氢对脓毒症相关性脑病小鼠海马线粒体生物合成的影响

Effect of hydrogen on mitochondrial biosynthesis in hippocampus of mice with sepsis-associated encephalopathy

目的评价氢对脓毒症相关性脑病(SAE)小鼠海马线粒体生物合成的影响。方法清洁级健康雄性C57BL/6J小鼠224只,6~8周龄,体重20~25 g,采用随机数字表法分为4组(n=56):假手术组(SH组)、假手术+氢气组(SH+H2组)、SAE组和SAE+氢气组(SAE+H2组)。采用盲肠结扎穿孔法制备小鼠SAE模型。SH+H2组和SAE+H2组分别于术后1和6 h时吸入2%氢气1 h。取20只小鼠,记录术后7 d生存情况。于术后24 h时,处死其余小鼠,取脑组织,光镜下观察海马CA1区病理学结果,TUNEL法观察神经元凋亡情况,计算神经元凋亡率;采用荧光分光光度法检测海马线粒体膜电位(MMP);采用荧光素-荧光酶发光法检测线粒体ATP含量。分别于术后6、12和24 h时,采用Western blot法测定海马过氧化物酶体增殖活化受体γ共激活因子-1α(PGC-1α)表达。结果与SH组比较,SAE组和SAE+H2组术后7 d生存率降低,海马神经元凋亡率升高,MMP和ATP含量降低,PGC-1α表达上调(P<0.05),SH+H2组上述指标差异无统计学意义(P>0.05);与SAE组比较,SAE+H2组术后7 d生存率升高,海马神经元凋亡率降低,MMP和ATP含量升高,PGC-1α表达上调(P<0.05),海马组织病理学损伤减轻。结论氢减轻小鼠SAE的机制可能与促进线粒体生物合成有关。

Objective To evaluate the effect of hydrogen on mitochondrial biosynthesis in the hippocampus of mice with sepsis-associated encephalopathy(SAE).Method Two hundred and twenty-four healthy clean-grade male C57BL/6J mice,aged 6-8 weeks,weighing 20-25 g,were divided into 4 groups(n=56 each)using a random number table method:sham operation group(group SH),sham operation plus hydrogen group(group SH+H2),group SAE,and SAE plus hydrogen group(group SAE+H2).The model of SAE was established by cecal ligation and puncture in anesthetized mice.Group SH+H2 and group SAE+H2 inhaled 2%hydrogen for 1 h starting from 1 and 6 h after operation,respectively.Twenty mice were selectde to record the postoperative 7-day survival rate.The remaining animals were sacrificed at 24 h after operation,and brain tissues were taken for examination of the pathological changes in hippocampal CA1 region(with a light microscope)and for determination of neuronal apoptosis(by TUNEL),mitochondrial membrane potential(MMP)(by fluorescence spectrophotometry)and ATP content(by a bioluminescence assay).The apoptosis rate was calculated.The expression of peroxisome proliferator-activated receptor gamma coactivator 1α(PGC-1α)in hippocampus was determined by Western blot at 6,12 and 24 h after operation.Results Compared with group SH,the postoperative 7-day survival rate was significantly decreased,the apoptosis rate of hippocampal neurons was increased,the contents of MMP and ATP were decreased,and the expression of PGC-1αwas up-regulated in SAE and SAE+H2groups(P<0.05),and no significant change was found in the parameters mentioned above in group SH+H2(P>0.05).Compared with group SAE,the postoperative 7-day survival rate was significantly increased,and the apoptosis rate of hippocampal neurons was decreased,the contents of MMP and ATP were increased,and the expression of PGC-1αwas up-regulated(P<0.05),and the pathological changes of hippocampal tissues were significantly attenuated in group SAE+H2.Conclusion The mechanism by which hydrogen mitigates SAE may be related to promoting mitochondrial biosynthesis in mice.