低氧预适应对小鼠海马HT22细胞线粒体能量代谢的影响

Effects of hypoxic preconditioning on energy metabolism of mitochondria in mouse hippocampal HT22 cells

目的探讨低氧预适应(HPC)对小鼠海马HT22细胞线粒体能量代谢的影响及其可能机制。方法将小鼠海马神经细胞HT22分为对照组、低氧组、HPC组,通过检测各组三磷酸腺苷(ATP)和活性氧(ROS)的水平,以观察HPC对细胞线粒体能量代谢的影响;采用Western blot法检测雷帕霉素靶蛋白(mTOR)、磷酸化mTOR蛋白和自噬底物P62蛋白的表达;细胞免疫荧光法检测磷酸化mTOR,LysoTracker^(TM)探针检测溶酶体,验证HPC引起细胞代谢改变是否与mTOR/自噬通路有关。结果与对照组相比,低氧组ATP明显下降,ROS水平增加,HPC处理后,ATP水平增加,ROS水平降低。与对照组相比,HPC组磷酸化mTOR表达下调,自噬底物P62表达下调。结论HPC可能通过mTOR/自噬信号通路影响HT22细胞能量代谢从而对HT22细胞发挥保护作用。

Objective To investigate the effect of hypoxic preconditioning(HPC)on mitochondrial energy metabolism in mouse hippocampal HT22 cells and its possible mechanism.Methods In this paper,mouse hippocampal nerve cells HT22 were divided into control group,hypoxia group,HPC group,and the levels of adenosine triphosphate(ATP)and reactive oxygen species(ROS)in each group were measured for observing the effect of HPC on cell mitochondrial metabolism.Western blot was used to detect the expression of target of rapamycin(mTOR),phosphorylated mTORprotein and autophagy substrate P62 protein;cellular immunofluorescence was used to detect phosphorylated mTOR,and LysoTracker^(TM) probe was used to detect lysosomes.Results Compared with the control group,the ATP level was significantly decreased and the ROS level was increased in the hypoxia group.Exposed to HPC,the ATP level was increased and the ROS level was decreased.Compared with the control group,the expression of phosphorylated mTORwas down-regulated and the expression of autophagy substrate P62 was down-regulated in the HPC group.Conclusion HPC may affect the energy metabolism of HT22 cells through the mTOR/autophagy signaling pathway,thereby exerting a protective effect on the HT22 cells.