A rapid and concentration-dependent generation of superoxide anion (·O2^-), measured with a superoxide-specific Cypridina luciferin-derived chemiluminescent reagent, was observed when two lanthanide salts (LaC...A rapid and concentration-dependent generation of superoxide anion (·O2^-), measured with a superoxide-specific Cypridina luciferin-derived chemiluminescent reagent, was observed when two lanthanide salts (LaCl3 and CdCl3 ) were added to tobacco ( Nicotiana tabacum) cell suspension culture. Addition of superoxide dismutase (480 U·ml^-1) and Tiron (5 μmol·L^-1) to cell culture suspension decreases the level of lanthanide cation-induced ·O2^- generation, suggesting that ·O2^- generation is extra-cellular. Pretreatment of the cell culture suspension with diphenyleneiodonium (10 and 50 μmol·L^-1 ), quinacrine ( 1 and 5 mmol· L^-1 ) and imidazol ( 10 mmol· L^-1 ), inhibitors of NADPH oxidase, notably inhibits the generation of superoxide induced by lanthanide cation, implying the possible involvement of activation of NADPH oxidase. In addition, addition of SHAM (1 and 5 mmol· L^-1), azide (0.2 and 1 mmol· L^-1 ), inhibitor of peroxidase, has no influence on ·O2^- generation.展开更多
A potted experiment was carried out to study the effect of an arbuscular mycorrhizal fungus(Diversispora versiformis)and arbuscular mycorrhizal like fungus(Piriformospora indica)on antioxidant enzyme defense system of...A potted experiment was carried out to study the effect of an arbuscular mycorrhizal fungus(Diversispora versiformis)and arbuscular mycorrhizal like fungus(Piriformospora indica)on antioxidant enzyme defense system of Satsuma orange(Citrus sinensis cv.Oita 4)grafted on Poncirus trifoliata under favourable temperature(25°C)and cold temperature(0°C)for 12 h.Such short-term treatment of cold temperature did not cause any significant change in root fungal colonization and spore density in soil.Under cold stress,D.versiformis inoculation did not change the activity of superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)in leaves and roots,whereas P.indica inoculation significantly increased the activity of CAT in roots and POD in leaves only.In addition,inoculation of two mycorrhizal fungi under cold stress significantly increased the relative expression levels of PtPOD and PtF-SOD in leaves,P.indica up-regulated the expression levels of PtCu/Zn-SOD in leaves,and D.versiformis also induced the expression levels of PtMn-SOD and PtCAT1 in leaves.In addition,inoculated Oita 4 trees maintained significantly lower hydrogen peroxide levels and malondialdehyde contents in leaves and roots under cold temperature,suggesting lower oxidative damage.Therefore,we concluded that arbuscular mycorrhizal fungi(especially P.indica)mainly induced the expression of antioxidant enzyme genes,depending on the fungal species,and thus mitigated oxidative damage for higher cold resistance in inoculated plants.展开更多
Carcinoembryonic antigen(CEA)is a surface glycoprotein expressed in human epithelial cells and is released from their surface,especially during colorectal cancer.Frequently,colorectal cancer is accompanied by in...Carcinoembryonic antigen(CEA)is a surface glycoprotein expressed in human epithelial cells and is released from their surface,especially during colorectal cancer.Frequently,colorectal cancer is accompanied by inflammation,where tumor-infiltrating neutrophils play an important role.CEA was also found to be a strong chemotactic agent for neutrophils.The purpose of this study was to find out if CEA can enhance neutrophil priming and activation.Primed neutrophils were activated by N-formyl-methionyl-leucyl-phenylalanine(formyl-MLP)and the resulting oxidative burst was measured luminometrically.Unexpectedly,in vitro priming of neutrophils by CEA,alone or preceded by LPS,inhibited subsequent activation of these cells by formyl-MLP.CEA may have anti-inflammatory properties in vivo.展开更多
Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, has been recently shown to induce both cytosolic and nuclear calcium transient increases an...Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, has been recently shown to induce both cytosolic and nuclear calcium transient increases and a correlated Programmed Cell Death (PCD) in tobacco BY-2 cells. In this study, in order to get deeper insight into the LCB signaling pathway leading to cell death, the putative role of Reactive Oxygen Species (ROS) has been investigated. We show that DHS triggers a rapid dose-dependent production of H2O2 that is blocked by diphenyleniodonium (DPI), indicating the involvement of NADPH oxidase(s) in the process. In addition, while DPI does not block DHS-induced calcium increases, the ROS production is inhibited by the broad spectrum calcium channel blocker lanthanum (La^3+). Therefore, ROS production occurs downstream of DHS-induced Ca^2+ transients. Interestingly, DHS activates expression of defense-related genes that is inhibited by both La^3+ and DPI. Since DPI does not prevent DHS-induced cell death, these results strongly indicate that DHS-induced H2O2 production is not implicated in PCD mechanisms but rather would be associated to basal cell defense mechanisms.展开更多
文摘A rapid and concentration-dependent generation of superoxide anion (·O2^-), measured with a superoxide-specific Cypridina luciferin-derived chemiluminescent reagent, was observed when two lanthanide salts (LaCl3 and CdCl3 ) were added to tobacco ( Nicotiana tabacum) cell suspension culture. Addition of superoxide dismutase (480 U·ml^-1) and Tiron (5 μmol·L^-1) to cell culture suspension decreases the level of lanthanide cation-induced ·O2^- generation, suggesting that ·O2^- generation is extra-cellular. Pretreatment of the cell culture suspension with diphenyleneiodonium (10 and 50 μmol·L^-1 ), quinacrine ( 1 and 5 mmol· L^-1 ) and imidazol ( 10 mmol· L^-1 ), inhibitors of NADPH oxidase, notably inhibits the generation of superoxide induced by lanthanide cation, implying the possible involvement of activation of NADPH oxidase. In addition, addition of SHAM (1 and 5 mmol· L^-1), azide (0.2 and 1 mmol· L^-1 ), inhibitor of peroxidase, has no influence on ·O2^- generation.
基金This study was supported by the Plan in Scientific and Technological Innovation Team of Outstanding Young Scientists,Hubei Provincial Department of Education(T201604)the Hubei Agricultural Science and Technology Innovation Action Project(Hubei Nongfa[2018]No.1)+1 种基金The authors would like to extend their sincere appreciation to the Researchers Supporting Project Number(RSP-2021/134)King Saud University,Riyadh,Saudi Arabia.
文摘A potted experiment was carried out to study the effect of an arbuscular mycorrhizal fungus(Diversispora versiformis)and arbuscular mycorrhizal like fungus(Piriformospora indica)on antioxidant enzyme defense system of Satsuma orange(Citrus sinensis cv.Oita 4)grafted on Poncirus trifoliata under favourable temperature(25°C)and cold temperature(0°C)for 12 h.Such short-term treatment of cold temperature did not cause any significant change in root fungal colonization and spore density in soil.Under cold stress,D.versiformis inoculation did not change the activity of superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)in leaves and roots,whereas P.indica inoculation significantly increased the activity of CAT in roots and POD in leaves only.In addition,inoculation of two mycorrhizal fungi under cold stress significantly increased the relative expression levels of PtPOD and PtF-SOD in leaves,P.indica up-regulated the expression levels of PtCu/Zn-SOD in leaves,and D.versiformis also induced the expression levels of PtMn-SOD and PtCAT1 in leaves.In addition,inoculated Oita 4 trees maintained significantly lower hydrogen peroxide levels and malondialdehyde contents in leaves and roots under cold temperature,suggesting lower oxidative damage.Therefore,we concluded that arbuscular mycorrhizal fungi(especially P.indica)mainly induced the expression of antioxidant enzyme genes,depending on the fungal species,and thus mitigated oxidative damage for higher cold resistance in inoculated plants.
基金Grant No:N N401332236 from The Ministry of Science and Higher Education of Poland.
文摘Carcinoembryonic antigen(CEA)is a surface glycoprotein expressed in human epithelial cells and is released from their surface,especially during colorectal cancer.Frequently,colorectal cancer is accompanied by inflammation,where tumor-infiltrating neutrophils play an important role.CEA was also found to be a strong chemotactic agent for neutrophils.The purpose of this study was to find out if CEA can enhance neutrophil priming and activation.Primed neutrophils were activated by N-formyl-methionyl-leucyl-phenylalanine(formyl-MLP)and the resulting oxidative burst was measured luminometrically.Unexpectedly,in vitro priming of neutrophils by CEA,alone or preceded by LPS,inhibited subsequent activation of these cells by formyl-MLP.CEA may have anti-inflammatory properties in vivo.
文摘Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, has been recently shown to induce both cytosolic and nuclear calcium transient increases and a correlated Programmed Cell Death (PCD) in tobacco BY-2 cells. In this study, in order to get deeper insight into the LCB signaling pathway leading to cell death, the putative role of Reactive Oxygen Species (ROS) has been investigated. We show that DHS triggers a rapid dose-dependent production of H2O2 that is blocked by diphenyleniodonium (DPI), indicating the involvement of NADPH oxidase(s) in the process. In addition, while DPI does not block DHS-induced calcium increases, the ROS production is inhibited by the broad spectrum calcium channel blocker lanthanum (La^3+). Therefore, ROS production occurs downstream of DHS-induced Ca^2+ transients. Interestingly, DHS activates expression of defense-related genes that is inhibited by both La^3+ and DPI. Since DPI does not prevent DHS-induced cell death, these results strongly indicate that DHS-induced H2O2 production is not implicated in PCD mechanisms but rather would be associated to basal cell defense mechanisms.