Energy Intake; Energy Metabolism; Environment; Environmental Risk Factor; Enzymes; Evolution; Exhibits; Exposure to; Fasting; Fibroblast Growth Factor 2; Food; Functional disorder; GRP78 gene; Genes; Glutamate Receptor; Glutamates; Heat-Shock Proteins 70; Hippocampus (Brain); Human; Huntington Disease; Impairment; Inflammatory; Inherited; Injury; Insecta; Insecticides; Intervention; Ischemic Brain Injury; Ischemic Stroke; Learning; Measures; Mediating; Membrane; Memory; Messenger RNA; Metabolic; Metals; Middle Cerebral Artery Occlusion; Mitochondria; Molecular; Molecular Chaperones; Motor; Mus; Mutant Strains Mice; Mutation; NQO1 gene; Nerve Degeneration; Neurodegenerative Disorders; Neurologic; Neurons; Neurotransmitters; Nuclear; Organism; Outcome; Oxidation-Reduction; Oxidative Stress; Pathology; Pathway interactions; Permeability; Pesticides; Phosphorylation; Physiological; Phytochemical; Placebos; Plants; Prevalence; Process; Production; Protein Binding; Proteins; RNA Interference; Reactive Oxygen Species; Receptor Activation; Recycling; Reperfusion Therapy; Reporter; Resistance; Response Elements; Risk Factors; Rodent; Running; Signal Pathway; Stress; Symptoms; Synapses; System; Technology; Therapeutic; Tissue Sample; Toxic effect; Ubiquinone; Up-Regulation; Water; Work; age related; base; biological adaptation to stress; biological systems; brain cell; brain tissue; chelation; cytochrome b5 reductase; cytokine; dietary restriction; enzyme activity; fighting; functional disability; functional outcomes; hazard; heme oxygenase-1; human Huntingtin protein; human SOD2 protein; improved; improved functioning; intravenous administration; kinase inhibitor; male; microchip; middle age; mimetics; mortality; mouse model; mutant; neuroblastoma cell; neurotrophic factor; novel; novel strategies; obesity risk; overexpression; oxidative DNA damage; oxidative damage; peptide A; plumbagin; polyglutamine; post stroke; presenilin-1; prevent; promoter; receptor coupling; repaired; response; stressor; tau mutation

Age and excessive energy intake/obesity are risk factors for cerebrovascular disease, but it is not known if and how these factors affect the extent of brain damage and outcome in ischemic stroke. We therefore determined the interactions of age and energy intake on the outcome of ischemic brain injury, and elucidated the underlying mechanisms. We utilized a novel microchip-based immunoaffinity capillary electrophoresis technology to measure a panel of neurotrophic factors, cytokines and cellular stress resistance proteins in brain tissue samples from young, middle age and old mice that had been maintained on control or energy restricted diets prior to middle cerebral artery occlusion and reperfusion (I/R). Mortality from focal ischemic stroke was increased with advancing age and reduced by an intermittent fasting (IF) diet. Brain damage and functional impairment were reduced by IF in young and middle age mice, but not in old mice. The basal and post-stroke levels of neurotrophic factors (BDNF and bFGF), protein chaperones (HSP70 and GRP78) and the antioxidant enzyme HO-1 were decreased, while levels of inflammatory cytokines were increased in the cerebral cortex and striatum of old mice compared to younger mice. IF coordinately increased levels of protective proteins and decreases inflammatory cytokines in young, but not in old mice. Reduction in dietary energy intake differentially modulates neurotrophic and inflammatory pathways to protect neurons against ischemic injury, and these beneficial effects of IF are compromised during aging resulting in increased brain damage and poorer functional outcome. In another study we developed a bioassay to screen a panel of botanical insecticides to identify those that activate adaptive stress responses in neurons at subtoxic doses. Many phytochemicals function as noxious agents that protect plants against insects and other damaging organisms. However, at subtoxic doses the same phytochemicals may activate adaptive cellular stress response pathways that can protect cells against a variety of adverse conditions. We screened a panel of botanical pesticides using cultured human and rodent neural cell models, and identified plumbagin as a potent activator of the nuclear factor E2-related factor 2 (Nrf2)/ antioxidant response element (ARE) pathway. Subtoxic concentrations of plumbagin increase nuclear localization and transcriptional activity of Nrf2 and induce the expression of the Nrf2/ARE-dependent gene heme oxygenase 1 (HO-1) in human neuroblastoma cells. Plumbagin specifically activates the Nrf2/ARE pathway in primary cortical neurons from ARE-human placental alkaline phosphatase (hPAP) reporter mice. The activation of the ARE and the induction of HO-1 are abolished by RNA interference-mediated knockdown of Nrf2 expression. Exposure of neuroblastoma cells and primary cortical neurons to plumbagin provides protection against subsequent oxidative and metabolic insults. The induction of HO-1 and the neuroprotective effects of plumbagin involve the PI3K/Akt signaling pathway upstream of Nrf2 activation. Intravenous administration of plumbagin significantly reduces the amount of brain damage and ameliorates associated neurological deficits in a mouse model of focal ischemic stroke. Our findings establish precedence for the identification and characterization of neuroprotective phytochemicals based upon their ability to activate adaptive cellular stress response pathways. Glutamate, the major excitatory neurotransmitter in the brain, activates receptors coupled to membrane depolarization and Ca(2+) influx that mediates functional responses of neurons including processes such as learning and memory. Here we show that reversible nuclear oxidative DNA damage occurs in cerebral cortical neurons in response to transient glutamate receptor activation using non-toxic physiological levels of glutamate. This DNA damage was prevented by intracellular Ca(2+) chelation, the mitochondrial superoxide dismutase mimetic MnTMPyP (Mn-5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine chloride tetrakis(methochloride)), and blockade of the permeability transition pore. The repair of glutamate-induced DNA damage was associated with increased DNA repair activity and increased mRNA and protein levels of apurinic endonuclease 1 (APE1). APE1 knockdown induced accumulation of oxidative DNA damage after glutamate treatment, suggesting that APE1 is a key repair protein for glutamate-induced DNA damage. A cAMP-response element-binding protein (CREB) binding sequence is present in the Ape1 gene (encodes APE1 protein) promoter and treatment of neurons with a Ca(2+)/calmodulin-dependent kinase inhibitor (KN-93) blocked the ability of glutamate to induce CREB phosphorylation and APE1 expression. Selective depletion of CREB using RNA interference prevented glutamate-induced up-regulation of APE1. Thus, glutamate receptor stimulation triggers Ca(2+)- and mitochondrial reactive oxygen species-mediated DNA damage that is then rapidly repaired by a mechanism involving Ca(2+)-induced, CREB-mediated APE1 expression. Our findings reveal a previously unknown ability of neurons to efficiently repair oxidative DNA lesions after transient activation of glutamate receptors. Membrane-associated oxidative stress has been implicated in the synaptic dysfunction and neuronal degeneration that occurs in AD, but the underlying mechanisms are unknown. Enzymes of the plasma membrane redox system (PMRS) provide electrons for energy metabolism and recycling of antioxidants. Here, we show that activities of several PMRS enzymes are selectively decreased in plasma membranes from the hippocampus and cerebral cortex of 3xTgAD mice, an animal model of AD. Our results that indicate the decreased PMRS enzyme activities are associated with decreased levels of coenzyme Q(10) and increased levels of oxidative stress markers. Neurons overexpressing the PMRS enzymes (NQO1 or cytochrome b5 reductase) exhibit increased resistance to amyloid β-peptide (Aβ). If and to what extent Aβ is the cause of the impaired PMRS enzymes in the 3xTgAD mice is unknown. Because these mice also express mutant tau and presenilin-1, it is possible that one or more of the PMRS could be adversely affected by these mutations. The impairment of the PMRS in an animal model of AD, and the ability of PMRS enzyme activities to protect neurons against Aβ-toxicity, suggest enhancement PMRS function as a novel approach for protecting neurons against oxidative damage in AD and related disorders. Huntington's disease (HD) is an inherited neurodegenerative disorder caused by expanded polyglutamine repeats in the huntingtin (Htt) protein. Because electroconvulsive shock (ECS) can stimulate the production of brain-derived neurotrophic factor (BDNF) and protect neurons against stress, we determined whether ECS treatment would modify the disease process and provide a therapeutic benefit in a mouse model of HD. ECS (50 mA for 0.2 s) or sham treatment was administered once weekly to male N171-82Q Htt mutant mice beginning at 2 months of age. Endpoints measured included motor function, striatal and cortical pathology, and levels of protein chaperones and BDNF. ECS treatment delayed the onset of motor symptoms and body weight loss and extended the survival of HD mice. Striatal neurodegeneration was attenuated and levels of protein chaperones (Hsp70 and Hsp40) and BDNF were elevated in striatal neurons of ECS-treated compared with sham-treated HD mice. Our findings demonstrate that ECS can increase the resistance of neurons to mutant Htt resulting in improved functional outcome and extended survival. The potential of ECS as an intervention in subjects that inherit the mutant Htt gene merits further consideration.

年龄和过度能量摄入/肥胖是脑血管疾病的危险因素，但尚不清楚这些因素是否以及如何影响缺血性中风中脑损伤和结果的程度。 因此，我们确定了年龄和能量摄入对缺血性脑损伤结果的相互作用，并阐明了潜在的机制。 我们利用了一种新型的基于微芯片的免疫接触毛细血管电泳技术来测量来自年轻，中年和老鼠的脑组织样品中的神经营养因子，细胞因子和细胞应激抗性蛋白，这些小鼠在对照或能量限制的饮食中维持在中脑脑闭塞和重复之前（i/i/r）。局灶性缺血性中风的死亡率随着年龄的增长而增加，并通过间歇性禁食（如果）饮食降低。 IF在年轻小鼠中，但在老鼠中却降低了脑损伤和功能障碍。神经营养因子（BDNF和BFGF），蛋白伴侣（HSP70和GRP78）和抗氧化剂HO-1的基础和后冲突水平降低了，而较年轻的小鼠的炎性细胞因子的水平升高。 如果协同增加了保护蛋白水平并降低了年轻小鼠的炎症细胞因子，但不会降低。 饮食能量摄入的降低会差异调节神经营养和炎症途径，以保护神经元免受缺血性损伤，并且在衰老期间受到IF的这些有益作用，导致脑损伤增加，功能较差。 在另一项研究中，我们开发了一项生物测定法，以筛选一组植物杀虫剂，以鉴定那些激活下毒性剂量神经元中适应性应激反应的人。许多植物化学物质是保护植物免受昆虫和其他破坏生物的有害剂的作用。 然而，在无毒剂量下，相同的植物化学物质可能会激活适应性的细胞应激反应途径，该途径可以保护细胞免受各种不良条件的影响。 我们使用培养的人类和啮齿动物神经细胞模型筛选了植物农药板，并将铅铅制鉴定为核因子E2相关因子2（NRF2）/抗氧化剂反应元件（AS）途径的有效激活剂。 铅pin的下毒性浓度增加了NRF2的核定位和转录活性，并诱导NRF2/依赖性基因血红素氧酶1（HO-1）在人神经母细胞瘤细胞中的表达。 Plumbagin特异性地激活来自人类胎盘碱性碱性磷酸酶（HPAP）记者小鼠的原代皮质神经元中的NRF2/途径。 通过RNA干扰介导的NRF2表达敲低，将其激活和HO-1的诱导消除。 神经母细胞瘤细胞和原发性皮质神经元暴露于铅垂蛋白可保护，以防止随后的氧化和代谢损伤。 HO-1的诱导和铅笔的神经保护作用涉及NRF2激活上游的PI3K/AKT信号通路。 静脉注射铅铅蛋白的静脉内施用可显着减少脑部缺血性中风的小鼠模型中脑损伤的量，并改善相关的神经缺陷。 我们的发现基于激活适应性细胞应激反应途径的能力来鉴定和表征神经保护性植物化学物质的优先级。 谷氨酸是大脑中主要的兴奋性神经递质，它激活与膜去极化的受体和Ca（2+）涌入，可介导神经元的功能反应，包括学习和记忆等过程。在这里，我们表明，使用非毒性生理水平的谷氨酸盐，在脑皮质神经元中发生可逆的核氧化DNA损伤。通过细胞内CA（2+）螯合，线粒体超氧化物歧化酶模拟MNTMPYM（MN-5,10,15,20-TETRA（4-吡啶基）-21H，23H-卟谷氨酸诱导的DNA损伤的修复与DNA修复活性增加，mRNA和蛋白质水平的增加有关（APE1）。 APE1敲低诱导的谷氨酸治疗后氧化DNA损伤的积累，这表明APE1是谷氨酸诱导的DNA损伤的关键修复蛋白。 APE1基因（编码APE1蛋白）启动子中存在营地反应元件结合蛋白（CREB）结合序列，并使用Ca（2+）/钙调蛋白依赖性激酶抑制剂（KN-93）对神经元进行处理，可阻止谷氨酸甘氨酸诱导CREB磷酸化和Apepelation和Apeapelation和Apeapelation和Apeape1表现。使用RNA干扰对CREB的选择性耗竭阻止了谷氨酸诱导的APE1上调。因此，谷氨酸受体刺激触发Ca（2+）和线粒体活性氧介导的DNA损伤，然后通过涉及Ca（2+）诱导的CREB介导的APE1表达的机制迅速修复。我们的发现揭示了神经元在短暂激活谷氨酸受体后有效修复氧化DNA病变的能力。 膜相关的氧化应激与AD中发生的突触功能障碍和神经元变性有关，但潜在的机制尚不清楚。质膜氧化还原系统（PMR）的酶为抗氧化剂的能量代谢和回收提供电子。在这里，我们表明，来自海马和3xtgad小鼠的海马和大脑皮层的质膜中几种PMRS酶的活性有选择性降低，这是AD的动物模型。我们的结果表明PMRS酶活性降低与辅酶Q（10）的水平降低和氧化应激标记水平升高有关。过表达PMRS酶（NQO1或细胞色素B5还原酶）的神经元表现出对淀粉样蛋白β-肽（Aβ）的耐药性。如果且在何种程度上Aβ的原因是3xTGAD小鼠中PMRS酶受损的原因是未知的。由于这些小鼠还表达突变的tau和Presenilin-1，因此可能会受到这些突变的不利影响。 PMR在AD动物模型中的损害以及PMRS酶活性保护神经元免受Aβ毒性的能力，这表明增强PMR是保护神经元免受AD和相关疾病中氧化损伤的新方法。 亨廷顿氏病（HD）是一种由亨廷顿蛋白（HTT）蛋白中聚谷氨酸重复膨胀引起的遗传神经退行性疾病。 由于电击性休克（ECS）可以刺激脑衍生的神经营养因子（BDNF）的产生，并保护神经元免受压力，因此我们确定ECS治疗是否会改变疾病过程并在HD小鼠模型中提供治疗益处。每周一次对雄性N171-82Q HTT突变小鼠的ECS（0.2 s 50 mA）或假治疗一次。测得的终点包括运动功能，纹状体和皮质病理学以及蛋白质伴侣和BDNF的水平。 ECS治疗延迟了运动症状和体重减轻的发作，并扩大了HD小鼠的存活。与假治疗的HD小鼠相比，在ECS处理的纹状体神经元中，纹状体神经变性被减弱，蛋白伴侣（HSP70和HSP40）的水平（HSP70和HSP40）升高。我们的发现表明，EC可以增加神经元对突变体HTT的抗性，从而改善功能结果和扩展的存活率。 EC作为对继承突变体HTT基因的受试者的一种干预的潜力，值得进一步考虑。