脑缺血再灌注及神经退行性变中PARP-1依赖性细胞死亡（parthanatos）机制研究

Ischemic stroke and neurodegenerative disease are two most common causes of death and disability among neuronal system diseases. For the former one, the key in treatment is the rescue of the neurons within the ischemia-reperfusion regions, while the latter one also demands great efforts to prevent the development of new lesions and the terminal goal is to save the neurons as many as possible. Recent research indicating that during ischemia-reperfusion injury, glutamate excitotoxicity and various inflammatory responses, as well as neurodegeneration, neuronal death is commonly caused by excessive activation of PARP-1, which further leads to an intrinsic cell death program, parthanatos (PARP-1-dependent cell death), since it is distinct from necrosis and apoptosis. However, the knowledge of the involved molecules and the linking mechanisms underlying diseases are still vague. Here in this study, we performed a screening based on the CRISPR-based genome wide knockout library and identify some novel genes involved in parthanatos, then we want further explore the cell signaling cascades and functional regulation of PARP-1 dependent DNA damage and cell death in neurologic diseases, at molecular, cellular and the animal model levels. Our study could improve the understanding of the molecular mechanism of Parthanatos and also provide novel targets for developing treatments to rescue neurons in ischemic stroke and neurodegenerative diseases.

缺血性中风和神经退行性疾病是两大类主要致死和致残性神经系统疾病，前者治疗的关键是挽救缺血-再灌注损伤区域的神经元，后者亦是阻止新病灶的发展并以挽救神经元为最终目的。目前发现脑缺血再灌注损伤,谷氨酸兴奋性毒性及各种炎性反应导致的神经死亡的主要原因之一是由聚腺苷酸二磷酸核糖转移酶-1（PARP-1）过度激活介导的区别于凋亡和坏死的细胞死亡，又称Parthanatos。然而对于其发生机制及与疾病的关联的研究还知之甚少。本研究基于CRISPR-Cas9的全基因组敲除文库在细胞水平筛选并初步确定多个参与parthanatos发生发展的相关基因。进一步通过分子，细胞和整体动物疾病模型水平对这些分子的作用机理和应用前景进行深入探讨，从而为明确Parthanatos发生发展的分子基础提供理论依据并为挽救脑卒中缺血再灌注损伤和多种神经退行性疾病中神经元的的损失提供新的治疗靶点。

阻止神经元死亡是未来治疗缺血性中风和神经退行性疾病的关键手段。本研究基于CRISPR-Cas9的全基因组敲除文库在细胞水平筛选及高通量测序技术初步确定多个参与神经细胞死亡发生发展的相关基因。我们发现在脑缺血/再灌注损伤（I / R）动物模型中，海马齿状回中短暂表达的内源性TRH可能在神经元的存活中起重要作用，提示给与外源性TRH可能有助于治疗缺血性中风。我们发现circ-camk4可能在脑I / R损伤中起关键作用，抑制circ-camk4的表达可能有助于治疗缺血性中风。我们还发现NSE和PKM是新的SIRT1结合分子。 SIRT1可能通过脱乙酰作用来调节NSE和PKM的乙酰化水平，并进一步调节它们的催化活性。这一作用可能在脑I / R损伤动物模型中受到抑制从而不利于神经细胞存活。我们进一步通过筛选发现CDK1，PIN4, HK1, TIM44，c-Myc等基因参与细胞parthanatos死亡。敲除或者敲减这些基因有助于脑I / R损伤和多种神经退行性疾病中神经元的存活，其详细机制研究仍在进行。这些研究发现将为未来开发新的治疗缺血性中风和神经退行性疾病的手段奠定基础。