Systemic inflammation in regulating the onset and progression of brain aging

 描述（由申请人提供）：拟议工作的目标是了解慢性炎症在促进衰老期间早发性记忆障碍和认知衰退进展中的作用。情景记忆受损是认知能力下降的早期指标，是由于氧化还原介导的突触NMDA受体功能下降所致。该机制涉及活性氧（ROS），可能来自活化的小胶质细胞，提供了炎症和记忆受损之间的潜在联系。目的1将检验以下假设：认知能力下降的发生受到炎症诱导的氧化应激增加的影响，导致氧化还原介导的NMDAR功能降低。LPS将用于诱导低度全身性炎症。研究对不同的认知过程采用敏感的行为测试，并可以检测运动功能或动机的变化。认知功能受损将与血清和局部脑细胞因子、氧化应激和NMDA受体功能的氧化还原调节的测量相关。我们预测血清中的炎症标志物与记忆力下降的出现相关，并且对于特定的神经系统，炎症标志物和受损的NMDA受体功能是认知障碍表型的诊断。目标2检查认知能力下降的进展。全身炎症诱导对小胶质细胞和突触功能的长期影响，其持续时间超过全身标志物。为了检查长期效应，我们将表征认知、NMDA受体的氧化还原调节和RNA测序，以获得与慢性炎症和认知障碍相关的转录谱图。研究表明，突触NMDA受体的活性降低导致与衰老和记忆障碍相关的转录谱类似的转录谱，这表明由于慢性炎症导致的NMDAR突触活性的降低改变了神经营养、神经保护和突触特异性基因的转录。我们预测，由于炎症引起的长期变化涉及氧化还原介导的突触NMDAR活性降低，导致衰老转录，这增加了细胞对年龄相关应激源的脆弱性，并降低了特定神经回路的连通性。目的3将检查抗炎药物对与炎症相关的认知和生物学变化的影响。

 DESCRIPTION (provided by applicant): The goal of the proposed work is to provide an understanding the role of chronic inflammation in promoting an early onset memory impairment and progression of cognitive decline during aging. Impaired episodic memory, an early indicator of cognitive decline, is due to a redox-mediated decrease in the function of synaptic NMDA receptors. The mechanism involves reactive oxygen species (ROS), possibly from activated microglia, providing a potential link between inflammation and the emergence of impaired memory. Aim 1 will test the hypothesis that the onset of cognitive decline is influenced by an inflammation induced increase in oxidative stress, resulting in a redox-mediated decrease in NMDAR function. LPS will be used to induce low- grade systemic inflammation. Studies employ sensitive behavioral tests for different cognitive processes, and can detect changes in motor function or motivation. Impaired cognitive function will be associated with measures of serum and local brain cytokines, oxidative stress, and redox regulation of NMDA receptor function. We predict that inflammatory markers in the serum correlated with the emergence of memory decline and that for specific neural systems, inflammation markers and impaired NMDA receptor function is diagnostic of cognitive impairment phenotypes. Aim 2 examines the progression of cognitive decline. Systemic inflammation induces long-term effects on microglia and synaptic function that outlast systemic markers. To examine long-term effects we will characterize cognition, redox regulation of NMDA receptors, and RNA sequencing to obtain a picture of the transcriptional profile associated with chronic inflammation and cognitive impairment. Research indicates that decreased activity of synaptic NMDA receptors results in a transcriptional profile similar to that associated with aging and memory impairment suggesting that a decrease in NMDAR synaptic activity, due to chronic inflammation, alters transcription of neurotrophic, neuroprotective, and synapse specific genes. We predict that long-lasting changes due to inflammation involve a redox-mediated decrease in synaptic NMDAR activity resulting in a senescent transcription, which increases cellular vulnerability to age-related stressors, and decreases connectivity in specific neural circuits. Aim 3 will examine the effect of anti-inflammatory drugs on cognitive and biological changes associated with inflammation.