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

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-1α was up-regulated in SAE and SAE+ H2groups (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-1α was 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. Key words: Hydrogen; Sepsis-associated encephalopathy; Mitochondria; Biosynthesis