Particulate matter(PM)can cause adverse health effects by overproducing reactive oxygen species(ROS).Although the ability of PM to induce ROS generation depends on its composi-tion and environmental factors.This study...Particulate matter(PM)can cause adverse health effects by overproducing reactive oxygen species(ROS).Although the ability of PM to induce ROS generation depends on its composi-tion and environmental factors.This study explores how photo-oxidation affects ROS gen-eration from aromatic compounds(ACs,including catechol(CAT),phthalic acid(PA),and 4,4-oxydibenzoic acid(4,4-OBA))and their mixtures with transition metals(TMs,includ-ing Fe(II),Mn(II),and Cu(II))using Fourier-transform infrared(FTIR)and Ultraviolet-visible spectroscopy(UV-Vis).Results showed that photo-oxidation facilitated ROS generation from ACs.CAT-Fe(II)/Cu(II)showed synergistic effects,but 4,4-OBA-Fe(II)/Cu(II)showed antag-onistic effects.ACs-Mn(II)and PA-Fe(II)/Cu(II)exhibited synergistic effects first and then showed antagonistic effects.The different interactions were due to complexation between ACs and TMs.The photo-oxidized ACs-TMs significantly enhanced ROS generation com-pared with ACs-TMs.The study suggested the photo-oxidation mechanism involved that the transfer ofπ-electrons from the ground to an excited state in benzene rings and func-tional groups,leading to the breakage and formation of chemical bonds or easierπ-electron transfer from ACs to TMs.The former could generate ROS directly or produce polymers that promoted ROS generation,while the latter promoted ROS generation by transferringπ-electrons to dissolved oxygen quickly.Our study revealed that both interactions among components and photo-oxidation significantly influenced ROS generation.Future studies should integrate broader atmospheric factors and PM components to fully assess oxidative potential and health impacts.展开更多
Prostate cancer(PCa)is a leading cause of cancer-related mortality among men.Radiotherapy is the cornerstone of PCa treatment.However,a major limitation of radiotherapy is the development of resistance,which compromis...Prostate cancer(PCa)is a leading cause of cancer-related mortality among men.Radiotherapy is the cornerstone of PCa treatment.However,a major limitation of radiotherapy is the development of resistance,which compromises treatment efficacy.Reactive oxygen species(ROS),which are generated by radiation,have a dual role in PCa by inducing DNA damage and apoptosis,while also promoting tumor progression and radioresistance.Elevated ROS levels enhance metabolic reprogramming,activate oncogenic pathways,and influence the tumor microenvironment by modulating immune responses and promoting the epithelial-mesenchymal transition(EMT).Key molecular mechanisms,including the Nrf2/Keap1 signaling axis,Bcl-2 mutations,and Speckle-type POZ protein alterations,contribute to radioresistance by enhancing antioxidant defenses and DNA repair capacity.Additionally,the interplay between hypoxia,androgen receptor variants(AR-Vs),and ferroptosis regulators further influence radiotherapy outcomes.Understanding these resistance mechanisms is crucial for developing targeted strategies to enhance radiosensitivity and improve therapeutic outcomes in PCa patients.展开更多
BACKGROUND High levels of acetaminophen(APAP)consumption can result in significant liver toxicity.Mogroside V(MV)is a bioactive,plant-derived triterpenoid known for its various pharmacological activities.However,the i...BACKGROUND High levels of acetaminophen(APAP)consumption can result in significant liver toxicity.Mogroside V(MV)is a bioactive,plant-derived triterpenoid known for its various pharmacological activities.However,the impact of MV on acute liver injury(ALI)is unknown.AIM To investigate the hepatoprotective potential of MV against liver damage caused by APAP and to examine the underlying mechanisms.METHODS Mice were divided into three groups:Saline,APAP and APAP+MV.MV(10 mg/kg)was given intraperitoneally one hour before APAP(300 mg/kg)administration.Twenty-four hours after APAP exposure,serum transaminase levels,liver necrotic area,inflammatory responses,nitrotyrosine accumulation,and c-jun-N-terminal kinase(JNK)activation were assessed.Additionally,we analyzed reactive oxygen species(ROS)levels,JNK activation,and cell death in alpha mouse liver 12(AML12)cells.RESULTS MV pre-treatment in vivo led to a reduction in the rise of aspartate transaminase and alanine transaminase levels,mitigated liver damage,decreased nitrotyrosine accumulation,and blocked JNK phosphorylation resulting from APAP exposure,without affecting glutathione production.Similarly,MV diminished the APAP-induced increase in ROS,JNK phosphorylation,and cell death in vitro.CONCLUSION Our study suggests that MV treatment alleviates APAP-induced ALI by reducing ROS and JNK activation.展开更多
Sepsis is a condition of severe organ failure caused by the maladaptive response of the host to an infection.It is a severe complication affecting critically ill patients,which can progress to severe sepsis,septic sho...Sepsis is a condition of severe organ failure caused by the maladaptive response of the host to an infection.It is a severe complication affecting critically ill patients,which can progress to severe sepsis,septic shock,and ultimately death.As a vital part of the human innate immune system,neutrophils are essential in resisting pathogen invasion,infection,and immune surveillance.Neutrophil-produced reactive oxygen species(ROS) play a pivotal role in organ dysfunction related to sepsis.In recent years,ROS have received a lot of attention as a major cause of sepsis,which can progress to severe sepsis and septic shock.This paper reviews the existing knowledge on the production mechanism of neutrophil ROS in human organ function impairment because of sepsis.展开更多
Atmospheric humic-like substances （HULIS） are not only an unresolved mixture of macro- organic compounds but also powerful chelating agents in atmospheric particulate matters （PMs）; impacting on both the propertie...Atmospheric humic-like substances （HULIS） are not only an unresolved mixture of macro- organic compounds but also powerful chelating agents in atmospheric particulate matters （PMs）; impacting on both the properties of aerosol particles and health effects by generating reactive oxygen spedes （ROS）. Currently, the interests of HULIS are intensively shifting to the investigations of HULIS-metal synergic effects and kinetics modeling studies, as well as the development of HULIS quantification, findings of possible HULIS sources and generation of ROS from HULIS. In light of HULIS studies, we comprehensively review the current knowledge of isolation and physicochemical characterization of HULIS from atmospheric samples as well as HULIS properties （hygroscopic, surface activity, and colloidal） and possible sources of HULIS. This review mainly highlights the generation of reactive oxygen species （ROS） from PMs, HULIS and transition metals, especially iron. This review also summarized the mechanism of iron-organic complexation and recent findings of OH formation from HULIS-metal complexes. This review will be helpful to carry out the modeling studies that concern with HULIS-transition metals and for further studies in the generation of ROS from HULIS-metal complexes,展开更多
Age related defect of the osteogenic differentiation of mesenchymal stem cells（MSCs） plays a key role in osteoporosis. Mechanical loading is one of the most important physical stimuli for osteoblast differentiation....Age related defect of the osteogenic differentiation of mesenchymal stem cells（MSCs） plays a key role in osteoporosis. Mechanical loading is one of the most important physical stimuli for osteoblast differentiation.Here, we compared the osteogenic potential of MSCs from young and adult rats under three rounds of 2 h of cyclic stretch of 2.5% elongation at 1 Hz on 3 consecutive days. Cyclic stretch induced a significant osteogenic differentiation of MSCs from young rats, while a compromised osteogenesis in MSCs from the adult rats.Accordingly, there were much more reactive oxygen species（ROS） production in adult MSCs under cyclic stretch compared to young MSCs. Moreover, ROS scavenger N-acetylcysteine rescued the osteogenic differentiation of adult MSCs under cyclic stretch. Gene expression analysis revealed that superoxide dismutase 1（SOD1） was significantly downregulated in those MSCs from adult rats. In summary, our data suggest that reduced SOD1 may result in excessive ROS production in adult MSCs under cyclic stretch, and thus manipulation of the MSCs from the adult donors with antioxidant would improve their osteogenic ability.展开更多
A number of studies have shown the existence of cross-tolerance in plants, but the physiological mechanism is poorly understood. In this study, we used the germination of barley seeds as a system to investigate the cr...A number of studies have shown the existence of cross-tolerance in plants, but the physiological mechanism is poorly understood. In this study, we used the germination of barley seeds as a system to investigate the cross-tolerance of low-temperature pretreatment to high-temperature stress and the possible involvement of reactive oxygen species （ROS） scavenging enzymes in the cross-tolerance. After pretreatment at 0 ℃ for different periods of time, barley seeds were germinated at 35 ℃, and the content of malondialdehyde （MDA） and the activities of ROS scavenging enzymes were measured by a spectrophotometer analysis. The results showed that barley seed germinated very poorly at 35 ℃, and this inhibitive effect could be overcome by pretreatment at 0 ℃. The MDA content varied, depending on the temperature at which seeds germinated, while barley seeds pretreated at 0 ℃ did not change the MDA content. Compared with seeds germinated directly at 35 ℃, the seeds pretreated first at 0 ℃ and then germinated at 35 ℃ had markedly increased activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, catalase （CAT）, and glutathione reductase （GR）. The SOD and APX activities of seeds germinated at 35 ℃ after 0 ℃-pretreatment were even substantially higher than those at 25 ℃, and GR activity was similar to that at 25 ℃, at which the highest germination performance of barley seeds was achieved. These results indicate that low-temperature pretreatment can markedly increase the tolerance of barley seed to high temperature during germination, this being related to the increase in ROS scavenging enzyme activity. This may provide a new method for increasing seed germination under stress environments, and may be an excellent model system for the study of cross-tolerance.展开更多
Honglian type-cytoplasmic male sterility(HL-CMS)is caused by the inter-communication between the nucleus and mitochondria.However,the mechanisms by which sterility genes regulate metabolic alterations and changes in m...Honglian type-cytoplasmic male sterility(HL-CMS)is caused by the inter-communication between the nucleus and mitochondria.However,the mechanisms by which sterility genes regulate metabolic alterations and changes in mitochondrial morphology in the pollen of HL-CMS remain unclear.In this study,we compared the morphological differences between the pollen of the male sterile line YA and the near-isogenic line NIL-Rf6 using hematoxylin-eosin staining and 4ʹ,6-diamidino-2-phenylindole(DAPI)staining.HL-CMS is characterized by gametophytic sterility,where the aborted pollen grains are empty,and the tapetal layer remains intact.Transmission electron microscopy was employed to observe mitochondrial morphological changes at the microspore stage,revealing significant mitochondrial alterations,characterized by the formation of'large spherical mitochondria',occurred at the binucleate stage in the YA line.Additionally,metabolomics analysis revealed decreased levels of metabolites associated with the carbohydrate and flavonoid pathways.Notably,the decrease in flavonoids was found to contribute to an elevation in reactive oxygen species(ROS)levels.Therefore,we propose a model in which rice fertility is modulated by the levels of pollen carbohydrates and flavonoid metabolites,with impaired mitochondrial energy production and reduced flavonoid biosynthesis as the main causes of ROS accumulation and pollen abortion in rice.展开更多
Objective: To study the adverse effects of advanced glycation end products(AGEs) on chondrocytes and the role of autophagy in this process. Methods: Chondrocytes were harvested from the human articular cartilage tissu...Objective: To study the adverse effects of advanced glycation end products(AGEs) on chondrocytes and the role of autophagy in this process. Methods: Chondrocytes were harvested from the human articular cartilage tissues in surgery. AGEs were administered during chondrocytes culture. The rapamycin was used to induce autophagy. The cell viability was determined by 3-[4,5-dimethylthiazol2-yl]-2,5-diphenyl tetrazolium bromide(MTT) assay.The expression of tumor necrosis factor-α(TNF-α) and nuclear factor-κ B(NF-κ B) was detected by quantitative real-time polymerase chain reaction. The reactive oxygen species(ROS) production and apoptosis of the chondrocytes were determined by fluorescent probe and flow cytometer, respectively. Results: The chondrocytes viability was significantly reduced after 12 h incubation with AGEs(P<0.01)). In contrast, rapamycin pretreatment increased the chondrocytes viability through autophagy. AGEs increased TNF-α and NF-κ B mRNA expression of chondrocytes and autophagy receded or proceeded the change. AGEs increased intracellular ROS accumulation and autophagy reversed the change. AGEs accelerated chondrocytes apoptosis and autophagy suspended apoptosis. Conclusions: Accumulation of AGEs may have an adverse role for chondrocytes by increasing TNF-α and NF-κB expression, ROS accumulation and apoptosis; meanwhile, autophagy ameliorates the AGEsinduced adverse effects.展开更多
To explore the mechanism of sperm dysfunction caused by dibutyl phthalate(DBP),the effects of DBP on intracellular[Ca^(2+)]and[pH],reactive oxygen species(ROS),lipid peroxidation(LPO),mitochondrial permeability transi...To explore the mechanism of sperm dysfunction caused by dibutyl phthalate(DBP),the effects of DBP on intracellular[Ca^(2+)]and[pH],reactive oxygen species(ROS),lipid peroxidation(LPO),mitochondrial permeability transition pore(mPTP)opening,mitochondrial membrane potential(MMP),adenosine triphosphate(ATP)levels,phosphorylation of protein kinase A(PKA)substrate proteins and phosphotyrosine(p-Tyr)proteins,sperm motility,spontaneous acrosome reaction,and tail bending were examined in mouse spermatozoa.At 100μg/mL,DBP significantly increased tail bending and[Ca^(2+)]i.Interestingly,DBP showed biphasic effects on[pH]i.DBP at 10–100μg/mL significantly decreased sperm motility.Similarly,Ca^(2+)ionophore A23187 decreased[pH]_(i)sperm motility,suggesting that DBP-induced excessive[Ca^(2+)]_(i)decreased sperm motility.DBP significantly increased ROS and LPO.DBP at 100μg/mL significantly decreased mPTP closing,MMP,and ATP levels in spermatozoa,as did H2O2,indicative of ROS-mediatedmitochondrial dysfunction caused by DBP.DBP as well as H2O2 increased p-Tyr sperm proteins and phosphorylated PKA substrate sperm proteins.DBP at 1–10μg/mL significantly increased the spontaneous acrosome reaction,suggesting that DBP can activate sperm capacitation.Altogether,DBP showed a biphasic effect on intracellular signaling in spermatozoa.At concentrations relevant to seminal ortho-phthalate levels,DBP activates[pH]i,protein tyrosine kinases and PKA via physiological levels of ROS generation,potentiating sperm capacitation.DBP at high doses excessively raises[Ca^(2+)]_(i)and ROS and disrupts[pH]i,impairing the mitochondrial function,tail structural integrity,and sperm motility.展开更多
Reactive oxygen species(ROS)are closely related to cell death,proliferation and inflammation.However,excessive ROS levels may exceed the cellular oxidative capacity and cause irreversible damage.Organisms are often in...Reactive oxygen species(ROS)are closely related to cell death,proliferation and inflammation.However,excessive ROS levels may exceed the cellular oxidative capacity and cause irreversible damage.Organisms are often inadvertently exposed to nanomaterials(NMs).Therefore,elucidating the specific routes of ROS generation induced by NMs is crucial for comprehending the toxicity mechanisms of NMs and regulating their potential applications.This paper provides a comprehensive review of the toxicity mechanisms and applications of NMs from three perspectives:(1)Organelle perspective.Investigating the impact of NMmediated ROS onmitochondria,unravelingmechanisms at the organelle level.(2)NMs’perspective.Exploring the broad applications and biosafety considerations of Nanozymes,a unique class of NMs.(3)Cellular system.Examining the toxic effects and mechanisms of NMs in cells at a holistic cellular level.Expanding on these perspectives,the paper scrutinizes the regulation of Fenton reactions by NMs in organisms.Furthermore,it introduces diseases resulting fromNM-mediated ROS at the organism level.This comprehensive review aims to provide valuable insights for studying NM-mediated mechanisms at both cellular and organism levels,offering considerations for the safe design of nanomaterials.展开更多
A geomagnetic field is a significant factor dur-ing the growth and development of trees.Changes in the magnetic field(MF)will result in reactions at the biochemi-cal,molecular,cellular and gene levels.However,it is no...A geomagnetic field is a significant factor dur-ing the growth and development of trees.Changes in the magnetic field(MF)will result in reactions at the biochemi-cal,molecular,cellular and gene levels.However,it is not clear how a magnetic field affects metabolism and home-ostasis under stressful conditions such as salinity.In this study,a novel method was developed of a static magnetic field(SMF)to investigate magnetobiological changes in trees.The results show that pre-treatment of poplar(Popu-lus×euramericana‘Neva’)cuttings with a static magnetic field significantly mitigated the negative effects of salinity stress on their growth and physiological activities.Bio-chemical assays revealed that several chemical messengers,including hydrogen peroxide(H2O2)and O_(2)^(·-),were sig-nificantly improved in roots treated with salt,implying an increase reactive oxygen species.A static magnetic field also significantly increased proline concentrations,soluble protein contents,and CAT and SOD activities.Electrophysiological experiments further revealed that pre-treatment with a static magnetic field remarkably decreased salt-induced Na^(+)influx and H^(+)efflux which control plant salt tolerance.In pharmacological experiments,because the Na^(+)/H^(+)cor-relation was closely related to the SMF-activated plasma membrane and Na^(+)antiporter activity alleviated the mas-sive accumulation of salt-induced reactive oxygen spe-cies(ROS)within the roots.In addition,a static magnetic field dramatically increased the transcriptional activity of stress-responsive genes,including PtrRBOHD and PtrHA5.Together,these results indicate that SMF reduced Na^(+)influx by activating Na^(+)/H^(+)antiporters and plasma membrane H^(+)-ATPase to effectively maintain homeostasis by regu-lating the reactive oxygen species system and cytoplasmic osmotic potential.Ultimately,these static magnetic field methods improved salt tolerance in poplar cuttings,and,for future research,similar methods could be applied to other plants.展开更多
Ambient particulate matter(PM)can cause adverse health effects via their ability to produce Reactive Oxygen Species(ROS).Water-Soluble Organic Compounds(WSOCs),a complex mixture of organic compounds which usually coex...Ambient particulate matter(PM)can cause adverse health effects via their ability to produce Reactive Oxygen Species(ROS).Water-Soluble Organic Compounds(WSOCs),a complex mixture of organic compounds which usually coexist with Transition Metals(TMs)in PM,have been found to contribute to ROS formation.However,the interaction between WSOCs and TMs and its effect on ROS generation are still unknown.In this study,we examined the ROS concentrations of V,Zn,Suwannee River Fulvic Acid(SRFA),Suwannee River Humic Acid(SRHA)and the mixtures of V/Zn and SRFA/SRHA by using a cell-free 2’,7’-Dichlorodihydrofluorescein(DCFH)assay.The results showed that V or Zn synergistically promoted ROS generated by SRFA,but had an antagonistic effect on ROS generated by SRHA.Fluorescence quenching experiments indicated that V and Zn were more prone to form stable complexes with aromatic humic acid-like component(C1)and fulvic acidlike component(C3)in SRFA and SRHA.Results suggested that the underlying mechanism involving the fulvic acid-like component in SRFA more tending to complex with TMs to facilitate ROS generation throughπelectron transfer.Our work showed that the complexing ability and complexing stability of atmospheric PM organics with metals could significantly affect ROS generation.It is recommended that the research deploying multiple analytical methods to quantify the impact of PM components on public health and environment is needed in the future.展开更多
OBJECTIVE:To investigate the effeicacy of Yishen Huoxue decoction(YSHX)on renal fibrosis induced by unilateral ureteric obstruction(UUO),and on reactive oxygen species(ROS)homeostasis in human umbilical vein endotheli...OBJECTIVE:To investigate the effeicacy of Yishen Huoxue decoction(YSHX)on renal fibrosis induced by unilateral ureteric obstruction(UUO),and on reactive oxygen species(ROS)homeostasis in human umbilical vein endothelial cells(HUVECs).METHODS:Forty male mice were randomly divided into six groups,sham group,UUO group,UUO+resveratrol(RSV)(15 mg/kg)group,UUO+YSHX20 mg/kg group(UUO+YSHX-L),UUO+YSHX 40 mg/kg group(UUO+YSHX-M),UUO+YSHX 80 mg/kg group(UUO+YSHX-H).Western blotting was used to measure protein expression levels.Reverse transcription-quantitative polymerase chain reaction was used to measure the m RNA expression.Immunohistochemistry was used to examine the histopathological changes of kidney tissue sample.Cell apoptosis was measured by Annexin V/PI staining.Cell viability was measured using CCK-8/WST-8 assay.RESULTS:YSHX treatment reducedα-SMA and Col-4 expressions,and increased CD31 and VE-cadherin expressions in UUO model mice.In vitro,YSHX increased cell viability and decreased apoptosis of HUVECs under hypoxic conditions.YSHX inhibited ROS generation by activating adenosine monophosphate-activated protein kinase(AMPK)/peroxisome proliferator-activated receptor coactivator-1α(PGC-1α)/silent mating-type information regulation2 homolog 3(Sirt3)signaling.CONCLUSION:YSHX treatment reduced 109 KJ UUO-induced renal injury and fibrosis.Furthermore,YSHX treatment attenuated hypoxia-induced oxidative stress by regulating AMPK/PGC-1α/Sirt3 signaling.展开更多
Objective:Although immunity to malaria is reduced in pregnancy,the maternal immune system still continues to respond to malaria infection by the production of antibodies.IgG has been reported to play significant role ...Objective:Although immunity to malaria is reduced in pregnancy,the maternal immune system still continues to respond to malaria infection by the production of antibodies.IgG has been reported to play significant role in immune response against P.falciparum.Anti-MSP-1_(19) antibody and reactive oxygen species have been shown to be protective against malaria infection in children.This work assessed the response of anti-MSP-1_(19) antibody(a promising blood stage vaccine candidate antigen) and oxidative stress in 250 pregnant women.Methods: Blood samples were collected in dry and wet seasons.Plasmodium falciparum infection was determined by microscopy, anti-MSP-1_(19) IgG level was investigated using ELISA.Malondiadelhyde(MDA) and reduced glutathione (GSH) were used as indicators of oxidative stress and they were quantified spectrophotometrically.Results: Parasitaemia was significantly higher(P<0.05) in wet than dry season and its level decreased with gravidity.There was a significant increase(P<0.05) in anti-MSP-1_(19) IgG and MDA levels in the dry than wet season.Anti-MSP-1_(19) IgG and MDA levels were significantly higher in P.falciparum positive primigravidae than P.falciparum negative primigravidae in both wet and dry seasons.In wet season anti-MSP-1_(19) IgG level was significantly increased(P<0.05) in P.falciparum positive multigravidae than P.falciparum negative. The anti-MSP-1_(19) IgG and MDA were significant higher in P.falciparum positive multigravidae than primigravidae. Reduced glutathione(GSH) level was significantly reduced(P<0.05) among malaria positive than malaria negative patients in both seasons.Conclusion:This study suggests that IgG and MDA response were positively associated with the presence of malaria infection.展开更多
Reactive oxygen species(ROS),including singlet oxygen(^(1)O_(2)),hydroxyl radicals(·OH),and superoxide anions(O_(2)^(·-)),are highly reactive molecules that play central roles in many chemical,biological,and...Reactive oxygen species(ROS),including singlet oxygen(^(1)O_(2)),hydroxyl radicals(·OH),and superoxide anions(O_(2)^(·-)),are highly reactive molecules that play central roles in many chemical,biological,and environmental processes due to their strong oxidative power[1].Generating ROS in a controlled manner under mild conditions is essential for achieving selective oxidation reactions.Light-driven methods are especially appealing for this purpose,as they offer precise control over where and when ROS are produced.展开更多
The Beijing“Coal to Electricity”program provides a unique opportunity to explore air quality impacts by replacing residential coal burning with electrical appliances.In this study,the atmospheric ROS(Gas-phase ROS a...The Beijing“Coal to Electricity”program provides a unique opportunity to explore air quality impacts by replacing residential coal burning with electrical appliances.In this study,the atmospheric ROS(Gas-phase ROS and Particle-phase ROS,abbreviated to G-ROS and P-ROS)were measured by an online instrument in parallel with concurrent PM_(2.5) sample collections analyzed for chemical composition and cellular ROS in a baseline year(Coal Use Year-CUY)and the first year following implementation of the“Coal to Electricity”program(Coal Ban Year-CBY).The results showed PM_(2.5) concentrations had no significant difference between the two sampling periods,but the activities of G-ROS,P-ROS,and cellular ROS in CBY were 8.72 nmol H_(2)O_(2)/m^(3),9.82 nmol H 2 O 2/m 3,and 2045.75μg UD/mg PM higher than in CUY.Six sources were identified by factor-analysis from the chemical components of PM_(2.5).Secondary sources(SECs)were the dominant source of PM_(2.5) in the two periods,with 15.90%higher contribution in CBY than in CUY.Industrial Emission&Coal Combustion sources(Ind.&CCs),mainly from regional transport,also increased significantly in CBY.The contributions of Aged Sea Salt&Residential Burning sources to PM_(2.5) decreased 5.31% from CUY to CBY.The correlation results illustrated that Ind.&CCs had significant positive correlations with atmospheric ROS,and SECs significantly associated with cellular ROS,especially nitrates(r=0.626,p=0.000).Therefore,the implementation of the“Coal to Electricity”program reduced PM_(2.5) contributions from coal and biomass combustion,but had little effect on the improvement of atmospheric and cellular ROS.展开更多
基金supported by the Weiqiao-UCAS Special Projects on Low-Carbon Technology Development(No.GYY-DTFZ-2022-007)the Fundamental Research Funds for the Central Universities(No.E0E48927×2)the National Natural Science Foundation of China(No.21677145).
文摘Particulate matter(PM)can cause adverse health effects by overproducing reactive oxygen species(ROS).Although the ability of PM to induce ROS generation depends on its composi-tion and environmental factors.This study explores how photo-oxidation affects ROS gen-eration from aromatic compounds(ACs,including catechol(CAT),phthalic acid(PA),and 4,4-oxydibenzoic acid(4,4-OBA))and their mixtures with transition metals(TMs,includ-ing Fe(II),Mn(II),and Cu(II))using Fourier-transform infrared(FTIR)and Ultraviolet-visible spectroscopy(UV-Vis).Results showed that photo-oxidation facilitated ROS generation from ACs.CAT-Fe(II)/Cu(II)showed synergistic effects,but 4,4-OBA-Fe(II)/Cu(II)showed antag-onistic effects.ACs-Mn(II)and PA-Fe(II)/Cu(II)exhibited synergistic effects first and then showed antagonistic effects.The different interactions were due to complexation between ACs and TMs.The photo-oxidized ACs-TMs significantly enhanced ROS generation com-pared with ACs-TMs.The study suggested the photo-oxidation mechanism involved that the transfer ofπ-electrons from the ground to an excited state in benzene rings and func-tional groups,leading to the breakage and formation of chemical bonds or easierπ-electron transfer from ACs to TMs.The former could generate ROS directly or produce polymers that promoted ROS generation,while the latter promoted ROS generation by transferringπ-electrons to dissolved oxygen quickly.Our study revealed that both interactions among components and photo-oxidation significantly influenced ROS generation.Future studies should integrate broader atmospheric factors and PM components to fully assess oxidative potential and health impacts.
基金supported by grants from Ningbo Yongjiang Talent programme-Project for Innovative Talents(Grant No.20240340)Jinhua Science and Technology Bureau(Grant No.2022-4-258)2022 Shandong Medical Association Clinical Research Special Fund for Dynamic Monitoring of Lymphocyte Subpopulations by Flow Cytometry(Grant No.YXH2022ZX03227)。
文摘Prostate cancer(PCa)is a leading cause of cancer-related mortality among men.Radiotherapy is the cornerstone of PCa treatment.However,a major limitation of radiotherapy is the development of resistance,which compromises treatment efficacy.Reactive oxygen species(ROS),which are generated by radiation,have a dual role in PCa by inducing DNA damage and apoptosis,while also promoting tumor progression and radioresistance.Elevated ROS levels enhance metabolic reprogramming,activate oncogenic pathways,and influence the tumor microenvironment by modulating immune responses and promoting the epithelial-mesenchymal transition(EMT).Key molecular mechanisms,including the Nrf2/Keap1 signaling axis,Bcl-2 mutations,and Speckle-type POZ protein alterations,contribute to radioresistance by enhancing antioxidant defenses and DNA repair capacity.Additionally,the interplay between hypoxia,androgen receptor variants(AR-Vs),and ferroptosis regulators further influence radiotherapy outcomes.Understanding these resistance mechanisms is crucial for developing targeted strategies to enhance radiosensitivity and improve therapeutic outcomes in PCa patients.
基金Supported by Guangxi Natural Science Foundation of China,No.2024GXNSFAA010040Special Fund of the Central Government Guiding Local Scientific and Technological Development by Guangxi Science and Technology Department,No.GuikeZY21195024National Natural Science Foundation of China,No.82260499 and No.82460463.
文摘BACKGROUND High levels of acetaminophen(APAP)consumption can result in significant liver toxicity.Mogroside V(MV)is a bioactive,plant-derived triterpenoid known for its various pharmacological activities.However,the impact of MV on acute liver injury(ALI)is unknown.AIM To investigate the hepatoprotective potential of MV against liver damage caused by APAP and to examine the underlying mechanisms.METHODS Mice were divided into three groups:Saline,APAP and APAP+MV.MV(10 mg/kg)was given intraperitoneally one hour before APAP(300 mg/kg)administration.Twenty-four hours after APAP exposure,serum transaminase levels,liver necrotic area,inflammatory responses,nitrotyrosine accumulation,and c-jun-N-terminal kinase(JNK)activation were assessed.Additionally,we analyzed reactive oxygen species(ROS)levels,JNK activation,and cell death in alpha mouse liver 12(AML12)cells.RESULTS MV pre-treatment in vivo led to a reduction in the rise of aspartate transaminase and alanine transaminase levels,mitigated liver damage,decreased nitrotyrosine accumulation,and blocked JNK phosphorylation resulting from APAP exposure,without affecting glutathione production.Similarly,MV diminished the APAP-induced increase in ROS,JNK phosphorylation,and cell death in vitro.CONCLUSION Our study suggests that MV treatment alleviates APAP-induced ALI by reducing ROS and JNK activation.
文摘Sepsis is a condition of severe organ failure caused by the maladaptive response of the host to an infection.It is a severe complication affecting critically ill patients,which can progress to severe sepsis,septic shock,and ultimately death.As a vital part of the human innate immune system,neutrophils are essential in resisting pathogen invasion,infection,and immune surveillance.Neutrophil-produced reactive oxygen species(ROS) play a pivotal role in organ dysfunction related to sepsis.In recent years,ROS have received a lot of attention as a major cause of sepsis,which can progress to severe sepsis and septic shock.This paper reviews the existing knowledge on the production mechanism of neutrophil ROS in human organ function impairment because of sepsis.
基金the Natural Science Foundation of China under NSFC Grant No. 21477073, 41273127 for support to conduct this research
文摘Atmospheric humic-like substances （HULIS） are not only an unresolved mixture of macro- organic compounds but also powerful chelating agents in atmospheric particulate matters （PMs）; impacting on both the properties of aerosol particles and health effects by generating reactive oxygen spedes （ROS）. Currently, the interests of HULIS are intensively shifting to the investigations of HULIS-metal synergic effects and kinetics modeling studies, as well as the development of HULIS quantification, findings of possible HULIS sources and generation of ROS from HULIS. In light of HULIS studies, we comprehensively review the current knowledge of isolation and physicochemical characterization of HULIS from atmospheric samples as well as HULIS properties （hygroscopic, surface activity, and colloidal） and possible sources of HULIS. This review mainly highlights the generation of reactive oxygen species （ROS） from PMs, HULIS and transition metals, especially iron. This review also summarized the mechanism of iron-organic complexation and recent findings of OH formation from HULIS-metal complexes. This review will be helpful to carry out the modeling studies that concern with HULIS-transition metals and for further studies in the generation of ROS from HULIS-metal complexes,
基金financially supported by National Natural Science Foundation of China (81100240)‘985’ project of Sun Yat-Sen University grant+2 种基金Sun Yat-Sen university young teachers training project (13YKPY42)Natural Science Foundation of Guangdong Province,China(S2012010009495)Science and Technology Planning Project of Guangdong Province,China(2012B031800185)
文摘Age related defect of the osteogenic differentiation of mesenchymal stem cells（MSCs） plays a key role in osteoporosis. Mechanical loading is one of the most important physical stimuli for osteoblast differentiation.Here, we compared the osteogenic potential of MSCs from young and adult rats under three rounds of 2 h of cyclic stretch of 2.5% elongation at 1 Hz on 3 consecutive days. Cyclic stretch induced a significant osteogenic differentiation of MSCs from young rats, while a compromised osteogenesis in MSCs from the adult rats.Accordingly, there were much more reactive oxygen species（ROS） production in adult MSCs under cyclic stretch compared to young MSCs. Moreover, ROS scavenger N-acetylcysteine rescued the osteogenic differentiation of adult MSCs under cyclic stretch. Gene expression analysis revealed that superoxide dismutase 1（SOD1） was significantly downregulated in those MSCs from adult rats. In summary, our data suggest that reduced SOD1 may result in excessive ROS production in adult MSCs under cyclic stretch, and thus manipulation of the MSCs from the adult donors with antioxidant would improve their osteogenic ability.
基金Project (No. 30870223) supported by the National Natural Science Foundation of China
文摘A number of studies have shown the existence of cross-tolerance in plants, but the physiological mechanism is poorly understood. In this study, we used the germination of barley seeds as a system to investigate the cross-tolerance of low-temperature pretreatment to high-temperature stress and the possible involvement of reactive oxygen species （ROS） scavenging enzymes in the cross-tolerance. After pretreatment at 0 ℃ for different periods of time, barley seeds were germinated at 35 ℃, and the content of malondialdehyde （MDA） and the activities of ROS scavenging enzymes were measured by a spectrophotometer analysis. The results showed that barley seed germinated very poorly at 35 ℃, and this inhibitive effect could be overcome by pretreatment at 0 ℃. The MDA content varied, depending on the temperature at which seeds germinated, while barley seeds pretreated at 0 ℃ did not change the MDA content. Compared with seeds germinated directly at 35 ℃, the seeds pretreated first at 0 ℃ and then germinated at 35 ℃ had markedly increased activities of superoxide dismutase （SOD）, ascorbate peroxidase （APX）, catalase （CAT）, and glutathione reductase （GR）. The SOD and APX activities of seeds germinated at 35 ℃ after 0 ℃-pretreatment were even substantially higher than those at 25 ℃, and GR activity was similar to that at 25 ℃, at which the highest germination performance of barley seeds was achieved. These results indicate that low-temperature pretreatment can markedly increase the tolerance of barley seed to high temperature during germination, this being related to the increase in ROS scavenging enzyme activity. This may provide a new method for increasing seed germination under stress environments, and may be an excellent model system for the study of cross-tolerance.
基金supported by the National Natural Science Foundation of China(Grant No.32472185)the Key Research and Development Program of Hubei Province,China(Grant No.2022BFE003)the Hubei Agriculture Science and Technology Innovation Center program,and the National Rice Industry Technology System,China(Grant No.CARS-01-07).
文摘Honglian type-cytoplasmic male sterility(HL-CMS)is caused by the inter-communication between the nucleus and mitochondria.However,the mechanisms by which sterility genes regulate metabolic alterations and changes in mitochondrial morphology in the pollen of HL-CMS remain unclear.In this study,we compared the morphological differences between the pollen of the male sterile line YA and the near-isogenic line NIL-Rf6 using hematoxylin-eosin staining and 4ʹ,6-diamidino-2-phenylindole(DAPI)staining.HL-CMS is characterized by gametophytic sterility,where the aborted pollen grains are empty,and the tapetal layer remains intact.Transmission electron microscopy was employed to observe mitochondrial morphological changes at the microspore stage,revealing significant mitochondrial alterations,characterized by the formation of'large spherical mitochondria',occurred at the binucleate stage in the YA line.Additionally,metabolomics analysis revealed decreased levels of metabolites associated with the carbohydrate and flavonoid pathways.Notably,the decrease in flavonoids was found to contribute to an elevation in reactive oxygen species(ROS)levels.Therefore,we propose a model in which rice fertility is modulated by the levels of pollen carbohydrates and flavonoid metabolites,with impaired mitochondrial energy production and reduced flavonoid biosynthesis as the main causes of ROS accumulation and pollen abortion in rice.
文摘Objective: To study the adverse effects of advanced glycation end products(AGEs) on chondrocytes and the role of autophagy in this process. Methods: Chondrocytes were harvested from the human articular cartilage tissues in surgery. AGEs were administered during chondrocytes culture. The rapamycin was used to induce autophagy. The cell viability was determined by 3-[4,5-dimethylthiazol2-yl]-2,5-diphenyl tetrazolium bromide(MTT) assay.The expression of tumor necrosis factor-α(TNF-α) and nuclear factor-κ B(NF-κ B) was detected by quantitative real-time polymerase chain reaction. The reactive oxygen species(ROS) production and apoptosis of the chondrocytes were determined by fluorescent probe and flow cytometer, respectively. Results: The chondrocytes viability was significantly reduced after 12 h incubation with AGEs(P<0.01)). In contrast, rapamycin pretreatment increased the chondrocytes viability through autophagy. AGEs increased TNF-α and NF-κ B mRNA expression of chondrocytes and autophagy receded or proceeded the change. AGEs increased intracellular ROS accumulation and autophagy reversed the change. AGEs accelerated chondrocytes apoptosis and autophagy suspended apoptosis. Conclusions: Accumulation of AGEs may have an adverse role for chondrocytes by increasing TNF-α and NF-κB expression, ROS accumulation and apoptosis; meanwhile, autophagy ameliorates the AGEsinduced adverse effects.
基金supported by the National Research Foundation of Republic of Korea(NRF)grant funded by the Republic of Korea government(MSIT)(No.2022R1A2C1007831).
文摘To explore the mechanism of sperm dysfunction caused by dibutyl phthalate(DBP),the effects of DBP on intracellular[Ca^(2+)]and[pH],reactive oxygen species(ROS),lipid peroxidation(LPO),mitochondrial permeability transition pore(mPTP)opening,mitochondrial membrane potential(MMP),adenosine triphosphate(ATP)levels,phosphorylation of protein kinase A(PKA)substrate proteins and phosphotyrosine(p-Tyr)proteins,sperm motility,spontaneous acrosome reaction,and tail bending were examined in mouse spermatozoa.At 100μg/mL,DBP significantly increased tail bending and[Ca^(2+)]i.Interestingly,DBP showed biphasic effects on[pH]i.DBP at 10–100μg/mL significantly decreased sperm motility.Similarly,Ca^(2+)ionophore A23187 decreased[pH]_(i)sperm motility,suggesting that DBP-induced excessive[Ca^(2+)]_(i)decreased sperm motility.DBP significantly increased ROS and LPO.DBP at 100μg/mL significantly decreased mPTP closing,MMP,and ATP levels in spermatozoa,as did H2O2,indicative of ROS-mediatedmitochondrial dysfunction caused by DBP.DBP as well as H2O2 increased p-Tyr sperm proteins and phosphorylated PKA substrate sperm proteins.DBP at 1–10μg/mL significantly increased the spontaneous acrosome reaction,suggesting that DBP can activate sperm capacitation.Altogether,DBP showed a biphasic effect on intracellular signaling in spermatozoa.At concentrations relevant to seminal ortho-phthalate levels,DBP activates[pH]i,protein tyrosine kinases and PKA via physiological levels of ROS generation,potentiating sperm capacitation.DBP at high doses excessively raises[Ca^(2+)]_(i)and ROS and disrupts[pH]i,impairing the mitochondrial function,tail structural integrity,and sperm motility.
基金supported by the National Natural Science Foundation of China(No.22176206).
文摘Reactive oxygen species(ROS)are closely related to cell death,proliferation and inflammation.However,excessive ROS levels may exceed the cellular oxidative capacity and cause irreversible damage.Organisms are often inadvertently exposed to nanomaterials(NMs).Therefore,elucidating the specific routes of ROS generation induced by NMs is crucial for comprehending the toxicity mechanisms of NMs and regulating their potential applications.This paper provides a comprehensive review of the toxicity mechanisms and applications of NMs from three perspectives:(1)Organelle perspective.Investigating the impact of NMmediated ROS onmitochondria,unravelingmechanisms at the organelle level.(2)NMs’perspective.Exploring the broad applications and biosafety considerations of Nanozymes,a unique class of NMs.(3)Cellular system.Examining the toxic effects and mechanisms of NMs in cells at a holistic cellular level.Expanding on these perspectives,the paper scrutinizes the regulation of Fenton reactions by NMs in organisms.Furthermore,it introduces diseases resulting fromNM-mediated ROS at the organism level.This comprehensive review aims to provide valuable insights for studying NM-mediated mechanisms at both cellular and organism levels,offering considerations for the safe design of nanomaterials.
基金supported by the the National Natural Science Foundation of China(32071751).
文摘A geomagnetic field is a significant factor dur-ing the growth and development of trees.Changes in the magnetic field(MF)will result in reactions at the biochemi-cal,molecular,cellular and gene levels.However,it is not clear how a magnetic field affects metabolism and home-ostasis under stressful conditions such as salinity.In this study,a novel method was developed of a static magnetic field(SMF)to investigate magnetobiological changes in trees.The results show that pre-treatment of poplar(Popu-lus×euramericana‘Neva’)cuttings with a static magnetic field significantly mitigated the negative effects of salinity stress on their growth and physiological activities.Bio-chemical assays revealed that several chemical messengers,including hydrogen peroxide(H2O2)and O_(2)^(·-),were sig-nificantly improved in roots treated with salt,implying an increase reactive oxygen species.A static magnetic field also significantly increased proline concentrations,soluble protein contents,and CAT and SOD activities.Electrophysiological experiments further revealed that pre-treatment with a static magnetic field remarkably decreased salt-induced Na^(+)influx and H^(+)efflux which control plant salt tolerance.In pharmacological experiments,because the Na^(+)/H^(+)cor-relation was closely related to the SMF-activated plasma membrane and Na^(+)antiporter activity alleviated the mas-sive accumulation of salt-induced reactive oxygen spe-cies(ROS)within the roots.In addition,a static magnetic field dramatically increased the transcriptional activity of stress-responsive genes,including PtrRBOHD and PtrHA5.Together,these results indicate that SMF reduced Na^(+)influx by activating Na^(+)/H^(+)antiporters and plasma membrane H^(+)-ATPase to effectively maintain homeostasis by regu-lating the reactive oxygen species system and cytoplasmic osmotic potential.Ultimately,these static magnetic field methods improved salt tolerance in poplar cuttings,and,for future research,similar methods could be applied to other plants.
基金supported by the Fundamental Research Funds for the Central Universities (No. E0E48927X2)the National Natural Science Foundation of China (No. 21677145)
文摘Ambient particulate matter(PM)can cause adverse health effects via their ability to produce Reactive Oxygen Species(ROS).Water-Soluble Organic Compounds(WSOCs),a complex mixture of organic compounds which usually coexist with Transition Metals(TMs)in PM,have been found to contribute to ROS formation.However,the interaction between WSOCs and TMs and its effect on ROS generation are still unknown.In this study,we examined the ROS concentrations of V,Zn,Suwannee River Fulvic Acid(SRFA),Suwannee River Humic Acid(SRHA)and the mixtures of V/Zn and SRFA/SRHA by using a cell-free 2’,7’-Dichlorodihydrofluorescein(DCFH)assay.The results showed that V or Zn synergistically promoted ROS generated by SRFA,but had an antagonistic effect on ROS generated by SRHA.Fluorescence quenching experiments indicated that V and Zn were more prone to form stable complexes with aromatic humic acid-like component(C1)and fulvic acidlike component(C3)in SRFA and SRHA.Results suggested that the underlying mechanism involving the fulvic acid-like component in SRFA more tending to complex with TMs to facilitate ROS generation throughπelectron transfer.Our work showed that the complexing ability and complexing stability of atmospheric PM organics with metals could significantly affect ROS generation.It is recommended that the research deploying multiple analytical methods to quantify the impact of PM components on public health and environment is needed in the future.
基金Supported by National Natural Science Foundation of China:Study on the Treatment Mechanism of"Kidney Benefiting and Blood Circulation Activation"in Renal Fibrosis Based on SIRT3 Regulation AMPK/PCG-1/CPT1A Signaling Pathways(No.81760807)Study on the Anti-renal Fibrosis Mechanism of Yishen Huoxue Formula Based on the Regulation of Hypoxia-glycolysis Pathway by Exosome Derived Mir-210(No.82060820)。
文摘OBJECTIVE:To investigate the effeicacy of Yishen Huoxue decoction(YSHX)on renal fibrosis induced by unilateral ureteric obstruction(UUO),and on reactive oxygen species(ROS)homeostasis in human umbilical vein endothelial cells(HUVECs).METHODS:Forty male mice were randomly divided into six groups,sham group,UUO group,UUO+resveratrol(RSV)(15 mg/kg)group,UUO+YSHX20 mg/kg group(UUO+YSHX-L),UUO+YSHX 40 mg/kg group(UUO+YSHX-M),UUO+YSHX 80 mg/kg group(UUO+YSHX-H).Western blotting was used to measure protein expression levels.Reverse transcription-quantitative polymerase chain reaction was used to measure the m RNA expression.Immunohistochemistry was used to examine the histopathological changes of kidney tissue sample.Cell apoptosis was measured by Annexin V/PI staining.Cell viability was measured using CCK-8/WST-8 assay.RESULTS:YSHX treatment reducedα-SMA and Col-4 expressions,and increased CD31 and VE-cadherin expressions in UUO model mice.In vitro,YSHX increased cell viability and decreased apoptosis of HUVECs under hypoxic conditions.YSHX inhibited ROS generation by activating adenosine monophosphate-activated protein kinase(AMPK)/peroxisome proliferator-activated receptor coactivator-1α(PGC-1α)/silent mating-type information regulation2 homolog 3(Sirt3)signaling.CONCLUSION:YSHX treatment reduced 109 KJ UUO-induced renal injury and fibrosis.Furthermore,YSHX treatment attenuated hypoxia-induced oxidative stress by regulating AMPK/PGC-1α/Sirt3 signaling.
基金partially supported by University of Ibadan senate research grant awarded to Dr OG Ademowo of Institute for Advanced Medical Re- search and Training,Universily of Ibadan,Ibadan, Nigeria
文摘Objective:Although immunity to malaria is reduced in pregnancy,the maternal immune system still continues to respond to malaria infection by the production of antibodies.IgG has been reported to play significant role in immune response against P.falciparum.Anti-MSP-1_(19) antibody and reactive oxygen species have been shown to be protective against malaria infection in children.This work assessed the response of anti-MSP-1_(19) antibody(a promising blood stage vaccine candidate antigen) and oxidative stress in 250 pregnant women.Methods: Blood samples were collected in dry and wet seasons.Plasmodium falciparum infection was determined by microscopy, anti-MSP-1_(19) IgG level was investigated using ELISA.Malondiadelhyde(MDA) and reduced glutathione (GSH) were used as indicators of oxidative stress and they were quantified spectrophotometrically.Results: Parasitaemia was significantly higher(P<0.05) in wet than dry season and its level decreased with gravidity.There was a significant increase(P<0.05) in anti-MSP-1_(19) IgG and MDA levels in the dry than wet season.Anti-MSP-1_(19) IgG and MDA levels were significantly higher in P.falciparum positive primigravidae than P.falciparum negative primigravidae in both wet and dry seasons.In wet season anti-MSP-1_(19) IgG level was significantly increased(P<0.05) in P.falciparum positive multigravidae than P.falciparum negative. The anti-MSP-1_(19) IgG and MDA were significant higher in P.falciparum positive multigravidae than primigravidae. Reduced glutathione(GSH) level was significantly reduced(P<0.05) among malaria positive than malaria negative patients in both seasons.Conclusion:This study suggests that IgG and MDA response were positively associated with the presence of malaria infection.
基金Part of this paper was presented at the 8th Congress of Toxicology in Developing Countries(8CTDC)under the auspices of International Union of Toxicology(IUTOX)September 10-13,2012:at Centara Grand at Central Ladprao,Bangkok,Thailand.
文摘Reactive oxygen species(ROS),including singlet oxygen(^(1)O_(2)),hydroxyl radicals(·OH),and superoxide anions(O_(2)^(·-)),are highly reactive molecules that play central roles in many chemical,biological,and environmental processes due to their strong oxidative power[1].Generating ROS in a controlled manner under mild conditions is essential for achieving selective oxidation reactions.Light-driven methods are especially appealing for this purpose,as they offer precise control over where and when ROS are produced.
基金supported by the National Natural Science Foundation of China(NSFC)(No.41877310)partly by the National Key Research and Development Program of China(No.2016YFC0503600).
文摘The Beijing“Coal to Electricity”program provides a unique opportunity to explore air quality impacts by replacing residential coal burning with electrical appliances.In this study,the atmospheric ROS(Gas-phase ROS and Particle-phase ROS,abbreviated to G-ROS and P-ROS)were measured by an online instrument in parallel with concurrent PM_(2.5) sample collections analyzed for chemical composition and cellular ROS in a baseline year(Coal Use Year-CUY)and the first year following implementation of the“Coal to Electricity”program(Coal Ban Year-CBY).The results showed PM_(2.5) concentrations had no significant difference between the two sampling periods,but the activities of G-ROS,P-ROS,and cellular ROS in CBY were 8.72 nmol H_(2)O_(2)/m^(3),9.82 nmol H 2 O 2/m 3,and 2045.75μg UD/mg PM higher than in CUY.Six sources were identified by factor-analysis from the chemical components of PM_(2.5).Secondary sources(SECs)were the dominant source of PM_(2.5) in the two periods,with 15.90%higher contribution in CBY than in CUY.Industrial Emission&Coal Combustion sources(Ind.&CCs),mainly from regional transport,also increased significantly in CBY.The contributions of Aged Sea Salt&Residential Burning sources to PM_(2.5) decreased 5.31% from CUY to CBY.The correlation results illustrated that Ind.&CCs had significant positive correlations with atmospheric ROS,and SECs significantly associated with cellular ROS,especially nitrates(r=0.626,p=0.000).Therefore,the implementation of the“Coal to Electricity”program reduced PM_(2.5) contributions from coal and biomass combustion,but had little effect on the improvement of atmospheric and cellular ROS.
