Background Urinary trypsin inhibitor inhibits the enhanced production of pro-inflammatory molecules. Hemeoxygenase-1 induction protects against ischemia/repeffusion injury, oxidative stress, inflammation, transplant r...Background Urinary trypsin inhibitor inhibits the enhanced production of pro-inflammatory molecules. Hemeoxygenase-1 induction protects against ischemia/repeffusion injury, oxidative stress, inflammation, transplant rejection, apoptosis, and other conditions. However, it is unknown if a combined hemin and ulinastatin pretreatment could result in protective effects for septic shock. In this study, we investigated the role of hemin pretreatment combined with ulinastatin on septic shock in rats. Methods Eighty healthy, male Sprague-Dawley rats were randomly divided into four groups： group S, group H, group U and group HU. Groups S and U received 1 ml normal saline intraperitoneally, while groups H and HU both received 1 ml （100 mg/kg） hemin. Twenty-four hours later, 0.5 ml （10 mg/kg） E. coil lipopolysaccharide was injected intravenously to replicate the experimental model of septic shock. After an initial 25% decrease in the mean arterial pressure, corresponding to time point 0, groups HU and U received 0.5 ml 10 000 U/kg ulinastatin intravenously, and the others received 0.5 ml normal saline. Results The number of deaths in groups H and U was lower than that in the group S （P〈0.05）, and was higher than that in group HU （all P〈0.05） respectively. The mean arterial pressure （MAP） in the group S was significantly greater than that in group H （P〈0.05）, and was lower than that in group HU and group U （P〈0.05）. The plasma levels of alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, creatinine （Cr） and blood urea nitrogen （BUN）, the malondial- dehyde （MDA） of liver, kidney and lung, and the lung Evans blue （EB） contents in groups H and U, were greater than that in group HU （all P〈0.05）, and were lower than that in group S （all P〈0.05）. In contrast, the plasma levels of CO in groups H and HU were higher than that in groups S and U （all P〈0.05）, and SOD of liver, kidney and lung in groups H and U were higher than that in group S, 展开更多
To investigate whether the expression of exogenous heme oxygenase-1 (HO-1) gene within vascular smooth muscle cells (VSMC) could protect the cells from free radical attack and inhibit cell proliferation, we establishe...To investigate whether the expression of exogenous heme oxygenase-1 (HO-1) gene within vascular smooth muscle cells (VSMC) could protect the cells from free radical attack and inhibit cell proliferation, we established an in vitro transfection of human HO-1 gene into rat VSMC mediated by a retroviral vector. The results showed that the profound expression of HO-1 protein as well as HO activity was 1.8- and 2.0-fold increased respectively in the transfected cells compared to the non-transfected ones. The treatment of VSMC with different concentrations of H2O2 led to the remarkable cell damage as indicated by survival rate and LDH leakage. However, the resistance of the HO-1 transfected VSMC against H2O2 was significantly raised. This protective effect was dramatically diminished when the transfected VSMC were pretreated with ZnPP-IX, a specific inhibitor of HO, for 24 h. In addition, we found that the growth potential of the transfected cells was significantly inhibited directly by increased activity of HO-1, and this effect might be related to decreased phosphorylation of MAPK. These results suggest that the overexpression of introduced hHO-1 is potentially able to reduce the risk factors of atherosclerosis, partially due to its cellular protection against oxidative injury and to its inhibitory effect on cellular proliferation.展开更多
AIM: To evaluate the in vivo effect of glutamine on cobaltgenerated oxidative stress and (HO-1) induction in rat liver.METHODS: Fasted female Wistar rats received a single injection of cobalt chloride (375 μmol/kg bo...AIM: To evaluate the in vivo effect of glutamine on cobaltgenerated oxidative stress and (HO-1) induction in rat liver.METHODS: Fasted female Wistar rats received a single injection of cobalt chloride (375 μmol/kg body weight) and then were killed at different times. Lipid peroxidation and soluble and enzymatic antioxidant defense system (reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD)) were measured in liver homogenates. Ferritin and ferritin iron contents as well as heme oxygenase-1 (HO-1) activity and expression were also determined. The antioxidant properties of glutamine (Gin) were also evaluated. RESULTS: Cobalt chloride increased lipid peroxidation (50% over control values) 1 h after treatment. GSH reached a minimum at 3 h (40%) increasing thereafter. Twelve hours after CoCl2 injection, the antioxidant enzymes CAT, GSH-Px and SOD also diminished by about 30%. Heme oxygenase-1 induction was observed 6 h after treatment reaching a maximum value of 14-fold over the controls, 12 h after cobalt treatment. A 1.7-fold increase in ferritin and ferritin-bound iron 24 h after treatment were also obtained. Administration of glutamine (300 mg/kg body weight) by gavage 24 h before CoCl2 treatment entirely prevented the increase in thiobarbituric acid reactive substances (TBARS) content, the decrease in GSH levels, and partially reverted heme oxygenase-1 induction. CONCLUSION: These results suggested that a natural product such as glutamine prevents glutathione depletion and consequently heme oxygenase induction.展开更多
Objective： To investigate the effect of ischemic postconditioning （1PO） on acute lung ischemia-reperfusion （I/R） injury and the protein expression of haeme oxygenase-1 （HO-1）, a cytoprotective defense against o...Objective： To investigate the effect of ischemic postconditioning （1PO） on acute lung ischemia-reperfusion （I/R） injury and the protein expression of haeme oxygenase-1 （HO-1）, a cytoprotective defense against oxidative injury. Methods： After being anesthetized with chloralhydrate, forty-eight healthy SD rats were randomly divided into 6 groups （8 in each）： sham operation group （S group）; I/R group： left lung hilum was clamped for 40 minutes followed by 105 minutes of reperfusion; IPO group： left lung hilum was clamped for40 minutes and postconditioned by 3 cycles of 30 seconds of reperfusion and 30 seconds of reocclusion; Heroin （HM）＋ I/R group： heroin, an inducer of HO-1 was injected intraperitoneally at 40 μmol·kg^-1·day^-1 for two consecutive days prior to 40 minutes clamping of left lung hilum; ZnPPIX＋IPO group： zinc protoporphyrin IX, an inhibitor of HO-1 was injected intraperitoneally at 20 mg·kg^-1 24 hours prior to 40 minutes clamping of left lung hilum; and HM＋S group： HM was administered as in the HM＋I/R group without inducing lung I/R. Arterial partial pressure of oxygen （PaO2） and malondialdehyde （MDA） content in serum were assessed. The left lung was removed for determination of wet/dry lung weight ratio and expression of HO-1 protein by immuno-histochemical technique and for light microscopic examination. Results： The PaO2 was significantly lower in all the experimental groups compared with sham group （90 roan Hg ±11 mmHg）. However, the values of PaO2in IPO （81 mm Hg±7 mm Hg） and HM＋I/R （80 mm Hg±9 mm Hg） were higher than that in I/R （63 mm Hg±9 mm Hg） and ZnPPIX＋IPO （65 mm Hg±8 mm Hg） groups （P〈0.01）. The protein expression of HO- 1 in lung tissue was significantly increased in I/R group compared with S group （P〈0.01）. While the HO-1 protein expression was higher in IPO and HM＋I/R groups as compared with I/R group （P〈0.05, P〈0.01 ）. The lung wet/ dry （W/D） weight ratio and MDA conte展开更多
Quercetin is a widely-occurring flavonoid that protects against cancer, and improves memory and cardiovascular functions.However, whether quercetin exhibits therapeutic effects in diabetic retinopathy remains unclear....Quercetin is a widely-occurring flavonoid that protects against cancer, and improves memory and cardiovascular functions.However, whether quercetin exhibits therapeutic effects in diabetic retinopathy remains unclear.In this study, we established a rat model of streptozocininduced diabetic retinopathy.Seventy-two hours later, the rats were intraperitoneally administered 150 mg/kg quercetin for 16 successive weeks.Quercetin markedly increased the thickness of the retinal cell layer, increased the number of ganglion cells, and decreased the overexpression of the pro-inflammatory factors interleukin-1β, interleukin-18, interleukin-6 and tumor necrosis factor-α in the retinal tissue as well as the overexpression of high mobility group box-1 and the overactivation of the NLRP3 inflammasome.Furthermore, quercetin inhibited the overexpression of TLR4 and NF-κBp65, reduced the expression of the pro-angiogenic vascular endothelial growth factor and soluble intercellular adhesion molecule-1, and upregulated the neurotrophins brain-derived neurotrophic factor and nerve growth factor.Intraperitoneal injection of the heme oxygenase-1 inhibitor zinc protoporphyrin blocked the protective effect of quercetin.These findings suggest that quercetin exerts therapeutic effects in diabetic retinopathy possibly by inducing heme oxygenase-1 expression.This study was approved by the Animal Ethics Committee of China Medical University, China(approval No.2016 PS229K) on April 8, 2016.展开更多
Pretreatment of lower H2O2 doses （0.05, 0.5 and 5 mM） for 24 h was able to dose-dependently attenuate lipid peroxidation in wheat seedling leaves mediated by further oxidative damage elicited by higher dose of H2O2 ...Pretreatment of lower H2O2 doses （0.05, 0.5 and 5 mM） for 24 h was able to dose-dependently attenuate lipid peroxidation in wheat seedling leaves mediated by further oxidative damage elicited by higher dose of H2O2 （150 mM） for 6 h, with 0.5 mM H2O2 being the most effective concentrations. Further results illustrated that 0.5 mM H2O2 pretreatment triggered the biphasic production of H2O2 during a 24 h period. We also noticed that only peak Ⅰ （0.25 h） rather than peak Ⅱ （4 h） was approximately consistent with the enhancement of heme oxygenase （HO） activity, HO-1 gene expression. Meanwhile, enhanced superoxide dismutase （SOD） activity, Mn-SOD and Cu, Zn-SOD transcripts might be a potential source of peak Ⅰ of endogenous H2O2. Further results confirmed that 0.5 mM H2O2 treatment for 0.5 h was able to upregulate HO gene expression, which was detected by enzyme activity determination, semi-quantitative reverse transcription-polymerase chain reaction and western blotting. Meanwhile, the application of N,N＇-dimethylthiourea, a trap for endogenous H2O2, not only blocked the upregulation of HO, but also reversed the corresponding oxidation attenuation. Together, the above results suggest that endogenous H2O2 production （peak Ⅰ） plays a positive role in the induction of HO by enhancing its mRNA level and protein expression, thus leading to the acclimation to oxidative stress.展开更多
AIM:To investigate the effects of heme oxygenase(HO)-1 on liver fibrosis and the expression of peroxisome proliferator-activated receptor gamma(PPARγ) and nuclear factor-kappa B(NF-κB) in rats.METHODS:Sixty Wistar r...AIM:To investigate the effects of heme oxygenase(HO)-1 on liver fibrosis and the expression of peroxisome proliferator-activated receptor gamma(PPARγ) and nuclear factor-kappa B(NF-κB) in rats.METHODS:Sixty Wistar rats were used to construct liver fibrosis models and were randomly divided into 5 groups:group A(normal,untreated),group B(model for 4 wk,untreated),group C(model for 6 wk,untreated),group D [model for 6 wk,treated with zinc protoporphyrin Ⅸ(ZnPP-Ⅸ) from week 4 to week 6],group E(model for 6 wk,treated with hemin from week 4 to week 6).Next,liver injury was assessed by measuring serum alanine aminotransferase(ALT),aspartate aminotransferase(AST) and albumin levels.The degree of hepatic fibrosis was evaluated by measuring serum hyaluronate acid(HA),type Ⅳ collagen(Ⅳ-C) and by histological examination.Hydroxyproline(Hyp) content in the liver homogenate was determined.The expres-sion levels of alpha-smooth muscle actin(α-SMA) in liver tissue were measured by real-time quantitative polymerase chain reaction(RT-PCR).The expression levels of PPARγ and NF-κB were determined by RT-PCR and Western blotting.RESULTS:The expression of HO-1 increased with the development of fibrosis.Induction of HO-1 by hemin significantly attenuated the severity of liver injury and the levels of liver fibrosis as compared with inhibition of HO-1 by ZnPP-Ⅸ.The concentrations of serum ALT,AST,HA and Ⅳ-C in group E decreased compared with group C and group D(P < 0.01).Amount of Hyp and α-SMA in the liver tissues in group E decreased compared with group C(0.62 ± 0.14 vs 0.84 ± 0.07,1.42 ± 0.17 vs 1.84 ± 0.17,respectively,P < 0.01) and group D(0.62 ± 0.14 vs 1.11 ± 0.16,1.42 ± 0.17 vs 2.56 ± 0.37,respectively,P < 0.01).The expression of PPARγ at levels of transcription and translation decreased with the development of fibrosis especially in group D;and it increased in group E compared with groups C and D(0.88 ± 0.15 vs 0.56 ± 0.19,0.88 ± 0.15 vs 0.41 ± 0.11,respectively,P < 0.01).The expression of NF-κB 展开更多
Hepatic ischemia-reperfusion injury (IRI) limits access to transplantation. Heme oxygenase-1 (HO-1) is a powerful antioxidant enzyme which degrades free heme into biliverdin,free iron and carbon monoxide. HO-1 and its...Hepatic ischemia-reperfusion injury (IRI) limits access to transplantation. Heme oxygenase-1 (HO-1) is a powerful antioxidant enzyme which degrades free heme into biliverdin,free iron and carbon monoxide. HO-1 and its metabolites have the ability to modulate a wide variety of inflammatory disorders including hepatic IRI. Mechanisms of this protective effect include reduction of oxygen free radicals,alteration of macrophage and T cell phenotype. Further work is required to understand the physiological importance of the many actions of HO-1 identified experimentally,and to harness the protective effect of HO-1 for therapeutic potential.展开更多
Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO prod...Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO production and heme oxygenase (HO) activity, an important CO synthetic enzyme, are first reported to increase in response to ABA treatment, which could result in stomatal closure. Inter- estingly, ABA-induced stomatal closure in V. faba guard cells is partially blocked when the synthetic CO inhibitor ZnPP, or the CO/NO scavenger Hb is added. Furthermore, we show that, exogenously applied CO donor, hematin, and CO aqueous solution not only result in the enhancement of CO release, but also time-dependently induce stomatal closure, and the latter is mimicked by the application of an NO donor SNP. The above-mentioned stomatal closure effects are differentially reversed by the addition of tungstate, a potent inhibitor of NO synthetic enzyme nitrate reductase (NR), the specific NO scavenger cPTIO, ZnPP, or Hb. During treatment for 4 h, SNP, 0.01% CO aqueous solution or hematin significantly triggers NO synthesis, whereas cPTIO, or tungstate approximately fully inhibits NO fluorescence. Ad- ditionally, application of the GC inhibitor ODQ blocks CO-induced stomatal closure. This inhibition could be reversed when 8-Br-cGMP is added. Thus, the above results suggest that CO produced by HO is involved in ABA-induced stomatal closure, and NO and cGMP may function as downstream interme- diates in the CO signaling responsible for stomatal closure.展开更多
文摘Background Urinary trypsin inhibitor inhibits the enhanced production of pro-inflammatory molecules. Hemeoxygenase-1 induction protects against ischemia/repeffusion injury, oxidative stress, inflammation, transplant rejection, apoptosis, and other conditions. However, it is unknown if a combined hemin and ulinastatin pretreatment could result in protective effects for septic shock. In this study, we investigated the role of hemin pretreatment combined with ulinastatin on septic shock in rats. Methods Eighty healthy, male Sprague-Dawley rats were randomly divided into four groups： group S, group H, group U and group HU. Groups S and U received 1 ml normal saline intraperitoneally, while groups H and HU both received 1 ml （100 mg/kg） hemin. Twenty-four hours later, 0.5 ml （10 mg/kg） E. coil lipopolysaccharide was injected intravenously to replicate the experimental model of septic shock. After an initial 25% decrease in the mean arterial pressure, corresponding to time point 0, groups HU and U received 0.5 ml 10 000 U/kg ulinastatin intravenously, and the others received 0.5 ml normal saline. Results The number of deaths in groups H and U was lower than that in the group S （P〈0.05）, and was higher than that in group HU （all P〈0.05） respectively. The mean arterial pressure （MAP） in the group S was significantly greater than that in group H （P〈0.05）, and was lower than that in group HU and group U （P〈0.05）. The plasma levels of alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, creatinine （Cr） and blood urea nitrogen （BUN）, the malondial- dehyde （MDA） of liver, kidney and lung, and the lung Evans blue （EB） contents in groups H and U, were greater than that in group HU （all P〈0.05）, and were lower than that in group S （all P〈0.05）. In contrast, the plasma levels of CO in groups H and HU were higher than that in groups S and U （all P〈0.05）, and SOD of liver, kidney and lung in groups H and U were higher than that in group S,
基金This work was supported by the British Heart Foundation, Heart Research UK, Biotechnology and Biological Sciences Research Council, Medical Research Council, Wellcome Trust, KC Wong/China Scholarship Council, and EU COST ACTION B35.
基金This work was kindly supported by Na-tional Natural Science Foundation of China(No.39670308)
文摘To investigate whether the expression of exogenous heme oxygenase-1 (HO-1) gene within vascular smooth muscle cells (VSMC) could protect the cells from free radical attack and inhibit cell proliferation, we established an in vitro transfection of human HO-1 gene into rat VSMC mediated by a retroviral vector. The results showed that the profound expression of HO-1 protein as well as HO activity was 1.8- and 2.0-fold increased respectively in the transfected cells compared to the non-transfected ones. The treatment of VSMC with different concentrations of H2O2 led to the remarkable cell damage as indicated by survival rate and LDH leakage. However, the resistance of the HO-1 transfected VSMC against H2O2 was significantly raised. This protective effect was dramatically diminished when the transfected VSMC were pretreated with ZnPP-IX, a specific inhibitor of HO, for 24 h. In addition, we found that the growth potential of the transfected cells was significantly inhibited directly by increased activity of HO-1, and this effect might be related to decreased phosphorylation of MAPK. These results suggest that the overexpression of introduced hHO-1 is potentially able to reduce the risk factors of atherosclerosis, partially due to its cellular protection against oxidative injury and to its inhibitory effect on cellular proliferation.
基金Supported by the Universidad de Buenos Aires (Argentina) and Consejo Nacional de Investigaciones Cientificas y Tecnicas Argentina
文摘AIM: To evaluate the in vivo effect of glutamine on cobaltgenerated oxidative stress and (HO-1) induction in rat liver.METHODS: Fasted female Wistar rats received a single injection of cobalt chloride (375 μmol/kg body weight) and then were killed at different times. Lipid peroxidation and soluble and enzymatic antioxidant defense system (reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD)) were measured in liver homogenates. Ferritin and ferritin iron contents as well as heme oxygenase-1 (HO-1) activity and expression were also determined. The antioxidant properties of glutamine (Gin) were also evaluated. RESULTS: Cobalt chloride increased lipid peroxidation (50% over control values) 1 h after treatment. GSH reached a minimum at 3 h (40%) increasing thereafter. Twelve hours after CoCl2 injection, the antioxidant enzymes CAT, GSH-Px and SOD also diminished by about 30%. Heme oxygenase-1 induction was observed 6 h after treatment reaching a maximum value of 14-fold over the controls, 12 h after cobalt treatment. A 1.7-fold increase in ferritin and ferritin-bound iron 24 h after treatment were also obtained. Administration of glutamine (300 mg/kg body weight) by gavage 24 h before CoCl2 treatment entirely prevented the increase in thiobarbituric acid reactive substances (TBARS) content, the decrease in GSH levels, and partially reverted heme oxygenase-1 induction. CONCLUSION: These results suggested that a natural product such as glutamine prevents glutathione depletion and consequently heme oxygenase induction.
基金This project was supported by the National Natural Science Foundation of China （No.30672033）.
文摘Objective： To investigate the effect of ischemic postconditioning （1PO） on acute lung ischemia-reperfusion （I/R） injury and the protein expression of haeme oxygenase-1 （HO-1）, a cytoprotective defense against oxidative injury. Methods： After being anesthetized with chloralhydrate, forty-eight healthy SD rats were randomly divided into 6 groups （8 in each）： sham operation group （S group）; I/R group： left lung hilum was clamped for 40 minutes followed by 105 minutes of reperfusion; IPO group： left lung hilum was clamped for40 minutes and postconditioned by 3 cycles of 30 seconds of reperfusion and 30 seconds of reocclusion; Heroin （HM）＋ I/R group： heroin, an inducer of HO-1 was injected intraperitoneally at 40 μmol·kg^-1·day^-1 for two consecutive days prior to 40 minutes clamping of left lung hilum; ZnPPIX＋IPO group： zinc protoporphyrin IX, an inhibitor of HO-1 was injected intraperitoneally at 20 mg·kg^-1 24 hours prior to 40 minutes clamping of left lung hilum; and HM＋S group： HM was administered as in the HM＋I/R group without inducing lung I/R. Arterial partial pressure of oxygen （PaO2） and malondialdehyde （MDA） content in serum were assessed. The left lung was removed for determination of wet/dry lung weight ratio and expression of HO-1 protein by immuno-histochemical technique and for light microscopic examination. Results： The PaO2 was significantly lower in all the experimental groups compared with sham group （90 roan Hg ±11 mmHg）. However, the values of PaO2in IPO （81 mm Hg±7 mm Hg） and HM＋I/R （80 mm Hg±9 mm Hg） were higher than that in I/R （63 mm Hg±9 mm Hg） and ZnPPIX＋IPO （65 mm Hg±8 mm Hg） groups （P〈0.01）. The protein expression of HO- 1 in lung tissue was significantly increased in I/R group compared with S group （P〈0.01）. While the HO-1 protein expression was higher in IPO and HM＋I/R groups as compared with I/R group （P〈0.05, P〈0.01 ）. The lung wet/ dry （W/D） weight ratio and MDA conte
基金sponsored by the National Natural Science Foundation of China, Nos.81200718(to HWY) and 81570866(to XLC)。
文摘Quercetin is a widely-occurring flavonoid that protects against cancer, and improves memory and cardiovascular functions.However, whether quercetin exhibits therapeutic effects in diabetic retinopathy remains unclear.In this study, we established a rat model of streptozocininduced diabetic retinopathy.Seventy-two hours later, the rats were intraperitoneally administered 150 mg/kg quercetin for 16 successive weeks.Quercetin markedly increased the thickness of the retinal cell layer, increased the number of ganglion cells, and decreased the overexpression of the pro-inflammatory factors interleukin-1β, interleukin-18, interleukin-6 and tumor necrosis factor-α in the retinal tissue as well as the overexpression of high mobility group box-1 and the overactivation of the NLRP3 inflammasome.Furthermore, quercetin inhibited the overexpression of TLR4 and NF-κBp65, reduced the expression of the pro-angiogenic vascular endothelial growth factor and soluble intercellular adhesion molecule-1, and upregulated the neurotrophins brain-derived neurotrophic factor and nerve growth factor.Intraperitoneal injection of the heme oxygenase-1 inhibitor zinc protoporphyrin blocked the protective effect of quercetin.These findings suggest that quercetin exerts therapeutic effects in diabetic retinopathy possibly by inducing heme oxygenase-1 expression.This study was approved by the Animal Ethics Committee of China Medical University, China(approval No.2016 PS229K) on April 8, 2016.
基金Supported by the fund for Creative Experimental Project of Undergraduate Students in Jiangsu Province of China (96)the program for New Century Excellent Talents in University (NCET-07-0441)+1 种基金the Natural Science Foundation of China (30671248)the grant obtained from the 111 Project of China (B07030)
文摘Pretreatment of lower H2O2 doses （0.05, 0.5 and 5 mM） for 24 h was able to dose-dependently attenuate lipid peroxidation in wheat seedling leaves mediated by further oxidative damage elicited by higher dose of H2O2 （150 mM） for 6 h, with 0.5 mM H2O2 being the most effective concentrations. Further results illustrated that 0.5 mM H2O2 pretreatment triggered the biphasic production of H2O2 during a 24 h period. We also noticed that only peak Ⅰ （0.25 h） rather than peak Ⅱ （4 h） was approximately consistent with the enhancement of heme oxygenase （HO） activity, HO-1 gene expression. Meanwhile, enhanced superoxide dismutase （SOD） activity, Mn-SOD and Cu, Zn-SOD transcripts might be a potential source of peak Ⅰ of endogenous H2O2. Further results confirmed that 0.5 mM H2O2 treatment for 0.5 h was able to upregulate HO gene expression, which was detected by enzyme activity determination, semi-quantitative reverse transcription-polymerase chain reaction and western blotting. Meanwhile, the application of N,N＇-dimethylthiourea, a trap for endogenous H2O2, not only blocked the upregulation of HO, but also reversed the corresponding oxidation attenuation. Together, the above results suggest that endogenous H2O2 production （peak Ⅰ） plays a positive role in the induction of HO by enhancing its mRNA level and protein expression, thus leading to the acclimation to oxidative stress.
文摘AIM:To investigate the effects of heme oxygenase(HO)-1 on liver fibrosis and the expression of peroxisome proliferator-activated receptor gamma(PPARγ) and nuclear factor-kappa B(NF-κB) in rats.METHODS:Sixty Wistar rats were used to construct liver fibrosis models and were randomly divided into 5 groups:group A(normal,untreated),group B(model for 4 wk,untreated),group C(model for 6 wk,untreated),group D [model for 6 wk,treated with zinc protoporphyrin Ⅸ(ZnPP-Ⅸ) from week 4 to week 6],group E(model for 6 wk,treated with hemin from week 4 to week 6).Next,liver injury was assessed by measuring serum alanine aminotransferase(ALT),aspartate aminotransferase(AST) and albumin levels.The degree of hepatic fibrosis was evaluated by measuring serum hyaluronate acid(HA),type Ⅳ collagen(Ⅳ-C) and by histological examination.Hydroxyproline(Hyp) content in the liver homogenate was determined.The expres-sion levels of alpha-smooth muscle actin(α-SMA) in liver tissue were measured by real-time quantitative polymerase chain reaction(RT-PCR).The expression levels of PPARγ and NF-κB were determined by RT-PCR and Western blotting.RESULTS:The expression of HO-1 increased with the development of fibrosis.Induction of HO-1 by hemin significantly attenuated the severity of liver injury and the levels of liver fibrosis as compared with inhibition of HO-1 by ZnPP-Ⅸ.The concentrations of serum ALT,AST,HA and Ⅳ-C in group E decreased compared with group C and group D(P < 0.01).Amount of Hyp and α-SMA in the liver tissues in group E decreased compared with group C(0.62 ± 0.14 vs 0.84 ± 0.07,1.42 ± 0.17 vs 1.84 ± 0.17,respectively,P < 0.01) and group D(0.62 ± 0.14 vs 1.11 ± 0.16,1.42 ± 0.17 vs 2.56 ± 0.37,respectively,P < 0.01).The expression of PPARγ at levels of transcription and translation decreased with the development of fibrosis especially in group D;and it increased in group E compared with groups C and D(0.88 ± 0.15 vs 0.56 ± 0.19,0.88 ± 0.15 vs 0.41 ± 0.11,respectively,P < 0.01).The expression of NF-κB
基金Supported by The Maurice Wohl Fellowship from the Royal College of Surgeons of Edinburgh and a Research Training Fel-lowship from The Wellcome Trust (to Richards JA)Tenovus Scotland and The Peel Medical Research Trust to support his cur-rent work (to Richards JA)A Clinician Scientist Fellowship from the Academy of Medical Sciences and the Health Foundation (to Devey LR)
文摘Hepatic ischemia-reperfusion injury (IRI) limits access to transplantation. Heme oxygenase-1 (HO-1) is a powerful antioxidant enzyme which degrades free heme into biliverdin,free iron and carbon monoxide. HO-1 and its metabolites have the ability to modulate a wide variety of inflammatory disorders including hepatic IRI. Mechanisms of this protective effect include reduction of oxygen free radicals,alteration of macrophage and T cell phenotype. Further work is required to understand the physiological importance of the many actions of HO-1 identified experimentally,and to harness the protective effect of HO-1 for therapeutic potential.
基金Supported by the National Natural Science Foundation of China (Grant No. 30671248)"Blue Project" of Jiangsu Province and the Student Research Train-ing (SRT) Project of Nanjing Agricultural University (Grant No. 0506A11)
文摘Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO production and heme oxygenase (HO) activity, an important CO synthetic enzyme, are first reported to increase in response to ABA treatment, which could result in stomatal closure. Inter- estingly, ABA-induced stomatal closure in V. faba guard cells is partially blocked when the synthetic CO inhibitor ZnPP, or the CO/NO scavenger Hb is added. Furthermore, we show that, exogenously applied CO donor, hematin, and CO aqueous solution not only result in the enhancement of CO release, but also time-dependently induce stomatal closure, and the latter is mimicked by the application of an NO donor SNP. The above-mentioned stomatal closure effects are differentially reversed by the addition of tungstate, a potent inhibitor of NO synthetic enzyme nitrate reductase (NR), the specific NO scavenger cPTIO, ZnPP, or Hb. During treatment for 4 h, SNP, 0.01% CO aqueous solution or hematin significantly triggers NO synthesis, whereas cPTIO, or tungstate approximately fully inhibits NO fluorescence. Ad- ditionally, application of the GC inhibitor ODQ blocks CO-induced stomatal closure. This inhibition could be reversed when 8-Br-cGMP is added. Thus, the above results suggest that CO produced by HO is involved in ABA-induced stomatal closure, and NO and cGMP may function as downstream interme- diates in the CO signaling responsible for stomatal closure.
