Hippocampal neuron-protective mechanism of hydrogen in a rat model of oxygen-glucose deprivation and restoration:promoting mitochondrial autophagy / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the relationship between the hippocampal neuron-protective mechanism of hydrogen in a rat model of oxygen-glucose deprivation and restoration(OGD/R)and mito-chondrial autophagy.Methods Hippocampal neurons isolated from healthy Sprague-Dawley rats(24 h af-ter birth)were cultured in vitro,seeded in polylysine-coated 6-well plates at a density of 7×105 cells/well and then divided into 5 groups(n＝30 each)using a random number table method: control group(C group),OGD/R group,OGD/R+H2 group,OGD/R plus 3-methyladenine(3-MA)group(OGD/R+3-MA group),and OGD/R plus H2 plus 3-MA group(OGD/R+H2+3-MA group).The cells were cultured for 24 h in normal culture atmosphere(75％N2-20％O2-5％CO2)in group C,and cells were subjected to oxygen-glucose deprivation for 2 h followed by O2-glucose supply for 24 h to establish the model of OGD/R injury in OGD/R,OGD/R+H2,OGD/R+3-MA and OGD/R+H2+3-MA groups.The cells were cultured for 24 h in a hydrogen-rich incubator(60％H2-10％O2-5％CO2-25％N2)after establishing the model in group OGD/R+H2.Autophagy inhibitor 3-MA 10 mmol/L was added,and then cultured for 24 h in normal culture atmosphere after establishing the model in group OGD/R+3-MA.Autophagy inhibitor 3-MA 10 mmol/L was added,and then cultured for 24 h in hydrogen-rich incubator after establishing the model in group OGD/R+H2+3-MA.The cell survival rate was measured using MTT assay.DCFH-DA fluorescent probe was applied for determination of reactive oxygen species(ROS)activity.The mitochondrial membrane potential was measured using a JC-10 assay kit.The neuronal apoptosis was detected by flow cytometry,and apoptosis rate was calculated.The expression of mitophagy-related protein microtubule-associated protein 1 light chain 3(LC3),PINK1 and Parkin was determined by Western blot,and LC3Ⅱ/LC3Ⅰ ratio was calculated.Results Compared with group C,the cell survival rate and MMP were significantly decreased,the apop-tosis rate and ROS activity were increased,and the expression of PINK1 and Parkin and LC3Ⅱ/LC3Ⅰrati-o were increased in OGD/R and OGD/R+H2 groups(P＜0.05).Compared with group OGD/R,the cell survival rate and MMP were significantly increased,the apoptosis rate and ROS activity were decreased,and the expression of PINK1 and Parkin and LC3Ⅱ/LC3Ⅰ ratio were increased in group OGD/R+H2(P＜0.05),and the cell survival rate and MMP were significantly decreased,the apoptosis rate and ROS activ-ity were increased,and the expression of PINK1 and Parkin and LC3Ⅱ/LC3Ⅰ ratio were decreased in group OGD/R+3-MA(P＜0.05).Compared with group OGD/R+H2,the cell survival rate and MMP were significantly decreased,the apoptosis rate and ROS activity were increased,and the expression of PINK1 and Parkin and LC3Ⅱ/LC3Ⅰ ratio were decreased in OGD/R+3-MA and OGD/R+H2+3-MA groups(P＜0.05).Conclusion Hippocampal neuron-protective mechanism of hydrogen against OGDR injury is relat-ed to promoting mitochondrial autophagy in rats.