Gasdermin-Driven Cell Death and Immune Activation in Parkinson's Disease

摘要 黑质中的细胞死亡和炎症是帕金森病（PD）的公认标志。 然而，控制这些过程的分子机制仍然知之甚少。焦亡是一种 由gasdermin（GSDM）家族蛋白驱动的炎性坏死。当细胞内被 半胱天冬酶、gasdermins在细胞膜中形成孔，其首先作为细胞因子分泌的管道， 最终可能导致细胞肿胀和明显坏死。一个新兴的文学机构表明，gasdermin- 驱动的细胞凋亡是引发细胞死亡和先天免疫激活的关键分子事件。而 我们的初步数据显示，大多数GSDM研究都集中在免疫细胞、上皮细胞和癌细胞上 两个家族成员GSDME（DFNA 5）和GSDMD在CNS中表达。我们发现 GSDME存在于神经元中，而GSDMD富集于小胶质细胞中。这些细胞死亡蛋白在 中枢神经系统病理学尚未研究。 这项提议的目的是描述gasdermins如何控制细胞死亡和炎症 在警局我推测，在PD的情况下，a）GSDME在神经元中起作用，以驱动神经元炎性细胞凋亡。 细胞死亡，而B）GSDMD在小胶质细胞中起作用以促进细胞因子分泌。为了检验这些假设， 我们将使用体外实验、GSDM表达的体内研究以及GSDME和D -/- 在常见的PD模型中的转基因小鼠。初步数据显示，敲除GSDME可以保护人类 神经元样细胞系（SH-SY 5 Y），其来自由引起PD的神经毒素（包括6-OHDA）诱导的焦亡， 鱼藤酮和MPP。在目标1中，我们将扩展这些结果，并研究GSDME是否是必要的 神经毒素（6-OHDA）和α-突触核蛋白诱导的原代中脑神经元和两种体内细胞死亡 PD小鼠模型。目的2探讨GSDMD是否在神经毒素和α-突触核蛋白中被切割 诱导的小胶质细胞变化，以及如果该分子是体外细胞死亡和细胞因子分泌所必需的， in vivo.总的来说，我们试图确定进化上保守的gasdermin通路是否是活跃的， 并导致PD。这项拟议的工作对先天免疫轴如何驱动 并可能为在神经元损伤和炎症中试验新型GSDM抑制剂提供理论基础。 神经退行性疾病

Abstract Cell death and inflammation in the substantia nigra are well established hallmarks of Parkinson’s disease (PD). However, the molecular mechanisms governing these processes are still poorly understood. Pyroptosis is an inflammatory necrosis driven by the gasdermin (GSDM) family proteins. When cleaved intracellularly by caspases, gasdermins form pores in cell membranes which first act as conduits for cytokine secretion and ultimately may cause cell swelling and overt necrosis. An emerging body of literature suggests that gasdermin- driven pyroptosis is a key molecular event in initiating cell death and innate immune activation. While the majority of GSDM studies have focused on immune, epithelial and cancer cells, our preliminary data shows that two family members, GSDME (DFNA5) and GSDMD, are expressed in the CNS. We have found that GSDME is present in neurons, while GSDMD is enriched in microglia. The role of these cell death proteins in CNS pathology has not yet been studied. The objective of this proposal is to characterize how the gasdermins may control cell death and inflammation in PD. I hypothesize that in the context of PD a) GSDME acts in neurons to drive pyroptotic neuronal cell death, while b) GSDMD acts in microglia to promote cytokine secretion. To test these hypotheses, we will use mechanistic in vitro experiments, in vivo studies of GSDM expression, and GSDME and D -/- transgenic mice in common PD models. Preliminary data shows that knockout of GSDME protects a human neuron-like cell line (SH-SY5Y) from pyroptosis induced by PD-causing neurotoxins including 6-OHDA, rotenone and MPP. In Aim 1, we will extend these results and investigate whether GSDME is necessary for neurotoxin (6-OHDA) and alpha-synuclein-induced cell death in primary midbrain neurons and two in vivo mouse models of PD. Aim 2 will explore whether GSDMD is cleaved in neurotoxin and alpha-synuclein induced microglia changes, and if this molecule is necessary for cell death and cytokine secretion in vitro and in vivo. Collectively, we seek to establish whether the evolutionarily conserved gasdermin pathways are active in the CNS and contribute to PD. This proposed work has broad implications for how innate immune axes drive neuronal injury and inflammation and may provide rationale for trialing novel GSDM inhibitors in neurodegenerative disease.