Roles of autophagy in microglial senescence and Parkinson's disease

项目摘要 帕金森氏病(PD)是最常见的年龄相关性运动障碍；然而，它仍然 神秘的是，衰老是如何使大脑易患帕金森病的。随着身体的衰老，衰老的细胞在体内积累 包括大脑在内的多个器官。最近的证据表明，去除衰老的胶质细胞，包括 小胶质细胞，减轻阿尔茨海默病(AD)和帕金森病(PD)动物模型的疾病表型。小胶质细胞是 大脑特定的巨噬细胞，持续观察大脑，以维持大脑的动态平衡。衰老 小胶质细胞可能失去神经保护功能和与衰老相关的秘密分泌表型 (SASP)，导致慢性炎症。因此，迫切需要研究衰老的影响。 人帕金森病患者的小胶质细胞。我们用单核RNA测序(SnRNA-seq)技术获得的初步数据 研究发现，在人类帕金森病患者脑内，部分小胶质细胞表达更多与衰老相关的基因。长的- 本研究的长期目标是阐明小胶质细胞在帕金森病中是否以及如何衰老。 表征衰老小胶质细胞的分子特征，以寻找治疗靶点。在Aim1，我们将 确定衰老的小胶质细胞是否在帕金森病中积聚，并建立 利用人帕金森氏病死后脑的自噬通量和小胶质细胞衰老。自噬是一种细胞 负责清除受损细胞器、蛋白质聚集体和入侵的降解途径 外来物质。自噬在延长健康寿命和防止细胞衰老方面发挥作用 动物模型。我们的初步数据强调，自噬可以防止小鼠的小胶质细胞衰老。在……里面 AIM2，我们将对人类帕金森病衰老小胶质细胞的转录和蛋白质组特征进行表征 利用SnRNA-seq和空间组学技术进行尸检。在目标3中，我们将利用人类 从诱导的多能干细胞(IPSC)中分离小胶质细胞，研究自噬在小胶质细胞衰老中的作用。 我们将应用RNA-SEQ和LC-MS/MS来阐明衰老小胶质细胞的转录图谱和SASP， 分别进行了分析。最后，我们将确定衰老小胶质细胞中的SASP对人类生存的影响。 多巴胺能神经元。该项目的成功完成将1)为小胶质细胞衰老提供证据 在人类帕金森病脑中，2)表征衰老小胶质细胞的分子特征，3)提供洞察 自噬调节小胶质细胞衰老的机制及其对衰老小胶质细胞的影响 多巴胺能神经元。

Project Summary Parkinson’s disease (PD) is the most common age-dependent movement disorder; however, it remains mysterious how aging predisposes the brain to PD. As the body ages, senescent cells become accumulated in multiple organs, including the brain. Recent evidence showed that removal of senescent glial cells, including microglia, alleviates disease phenotypes in animal models of Alzheimer’s disease (AD) and PD. Microglia are brain-specific macrophages that continuously survey the brain to maintain brain homeostasis. Senescent microglia may lose their neuroprotective functions and secret senescence-associated secretory phenotype (SASP), leading to chronic inflammation. Therefore, there is a critical need to examine the impact of senescent microglia on human PD. Our preliminary data with single-nucleus RNA sequencing (snRNA-seq) technology revealed that a subset of microglia expresses more senescence-related genes in human PD brain. The long- term objectives of this research are to elucidate whether and how microglia become senescent in PD and to characterize the molecular signature of senescent microglia for finding out therapeutic targets. In Aim1, we will determine whether senescent microglia become accumulated in PD and establish the relationship between autophagic flux and microglial senescence using human PD postmortem brain. Autophagy is a cellular degradation pathway responsible for removing damaged cellular organelles, protein aggregates, and invading foreign substances. Autophagy plays a role in extending healthy lifespan and preventing cellular senescence in animal models. Our preliminary data highlights that autophagy prevents microglial senescence in mouse. In Aim2, we will characterize the transcriptomic and proteomic signatures of senescent microglia in human PD postmortem brain by employing snRNA-seq and spatial omics technologies. In Aim 3, we will utilize human microglia from induced pluripotent stem cells (iPSC) to study the roles of autophagy in microglial senescence. We will apply RNA-seq and LC-MS/MS to elucidate the transcriptomic profile and SASP of senescent microglia, respectively. Lastly, we will determine the effect of SASP from senescent microglia on the survival of human dopaminergic neurons. Successful completion of this project will 1) provide evidence for microglial senescence in human PD brain, 2) characterize the molecular signature of senescent microglia, and 3) provide insight into the mechanism of how autophagy regulates microglial senescence and how senescent microglia affect dopaminergic neurons.