Superoxide anion,one of the most active reactive oxygen species,is associated with the development of many diseases.So monitoring superoxide anion in living cells is of great significance for the pathological research...Superoxide anion,one of the most active reactive oxygen species,is associated with the development of many diseases.So monitoring superoxide anion in living cells is of great significance for the pathological research of many diseases.In this work,a new non-enzymatic sensor tor the detection of superoxide anion(O^·-2)was developed,which was iabricated by the nanocomposites composed of manganese(Ⅲ)tetraphenyl porphine(MnTPP)as superoxide dismutase mimic and electrochemical reduced graphene oxide(ERGO)as electrode support material to modify the glassy carbon electrode(GCE).The electrochemical behavior of the fabricated electrode(MiiTPP/ERGO/GCE)was performed by electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV),which revealed that MnTPP/ERGO/GCE possessed good catalytic ability to theelectrochemical reduction of O^·-2.The MnTPP/ERGO/GCE showed excellent electroanalysis perfonnance towards O^·-2 using the technique of diflerential pulse voltanimetry(DPV)with a linear relationship in the range of 0.2—110.0μmol/L,a sensitivity of 445 μA· L·mmol^-1·cm^- 2 and a detection limit of 0.039 μmol/L(S/N=3).The real-time monitoring of O^·-2 from MCF-7 breast cancer cells stimulated by zymosan was realized in this work,which indicates that the MnTPP/ERGO/GCE hold potential application for electrochemical quantification of superoxide anions in biological applications.展开更多
AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells.METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders ...AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells.METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders oxidative stress, and the protective effect of L-carnitine(a nutrient involved in fatty acid metabolism and the control of the oxidative process), was assessed by monitoring various parameters related to the oxidative stress, autophagy and cell death. RESULTS Associated with its physiological function, a muscle cell metabolism is highly dependent on oxygen and may produce reactive oxygen species(ROS), especially under pathological conditions. High levels of ROS are known to induce injuries in cell structure as they interact at many levels in cell function. In C2C12 cells, a treatment with menadione induced a loss of transmembrane mitochondrial potential, an increase in mitochondrial production of ROS; it also induces autophagy and was able to provoke cell death. Pre-treatment of the cells with L-carnitine reduced ROS production, diminished autophagy and protected C2C12 cells against menadione-induced deleterious effects. CONCLUSION In conclusion, L-carnitine limits the oxidative stress in these cells and prevents cell death.展开更多
Background: To investigate the effects of unsafe decompression on rat pulmonary endothelial function and its relevant mechanisms.Methods: Sixty male Sprague-Dawley(SD) rats were randomly divided into a control group(n...Background: To investigate the effects of unsafe decompression on rat pulmonary endothelial function and its relevant mechanisms.Methods: Sixty male Sprague-Dawley(SD) rats were randomly divided into a control group(n=30) and a decompression sickness(DCS) group(n=30). The DCS model was established by placing the rats in the DCS group in a pressurized cabin where they were exposed to a 600 k Pa compressed air environment for 60 min, and the pressure was then reduced by 100 k Pa/min until it reached atmospheric pressure. After the surviving rats in the DCS group and the rats in the control group were anesthetized, their pulmonary arteries were stripped to test the in vitro pulmonary artery endothelium-dependent vasodilation capacity. Western blotting was used to measure the expression and dissociation of endothelial nitric oxide synthase(e NOS) in pulmonary artery tissues and all protein nitration levels in pulmonary artery tissues; reactive oxygen species(ROS) formation was measured via in vitro pulmonary artery superoxide anion probe dihydroethidium(DHE) staining.Results: After experiencing unsafe decompression, 10 of the 30 rats in the DCS group died. The pulmonary artery endothelium-dependent vasodilation capacity in the surviving rats decreased significantly(P<0.05). The difference in e NOS expression between the DCS group and the control group was statistically insignificant(P>0.05), but the ratio of e NOS monomer/dimer in the DCS group was significantly higher than that in the control group(P<0.05). All protein tyrosine nitration levels in the pulmonary artery tissues of the DCS group were significantly higher than those of the control group(P<0.05). The results of DHE staining showed that the amount of ROS formation in the pulmonary arteries of the DCS group was significantly higher than that of the control group(P<0.05).Conclusion: Unsafe decompression during a simulated submarine escape process can lead to e NOS dimer uncoupling in the pulmonary artery endothelium. The dissociated e NOS monomer cannot synthesize nitric oxide(NO) and thus affect the endothelium-dependent vasodilation capacity. The e NOS monomer can promote peroxynitrite(ONOO–) synthesis, leading to an increase in protein tyrosine nitration levels in pulmonary artery tissues and causing disorder in cell cycle regulation. The e NOS monomer can also cause an increase in the formation of ROS and thus mediate peroxidation damage.展开更多
In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton a...In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl^(-),the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon,and the removal and formation mechanism of organic chlorine.The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine,and the content of adsorbable organic chlorine (AOCl) was 0.30 mg/g (dry sludge).In the Fenton system with pH=3,500 mg/L Cl-,30 mmol/L Fe^(2+)and 30 mmol/L H_(2)O_(2),the removal of phenanthrene was promoted by chlorine radicals (·Cl),and the AOCl in sludge solid phase increased to 0.55 mg/g (dry sludge) at 30 min.According to spectral analysis,it was found that ·Cl could chlorinate aromatic and aliphatic compounds (excluding PAHs) in solid phase at the same time,and eventually led to the accumulation of aromatic chlorides in solid phase.Strengthening the oxidation ability of Fenton system increased the formation of organic chlorines in liquid and solid phases.In weak acidity,the oxidation and desorption of superoxide anion promoted the removal and migration of PAHs and organic carbon in solid phase,and reduced the formation of total organic chlorine.The Fenton-like system dominated by nonhydroxyl radical could realize the mineralization of PAHs,organic carbon and organic chlorines instead of migration.This paper builds a basis for the selection of sludge conditioning methods.展开更多
Photodynamic therapy(PDT)usually shows limited efficacy in solid tumors since traditional PDT is O_(2)^(-)dependent while solid tumors are inherently hypoxic.In addition,hypoxic tumor cells possess antiapoptotic pathw...Photodynamic therapy(PDT)usually shows limited efficacy in solid tumors since traditional PDT is O_(2)^(-)dependent while solid tumors are inherently hypoxic.In addition,hypoxic tumor cells possess antiapoptotic pathways that resist PDT-induced apoptosis.Therefore,developing photosensitizers(PSs)that show low O_(2)^(-)dependency and can induce nonapoptotic cell death pathways is critically needed.Herein,a series of Ru(II)polypyridine complex-based PSs,RuNMe,RuH,and RuCN,were synthesized,and their applications against hypoxic tumor cells through PDT were investigated.All three complexes showthe ability to generate the superoxide anion radical(·O_(2)^(-)),which is the type I photoreaction and less O_(2)^(-)dependent.RuNMe shows the best PDT performance against MCF-7 cells and three-dimensional multicellular spheroids,due to its higher cellular uptake and more reactive oxygen species generation.More importantly,RuNMe-incubated MCF-7 cells show photoinduced ferroptosis as evidenced by glutathione peroxidase 4 downregulation and lipid peroxide accumulation.This work not only develops a novel ferroptosis-inducing Ru(II)complex with the type I PDT process but also offers an effective strategy to solve tumor hypoxia in PDT.展开更多
Recently,a study of mimic enzyme has received more attentions.However,the investigation on the oxidoreductase activity of electron mediators in the biological respiratory chain is still rare.Herein,we found that cadmi...Recently,a study of mimic enzyme has received more attentions.However,the investigation on the oxidoreductase activity of electron mediators in the biological respiratory chain is still rare.Herein,we found that cadmium sulfide(CdS)nanorods can catalyze the formation of superoxide anions.Due to the role of the photo-generated holes and the nicotinamide adenine dinucleotide(NADH)oxidation promoted by superoxide anion(O_(2)^(•−)),the CdS exhibits NADH oxidase-like activity and can be coupled with dehydrogenase to realize the recycling of NADH.It is worth mentioning that the bio-electron acceptor,cytochrome c(Cyt c),as a chromogenic substrate,can accept electrons transferred from O_(2)^(•−),which demonstrates the Cyt c reductase-like activity of CdS under physiological pH conditions.For different substrates,O_(2)^(•−)induced from CdS show oxidizing capacity for NADH and reducing capacity for Cyt c,which provides a new perspective for the in-depth study of new nanozyme.展开更多
基金Supported by the National Natural Science Foundation of China(No.81872669)the Scientific Research Projects of the Department of Education of Hebei Province,China(Nos.ZD2018037,QN2019140).
文摘Superoxide anion,one of the most active reactive oxygen species,is associated with the development of many diseases.So monitoring superoxide anion in living cells is of great significance for the pathological research of many diseases.In this work,a new non-enzymatic sensor tor the detection of superoxide anion(O^·-2)was developed,which was iabricated by the nanocomposites composed of manganese(Ⅲ)tetraphenyl porphine(MnTPP)as superoxide dismutase mimic and electrochemical reduced graphene oxide(ERGO)as electrode support material to modify the glassy carbon electrode(GCE).The electrochemical behavior of the fabricated electrode(MiiTPP/ERGO/GCE)was performed by electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV),which revealed that MnTPP/ERGO/GCE possessed good catalytic ability to theelectrochemical reduction of O^·-2.The MnTPP/ERGO/GCE showed excellent electroanalysis perfonnance towards O^·-2 using the technique of diflerential pulse voltanimetry(DPV)with a linear relationship in the range of 0.2—110.0μmol/L,a sensitivity of 445 μA· L·mmol^-1·cm^- 2 and a detection limit of 0.039 μmol/L(S/N=3).The real-time monitoring of O^·-2 from MCF-7 breast cancer cells stimulated by zymosan was realized in this work,which indicates that the MnTPP/ERGO/GCE hold potential application for electrochemical quantification of superoxide anions in biological applications.
基金the Association Francaise contre les Myopathies for financial support
文摘AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells.METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders oxidative stress, and the protective effect of L-carnitine(a nutrient involved in fatty acid metabolism and the control of the oxidative process), was assessed by monitoring various parameters related to the oxidative stress, autophagy and cell death. RESULTS Associated with its physiological function, a muscle cell metabolism is highly dependent on oxygen and may produce reactive oxygen species(ROS), especially under pathological conditions. High levels of ROS are known to induce injuries in cell structure as they interact at many levels in cell function. In C2C12 cells, a treatment with menadione induced a loss of transmembrane mitochondrial potential, an increase in mitochondrial production of ROS; it also induces autophagy and was able to provoke cell death. Pre-treatment of the cells with L-carnitine reduced ROS production, diminished autophagy and protected C2C12 cells against menadione-induced deleterious effects. CONCLUSION In conclusion, L-carnitine limits the oxidative stress in these cells and prevents cell death.
基金supported by the Army on the Subject of China (10ZYZ219)
文摘Background: To investigate the effects of unsafe decompression on rat pulmonary endothelial function and its relevant mechanisms.Methods: Sixty male Sprague-Dawley(SD) rats were randomly divided into a control group(n=30) and a decompression sickness(DCS) group(n=30). The DCS model was established by placing the rats in the DCS group in a pressurized cabin where they were exposed to a 600 k Pa compressed air environment for 60 min, and the pressure was then reduced by 100 k Pa/min until it reached atmospheric pressure. After the surviving rats in the DCS group and the rats in the control group were anesthetized, their pulmonary arteries were stripped to test the in vitro pulmonary artery endothelium-dependent vasodilation capacity. Western blotting was used to measure the expression and dissociation of endothelial nitric oxide synthase(e NOS) in pulmonary artery tissues and all protein nitration levels in pulmonary artery tissues; reactive oxygen species(ROS) formation was measured via in vitro pulmonary artery superoxide anion probe dihydroethidium(DHE) staining.Results: After experiencing unsafe decompression, 10 of the 30 rats in the DCS group died. The pulmonary artery endothelium-dependent vasodilation capacity in the surviving rats decreased significantly(P<0.05). The difference in e NOS expression between the DCS group and the control group was statistically insignificant(P>0.05), but the ratio of e NOS monomer/dimer in the DCS group was significantly higher than that in the control group(P<0.05). All protein tyrosine nitration levels in the pulmonary artery tissues of the DCS group were significantly higher than those of the control group(P<0.05). The results of DHE staining showed that the amount of ROS formation in the pulmonary arteries of the DCS group was significantly higher than that of the control group(P<0.05).Conclusion: Unsafe decompression during a simulated submarine escape process can lead to e NOS dimer uncoupling in the pulmonary artery endothelium. The dissociated e NOS monomer cannot synthesize nitric oxide(NO) and thus affect the endothelium-dependent vasodilation capacity. The e NOS monomer can promote peroxynitrite(ONOO–) synthesis, leading to an increase in protein tyrosine nitration levels in pulmonary artery tissues and causing disorder in cell cycle regulation. The e NOS monomer can also cause an increase in the formation of ROS and thus mediate peroxidation damage.
基金supported by the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (No.2017BT01Z032)the National Natural Science Foundation of China (No.21577027)。
文摘In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl^(-),the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon,and the removal and formation mechanism of organic chlorine.The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine,and the content of adsorbable organic chlorine (AOCl) was 0.30 mg/g (dry sludge).In the Fenton system with pH=3,500 mg/L Cl-,30 mmol/L Fe^(2+)and 30 mmol/L H_(2)O_(2),the removal of phenanthrene was promoted by chlorine radicals (·Cl),and the AOCl in sludge solid phase increased to 0.55 mg/g (dry sludge) at 30 min.According to spectral analysis,it was found that ·Cl could chlorinate aromatic and aliphatic compounds (excluding PAHs) in solid phase at the same time,and eventually led to the accumulation of aromatic chlorides in solid phase.Strengthening the oxidation ability of Fenton system increased the formation of organic chlorines in liquid and solid phases.In weak acidity,the oxidation and desorption of superoxide anion promoted the removal and migration of PAHs and organic carbon in solid phase,and reduced the formation of total organic chlorine.The Fenton-like system dominated by nonhydroxyl radical could realize the mineralization of PAHs,organic carbon and organic chlorines instead of migration.This paper builds a basis for the selection of sludge conditioning methods.
基金This work was financially supported by the National Natural Science Foundation of China(grant nos.22122701,21731004,91953201,92153303,21977044,and 21907050)the Natural Science Foundation of Jiangsu Province(grant nos.BK20202004 and BK20190282)the Excellent Research Program of Nanjing University(grant no.ZYJH004).
文摘Photodynamic therapy(PDT)usually shows limited efficacy in solid tumors since traditional PDT is O_(2)^(-)dependent while solid tumors are inherently hypoxic.In addition,hypoxic tumor cells possess antiapoptotic pathways that resist PDT-induced apoptosis.Therefore,developing photosensitizers(PSs)that show low O_(2)^(-)dependency and can induce nonapoptotic cell death pathways is critically needed.Herein,a series of Ru(II)polypyridine complex-based PSs,RuNMe,RuH,and RuCN,were synthesized,and their applications against hypoxic tumor cells through PDT were investigated.All three complexes showthe ability to generate the superoxide anion radical(·O_(2)^(-)),which is the type I photoreaction and less O_(2)^(-)dependent.RuNMe shows the best PDT performance against MCF-7 cells and three-dimensional multicellular spheroids,due to its higher cellular uptake and more reactive oxygen species generation.More importantly,RuNMe-incubated MCF-7 cells show photoinduced ferroptosis as evidenced by glutathione peroxidase 4 downregulation and lipid peroxide accumulation.This work not only develops a novel ferroptosis-inducing Ru(II)complex with the type I PDT process but also offers an effective strategy to solve tumor hypoxia in PDT.
基金supported by the National Key R&D Program of China(No.2019YFA0709202)MOST China(No.2016YFA0203200)+1 种基金the International Cooperation Project of Jilin Scientific and Technological Development Program(No.20190701059GH)the National Natural Science Foundation of China(Nos.21721003 and 31301177).
文摘Recently,a study of mimic enzyme has received more attentions.However,the investigation on the oxidoreductase activity of electron mediators in the biological respiratory chain is still rare.Herein,we found that cadmium sulfide(CdS)nanorods can catalyze the formation of superoxide anions.Due to the role of the photo-generated holes and the nicotinamide adenine dinucleotide(NADH)oxidation promoted by superoxide anion(O_(2)^(•−)),the CdS exhibits NADH oxidase-like activity and can be coupled with dehydrogenase to realize the recycling of NADH.It is worth mentioning that the bio-electron acceptor,cytochrome c(Cyt c),as a chromogenic substrate,can accept electrons transferred from O_(2)^(•−),which demonstrates the Cyt c reductase-like activity of CdS under physiological pH conditions.For different substrates,O_(2)^(•−)induced from CdS show oxidizing capacity for NADH and reducing capacity for Cyt c,which provides a new perspective for the in-depth study of new nanozyme.
