氢气调节自噬保护一氧化碳中毒迟发性脑损伤的研究

Acute carbon monoxide (CO) poisoning is one of the most common causes of unintentional poisoning neurological disability or deaths worldwide, delayed neurologic sequelae (DNS) is the most severe complication, therefore its effective treatment has become an important clinical concern. Autophagy plays an important role in DNS-related ischemia-reperfusion injury, hypoxic injury, and neurodegenerative diseases，but its role in the DNS has never been determined. Regulation of autophagy may provide us a new therapeutic strategy in DNS treatment. In our previous studies, we found that hydrogen could effectively prevent DNS following acute CO poisoning, reduce oxidative stress and inflammative cascade in addition to maintaining cognitive function, but the underlying mechanism needs to be investigated. Recent studies reported that hydrogen could inhibit autophagy in neurons in vivo. Therefore, we hypothesized that the protective effect of hydrogen on the DNS may be related to the inhibition of autophagy pathway. In this project, we focus on autophagy, investigate differences in autophagosome number, autophagy-related gene and protein activity. Furthermore, we will observe the aboving changes after suppression of PI3K/Akt/mTOR signaling pathway during hydrogen therapy in DNS after carbon monoxide poisoning. This research will contribute to clarify the interactions between autophagy and DNS, enlighten the mechanism involving autophagy regulation by hydrogen, thus build a new theoretical basis for the clinical application of hydrogen on DNS.

迟发性脑病(DNS)是影响急性一氧化碳(CO)中毒预后的最主要并发症，其发病机制尚不明确，亦无特效防治手段。自噬在DNS相关性缺血性脑损伤和神经退行性变中发挥着重要的作用，调控自噬成为保护DNS治疗中一个新的靶点。我们前期的研究发现氢气可以有效减轻大鼠急性CO中毒及DNS，抑制氧化应激、炎症反应并改善认知功能，但机制尚不清楚。最新研究证实氢在体内能抑制神经细胞自噬。因此，我们推测氢气对DNS的保护作用可能是通过调控自噬实现的。本课题采用在体和离体CO中毒模型，观察自噬体数量和自噬相关基因的变化，探索氢气DNS保护作用与自噬的关系；进一步通过特异性阻断PI3K/Akt/mTOR通路中的信号分子，观察氢气处理后该信号通路活性改变和自噬调节的关系，以期了解氢气影响神经元自噬的分子机制。本课题着眼点在于自噬与DNS的关系以及氢气保护DNS的机制，为其远期临床应用提供新思路。

大量的国内外研究已经证实了氢气的生物学效应，它具备抗氧化、抗炎、抗凋亡的作用，但目前氢气的机制研究尚不深入。自噬在维持神经元稳态和能量代谢方面发挥着重要的作用，也是开发DNS治疗药物的靶点，本项目在前期研究的基础上，采用在体和离体CO中毒模型，通过观察自噬体数量和自噬相关基因的变化，探索氢气DNS保护作用与自噬的关系。并通过特异性阻断PI3K/Akt/mTOR信号通路，观察氢气处理后保护效应的变化，以期阐明氢气防治DNS的作用机制。研究结果表明：氢气可以有效的抑制CO中毒导致的自噬增多、减少自噬相关基因的表达、上调PI3K/Akt/mTOR信号通路。而通过特异性阻断PI3K和mTOR，氢气的保护作用被逆转，从而证实了氢气抑制DNS引起的脑神经元自噬是通过PI3K/Akt/mTOR信号通路介导的。本项目对于氢气的作用机制提供了新的认识，可以为氢气后续进入临床应用提供重要的实验和理论依据。课题组拟在临床水平进一步观察氢气治疗对一氧化碳中毒患者的预后的影响，以期将本研究成果转化到临时应用上造福患者。