调控Sirt6对缺血性神经损伤的保护及其机制研究

脑卒中已成为我国排名第一的致死因素，研究缺血性脑损伤的机制和发现新的保护性分子有着重要的临床意义。Sirtuin作为关键的表观遗传学调控蛋白, 参与影响神经系统疾病的发生。我们前期研究发现Sirt6调控炎症反应，而在小鼠短暂性大脑中动脉栓塞（tMCAO）模型中，损伤后Sirt6水平显著降低。在本课题中，我们将应用原代神经元氧糖剥夺（OGD）、Sirt6过表达慢病毒转染和Sirt6转基因小鼠的tMCAO模型，研究在神经元或星形胶质细胞特异性过表达Sirt6对缺血性神经损伤的调节作用。我们从细胞存活和死亡、影像和代谢、炎症反应和行为学等多方面验证Sirt6的过表达是否缓解缺血性脑损伤，并利用计算生物学和药物筛选平台发现激活Sirt6 的小分子化合物，在脑缺血模型中验证其是否能缓解神经损伤。通过研究，我们将明确Sirt6在脑缺血时的功能并可能找到具有神经保护作用的Sirt6 激活性药物。

Stroke is the leading cause of mortality in Chinese population, hence it is critical to delineate the mechanisms of ischemic brain injury and search for new neuroprotective molecules. Sirtuins as histone deacetylase are a key group of epigenetic modulators that regulate normal and pathophysiology including cancer and metabolic diseases. Our previous experiments demonstrated that Sirt6 could regulate neuroinflammation whereas in the mouse transient middle cerebral artery occlusion (tMCAO) model, Sirt6 level is downregulated. In this project, we seek to identify the regulatory role of Sirt6 in ischemic stroke using oxygen-glucose deprivation (OGD) model of primary neuron cultures, as well as tMCAO model in normal and Sirt6 transgenic mice. By using neuron- or astrocyte-specific and tetracycline-inducible lentiviral system or transgenic mice overexpressing Sirt6, we will modulate the up-regulation of Sirt6 in a time-controlled and cell-specific manner. By analyzing a panel of parameters including neuronal cell survival, death and infarct area, blood vessel density and glucose metabolic rate, inflammatory response and behavioral scores in animals with or without Sirt6 overexpression, we will confirm whether Sirt6 plays a role to attenuate ischemic brain injury. Furthermore, based on this information, we will simulate compound-Sirt6 binding and identify small molecules that activate Sirt6 using a platform of computational biology and drug screening, which will again be tested in OGD primary culture and tMCAO models. In summary, this project will delineate the role of Sirt6 in ischemic brain injury and identify small molecule drugs that might be neuroprotective through activating Sirt6.