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Objective To investigate whether hydrogen can regulate the expressions of inflammatory factors by ultraviolet B (UVB)-induced human HaCaT keratinocytes through the autophagy pathway.Methods Cultured HaCaT keratinocytes were divided into several groups:blank control group receiving no treatment,hydrogen group cultured in hydrogen-rich medium,three UVB groups irradiated with UVB at 1,10,50 mJ/cm2 respectively,three UVB + hydrogen groups irradiated with UVB at 1,10,50 mJ/cm2 respectively followed by culture in hydrogen-rich medium,UVB + 3MA group pretreated with the autophagy inhibitor 3MA for 1 hour followed by UVB radiation at 50 mJ/cm2,UVB + rapamycin group pretreated with the autophagy activator rapamycin for 1 hour followed by UVB radiation at 50 mJ/cm2,UVB + 3MA +hydrogen group pretreated with 3MA for 1 hour followed by UVB radiation at 50 mJ/cm2 and culture in hydrogen-rich medium,UVB + rapamycin + hydrogen group pretreated with rapamycin for 1 hour followed by UVB radiation at 50 mJ/cm2 and culture in hydrogen-rich medium.After additional culture with or without hydrogen for 12 hours,methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate cellular proliferative activity,Western-blot analysis to measure the expressions of autophagy-associated protein 1 light chain 3 (LC3) and Beclin 1,and enzyme-linked immunosorbent assay (ELISA) to measure the supernatant levels of inflammatory factors including tumor necrosis factor (TNF)-α,interleukin (IL)-1β,IL-6 and high mobility group protein B1 (HMGB1),and a test kit was used to determine the level of lactate dehydrogenase (LDH).Results Compared with the blank control group,the 10-and 50-mJ/cm2 UVB groups showed significantly increased release of LDH,expressions of LC3 and Beclin1 and supernatant levels of TNF-α,IL-1 β,IL-6 and HMGB 1,but decreased cellular proliferative activity (all P ＜ 0.05).Hydrogen significantly attenuated the release of LDH,down-regulated the supernatant levels of TNF-α,IL-1β,IL-6 and HMGB1,but up-regulated cellular proliferative activity as well as LC3 and Beclin1 expressions in the 10-and 50-mJ/cm2 UVB + hydrogen groups compared with the 10-and 50-mJ/cm2 UVB groups respectively (all P ＜ 0.05).In addition,the levels of TNF-α,IL-1β,II-6 and HMGB1 were significantly higher in the 50-mJ/cm2 UVB + 3MA group than in the 50-mJ/cm2 UVB group,and higher in the 50-mJ/cm2 UVB + 3MA + hydrogen group than in the 50-mJ/cm2 UVB + hydrogen group,but lower in the 50-mJ/cm2 UVB + rapamycin group than in the 50-mJ/cm2 UVB group (all P＜ 0.05).Conclusion UVB radiation can increase the expressions ofautophagy-associated proteins,and hydrogen-rich medium can down-regulate the expressions of inflammatory factors by UVB-induced HaCaT cells through the autophagy pathway.
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Objective To observe the effect of hydrogen on ultraviolet B (UVB)-induced oxidative damage to skin fibroblasts.Methods Primary human skin fibroblasts from foreskin tissues were divided into five groups:normal control group receiving no treatment,hydrogen control group treated with hydrogen-rich saline,UVB group receiving irradiation only,post-treatment group irradiated with UVB followed by hydrogen-rich saline treatment,and pre-treatment group treated with hydrogen-rich saline followed by UVB irradiation.The dose of UVB was 30,60 and 90 mJ/cm2 in the cell proliferation assay and 90 mJ/cm2 in the other experiments.Methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate the proliferative activity of fibroblasts,a chemiluminescence method to estimate the activity of superoxide dismutase (SOD) and catalase as well as to determine the level of malondialdehyde in the culture supernatant of fibroblasts,enzyme linked immunosorbent assay (ELISA) to determine the supernatant level of 8-isoprostane-prostaglandin F2α (8-iso-PGF2α),Western blot to detect the expression of heme oxygenase-1 (HO-1) in fibroblasts.One-factor analysis of variance was conducted to assess differences in these parameters among these groups.Results UVB irradiation decreased the proliferative activity (absorbence value at 490 nm) of fibroblasts in a dose-dependent manner.Both the pre-treatment group and post-treatment group showed a statistical increase in proliferative activity of cells compared with the corresponding UVB control groups (all P ＜ 0.05).The activity of SOD and catalase as well as the protein expression of HO-1 were significantly higher (all P ＜ 0.05),whereas the supernatant levels of malondialdehyde and 8-iso-PGF2α were statistically lower (both P ＜ 0.05) in the pre-treatment group and post-treatment group than in the UVB control group.Conclusion Hydrogen may mitigate UVB-induced oxidative damage to skin fibroblasts.
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Objective To evaluate the therapeutic effect of hydrogen-rich saline on allergic contact dermatitis (ACD) in mice and to explore its underlying mechanisms.Methods Forty mice were equally divided into 4 groups:control group,control treatment group,ACD group and ACD treatment group.ACD was induced by repetitive topical application of dinitrofluorobene (DNFB) to the left ear of mice on day 1,2 and 5.Hydrogen-rich saline was intraperitoneally given to the mice in the ACD treatment group at a dose of 5 ml/kg per day from day 1 to 5.On day 6,the mice were sacrificed,ear tissue was removed from them and subjected to measurement of thickness and weight,detection of tumor necrosis factor (TNF)-α,interleukin (IL)-6,IL-17 and interferon (IFN)-γ expression by enzyme linked immunosorbent assay,as well as numeration of inflammatory cells in lesions after hematoxylin-eosin (HE) staining.Data were processed by SPSS 18.0 software,and statistical analysis was carried out by one-way analysis of variance and least significant difference (LSD) procedure.Results Compared with the control group,the ACD group showed a significant increase in lesion score (7.33 ± 1.53 vs.0,P ＜ 0.05),differences in the thickness ((0.73 ± 0.15) mm vs.(0.13 ± 0.05) mm,P ＜ 0.05) and swelling degree (expressed as tissue weight:(18.67 ± 3.05) mg vs.(3.33 ± 1.52) mg,P ＜ 0.05) between the left and right ear,expressions of TNF-α ((1475.52 ± 233.81) pg/mg vs.(239.01 ± 52.39) pg/mg,P＜ 0.05),IL-6 ((184.65 ± 78.39) pg/mg vs.(42.28 ± 17.64) pg/mg,P＜ 0.05),IL-17 ((628.56 ± 201.44) pg/mg vs.(127.58 ± 50.28) pg/mg,P＜ 0.05) and IFN-γ ((197.72 ± 37.81) pg/mg vs.(24.57 ± 8.31) pg/mg,P ＜ 0.05),and the number of inflammatory cells per square millimetre in the left ear tissue (752.00 ± 166.06 vs.127.33 ± 77.18,P ＜ 0.05).However,hydrogen-rich saline treatment induced a statistical decrease in all of these parameters in the ACD treatment group compared with the ACD group,including lesion score (3.33 ± 0.58,P ＜ 0.05),difference in thickness ((0.46 ± 0.11) mm,P ＜ 0.05) and swelling degree ((11.00 ± 2.64) mg,P ＜ 0.05),expressions of TNF-α ((817.72 ± 101.13) pg/mg,P＜ 0.05),IL-6 ((95.86 ± 36.65) pg/mg,P＜ 0.05),IL-17 ((373.38 ± 126.74) pg/mg,P＜ 0.05),IFN-γ ((63.31± 17.38) pg/mg,P ＜ 0.05) and the number of inflammatory cells per square millimetre (384.00 ± 97.35,P ＜0.05).Conclusion Hydrogen may inhibit the release of inflammatory factors in ACD.