Protein ubiquitination based neuroprotection for stroke

耐受性是细胞对轻微压力的反应，它可以防止毒性压力，这是许多生物体的保守特征。经典的耐受性是基因介导的，依赖蛋白质合成，至少需要24小时才能发生。相反，快速缺血耐受发生在缺血预处理后1小时内，不依赖于新蛋白的合成。因此，了解参与快速缺血耐受的神经保护内源性机制，可能会找到新的快速治疗策略来治疗急性脑卒中。我们的初步数据表明，细胞死亡促进蛋白在预处理后迅速下调，这可能解释了在快速缺血耐受中观察到的神经保护作用。我们的中心假设是，通过泛素化过程中细胞死亡促进蛋白水平的急性改变，短暂缺血刺激了快速缺血耐受的产生，泛素化过程以蛋白酶体降解的蛋白质为目标。具体目标是：-1。我们将使用候选的细胞死亡促进蛋白Bim来验证我们的假设。实验旨在研究缺血后1小时内Bim的泛素化和降解

Tolerance, the cellular response to mild stress, which protects against a toxic stress, is a conserved feature of many organisms. Classic tolerance is gene-mediated, protein synthesis-dependent and requires at least 24 hours to occur. In contrast, rapid ischemic tolerance occurs within 1 hour of the preconditioning ischemia and is not dependent on the synthesis of new proteins. As such understanding the endogenous mechanism of neuroprotection which are involved in rapid ischemic tolerance, may identify novel fast acting therapeutic strategies to treat acute stroke. Our preliminary data suggests that cell death promoting proteins are rapidly down regulated, following preconditioning, which may account for the neuroprotective effects observed in rapid ischemic tolerance. Our central hypothesis is that brief ischemia stimulates the generation of rapid ischemic tolerance by acute alterations in the levels of cell death promoting proteins by the process of ubiquitination, which targets the proteins for degradation by the proteasome. The specific aims are:-1. We will test our hypothesis using a candidate cell death promoting protein, Bim. Experiments are designed to investigate Bim ubiquitination and degradation in the 1 hour period following ischemic preconditioning. 2. We will further test our hypothesis broadly with immunoprecipitation and mass spectrographic analysis to identify novel proteins that are ubiquitinated following preconditioning ischemia. Experiments will then further validate this data, and identify potential new targets for regulating cell death following ischemia. These studies will support our hypothesis that protein down regulation is a powerful endogenous neuroprotective mechanism in the brain. We will identify the molecular mechanisms that favor the degradation of pro-apoptotic proteins, which may offer new acute therapeutic targets for the treatment of stroke and other neurological insults, which would not be available via gene modulation strategies based on classic tolerance, requiring over 24h to exert a neuroprotective effect.