Mutations in the Sfpi1 gene are essential for the development of radia-tion-induced acute myeloid leukemia. In this study, we investigated long-term interaction among immature hematopoietic cell number, intra-cellular...Mutations in the Sfpi1 gene are essential for the development of radia-tion-induced acute myeloid leukemia. In this study, we investigated long-term interaction among immature hematopoietic cell number, intra-cellular reactive oxygen species contents, and oxidative DNA damage fre-quency after irradiation. Lin-/Sca-1+ cells were isolated from C3H/HeN mice on days 1 - 400 after 0 - 3 Gy total body irradiation. On days 1 - 7, the number of surviving cells decreased and reached a minimum;however, the number of cells gradually recovered until day 200. Intracellular reactive oxygen species contents significantly increased from day 1 to day 30. In addition, the frequency of oxidative DNA damage tended to increase from day 1 and day 30, and that at day 30 was significantly increased in the 3 Gy group compared with that in the control group. In contrast, decreased cell number, increased intracellular reactive oxygen species content, and decreased oxidative DNA damage frequency were observed on day 400. These results suggested that oxidative DNA damage was involved in intracellular reactive oxygen species generation induced by cell proliferation to compensate for cell death after irradiation.展开更多
Skin is the largest organ of human body and it protects the organism from external stimuli.Skin will age as the organism ages in normal circumstances.Skin photoaging refers to the accumulation of ultraviolet radiation...Skin is the largest organ of human body and it protects the organism from external stimuli.Skin will age as the organism ages in normal circumstances.Skin photoaging refers to the accumulation of ultraviolet radiation due to long-term exposure to sunlight,which results in the premature aging of skin,wrinkles,pigmentation,skin laxity,and other signs of aging.The increase in the level of reactive oxygen species(ROS)induced by ultraviolet radiation,which causes the oxidation of cells,proteins,lipids,and other components,is an important cause of accelerated photoaging of skin.For this reason,the skin's antioxidant system will further play an antioxidant role to reduce oxidative damage by inhibiting ROS production,breaking down ROS,and degrading oxides.Therefore,it is important to understand the mechanism of skin damage caused by Ultraviolet radiation,the effects of reactive oxygen species and how the body's antioxidant system exerts its antioxidant effect.This will not only deepen the understanding of skin photoaging but also provide a scientific basis for the research on how to prevent and treat photoaging.展开更多
Oxidative stress and mitochondrial damage have been implicated in the pathogenesis of several neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Oxidati...Oxidative stress and mitochondrial damage have been implicated in the pathogenesis of several neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Oxidative stress is characterized by the overproduction of reactive oxygen species, which can induce mitochondrial DNA mutations, damage the mitochondrial respiratory chain, alter membrane permeability, and influence Ca2＋ homeostasis and mitochondrial defense systems. All these changes are implicated in the development of these neurodegenerative diseases, mediating or amplifying neuronal dysfunction and triggering neurodegeneration. This paper summarizes the contribution of oxidative stress and mitochondrial damage to the onset of neurodegenerative diseases and discusses strategies to modify mitochondrial dysfunction that may be attractive therapeutic interventions for the treatment of various neurodegenerative diseases.展开更多
The changes of hydrogen peroxide(H2O2) metabolism and antioxidant enzyme activities in a hybrid poplar(Populus simonii ×P.pyramidalis ‘Opera 8277') in response to mechanical damage(MD) and herbivore wounding...The changes of hydrogen peroxide(H2O2) metabolism and antioxidant enzyme activities in a hybrid poplar(Populus simonii ×P.pyramidalis ‘Opera 8277') in response to mechanical damage(MD) and herbivore wounding(HW) were investigated to determine whether H2O2 could function as the secondary messenger in the signaling of systemic resistance.Results show that H2O2 was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves.The activities of antioxidant enzymes such as superoxide dismutase(SOD), catalase(CAT) and ascorbate peroxidase(APX) were also enhanced.However, the H2O2 accumulation and antioxidant enzyme activities were inhibited in MD leaves through the pretreatment with DPI(which is a specific inhibitor of NADPH oxidase).The results of this study suggest that H2O2 could be systemically induced by MD and HW treatments, and H2O2 metabolism was closely related to the change in SOD, APX and CAT activities.A high level of antioxidant enzymes could decrease membrane lipid peroxidation levels and effectively induce plant defense responses.展开更多
Eight-year-old ＂Shixia＂ longan （ Dimocarpus longan Loureiro ） trees were treated under low temperature stress, oxidative stress, and natural low temperature conditions ＋ experimental agents to investigate the rel...Eight-year-old ＂Shixia＂ longan （ Dimocarpus longan Loureiro ） trees were treated under low temperature stress, oxidative stress, and natural low temperature conditions ＋ experimental agents to investigate the relationship between oxidative damage and flowering of longan. The results indicated that oxidative stress was conducive to flowering of longan, which also led to accumulation of reactive oxygen species in various tissues of longan. The detection results of reactive oxygen species, ascorbic acid content and MDA content in apical buds and leaves showed that ascorbic acid could inhibit flowering of longan, while MDA could promote flowering of longan. Therefore, there was a positive correlation between reactive oxygen species and flowering of longan.展开更多
Selenium compounds,as an effective chemopreventive agent,can induce apoptosis in tumor cells.Reactive oxygen species(ROS)are important mediators in apoptosis induced by various stimuli,which include chemopreventive ag...Selenium compounds,as an effective chemopreventive agent,can induce apoptosis in tumor cells.Reactive oxygen species(ROS)are important mediators in apoptosis induced by various stimuli,which include chemopreventive agents.In this study,we investigated the relationship between ROS and the levels of DNA damage induced by selenite in HepG2 cells.After HepG2 cells were treated with selenite,there was a dose-dependent decrease in cell viability.The levels of ROS induced by selenite were measured by 2p,7p-dichlorofluorescein diacetate(DCFH-DA)fluorescence,which shows a dose-and time-dependent increase in HepG2 cells.The levels of DNA damage in HepG2 increased in all cells treated with an increasing dose of selenite at 0,2.5,5,10,and 20μmol/L.N-acetylcysteine(NAC),a known antioxidant,increased cell viability and decreased ROS generation.Moreover,NAC effectively blocked DNA damage induced by selenite.These results revealed that ROS might play an important role in selenite-induced DNA damage that can be reduced by NAC treatment.展开更多
Numerous therapeutic anti-tumor strategies have been developed in recent decades.However,their therapeutic efficacy is reduced by the intrinsic protective autophagy of tumors.Autophagy plays a key role in tumorigenesi...Numerous therapeutic anti-tumor strategies have been developed in recent decades.However,their therapeutic efficacy is reduced by the intrinsic protective autophagy of tumors.Autophagy plays a key role in tumorigenesis and tumor treatment,in which the overproduction of reactive oxygen species(ROS)is recognized as the direct cause of protective autophagy.Only a few molecules have been employed as autophagy inhibitors in tumor therapy to reduce protective autophagy.Among them,hydroxychloroquine is the most commonly used autophagy inhibitor in clinics,but it is severely limited by its high therapeutic dose,significant toxicity,poor reversal efficacy,and nonspecific action.Herein,we demonstrate a reductive-damage strategy to enable tumor therapy by the inhibition of protective autophagy via the catalytic scavenging of ROS using porous nanorods of ceria(PN-CeO_(2))nanozymes as autophagy inhibitor.The antineoplastic effects of PN-CeO_(2)were mediated by its high reductive activity for intratumoral ROS degradation,thereby inhibiting protective autophagy and activating apoptosis by suppressing the activities of phosphatidylinositide 3-kinase/protein kinase B and p38 mitogen-activated protein kinase pathways in human cutaneous squamous cell carcinoma.Further investigation highlighted PN-CeO_(2)as a safe and efficient anti-tumor autophagy inhibitor.Overall,this study presents a reductive-damage strategy as a promising anti-tumor approach that catalytically inhibits autophagy and activates the intrinsic antioxidant pathways of tumor cells and also shows its potential for the therapy of other autophagy-related diseases.展开更多
The changes of hydrogen peroxide （H2O2） metabolism and antioxidant enzyme activities in a hybrid poplar （Populus simonii xp. pyramidalis ＇Opera 8277＇） in response to rnechanical damage （MD） and herbivore wound...The changes of hydrogen peroxide （H2O2） metabolism and antioxidant enzyme activities in a hybrid poplar （Populus simonii xp. pyramidalis ＇Opera 8277＇） in response to rnechanical damage （MD） and herbivore wounding （HW） were investigated to determine whether H2O2 could function as the secondary messenger in the signaling of systemic resistance. Results show that H2O2 was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves. The activities of antioxidant enzymes such as superoxide dismutase （SOD）, catalase （CAT） and ascorbate peroxidase （APX） were also enhanced. However, the H2O2 accumulation and antioxidant enzyme activities were inhibited in MD leaves through the pretreatment with DPI （which is a specific inhibitor of NADPH oxidase）. The results of this study suggest that H2O2 could be systemically induced by MD and HW treatments, and H2O2 metabolism was closely related to the change in SOD, APX and CAT activities. A high level of antioxidant enzymes could decrease membrane lipid peroxidation levels and effectively induce plant defense responses.展开更多
文摘Mutations in the Sfpi1 gene are essential for the development of radia-tion-induced acute myeloid leukemia. In this study, we investigated long-term interaction among immature hematopoietic cell number, intra-cellular reactive oxygen species contents, and oxidative DNA damage fre-quency after irradiation. Lin-/Sca-1+ cells were isolated from C3H/HeN mice on days 1 - 400 after 0 - 3 Gy total body irradiation. On days 1 - 7, the number of surviving cells decreased and reached a minimum;however, the number of cells gradually recovered until day 200. Intracellular reactive oxygen species contents significantly increased from day 1 to day 30. In addition, the frequency of oxidative DNA damage tended to increase from day 1 and day 30, and that at day 30 was significantly increased in the 3 Gy group compared with that in the control group. In contrast, decreased cell number, increased intracellular reactive oxygen species content, and decreased oxidative DNA damage frequency were observed on day 400. These results suggested that oxidative DNA damage was involved in intracellular reactive oxygen species generation induced by cell proliferation to compensate for cell death after irradiation.
基金supported by Yunnan Provincial Department of Education Science Research Fund Project(2021Y426/2018JS411).
文摘Skin is the largest organ of human body and it protects the organism from external stimuli.Skin will age as the organism ages in normal circumstances.Skin photoaging refers to the accumulation of ultraviolet radiation due to long-term exposure to sunlight,which results in the premature aging of skin,wrinkles,pigmentation,skin laxity,and other signs of aging.The increase in the level of reactive oxygen species(ROS)induced by ultraviolet radiation,which causes the oxidation of cells,proteins,lipids,and other components,is an important cause of accelerated photoaging of skin.For this reason,the skin's antioxidant system will further play an antioxidant role to reduce oxidative damage by inhibiting ROS production,breaking down ROS,and degrading oxides.Therefore,it is important to understand the mechanism of skin damage caused by Ultraviolet radiation,the effects of reactive oxygen species and how the body's antioxidant system exerts its antioxidant effect.This will not only deepen the understanding of skin photoaging but also provide a scientific basis for the research on how to prevent and treat photoaging.
基金supported by the National Natural Science Foundation of China,No.81274005Medical Science Research,Health Department of Hebei Province,No.20110173,20090588Hebei Education Department Science Foundation,No.2007302
文摘Oxidative stress and mitochondrial damage have been implicated in the pathogenesis of several neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Oxidative stress is characterized by the overproduction of reactive oxygen species, which can induce mitochondrial DNA mutations, damage the mitochondrial respiratory chain, alter membrane permeability, and influence Ca2＋ homeostasis and mitochondrial defense systems. All these changes are implicated in the development of these neurodegenerative diseases, mediating or amplifying neuronal dysfunction and triggering neurodegeneration. This paper summarizes the contribution of oxidative stress and mitochondrial damage to the onset of neurodegenerative diseases and discusses strategies to modify mitochondrial dysfunction that may be attractive therapeutic interventions for the treatment of various neurodegenerative diseases.
基金supported by the Key Science Pro-gram of the Sate Forestry Administration of China (2006-59)the National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science & Technology of China(2006BAD01A15 2006BAD24B04).
文摘The changes of hydrogen peroxide(H2O2) metabolism and antioxidant enzyme activities in a hybrid poplar(Populus simonii ×P.pyramidalis ‘Opera 8277') in response to mechanical damage(MD) and herbivore wounding(HW) were investigated to determine whether H2O2 could function as the secondary messenger in the signaling of systemic resistance.Results show that H2O2 was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves.The activities of antioxidant enzymes such as superoxide dismutase(SOD), catalase(CAT) and ascorbate peroxidase(APX) were also enhanced.However, the H2O2 accumulation and antioxidant enzyme activities were inhibited in MD leaves through the pretreatment with DPI(which is a specific inhibitor of NADPH oxidase).The results of this study suggest that H2O2 could be systemically induced by MD and HW treatments, and H2O2 metabolism was closely related to the change in SOD, APX and CAT activities.A high level of antioxidant enzymes could decrease membrane lipid peroxidation levels and effectively induce plant defense responses.
基金Supported by National Nonprofit Institute Research Grant of CATAS-TCGRI(1630032014017)Special Fund for Agro-scientific Research in the Public Interest(201003021)China Agriculture Research System(CARS-33-25)
文摘Eight-year-old ＂Shixia＂ longan （ Dimocarpus longan Loureiro ） trees were treated under low temperature stress, oxidative stress, and natural low temperature conditions ＋ experimental agents to investigate the relationship between oxidative damage and flowering of longan. The results indicated that oxidative stress was conducive to flowering of longan, which also led to accumulation of reactive oxygen species in various tissues of longan. The detection results of reactive oxygen species, ascorbic acid content and MDA content in apical buds and leaves showed that ascorbic acid could inhibit flowering of longan, while MDA could promote flowering of longan. Therefore, there was a positive correlation between reactive oxygen species and flowering of longan.
基金The study was supported by the National Natural Science Foundation of China(Grant No.30471431).
文摘Selenium compounds,as an effective chemopreventive agent,can induce apoptosis in tumor cells.Reactive oxygen species(ROS)are important mediators in apoptosis induced by various stimuli,which include chemopreventive agents.In this study,we investigated the relationship between ROS and the levels of DNA damage induced by selenite in HepG2 cells.After HepG2 cells were treated with selenite,there was a dose-dependent decrease in cell viability.The levels of ROS induced by selenite were measured by 2p,7p-dichlorofluorescein diacetate(DCFH-DA)fluorescence,which shows a dose-and time-dependent increase in HepG2 cells.The levels of DNA damage in HepG2 increased in all cells treated with an increasing dose of selenite at 0,2.5,5,10,and 20μmol/L.N-acetylcysteine(NAC),a known antioxidant,increased cell viability and decreased ROS generation.Moreover,NAC effectively blocked DNA damage induced by selenite.These results revealed that ROS might play an important role in selenite-induced DNA damage that can be reduced by NAC treatment.
基金supported by grants from the National Natural Science Foundation of China(Nos.81972938,52002314,and 21872109)partially supported by Funds of Shaanxi Province(Nos.2021ZDLSF03-01,2020TD-043,and TZ0124)+2 种基金General Project of Shaanxi Natural Science Basic Research Plan(No.2021JM-589)Xi’an People’s Hospital(Xi’an Fourth Hospital)Research Incubation Fund Project(LH-1)the support from the Fundamental Research Funds for the Central Universities(Nos.D5000210829 and G2021KY05102).
文摘Numerous therapeutic anti-tumor strategies have been developed in recent decades.However,their therapeutic efficacy is reduced by the intrinsic protective autophagy of tumors.Autophagy plays a key role in tumorigenesis and tumor treatment,in which the overproduction of reactive oxygen species(ROS)is recognized as the direct cause of protective autophagy.Only a few molecules have been employed as autophagy inhibitors in tumor therapy to reduce protective autophagy.Among them,hydroxychloroquine is the most commonly used autophagy inhibitor in clinics,but it is severely limited by its high therapeutic dose,significant toxicity,poor reversal efficacy,and nonspecific action.Herein,we demonstrate a reductive-damage strategy to enable tumor therapy by the inhibition of protective autophagy via the catalytic scavenging of ROS using porous nanorods of ceria(PN-CeO_(2))nanozymes as autophagy inhibitor.The antineoplastic effects of PN-CeO_(2)were mediated by its high reductive activity for intratumoral ROS degradation,thereby inhibiting protective autophagy and activating apoptosis by suppressing the activities of phosphatidylinositide 3-kinase/protein kinase B and p38 mitogen-activated protein kinase pathways in human cutaneous squamous cell carcinoma.Further investigation highlighted PN-CeO_(2)as a safe and efficient anti-tumor autophagy inhibitor.Overall,this study presents a reductive-damage strategy as a promising anti-tumor approach that catalytically inhibits autophagy and activates the intrinsic antioxidant pathways of tumor cells and also shows its potential for the therapy of other autophagy-related diseases.
文摘The changes of hydrogen peroxide （H2O2） metabolism and antioxidant enzyme activities in a hybrid poplar （Populus simonii xp. pyramidalis ＇Opera 8277＇） in response to rnechanical damage （MD） and herbivore wounding （HW） were investigated to determine whether H2O2 could function as the secondary messenger in the signaling of systemic resistance. Results show that H2O2 was generated in wounded leaves through MD and HW treatments and systemically in unwounded leaves around the wounded leaves. The activities of antioxidant enzymes such as superoxide dismutase （SOD）, catalase （CAT） and ascorbate peroxidase （APX） were also enhanced. However, the H2O2 accumulation and antioxidant enzyme activities were inhibited in MD leaves through the pretreatment with DPI （which is a specific inhibitor of NADPH oxidase）. The results of this study suggest that H2O2 could be systemically induced by MD and HW treatments, and H2O2 metabolism was closely related to the change in SOD, APX and CAT activities. A high level of antioxidant enzymes could decrease membrane lipid peroxidation levels and effectively induce plant defense responses.
