Ischemia/reperfusion (I/R) injury of the gut is a significant problem in a variety of clinical settings and is associated with a high morbidity and mortality. Although the mechanisms involved in the pathogenesis of gu...Ischemia/reperfusion (I/R) injury of the gut is a significant problem in a variety of clinical settings and is associated with a high morbidity and mortality. Although the mechanisms involved in the pathogenesis of gut I/R injury have not been fully elucidated, it is generally believed that oxidative stress with subsequent inflammatory injury plays an important role. Heme oxygenase (HO) is the rate-limiting enzyme in the catabolism of heme, followed by production of CO, biliverdin, and free iron. The HO system is believed to confer cytoprotection by inhibiting inflammation, oxidation, and apoptosis, and maintaining microcirculation. HO-1, an inducible form of HO, serves a vital metabolic function as the rate-limiting step in the heme degradation pathway, and affords protection in models of intestinal I/R injury. HO-1 system is an important player in intestinal I/R injury condition, and may offer new targets for the management of this condition.展开更多
AIM： To test the hypothesis that enhancement of the activity of heine oxygenase can interfere with processes of fibrogenesis associated with recurrent liver injury, we investigated the therapeutic potential of over-e...AIM： To test the hypothesis that enhancement of the activity of heine oxygenase can interfere with processes of fibrogenesis associated with recurrent liver injury, we investigated the therapeutic potential of over-expression of heine oxygense-1 in a CCl4-induced micronodular cirrhosis model. METHODS： Recombinant adeno-associated viruses carrying rat HO-1 or GFP gene were generated, 1×10^12 vg of adeno-associated viruses were administered through portal injection at the time of the induction of liver fibrosis. RESULTS： Conditioning the rat liver with over-expression of HO-1 by rAAV/HO-1 significantly increased the HO enzymatic activities in a stable manner. The development of micronodular cirrhosis was significantly inhibited in rAAV/HO-1-transduced animals as compared to controls. Portal hypertension was markedly diminished in rAAV/HO-1-transduced animals as compared to controls, whereas there are no significant changes in systolic blood pressure. This finding was accompanied with improved liver biochemistry, less infiltrating macrophages and less activated hepatic stellate cells （HSCs） in rAAV/ HO-1-transduced livers. CONCLUSIONS： Enhancement of HO activity in the livers suppresses the development of cirrhosis.展开更多
Aim： To assess heine oxygenase-1 （HO-1） activity in the cavemous tissue of sildenafil citrate-treated rats. Methods： One hundred and ninety-two Sprague-Dawley male rats, divided into four equal groups, were invest...Aim： To assess heine oxygenase-1 （HO-1） activity in the cavemous tissue of sildenafil citrate-treated rats. Methods： One hundred and ninety-two Sprague-Dawley male rats, divided into four equal groups, were investigated. Group 1, the control group, received regular animal chow; group 2 received sildenafil citrate by intragastric tube; group 3 received sildenafil and HO inhibitor （zinc protoporphyrin, ZnPP）; and group 4 received sildenafil and nitric oxide synthase （NOS） inhibitor L-nitroarginine methyl ester （L-NAME）. Twelve rats from each group were killed after 0.5 h, 1 h, 2 h and 3 h of drug administration. Then HO-1 activity, cGMP levels and NOS enzymatic activity in the cavernous tissues were estimated. Results： In cavemous tissue, HO-1 activity, NOS enzymatic activity and cGMP concentration increased significantly in sildenafil-treated rats compared to other groups throughout the experiment. Rats receiving either HO or NOS inhibitors showed a significant decrease in these parameters. HO- 1 cavemous tissue activity and NOS enzymatic activity demonstrated a positive significant correlation with cGMP levels （r = 0.646, r = 0.612 respectively; P 〈 0.001）. Conclusion： The actions of PDE5 inhibitor sildenafil citrate in the cavernous tissue are partly mediated through the interdependent relationship between both HO-1 and NOS activities.展开更多
To confirm the existence of heme oxygenase (HO)-carbon monoxide (CO)- cyclic guanosine monophosphate (cGMP) pathway in the cultured human trabecular meshwork cells (HTMCs) in vitro, and to evaluate the inductive role...To confirm the existence of heme oxygenase (HO)-carbon monoxide (CO)- cyclic guanosine monophosphate (cGMP) pathway in the cultured human trabecular meshwork cells (HTMCs) in vitro, and to evaluate the inductive role of hemin on this pathway, HTMCs of the third to fourth generation were cultured in vitro. Reverse transcripase-polymerase chain reaction (RT-PCR) was employed for detection of HO-1 and HO-2 mRNA. Immunohistochemical staining was used to detect HO-1 and HO-2 proteins. Hemin was added into the culture solution. The HO-1 mRNA levels were quantified by RT-PCR. The relative amount of carbon monoxide released into the media was measured with the quantifying carbon monoxide hemoglobin (HbCO) by spectrophotometry. Radioimmunoassay was used to determine changes of cGMP in HTMCs. The results showed that cultured cells had the specific characteristics of HTMCs. Both HO-1 and HO-2 genes were expressed in HTMCs, as well as HO-1 and HO-2 proteins in HTMCs. Hemin induced HO-1 mRNA, HbCO and cGMP in a dose-dependent manner. In conclusion, HO-CO-cGMP pathway exists in the cultured HTMCs and can be induced by hemin. Pharmacological stimulation of HO-CO-cGMP pathway may constitute a novel therapeutic approach to rescuing glaucoma.展开更多
AIM:To study the effect of both acute and chronic alcohol exposure on heme oxygenases(HOs) in the brain,liver and duodenum.METHODS:Wild-type C57BL/6 mice,heterozygous Sod2 knockout mice,which exhibit attenuated mangan...AIM:To study the effect of both acute and chronic alcohol exposure on heme oxygenases(HOs) in the brain,liver and duodenum.METHODS:Wild-type C57BL/6 mice,heterozygous Sod2 knockout mice,which exhibit attenuated manganese superoxide dismutase activity,and liver-specific ARNT knockout mice were used to investigate the role of alcohol-induced oxidative stress and hypoxia.For acute alcohol exposure,ethanol was administered in the drinking water for 1 wk.Mice were pair-fed with regular or ethanol-containing Lieber De Carli liquid diets for 4 wk for chronic alcohol studies.HO expression was analyzed by real-time quantitative polymerase chain reaction and Western blotting.RESULTS:Chronic alcohol exposure downregulated HO-1 expression in the brain but upregulated it in the duodenum of wild-type mice.It did not alter liver HO-1 expression,nor HO-2 expression in the brain,liver or duodenum.In contrast,acute alcohol exposure decreased both liver HO-1 and HO-2 expression,and HO-2 expression in the duodenum of wild-type mice.The decrease in liver HO-1 expression was abolished in ARNT+/-mice.Sod2+/-mice with acute alcohol exposure did not exhibit any changes in liver HO-1 and HO-2 expression or in brain HO-2 expression.However,alcohol inhibited brain HO-1 and duodenal HO-2 but increased duodenal HO-1 expression in Sod2+/-mice.Collectively,these findings indicate that acute and chronic alcohol exposure regulates HO expression in a tissue-specific manner.Chronic alcohol exposure alters brain and duodenal,but not liver HO expression.However,acute alcohol exposure inhibits liver HO-1 and HO-2,and also duodenal HO-2 expression.CONCLUSION:The inhibition of liver HO expression by acute alcohol-induced hypoxia may play a role in the early phases of alcoholic liver disease progression.展开更多
To compare the early effects of hypertonic and isotonic saline resuscitation on heme oxygenase-1 （HO-1） expression in organs of rats with hemorrhagic shock. Rats were randomly divided into hypertonic saline resuscit...To compare the early effects of hypertonic and isotonic saline resuscitation on heme oxygenase-1 （HO-1） expression in organs of rats with hemorrhagic shock. Rats were randomly divided into hypertonic saline resuscitation （HTS）, normal saline resuscitation （NS） and sham groups. HO-1 mRNA, protein expression and apoptosis were evaluated in organs. In the HTS group, significant difference was noted in HO-1 protein in small intestinal mucosa and liver compared with the NS and sham groups, and in HO-1 mRNA in liver and kidney compared with the sham group. The apoptosis of small intestinal mucosa, liver, heart, and lung was significantly lower in the HTS group than that in the NS group. In this study, small volume resuscitation with HTS can efficiently up-regulate the expression level of HO-1 in small intestinal mucosa and liver, which may be one of the mechanisms alleviating organ damage.展开更多
Objective: To investigate the role of human host heme-oxygenase-1(HO-1) in pathogenesis of cerebral malaria in the in vitro model,Methods: The effect of human host HO-1 [human brain microvascular endothelial cell(HBME...Objective: To investigate the role of human host heme-oxygenase-1(HO-1) in pathogenesis of cerebral malaria in the in vitro model,Methods: The effect of human host HO-1 [human brain microvascular endothelial cell(HBMEC)] on hemoglobin degradation in the co-culture model of HBMEC and ITG Plasmodium falciparum-infected red cells(i RBC) through measurement of the enzymatic products iron and bilirubin,Results: Following exposure to the HO-1 inducer Co PPIX at all concentrations,the HBMEC cells apoptosis occurred,which could be prominently observed at 15 μM of 3 h exposure,In contrast,there was no significant change in the morphology in the non-exposed i RBC at all concentrations and exposure time,This observation was in agreement with the levels of the enzymatic degradation products iron and bilirubin,of which the highest levels(106.03 and 1 753.54% of baseline level,respectively) were observed at 15 μM vs,20 μM at 3 h vs,24 h exposure,For the effect of the HO-1 inhibitor Zn PPIX,HBMEC cell morphology was mostly unchanged,but significant inhibitory effect on cell apoptosis was seen at 10 μM for the exposure period of 3 h(37.17% of baseline level),The degree of the inhibitory effect as reflected by the level of iron produced was not clearly observed(highest effect at 10 μM and 3 h exposure),Conclusions: Results provide at least in part,insight into the contribution of HO-1 on CM pathogenesis and need to be confirmed in animal model.展开更多
基金Supported by Natural Science Foundation of Ningbo City, No.2012A610194National Natural Science Foundation of China,No. 81071697Natural Science Foundation of Guangdong Province, No. S2011040003694
文摘Ischemia/reperfusion (I/R) injury of the gut is a significant problem in a variety of clinical settings and is associated with a high morbidity and mortality. Although the mechanisms involved in the pathogenesis of gut I/R injury have not been fully elucidated, it is generally believed that oxidative stress with subsequent inflammatory injury plays an important role. Heme oxygenase (HO) is the rate-limiting enzyme in the catabolism of heme, followed by production of CO, biliverdin, and free iron. The HO system is believed to confer cytoprotection by inhibiting inflammation, oxidation, and apoptosis, and maintaining microcirculation. HO-1, an inducible form of HO, serves a vital metabolic function as the rate-limiting step in the heme degradation pathway, and affords protection in models of intestinal I/R injury. HO-1 system is an important player in intestinal I/R injury condition, and may offer new targets for the management of this condition.
文摘AIM： To test the hypothesis that enhancement of the activity of heine oxygenase can interfere with processes of fibrogenesis associated with recurrent liver injury, we investigated the therapeutic potential of over-expression of heine oxygense-1 in a CCl4-induced micronodular cirrhosis model. METHODS： Recombinant adeno-associated viruses carrying rat HO-1 or GFP gene were generated, 1×10^12 vg of adeno-associated viruses were administered through portal injection at the time of the induction of liver fibrosis. RESULTS： Conditioning the rat liver with over-expression of HO-1 by rAAV/HO-1 significantly increased the HO enzymatic activities in a stable manner. The development of micronodular cirrhosis was significantly inhibited in rAAV/HO-1-transduced animals as compared to controls. Portal hypertension was markedly diminished in rAAV/HO-1-transduced animals as compared to controls, whereas there are no significant changes in systolic blood pressure. This finding was accompanied with improved liver biochemistry, less infiltrating macrophages and less activated hepatic stellate cells （HSCs） in rAAV/ HO-1-transduced livers. CONCLUSIONS： Enhancement of HO activity in the livers suppresses the development of cirrhosis.
文摘Aim： To assess heine oxygenase-1 （HO-1） activity in the cavemous tissue of sildenafil citrate-treated rats. Methods： One hundred and ninety-two Sprague-Dawley male rats, divided into four equal groups, were investigated. Group 1, the control group, received regular animal chow; group 2 received sildenafil citrate by intragastric tube; group 3 received sildenafil and HO inhibitor （zinc protoporphyrin, ZnPP）; and group 4 received sildenafil and nitric oxide synthase （NOS） inhibitor L-nitroarginine methyl ester （L-NAME）. Twelve rats from each group were killed after 0.5 h, 1 h, 2 h and 3 h of drug administration. Then HO-1 activity, cGMP levels and NOS enzymatic activity in the cavernous tissues were estimated. Results： In cavemous tissue, HO-1 activity, NOS enzymatic activity and cGMP concentration increased significantly in sildenafil-treated rats compared to other groups throughout the experiment. Rats receiving either HO or NOS inhibitors showed a significant decrease in these parameters. HO- 1 cavemous tissue activity and NOS enzymatic activity demonstrated a positive significant correlation with cGMP levels （r = 0.646, r = 0.612 respectively; P 〈 0.001）. Conclusion： The actions of PDE5 inhibitor sildenafil citrate in the cavernous tissue are partly mediated through the interdependent relationship between both HO-1 and NOS activities.
文摘To confirm the existence of heme oxygenase (HO)-carbon monoxide (CO)- cyclic guanosine monophosphate (cGMP) pathway in the cultured human trabecular meshwork cells (HTMCs) in vitro, and to evaluate the inductive role of hemin on this pathway, HTMCs of the third to fourth generation were cultured in vitro. Reverse transcripase-polymerase chain reaction (RT-PCR) was employed for detection of HO-1 and HO-2 mRNA. Immunohistochemical staining was used to detect HO-1 and HO-2 proteins. Hemin was added into the culture solution. The HO-1 mRNA levels were quantified by RT-PCR. The relative amount of carbon monoxide released into the media was measured with the quantifying carbon monoxide hemoglobin (HbCO) by spectrophotometry. Radioimmunoassay was used to determine changes of cGMP in HTMCs. The results showed that cultured cells had the specific characteristics of HTMCs. Both HO-1 and HO-2 genes were expressed in HTMCs, as well as HO-1 and HO-2 proteins in HTMCs. Hemin induced HO-1 mRNA, HbCO and cGMP in a dose-dependent manner. In conclusion, HO-CO-cGMP pathway exists in the cultured HTMCs and can be induced by hemin. Pharmacological stimulation of HO-CO-cGMP pathway may constitute a novel therapeutic approach to rescuing glaucoma.
基金Supported by University of Nebraska Medical Center Funds and NIH grant (R01AA017738) to Harrison-Findik DD
文摘AIM:To study the effect of both acute and chronic alcohol exposure on heme oxygenases(HOs) in the brain,liver and duodenum.METHODS:Wild-type C57BL/6 mice,heterozygous Sod2 knockout mice,which exhibit attenuated manganese superoxide dismutase activity,and liver-specific ARNT knockout mice were used to investigate the role of alcohol-induced oxidative stress and hypoxia.For acute alcohol exposure,ethanol was administered in the drinking water for 1 wk.Mice were pair-fed with regular or ethanol-containing Lieber De Carli liquid diets for 4 wk for chronic alcohol studies.HO expression was analyzed by real-time quantitative polymerase chain reaction and Western blotting.RESULTS:Chronic alcohol exposure downregulated HO-1 expression in the brain but upregulated it in the duodenum of wild-type mice.It did not alter liver HO-1 expression,nor HO-2 expression in the brain,liver or duodenum.In contrast,acute alcohol exposure decreased both liver HO-1 and HO-2 expression,and HO-2 expression in the duodenum of wild-type mice.The decrease in liver HO-1 expression was abolished in ARNT+/-mice.Sod2+/-mice with acute alcohol exposure did not exhibit any changes in liver HO-1 and HO-2 expression or in brain HO-2 expression.However,alcohol inhibited brain HO-1 and duodenal HO-2 but increased duodenal HO-1 expression in Sod2+/-mice.Collectively,these findings indicate that acute and chronic alcohol exposure regulates HO expression in a tissue-specific manner.Chronic alcohol exposure alters brain and duodenal,but not liver HO expression.However,acute alcohol exposure inhibits liver HO-1 and HO-2,and also duodenal HO-2 expression.CONCLUSION:The inhibition of liver HO expression by acute alcohol-induced hypoxia may play a role in the early phases of alcoholic liver disease progression.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (No.Y2100430)the Zhejiang Provincial Education and Research Foundation of China (No. Y201019154)
文摘To compare the early effects of hypertonic and isotonic saline resuscitation on heme oxygenase-1 （HO-1） expression in organs of rats with hemorrhagic shock. Rats were randomly divided into hypertonic saline resuscitation （HTS）, normal saline resuscitation （NS） and sham groups. HO-1 mRNA, protein expression and apoptosis were evaluated in organs. In the HTS group, significant difference was noted in HO-1 protein in small intestinal mucosa and liver compared with the NS and sham groups, and in HO-1 mRNA in liver and kidney compared with the sham group. The apoptosis of small intestinal mucosa, liver, heart, and lung was significantly lower in the HTS group than that in the NS group. In this study, small volume resuscitation with HTS can efficiently up-regulate the expression level of HO-1 in small intestinal mucosa and liver, which may be one of the mechanisms alleviating organ damage.
基金supported by The Commission on Higher Education,Ministry of Education of Thailand,The National Research University Project of Thailand(NRU)Office of Higher Education Commission,Thammasat University(Center of Excellence in Pharmacology and Molecular Biology of Malaria and Cholangiocarcinoma)+1 种基金Liverpool School of Tropical Medicine,University of Liverpool,UKThe Royal Golden Jubilee PhD Programme,Thailand Research Fund-Thammasat University Joint Fund and Graduated Student Grant to P.Thongdee(Grant No.PHD/0365/2552)
文摘Objective: To investigate the role of human host heme-oxygenase-1(HO-1) in pathogenesis of cerebral malaria in the in vitro model,Methods: The effect of human host HO-1 [human brain microvascular endothelial cell(HBMEC)] on hemoglobin degradation in the co-culture model of HBMEC and ITG Plasmodium falciparum-infected red cells(i RBC) through measurement of the enzymatic products iron and bilirubin,Results: Following exposure to the HO-1 inducer Co PPIX at all concentrations,the HBMEC cells apoptosis occurred,which could be prominently observed at 15 μM of 3 h exposure,In contrast,there was no significant change in the morphology in the non-exposed i RBC at all concentrations and exposure time,This observation was in agreement with the levels of the enzymatic degradation products iron and bilirubin,of which the highest levels(106.03 and 1 753.54% of baseline level,respectively) were observed at 15 μM vs,20 μM at 3 h vs,24 h exposure,For the effect of the HO-1 inhibitor Zn PPIX,HBMEC cell morphology was mostly unchanged,but significant inhibitory effect on cell apoptosis was seen at 10 μM for the exposure period of 3 h(37.17% of baseline level),The degree of the inhibitory effect as reflected by the level of iron produced was not clearly observed(highest effect at 10 μM and 3 h exposure),Conclusions: Results provide at least in part,insight into the contribution of HO-1 on CM pathogenesis and need to be confirmed in animal model.
