我们的预实验发现脑预适应时TIGAR(TP53诱导糖酵解和细胞凋亡调节子)上调并转位于内质网（ER），但生物意义不明。我们推测在脑预适应时TIGAR转位于ER，促进ER内磷酸戊糖途径，或调节ER分子伴侣GRP78，减轻ER内氧化应激和ER应激依赖的细胞凋亡，或经STX17/Rab1/FAM134B调节内质网自噬，介导缺血耐受。本课题建立整体动物和离体神经细胞预适应模型，应用多种分子生物学方法研究脑预适应中TIGAR分布于ER并调节GRP78产生神经保护作用的机制，旨在：① 研究脑预适应时TIGAR转位于ER介导缺血耐受，扩展TIGAR细胞器分布和生物功能。② 深入研究TIGAR是否通过GRP78调节ER应激，ER内ROS生成和内质网自噬，丰富内质网自噬的生物活性与调节信号。③ 探索神经细胞内TIGAR转位ER并调节GRP78的分子机制，为防治脑缺血提供靶向TIGAR或GRP78的候选药物。

Our preliminary data showed that TP53-induced glycolysis and apoptosis regulator (TIGAR) relocates to the endoplasmic reticulum (ER) during cerebral preconditioning, but the biological significance of TIGAR’s relocation in ER remains to be elucidated. We hypothesize that during cerebral preconditioning, TIGAR relocates to the ER, where it regulates pentose phosphate pathway (PPP) to remove reactive oxygen species (ROS) and to maintain cell survival. Alternatively, TIGAR may regulate the ER molecular chaperone GRP78 to relieve oxidative stress in ER and ER stress dependent apoptosis. Another possibility is that TIGAR may act on GRP78 to regulate ER-phagy through STX17/Rab1/FAM134B pathway. In this project, we will establish isoflurane, hypoxic and ischemic preconditioning models in mice, primary murine cortical neurons and HT22 hipocampal neuronal cells to characterize the neuroprotective role of ER resident TIGAR and its regulation on GRP78 in cerebral preconditioning and the mechanisms. First, we intend to demonstrate that TIGAR translocates to ER to mediate ischemic tolerance during cerebral preconditioning. This study will extend our knowledge of the organelle distribution and bioactivity of TIGAR. Second, we will test whether TIGAR regulates ER stress, ROS production in ER and ER-phagy through regulation on GRP78 to broaden the bioactivity and signals of ER-phagy. Finally, we want to characterize the molecular mechanism of TIGAR’s ER relocation and its regulation on GRP78. We will use agents acting on TIGAR or GRP78 to mimic preconditioning-induced neuroprotection, thus proposing a therapeutic strategy for ischemic cerebrovascular diseases.