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

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 mitochondrial autophagy.@*Methods@#Hippocampal neurons isolated from healthy Sprague-Dawley rats (24 h after 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 apoptosis rate and ROS activity were increased, and the expression of PINK1 and Parkin and LC3Ⅱ/LC3Ⅰ ratio 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 activity 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 related to promoting mitochondrial autophagy in rats.

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

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.

Ensemble Partial Least Squares Algorithm Based on Variable Clustering for Quantitative Infrared Spectrometric Analysis / 分析化学

Due to the ability of overcoming both the dimensionality and the collinear problems of the spectral data, partial least squares ( PLS ) is in ever increasingly used for quantitative spectrometric analysis, especially for near-infrared spectrum, mid-infrared spectrum and Raman spectrum. In this work, an improved PLS algorithm is proposed for efficient information extraction and noise reduction. The spectral variables are clustering to several subsets, and several sub-models are built for each subset. Then, the sub-models are re-weighted and ensemble to the final model. Experiments on two near-infrared datasets ( octane number prediction in gasoline and nicotine prediction in tobacco leafs ) demonstrate that the new method provides superior prediction performance and outperformed the conventional PLS algorithm, and the root mean square error of prediction ( RMSEP) is reduced by 32% and 22%, respectively.

Assessing cytogenotoxicity of cigarette smoke condensates using three in vitro assays.

Cigarette smoke condensates (CSCs) are complex mixed compounds that contain both direct and indirect mutagens/carcinogens. To detect genotoxicity of CSCs in vitro, a combination of various enzymes (e.g. activation and detoxification enzymes) called S9 is usually added. However, as S9 may induce cytotoxicity in target cells, it is unclear whether the addition of S9 can impact CSC-induced toxicity. Here, differences in cytogenotoxicity between CSCs in the presence or absence of S9 were studied using three in vitro assays (neutral red uptake assay, comet assay, and TCR gene mutation test) in human peripheral lymphocytes, which were exposed to CSCs at doses of 25, 50, 75, 100 and 125 microg/ml for 4 h. Assay results showed that both CSCs + S9 or CSCs - S9 could induce a dose-dependent elevation of cytogenotoxic effects in human lymphocytes with some differences between the two groups. The cytogenotoxicity induced by CSCs - S9 was significantly higher than that induced by CSCs + S9 in all three assays. The comet and NRU assays revealed that a dose-response relationship of cytogenotoxicity induced by CSCs + S9 was less typical than that induced by CSCs - S9, possibly due to specific cytogenotoxic agents in CSCs and enzymes contained in the S9 mixture. Thus, the three in vitro assays used in the present study are suitable for detecting cytogenotoxic effects in human lymphocytes induced by CSCs. Furthermore, the cytogenotoxicity induced by both CSCs + S9 and CSCs - S9 should be measured simultaneously when assessing and comparing the biological activity of different CSCs.

Studying the impact of S9 on cyto-genotoxicity of cigarette smoke in human peripheral blood lymphocytes in vitro.

In present study, human lymphocytes were exposed to cigarette smoke condensates (CSCs) at the doses of 25, 50, 75, 100 and 125 µg ml(-1) with and without S9, and the cyto-genotoxic effects were detected with CCK-8, cell apoptosis and micronucleus assays. DNA repair kinetics was observed with comet assay. Our results indicated that the cell viability decreased with CSCs doses, the percentages of apoptosis cell and the frequencies of micronuclei increased with CSCs doses, and DNA damage of human lymphocytes induced by CSCs could be basically repaired within 240 min. However, the cytotoxicity induced by CSCs +S9 was significantly lower than that induced by CSCs -S9 in CCK-8 and cell apoptosis assays, and the DNA repair speed in +S9 group was quicker than that in -S9 group. In conclusion, S9 may affect not only the cyto-genotoxicity of CSCs but also the repair process of DNA damage induced by CSCs in lymphocytes.