自噬相关基因Atg7维持成体神经干细胞稳态及其潜能的研究

成体神经干细胞（aNSCs）老化与干细胞库耗竭是神经退行性疾病的共同病因。应激刺激蓄积是aNSCs衰老进程中的关键事件。课题组前期结果显示20S蛋白酶体活性降低，异常蛋白清除障碍导致骨髓间充质干细胞复制性衰老；20S蛋白酶体与aNSCs衰老相关。自噬是除蛋白酶体之外维持细胞内稳态的另一有效途径，参与细胞发育、分化和代谢更新调控。近期研究提示自噬与干细胞功能维持密切相关。为此，本课题拟以自噬体形成关键基因Atg7作为切入点，借助基因沉默技术手段，通过电镜、组织化学和分子生物学等方法观察自噬功能障碍对aNSCs 衰老标志物、端粒酶活性以及增殖和分化潜能的影响；并建立aNSCs氧化应激模型，探讨氧化应激对自噬功能障碍aNSCs生存能力的影响。本课题旨在全面揭示自噬在aNSCs功能维持中的重要作用，阐明aNSCs衰老机理，寻求恢复aNSCs活力的新靶标，从而为神经退行性疾病治疗提供新的突破方向。

Senescence and depletion of adult neural stem cells (aNSCs) are the common pathogeny of neurodegenerative diseases. Accumulative stress from hazardous stimuli plays a critical role in the aging process. Prior results of our research have revealed that the malfunctional clearance of abnormal proteins, due to the reduced catalytic ability of 20S proteasomes, contributes to replicative senescence in human bone marrow stromal cells which are similar to aNSCs in terms of their pluripotency and neural differentiation capability. As another effective regulator to sustain intracellular homostasis in addition to proteasomes, autophagy takes part in the regulation of cell development, differentiation, metabolism and renewal. Given the tight association between autophagy and maintenance of stem cell integrity suggested by multiple studies recently, we shall focus on Atg7, the crucial gene for autophagosome formation, and delve into the underlying mechanism.By virtue of the RNA interference techinque, we shall investigate the potential impact of autophagic dysfunction on the appearance of senescent markers, telomerase activity, as well as proliferation and differentiation states of aNSCs, using a combination of electromicroscopic, immunohistochemical, cellular and molecular biological methods. We shall also establish the aNSC model for oxidative stress in order to explore its influence on autophagy. The overall aim is to delineate the comprehensive effects of autophagy in maintaining the stemness of aNSCs, and the mechanism underlies the progress of aging, which raises the intriguing possibility of treating neurodegenerative diseases by potentially reviving aNSCs through modulating their autophagy.