Wounds pose a risk to the skin,our body's primary defence against infections.The rise of antibiotic resistance has prompted the development of novel therapies.RO-101^(■)is an antimicrobial gel that delivers thera...Wounds pose a risk to the skin,our body's primary defence against infections.The rise of antibiotic resistance has prompted the development of novel therapies.RO-101^(■)is an antimicrobial gel that delivers therapeutic levels of hydrogen peroxide(H_(2)O_(2)),a reactive oxygen species,directly to the wound bed.In this study,electrospinning was used to incorporate RO-101^(■)into a polyvinyl alcohol(PVA)sub-micron fibrous mesh that can act as a delivery agent,achieve a sustained release profile,and provide a barrier against infection.Adequate incorporation of this gel into sub-micron fibres was confirmed via nuclear magnetic resonance spectroscopy.Furthermore,scanning electron microscopy exhibited smooth and uniform meshes with diameters in the 200-500 nm range.PVA/RO-101 electrospun meshes generated H_(2)O_(2) in concentrations exceeding 1 m M/(g·m L)(1 m M=1 mmol/L)after 24 h,and the role of sterilisation on H_(2)O_(2) release was evaluated.PVA/RO-101meshes exhibited antimicrobial activity against both Gram-positive Staphylococcus aureus(S.aureus)and Gram-negative Pseudomonas aeruginosa(P.aeruginosa)bacteria,achieving viable count reductions of up to 1 log unit CFU/mm^(2)(CFU:colony-forming units).Moreover,these meshes were capable of disrupting biofilm formation,even against multidrug-resistant organisms such as methicillin-resistant S.aureus(MRSA).Furthermore,increasing the RO-101^(■)concentration resulted in higher H_(2)O_(2) production and an enhanced antimicrobial effect,while fibroblast cell viability and proliferation tests showed a concentration-dependent response with high cytocompatibility at low RO-101^(■)concentrations.This study therefore demonstrates the potential of highly absorbent PVA/RO-101 meshes as potential antimicrobial wound dressings.展开更多
Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberel...Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberellins(GAs)play crucial roles in plant growth,development,and responses to drought stress.Previous studies have shown significant reductions of GA levels in plants under drought stress;however,our understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited.Here,we show that drought stress can impair the accumulation of bioactive GAs(BGAs),and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene.This gene was significantly induced by drought stress and abscisic acid(ABA)treatment,but was suppressed by GA_(3)treatment.PbrGA2ox1-overexpressing transgenic tobacco plants(Nicotiana benthamiana)exhibited enhanced tolerance to dehydration and drought stresses,whereas knock-down of PbrGA2ox1 in pear(Pyrus betulaefolia)by virus-induced gene silencing led to elevated drought sensitivity.Transgenic plants were hypersensitive to ABA,and had a lower BGAs content,enhanced reactive oxygen species(ROS)scavenging ability,and augmented ABA accumulation and signaling under drought stress compared to wild-type plants.However,the opposite effects were observed with PbrGA2ox1 silencing in pear.Moreover,exogenous GA_(3)treatment aggravated the ROS toxic effect and restrained ABA synthesis and signaling,resulting in the compromised drought tolerance of pear.In summary,our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress,providing further insights into the mechanism regulating the effects of GA on the drought tolerance of plants.展开更多
The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzin...The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic plants.To further investigate the biological functions of OsbZIP53,we generated osbzip53 mutants using CRISPR/Cas9 editing and also constructed OsbZIP53 over-expression transgenic plants.Comprehensive analysis of phenotypical,physiological,and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants,but also regulated the immune response through the salicylic acid pathway.Specifically,disrupting OsbZIP53 increased H2O2 accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs(Osrboh genes)and weakened H2O2 degradation by directly targeting OsMYBS1.In addition,the growth of osbzip53 mutants was seriously impaired,while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type,suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.展开更多
Gastric cancer(GC)ranks fifth in cancer incidence and fourth in cancer-related mortality worldwide.Reactive oxygen species(ROS)are highly oxidative oxygen-derived products that have crucial roles in cell signaling reg...Gastric cancer(GC)ranks fifth in cancer incidence and fourth in cancer-related mortality worldwide.Reactive oxygen species(ROS)are highly oxidative oxygen-derived products that have crucial roles in cell signaling regulation and maintaining internal balance.ROS are closely associated with the occurrence,development,and treatment of GC.This review summarizes recent findings on the sources of ROS and the bidirectional regulatory effects on GC and discusses various treatment modalities for GC that are related to ROS induction.In addition,the regulation of ROS by natural small molecule compounds with the highest potential for development and applications in anti-GC research is summarized.The aim of the review is to accelerate the clinical application of modulating ROS levels as a therapeutic strategy for GC.展开更多
Conventional blood sampling for glucose detection is prone to cause pain and fails to continuously record glucose fluctuations in vivo.Continuous glucose monitoring based on implantable electrodes could induce pain an...Conventional blood sampling for glucose detection is prone to cause pain and fails to continuously record glucose fluctuations in vivo.Continuous glucose monitoring based on implantable electrodes could induce pain and potential tissue inflammation,and the presence of reactive oxygen species(ROS)due to inflammationmay affect glucose detection.Microneedle technology is less invasive,yet microneedle adhesion with skin tissue is limited.In this work,we developed a microarrow sensor array(MASA),which provided enhanced skin surface adhesion and enabled simultaneous detection of glucose and H_(2)O_(2)(representative of ROS)in interstitial fluid in vivo.The microarrows fabricated via laser micromachining were modified with functional coating and integrated into a patch of a three-dimensional(3D)microneedle array.Due to the arrow tip mechanically interlocking with the tissue,the microarrow array could better adhere to the skin surface after penetration into skin.The MASA was demonstrated to provide continuous in vivo monitoring of glucose and H_(2)O_(2) concentrations,with the detection of H_(2)O_(2) providing a valuable reference for assessing the inflammation state.Finally,the MASA was integrated into a monitoring system using custom circuitry.This work provides a promising tool for the stable and reliable monitoring of blood glucose in diabetic patients.展开更多
Acute pancreatitis(AP)is a common acute gastrointestinal disorder affecting approximately 20%of patients with systemic inflammatory responses that may cause pancreatic and peripancreatic fat necrosis.This condition of...Acute pancreatitis(AP)is a common acute gastrointestinal disorder affecting approximately 20%of patients with systemic inflammatory responses that may cause pancreatic and peripancreatic fat necrosis.This condition often progresses to multiple organ failure,significantly increasing morbidity and mortality.Oxidative stress,characterized by an imbalance between the body’s reactive oxygen species(ROS)and antioxidants,activates the inflammatory signaling pathways.Although the pathogenesis of AP is not fully understood,ROS are increasingly recognized as critical in the disease's progression and development.Modulating the oxidative stress pathway has shown efficacy in mitigating the progression of AP.Despite numerous basic studies examining this pathway,comprehensive reviews of recent research remain sparse.This systematic review offers an in-depth examination of the critical role of oxidative stress in the pathogenesis and progression of AP and evaluates the therapeutic potential of antioxidant interventions in its management.展开更多
Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even t...Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even the elongation of radicle and plumule were dramatically promoted by SNP treatments during the germination under osmotic stress. Meanwhile, activities of amylase and EP were enhanced, thus leading to the degradation of storage reserve in seeds. After osmotic stress was removed, higher viability of wheat seeds was also maintained. In addition, the activities of CAT, APX and the content of proline were increased by SNP treatment simultaneously, but activities of LOX were inhibited, and both of which were beneficial for improving the antioxidant capacity during the germination of wheat seeds under osmotic stress. It was also shown that the increase of the activity of amylase induced by SNP in embryoless half-seeds of wheat in the beginning period of germination (6 h) might be indirectly related to GA(3).展开更多
Objective: To evaluate the anti-tumor effects of SeO2 and its mechanisms on three human lung cancer cell lines. Methods: Three lung cancer cells A549, GLC-82 and PG were treated with 3-30 μmol/L SeO2. Flow cytometry ...Objective: To evaluate the anti-tumor effects of SeO2 and its mechanisms on three human lung cancer cell lines. Methods: Three lung cancer cells A549, GLC-82 and PG were treated with 3-30 μmol/L SeO2. Flow cytometry was used to detect apoptosis, and analyze the changes of expression of p53 and Bcl-2, as well as ROS and Ca2+ level within cells. Results:SeO2 markedly inhibited cell proliferation and viability, and prompted apoptosis after 48 h treatment. SeO2 at 10 μmol/L induced 47.8% apoptosis in A549 cells, 40.8% in GLC-82 cells, 18.2% in PG cells. SeO2 at 30 μmol/L induced 37.8% apoposis in PG cells,but did not increase apoptotic raes in other two cells. SeO2 could down-regulate the mean fluorescent intensity of Bcl-2 from 65.8 to 9.6 in A549, but not in GLC-82 and in PG cells, up-regulate wild type p53 level in all three cells. SeO2 decreased the ROS and Ca2+ level markedly within three tested cells. Conclusion: SeO2 showed anti-tumor effect via apoptosis pathway in three lung cancer cell lines. The decrease of ROS and Ca2+ level within cells as well as regulation of Bcl-2 and p53 expression may play important roles in above apoptotic procedure.展开更多
AIM: To identify whether JTE-522 can induce apoptosis in AGS cells and ROS also involved in the process, and to investigate the changes in NF-kB, p53, bcl-2 and caspase in the apoptosis process. METHODS: Cell culture,...AIM: To identify whether JTE-522 can induce apoptosis in AGS cells and ROS also involved in the process, and to investigate the changes in NF-kB, p53, bcl-2 and caspase in the apoptosis process. METHODS: Cell culture, MTT, Electromicroscopy, agarose gel electrophoresis, lucigenin, Western blot and electrophoretic mobility shift assay (EMSA) analysis were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanisms. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Lucigenin assay showed the generation of ROS in cells under incubation with JTE-522. The increased ROS generation might contribute to the induction of AGS cells to apoptosis. EMSA and Western blot revealed that NF-kB activity was almost completely inhibited by preventing the degradation of IkBalpha. Additionally, by using Western blot we confirmed that the level of bcl-2 was decreased, whereas p53 showed a great increase following JTE-522 treatment. Their changes were in a dose-dependent manner. CONCLUSION: These findings suggest that reactive oxygen species, NF-kB, p53, bcl-2 and caspase-3 may play an important role in the induction of apoptosis in AGS cells after treatment with JTE-522.展开更多
<abstract>Aim: To investigate the level of malondialdehyde (MDA), a direct indicator of lipid peroxidation-induced injury by reactive oxygen species (ROS), in testicular biopsy specimens from infertile patients....<abstract>Aim: To investigate the level of malondialdehyde (MDA), a direct indicator of lipid peroxidation-induced injury by reactive oxygen species (ROS), in testicular biopsy specimens from infertile patients. Methods: Levels of MDA were measured in testicular biopsy specimens from 29 consequent-randomized infertile men, aged 29.58±4.76 (21-45) years. All patients were evaluated by a complete medical and reproductive history, physical examination, semen analysis (at least two), serum follicle-stimulating hormone and free testosterone levels, testicular biopsy and contact imprint. Scrotal colour Doppler ultrasonography was used to confirm suspected varicocele. The testicular MDA level was measured using the thiobarbituric acid test and the results were expressed per unit tissue weight. Results: As a causal factor in infertility, varicocele was identified in 17 (58.6 %) patients, and idiopathic infertility, testicular failure and obstruction in 4 (13.8 %) patients each. The testicular MDA level was 13.56 (6.01), 49.56 (24.04), 58.53 (48.07), and 32.64 (21.51), 32.72 (13.61), 23.07 (7.82), 42,12 (34.76) pmol/mg tissue in the normal spermatogenesis (control), late maturation arrest, Sertoli cell only (SCO) and hypospermatogenesis (mild, moderete, severe) groups, respectively. The elevation of MDA levels was significant in the testicular tissue from SCO and maturation arrest groups compared with the controls (P<0.05). In addition, the elevation in testicular MDA levels between the SCO and the moderete hypospermatogenesis, and the moderate hypospermatogenesis and the maturation arrest groups was significant (P<0.05). Conclusion: Severe pathologic changes in the testicular tissue are associated with a high level of lipid peroxidation. These findings suggest that overproduction of ROS may play a role in the mechanism of testicular degeneration associated with infertility.展开更多
Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cel...Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cell cycle of normal NB4 cells. Our results showed that NB4 cells possessed higher level of ROS in G2/M phase than in G1 and S phases. Double staining flow cytometry,with TdT mediated dUTP nick end labeling (Tunel) and propidium iodide (PI),indicated that As2O3 (2 μM) could induce apoptosis in NB4 cells prevailingly from G2/M phase,and this efficacy was enhanced upon co-administration of 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) (2.5 μM) which could produce the endogenous ROS. These results suggested that different ROS level in different cell cycle phases of NB4 cells might determin the selective induction of G2/M apoptosis and the cells' susceptibility to apoptosis by As2O3.展开更多
AIM: To investigate the potential role of nuclear factor kappa-B (NF-κB) activation on the reactive oxygen species in rat acute necrotizing pancreatitis (ANP) and to assess the effect of pyrrolidine dithiocarbam...AIM: To investigate the potential role of nuclear factor kappa-B (NF-κB) activation on the reactive oxygen species in rat acute necrotizing pancreatitis (ANP) and to assess the effect of pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB).METHODS: Rat ANP model was established by retrograde injection of 5% sodium taurocholate into biliopancreatic duct. Rats were randomly assigned to three groups (10 rats each): Control group, ANP group and PDTC group. At the 6^th of the model, the changes of the serum amylase,nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD) and pancreatic morphological damage were observed. The expressions of inducible nitric oxide (iNOS) were observed by SP immunohistochemistry. And bhe expressions of NF-κB p65 subunit mRNA were observed by hybridization in situ.RESULTS: Serum amylase and NO level decreased significantly in ANP group as compared with PDTC administrated group [(7 170.40+1 308.63) U/L vs(4 074.10+1 719.78) U/L,P〈0.05], [(76.95±9.04) μmol/L vs (65.18±9.02) μmol/L,P〈0.05] respectively. MDA in both ANP and PDTC group rose significantly over that in control group [(9.88+1.52)nmol/L, (8.60±1.41) nmol/L, vs (6.04:hl.78) nmol/L,P〈0.05], while there was no significant difference between them. SOD levels in both ANP and PDTC group underwent a significant decrease as compared with that in control[(3 214.59±297.74) NU/mL, (3 260.62±229.44) NU/mL,vs(3 977.80+309.09) NU/mL, P〈0.05], but there was no significant difference between them. Though they were still higher bhan those in Control group, pancreas destruction was slighter in PDTC group, iNOS expression and NF-κB p65 subunit mRNA expression were lower in PDTC group as compared with ANP group.CONCLUSION: We conclude that correlation among NF-κB activation, serum amylase, reactive oxygen species level and tissue damage suggests a key role of NF-κB in the pathogenesis of ANP. Inhibition of NF-κB activation may reverse the pancreatic damage of rat ANP and the production of reactive oxygen species.展开更多
Silver nanoparticles (Ag NPs) can effectively address the issue of antibiotic-resistant bacterial infections to reduce the potential toxicity of Ag NPs. Although challenging, it is, therefore, necessary to achieve the...Silver nanoparticles (Ag NPs) can effectively address the issue of antibiotic-resistant bacterial infections to reduce the potential toxicity of Ag NPs. Although challenging, it is, therefore, necessary to achieve the sustainable release of Ag+ ions from a finite amount of Ag NPs. This study aims at designing an efficient and benign antimicrobial silver-based ternary composite composed of photocatalysis zinc oxide (ZnO) and reduced graphene oxide (rGO) as a carrier, in which the reactive oxygen species (ROS) excited from ZnO and Ag+ ions released from the Ag NPs cooperate to realize an effective antibacterial activity against E. coli and S. aureus. The constant effective bacterial performance of the ternary photocatalyst with minimum Ag content can be attributed to the increase in the available quantity of ROS, which results from the enhanced separation efficiency of the photogenerated carriers. The proposed system notably realized the long-term sustainable release of Ag+ ions with low concentration for 30 days when compared with an equivalent amount of silver nitrate. Moreover, the use of the composite prevents biotoxicity and silver wastage, and imparts enhanced stability to the long-lasting antibacterial efficacy.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
Reactive oxygen species (ROS) are molecules or ions formed by the incomplete one-electron reduction of oxygen. Ofinterest, it seems that ROS manifest dual roles, cancer promoting or cancer suppressing, in tumorigenesi...Reactive oxygen species (ROS) are molecules or ions formed by the incomplete one-electron reduction of oxygen. Ofinterest, it seems that ROS manifest dual roles, cancer promoting or cancer suppressing, in tumorigenesis. ROS participate simultaneously in two signaling pathways that have inverse functions in tumorigenesis, Ras-Raf-MEK1/2-ERK1/2 signaling and the p38 mitogen-activated protein kinases (MAPK) pathway. It is well known that Ras-Raf-MEK1/2-ERK1/2 signaling is related to oncogenesis, while the p38 MAPK pathway contributes to cancer suppression, which involves oncogene-induced senescence, inflammationinduced cellular senescence, replicative senescence, contact inhibition and DNA-damage responses. Thus, ROS may not be an absolute carcinogenic factor or cancer suppressor. The purpose of the present review is to discuss the dual roles of ROS in the pathogenesis of cancer, and the signaling pathway mediating their role in tumorigenesis.展开更多
This study investigated the role of reactive oxygen species(ROS) in the pathogenesis of triptolide-induced renal injury in vivo.Rats were randomly divided into 4 groups(n=5 in each):triptolide group in which the ...This study investigated the role of reactive oxygen species(ROS) in the pathogenesis of triptolide-induced renal injury in vivo.Rats were randomly divided into 4 groups(n=5 in each):triptolide group in which the rats were intraperitoneally injected with triptolide solution at a dose of 1 mg/kg of body weight on day 8;control group in which the rats received a single intraperitoneal injection of 0.9% physiological saline on day 8;vitamin C group in which the rats were pretreated with vitamin C by gavage at a dose of 250 mg/kg of body weight per day for 7 days before the same treatment as the control group on day 8;triptolide+vitamin C group in which the rats were first subjected to an oral administration of vitamin C at a dose of 250 mg/kg of body weight per day for 7 days,and then to the same treatment as the triptolide group on day 8.All the rats were sacrificed on day 10.Blood samples were collected for detection of plasma creatinine(Pcr) and plasma urea nitrogen(PUN) concentrations.Both kidneys were removed.The histological changes were measured by haematoxylin-eosin(HE) staining.The production of ROS was determined by detecting the fluorescent intensity of the oxida-tion-sensitive probe rhodamine 123 in renal tissue.Renal malondialdehyde(MDA) content was meas-ured to evaluate lipid peroxidation level in renal tissue.TUNEL staining was performed to assess apop-tosis of renal tubular cells.Renal expression of apoptosis-related proteins Bcl-2,Bax,Bid,Bad,Fas and FasL,as well as corresponding encoding genes were assessed by Western Blotting and real-time PCR.The results showed that triptolide treatment promoted the generation of a great amount of ROS,up-regulated the expression of Bax,Bid,Bad,Fas and FasL at both protein and mRNA levels,as well as the ratio of Bax to Bcl-2,and caused the apoptosis of renal tubular cells and renal injury.However,pretreatment with an antioxidant,vitamin C,significantly reduced the generation of ROS and effectively inhibited the triptolide-induced apoptosis of renal tubular cells and renal injury.It was concluded that ROS plays a critical role in triptolide-induced apoptosis of renal tubular cells and renal injury.The protective administration of vitamin C may help alleviate triptolide-induced renal injury and nephrotoxicity.展开更多
Rice is one of the main staple food crops in the world, but it may suffer serious water stress during growth period. Water stress during grain filling results in decreased grain yeild, but its mechanism generating and...Rice is one of the main staple food crops in the world, but it may suffer serious water stress during growth period. Water stress during grain filling results in decreased grain yeild, but its mechanism generating and scavenging the active oxygen is unclear under continuance of the water stress. The experiment was carried out in growth chamber to investigate the effects of water stress on the production of superoxide free radical (O2), hydrogen peroxide (H202), malondialdehyde (MDA), reduced glutathione (GSH), ascorbic acid (AsA), and antioxidative enzyme activities in three rice hybrids with differing drought resistant under both normal and drought conditions during grain-filling stage. The results showed that water stress aggravated the membrane lipid peroxidation in rice leaves, which was more severe in less drought resistant hybrids than that in more tolerant ones. Also O2' and H2O2 accumulated more rapidly in less drought resistant hybrids than that in more tolerant ones. During water stress, decreases of GSH, AsA, chlorophyll, and relative water contents in more drought resistant hybrids were obvious less than those in less tolerant ones. Activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in/eaves increased obviously in 0-14 d after heading and subsequently decreased rapidly, and those in more drought resistant hybrids were more than those in less tolerant ones. The results showed that changes of O2, H2O2, MDA, GSH, and AsA contents and antioxidative enzyme activities correlated significantly to drought resistance of rice hybrids, and more drought resistant hybrids possessed high ant oxidation capacity.展开更多
Different amounts of vitamin C were added to diets fed to juveniles (2.5+0.15 g) of sea cucumber Apostichopus japonicus (Selenka) in an attempt to reduce the stress response of specimens exposed to nitrite stress...Different amounts of vitamin C were added to diets fed to juveniles (2.5+0.15 g) of sea cucumber Apostichopus japonicus (Selenka) in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels (0.5, 1.0, and 1.5 mg/L) of nitrite stress for 4, 8, and 12 h at four time intervals (0, 15, 30, and 45 d). Growth of the animals was recorded during the experiment. Reactive oxygen species (ROS) (i.e. hydroxyl free radical (-OH), malondialdehyde (MDA) and total antioxidant capacity (T-AOC)) and antioxidant enzyme activities (i.e., superoxide dismutase (SOD) and eatalase (CAT)) were measured. Response surface methodology (RSM) was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain (WG) and special growth rate (SGR) of vitamin C supplementation groups were significantly higher than those of control group (P〈0.05). The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.展开更多
OBJECTIVE: Preventive measures against skin melanoma like chemotherapy are useful but suffer from chronic side effects and drug resistance. Ethanolic extract of Phytolacca decandra (PD), used in homeopathy for the ...OBJECTIVE: Preventive measures against skin melanoma like chemotherapy are useful but suffer from chronic side effects and drug resistance. Ethanolic extract of Phytolacca decandra (PD), used in homeopathy for the treatment of various ailments like chronic rheumatism, regular conjunctivitis, psoriasis, and in some skin diseases was tested for its possible anticancer potential. METHODS: Cytotoxicity of the drug was tested by conducting 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay on both normal (peripheral blood mononuclear cells) and A375 cells. Fluorescence microscopic study of 4',6-diamidino-2-phenylindole dihydrochloride-stained cells was conducted for DNA fragmentation assay, and changes in cellular morphology, if any, were also recorded. Lactate dehydrogenase activity assay was done to evaluate the percentages of apoptosis and necrosis. Reactive oxygen species (ROS) accumulation, if any, and expression study of apoptotic genes also were evaluated to pin-point the actual events of apoptosis. RESULTS: Results showed that PD administration caused a remarkable reduction in proliferation of A375 cells, without showing much cytotoxicity on peripheral blood mononuclear cells. Generation of ROS and DNA damage, which made the cancer cells prone to apoptosis, were found to be enhanced in PD-treated cells. These results were duly supported by the analytical data on expression of different cellular and nuclear proteins, as for example, by down- regulation of Akt and Bcl-2, up-regulation of p53, Bax and caspase 3, and an increase in number of cell deaths by apoptosis in A375 cells. CONCLUSION: Overall results demonstrate anticancer potentials of PD on A375 cells through activation of caspase-mediated signaling and ROS generation.展开更多
The combinative effects of applied zinc (Zn) and soil moisture on the plant growth, Zn uptake, and the metabolism of reactive oxygen species (ROS) in maize (Zea mays L.) plants were examined through two pot expe...The combinative effects of applied zinc (Zn) and soil moisture on the plant growth, Zn uptake, and the metabolism of reactive oxygen species (ROS) in maize (Zea mays L.) plants were examined through two pot experiments under greenhouse conditions. Maize variety Zhongdan 9409 was used. In experiment 1, maize plants were grown in cumulic cinnamon soil with five Zn treatments (0, 3.0, 9.0, 27.0, and 81.0 mg Zn kg^-1 soil). Three treatments of soil moisture including serious drought, mild drought, and adequate water supply were set at 30-35%, 40-45%, and 70-75% (w/w) of soil saturated water content, respectively. Soil saturated water content was 36% (w/w). The dry matter weights of shoots were enhanced by Zn application and adequate water supply. There was no apparent difference in plant growth among Zn application rates from 3.0 to 81.0 mg Zn kg^-1 soil. The increases of plant growth and Zn uptake due to Zn application were found more significant under well-watered condition than under drying condition. In experiment 2, two levels of Zn (0 and 5.0 mg Zn kg^-1 soil) and soil moisture regimen (40-45% and 70-75% of soil saturated water content, respectively) were set. Zn deficiency or water stress resulted in higher concentrations of O2^- and malondiadehyde in the first fully expanded leaves. Zn deficiency lowered the activity of superoxide dismutase (SOD, EC 1.15.1.1) in leaves. Drought stress increased SOD activity in leaves regardless of Zn supply. The activity of guaiacol peroxidase (POD, ECI.11.1.11) was found to be enhanced by Zn supply only in well-watered leaves. Zinc deficiency or water stress had little effect on the activity of catalase (CAT, EC 1.11.1.6). The higher ROS level in early maize leaves due to water stress seemed not to be alleviated or lowered partially by Zn application. However, Zn fertilizer was recommended to apply to maize plants irrigated or supplied with adequate water, otherwise Zn deficiency would reduce the water use for plant biomass production.展开更多
基金supported by Matoke Holdings,the United Kingdom(UK)Engineering and Physical Sciences Research Council(EPSRC)Doctoral Prize Fellowship(No.EP/R513131/1)the Henry Royce Institute for Advanced Materials,funded through EPSRC grants(Nos.EP/R00661X/1,EP/S019367/1,EP/P025021/1,and EP/P025498/1)+1 种基金Ruth Edge and Kevin Warren(Dalton Nuclear Institute,The University of Manchester)for facilitating gamma sterilisation for our samplesfinancial support from Matoke Holdings。
文摘Wounds pose a risk to the skin,our body's primary defence against infections.The rise of antibiotic resistance has prompted the development of novel therapies.RO-101^(■)is an antimicrobial gel that delivers therapeutic levels of hydrogen peroxide(H_(2)O_(2)),a reactive oxygen species,directly to the wound bed.In this study,electrospinning was used to incorporate RO-101^(■)into a polyvinyl alcohol(PVA)sub-micron fibrous mesh that can act as a delivery agent,achieve a sustained release profile,and provide a barrier against infection.Adequate incorporation of this gel into sub-micron fibres was confirmed via nuclear magnetic resonance spectroscopy.Furthermore,scanning electron microscopy exhibited smooth and uniform meshes with diameters in the 200-500 nm range.PVA/RO-101 electrospun meshes generated H_(2)O_(2) in concentrations exceeding 1 m M/(g·m L)(1 m M=1 mmol/L)after 24 h,and the role of sterilisation on H_(2)O_(2) release was evaluated.PVA/RO-101meshes exhibited antimicrobial activity against both Gram-positive Staphylococcus aureus(S.aureus)and Gram-negative Pseudomonas aeruginosa(P.aeruginosa)bacteria,achieving viable count reductions of up to 1 log unit CFU/mm^(2)(CFU:colony-forming units).Moreover,these meshes were capable of disrupting biofilm formation,even against multidrug-resistant organisms such as methicillin-resistant S.aureus(MRSA).Furthermore,increasing the RO-101^(■)concentration resulted in higher H_(2)O_(2) production and an enhanced antimicrobial effect,while fibroblast cell viability and proliferation tests showed a concentration-dependent response with high cytocompatibility at low RO-101^(■)concentrations.This study therefore demonstrates the potential of highly absorbent PVA/RO-101 meshes as potential antimicrobial wound dressings.
基金supported by grants from the China Agriculture Research System(CARS-28-14)the Technical System of Fruit Industry in Anhui Province,China(AHCYTX-10)the Scientific Research Projects for Postgraduates of Anhui Universities,China(YJS20210207).
文摘Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberellins(GAs)play crucial roles in plant growth,development,and responses to drought stress.Previous studies have shown significant reductions of GA levels in plants under drought stress;however,our understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited.Here,we show that drought stress can impair the accumulation of bioactive GAs(BGAs),and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene.This gene was significantly induced by drought stress and abscisic acid(ABA)treatment,but was suppressed by GA_(3)treatment.PbrGA2ox1-overexpressing transgenic tobacco plants(Nicotiana benthamiana)exhibited enhanced tolerance to dehydration and drought stresses,whereas knock-down of PbrGA2ox1 in pear(Pyrus betulaefolia)by virus-induced gene silencing led to elevated drought sensitivity.Transgenic plants were hypersensitive to ABA,and had a lower BGAs content,enhanced reactive oxygen species(ROS)scavenging ability,and augmented ABA accumulation and signaling under drought stress compared to wild-type plants.However,the opposite effects were observed with PbrGA2ox1 silencing in pear.Moreover,exogenous GA_(3)treatment aggravated the ROS toxic effect and restrained ABA synthesis and signaling,resulting in the compromised drought tolerance of pear.In summary,our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress,providing further insights into the mechanism regulating the effects of GA on the drought tolerance of plants.
基金the Zhejiang Natural Science Foundation,China(Grant No.LY21C130004)the Key Research and Development Program of Zhejiang Province,China(Grant No.2021C02056-3)+1 种基金the Central Public-Interest Scientific Institution Basal Research Fund,China(Grant No.CPSIBRF-CNRRI-202202)the Agricultural Science and Technology Innovation Program,China(Grant No.CAASASTIP-2021-CNRRI).
文摘The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic plants.To further investigate the biological functions of OsbZIP53,we generated osbzip53 mutants using CRISPR/Cas9 editing and also constructed OsbZIP53 over-expression transgenic plants.Comprehensive analysis of phenotypical,physiological,and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants,but also regulated the immune response through the salicylic acid pathway.Specifically,disrupting OsbZIP53 increased H2O2 accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs(Osrboh genes)and weakened H2O2 degradation by directly targeting OsMYBS1.In addition,the growth of osbzip53 mutants was seriously impaired,while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type,suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.
基金supported by The National Key Research and Development Program of China (Grant No. 2021YFA0910100)Healthy Zhejiang One Million People Cohort (Grant No. K-20230085)+7 种基金Post-doctoral Innovative Talent Support Program (Grant No. BX2023375)Zhejiang Provincial Research Center for Upper Gastrointestinal Tract Cancer (Grant No. JBZX-202006)Medical Science and Technology Project of Zhejiang Province (Grant No. WKJ-ZJ-2202 and WKJ-ZJ-2104)National Natural Science Foundation of China (Grant Nos. 82304946, 82074245, 81973634, and 81903842)Natural Science Foundation of Zhejiang Province (Grant No. LR21H280001)Science and Technology Projects of Zhejiang Province (Grant No. 2019C03049)Program of Zhejiang Provincial TCM Scitech Plan (Grant Nos. 2018ZY006, 2020ZZ005)China Postdoctoral Science Foundation (Grant No. 2023M733563)
文摘Gastric cancer(GC)ranks fifth in cancer incidence and fourth in cancer-related mortality worldwide.Reactive oxygen species(ROS)are highly oxidative oxygen-derived products that have crucial roles in cell signaling regulation and maintaining internal balance.ROS are closely associated with the occurrence,development,and treatment of GC.This review summarizes recent findings on the sources of ROS and the bidirectional regulatory effects on GC and discusses various treatment modalities for GC that are related to ROS induction.In addition,the regulation of ROS by natural small molecule compounds with the highest potential for development and applications in anti-GC research is summarized.The aim of the review is to accelerate the clinical application of modulating ROS levels as a therapeutic strategy for GC.
基金This work was financially supported by the National Key R&D Program of China(Nos.2021YFF1200700 and 2021YFA0911100)the National Natural Science Foundation of China(Nos.32171399,32171456,and T2225010)+6 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515012261)the Science and Technology Program of Guangzhou,China(No.202103000076)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(No.22dfx02),and Pazhou Lab,Guangzhou(No.PZL2021KF0003)FML would like to thank the National Natural Science Foundation of China(Nos.32171335 and 31900954)JL would like to thank the National Natural Science Foundation of China(No.62105380)the China Postdoctoral Science Foundation(No.2021M693686)QQOY would like to thank the China Postdoctoral Science Foundation(No.2022M713645).
文摘Conventional blood sampling for glucose detection is prone to cause pain and fails to continuously record glucose fluctuations in vivo.Continuous glucose monitoring based on implantable electrodes could induce pain and potential tissue inflammation,and the presence of reactive oxygen species(ROS)due to inflammationmay affect glucose detection.Microneedle technology is less invasive,yet microneedle adhesion with skin tissue is limited.In this work,we developed a microarrow sensor array(MASA),which provided enhanced skin surface adhesion and enabled simultaneous detection of glucose and H_(2)O_(2)(representative of ROS)in interstitial fluid in vivo.The microarrows fabricated via laser micromachining were modified with functional coating and integrated into a patch of a three-dimensional(3D)microneedle array.Due to the arrow tip mechanically interlocking with the tissue,the microarrow array could better adhere to the skin surface after penetration into skin.The MASA was demonstrated to provide continuous in vivo monitoring of glucose and H_(2)O_(2) concentrations,with the detection of H_(2)O_(2) providing a valuable reference for assessing the inflammation state.Finally,the MASA was integrated into a monitoring system using custom circuitry.This work provides a promising tool for the stable and reliable monitoring of blood glucose in diabetic patients.
基金Supported by the National Natural Science Foundation of China,No.8217030254.
文摘Acute pancreatitis(AP)is a common acute gastrointestinal disorder affecting approximately 20%of patients with systemic inflammatory responses that may cause pancreatic and peripancreatic fat necrosis.This condition often progresses to multiple organ failure,significantly increasing morbidity and mortality.Oxidative stress,characterized by an imbalance between the body’s reactive oxygen species(ROS)and antioxidants,activates the inflammatory signaling pathways.Although the pathogenesis of AP is not fully understood,ROS are increasingly recognized as critical in the disease's progression and development.Modulating the oxidative stress pathway has shown efficacy in mitigating the progression of AP.Despite numerous basic studies examining this pathway,comprehensive reviews of recent research remain sparse.This systematic review offers an in-depth examination of the critical role of oxidative stress in the pathogenesis and progression of AP and evaluates the therapeutic potential of antioxidant interventions in its management.
文摘Effects of sodium nitroprusside (SNP), a nitric oxide (NO) donor, on the germination and metabolism of reactive oxygen species were surveyed in wheat (Triticum aestivum L.) seeds. Germination of wheat seeds and even the elongation of radicle and plumule were dramatically promoted by SNP treatments during the germination under osmotic stress. Meanwhile, activities of amylase and EP were enhanced, thus leading to the degradation of storage reserve in seeds. After osmotic stress was removed, higher viability of wheat seeds was also maintained. In addition, the activities of CAT, APX and the content of proline were increased by SNP treatment simultaneously, but activities of LOX were inhibited, and both of which were beneficial for improving the antioxidant capacity during the germination of wheat seeds under osmotic stress. It was also shown that the increase of the activity of amylase induced by SNP in embryoless half-seeds of wheat in the beginning period of germination (6 h) might be indirectly related to GA(3).
基金This project was partially supported by Science Foundation of Lanzhou Command of PLA(No.YZ-0106).
文摘Objective: To evaluate the anti-tumor effects of SeO2 and its mechanisms on three human lung cancer cell lines. Methods: Three lung cancer cells A549, GLC-82 and PG were treated with 3-30 μmol/L SeO2. Flow cytometry was used to detect apoptosis, and analyze the changes of expression of p53 and Bcl-2, as well as ROS and Ca2+ level within cells. Results:SeO2 markedly inhibited cell proliferation and viability, and prompted apoptosis after 48 h treatment. SeO2 at 10 μmol/L induced 47.8% apoptosis in A549 cells, 40.8% in GLC-82 cells, 18.2% in PG cells. SeO2 at 30 μmol/L induced 37.8% apoposis in PG cells,but did not increase apoptotic raes in other two cells. SeO2 could down-regulate the mean fluorescent intensity of Bcl-2 from 65.8 to 9.6 in A549, but not in GLC-82 and in PG cells, up-regulate wild type p53 level in all three cells. SeO2 decreased the ROS and Ca2+ level markedly within three tested cells. Conclusion: SeO2 showed anti-tumor effect via apoptosis pathway in three lung cancer cell lines. The decrease of ROS and Ca2+ level within cells as well as regulation of Bcl-2 and p53 expression may play important roles in above apoptotic procedure.
基金National Natural Science Foundation of China,No.39770300,30070873the Overseas Chinese Affairs Office of the State Council Foundation,No.98-33
文摘AIM: To identify whether JTE-522 can induce apoptosis in AGS cells and ROS also involved in the process, and to investigate the changes in NF-kB, p53, bcl-2 and caspase in the apoptosis process. METHODS: Cell culture, MTT, Electromicroscopy, agarose gel electrophoresis, lucigenin, Western blot and electrophoretic mobility shift assay (EMSA) analysis were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanisms. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Lucigenin assay showed the generation of ROS in cells under incubation with JTE-522. The increased ROS generation might contribute to the induction of AGS cells to apoptosis. EMSA and Western blot revealed that NF-kB activity was almost completely inhibited by preventing the degradation of IkBalpha. Additionally, by using Western blot we confirmed that the level of bcl-2 was decreased, whereas p53 showed a great increase following JTE-522 treatment. Their changes were in a dose-dependent manner. CONCLUSION: These findings suggest that reactive oxygen species, NF-kB, p53, bcl-2 and caspase-3 may play an important role in the induction of apoptosis in AGS cells after treatment with JTE-522.
文摘<abstract>Aim: To investigate the level of malondialdehyde (MDA), a direct indicator of lipid peroxidation-induced injury by reactive oxygen species (ROS), in testicular biopsy specimens from infertile patients. Methods: Levels of MDA were measured in testicular biopsy specimens from 29 consequent-randomized infertile men, aged 29.58±4.76 (21-45) years. All patients were evaluated by a complete medical and reproductive history, physical examination, semen analysis (at least two), serum follicle-stimulating hormone and free testosterone levels, testicular biopsy and contact imprint. Scrotal colour Doppler ultrasonography was used to confirm suspected varicocele. The testicular MDA level was measured using the thiobarbituric acid test and the results were expressed per unit tissue weight. Results: As a causal factor in infertility, varicocele was identified in 17 (58.6 %) patients, and idiopathic infertility, testicular failure and obstruction in 4 (13.8 %) patients each. The testicular MDA level was 13.56 (6.01), 49.56 (24.04), 58.53 (48.07), and 32.64 (21.51), 32.72 (13.61), 23.07 (7.82), 42,12 (34.76) pmol/mg tissue in the normal spermatogenesis (control), late maturation arrest, Sertoli cell only (SCO) and hypospermatogenesis (mild, moderete, severe) groups, respectively. The elevation of MDA levels was significant in the testicular tissue from SCO and maturation arrest groups compared with the controls (P<0.05). In addition, the elevation in testicular MDA levels between the SCO and the moderete hypospermatogenesis, and the moderate hypospermatogenesis and the maturation arrest groups was significant (P<0.05). Conclusion: Severe pathologic changes in the testicular tissue are associated with a high level of lipid peroxidation. These findings suggest that overproduction of ROS may play a role in the mechanism of testicular degeneration associated with infertility.
基金supported by research grants from National Natural Science Foundation of China(No.30170475)
文摘Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate,to detect the level fluctuation of reactive oxygen species (ROS) during the cell cycle of normal NB4 cells. Our results showed that NB4 cells possessed higher level of ROS in G2/M phase than in G1 and S phases. Double staining flow cytometry,with TdT mediated dUTP nick end labeling (Tunel) and propidium iodide (PI),indicated that As2O3 (2 μM) could induce apoptosis in NB4 cells prevailingly from G2/M phase,and this efficacy was enhanced upon co-administration of 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) (2.5 μM) which could produce the endogenous ROS. These results suggested that different ROS level in different cell cycle phases of NB4 cells might determin the selective induction of G2/M apoptosis and the cells' susceptibility to apoptosis by As2O3.
文摘AIM: To investigate the potential role of nuclear factor kappa-B (NF-κB) activation on the reactive oxygen species in rat acute necrotizing pancreatitis (ANP) and to assess the effect of pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB).METHODS: Rat ANP model was established by retrograde injection of 5% sodium taurocholate into biliopancreatic duct. Rats were randomly assigned to three groups (10 rats each): Control group, ANP group and PDTC group. At the 6^th of the model, the changes of the serum amylase,nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD) and pancreatic morphological damage were observed. The expressions of inducible nitric oxide (iNOS) were observed by SP immunohistochemistry. And bhe expressions of NF-κB p65 subunit mRNA were observed by hybridization in situ.RESULTS: Serum amylase and NO level decreased significantly in ANP group as compared with PDTC administrated group [(7 170.40+1 308.63) U/L vs(4 074.10+1 719.78) U/L,P〈0.05], [(76.95±9.04) μmol/L vs (65.18±9.02) μmol/L,P〈0.05] respectively. MDA in both ANP and PDTC group rose significantly over that in control group [(9.88+1.52)nmol/L, (8.60±1.41) nmol/L, vs (6.04:hl.78) nmol/L,P〈0.05], while there was no significant difference between them. SOD levels in both ANP and PDTC group underwent a significant decrease as compared with that in control[(3 214.59±297.74) NU/mL, (3 260.62±229.44) NU/mL,vs(3 977.80+309.09) NU/mL, P〈0.05], but there was no significant difference between them. Though they were still higher bhan those in Control group, pancreas destruction was slighter in PDTC group, iNOS expression and NF-κB p65 subunit mRNA expression were lower in PDTC group as compared with ANP group.CONCLUSION: We conclude that correlation among NF-κB activation, serum amylase, reactive oxygen species level and tissue damage suggests a key role of NF-κB in the pathogenesis of ANP. Inhibition of NF-κB activation may reverse the pancreatic damage of rat ANP and the production of reactive oxygen species.
基金supported by the National Natural Science Foundation of China(51472101,51572114,21773062,21577036)the Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials(JSKC17003)~~
文摘Silver nanoparticles (Ag NPs) can effectively address the issue of antibiotic-resistant bacterial infections to reduce the potential toxicity of Ag NPs. Although challenging, it is, therefore, necessary to achieve the sustainable release of Ag+ ions from a finite amount of Ag NPs. This study aims at designing an efficient and benign antimicrobial silver-based ternary composite composed of photocatalysis zinc oxide (ZnO) and reduced graphene oxide (rGO) as a carrier, in which the reactive oxygen species (ROS) excited from ZnO and Ag+ ions released from the Ag NPs cooperate to realize an effective antibacterial activity against E. coli and S. aureus. The constant effective bacterial performance of the ternary photocatalyst with minimum Ag content can be attributed to the increase in the available quantity of ROS, which results from the enhanced separation efficiency of the photogenerated carriers. The proposed system notably realized the long-term sustainable release of Ag+ ions with low concentration for 30 days when compared with an equivalent amount of silver nitrate. Moreover, the use of the composite prevents biotoxicity and silver wastage, and imparts enhanced stability to the long-lasting antibacterial efficacy.
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Supported by National Natural Science Foundation of China, No. 30750013 Key Science Research Project Natural Science Foundation of Xiamen, No. WKZ0501
文摘Reactive oxygen species (ROS) are molecules or ions formed by the incomplete one-electron reduction of oxygen. Ofinterest, it seems that ROS manifest dual roles, cancer promoting or cancer suppressing, in tumorigenesis. ROS participate simultaneously in two signaling pathways that have inverse functions in tumorigenesis, Ras-Raf-MEK1/2-ERK1/2 signaling and the p38 mitogen-activated protein kinases (MAPK) pathway. It is well known that Ras-Raf-MEK1/2-ERK1/2 signaling is related to oncogenesis, while the p38 MAPK pathway contributes to cancer suppression, which involves oncogene-induced senescence, inflammationinduced cellular senescence, replicative senescence, contact inhibition and DNA-damage responses. Thus, ROS may not be an absolute carcinogenic factor or cancer suppressor. The purpose of the present review is to discuss the dual roles of ROS in the pathogenesis of cancer, and the signaling pathway mediating their role in tumorigenesis.
文摘This study investigated the role of reactive oxygen species(ROS) in the pathogenesis of triptolide-induced renal injury in vivo.Rats were randomly divided into 4 groups(n=5 in each):triptolide group in which the rats were intraperitoneally injected with triptolide solution at a dose of 1 mg/kg of body weight on day 8;control group in which the rats received a single intraperitoneal injection of 0.9% physiological saline on day 8;vitamin C group in which the rats were pretreated with vitamin C by gavage at a dose of 250 mg/kg of body weight per day for 7 days before the same treatment as the control group on day 8;triptolide+vitamin C group in which the rats were first subjected to an oral administration of vitamin C at a dose of 250 mg/kg of body weight per day for 7 days,and then to the same treatment as the triptolide group on day 8.All the rats were sacrificed on day 10.Blood samples were collected for detection of plasma creatinine(Pcr) and plasma urea nitrogen(PUN) concentrations.Both kidneys were removed.The histological changes were measured by haematoxylin-eosin(HE) staining.The production of ROS was determined by detecting the fluorescent intensity of the oxida-tion-sensitive probe rhodamine 123 in renal tissue.Renal malondialdehyde(MDA) content was meas-ured to evaluate lipid peroxidation level in renal tissue.TUNEL staining was performed to assess apop-tosis of renal tubular cells.Renal expression of apoptosis-related proteins Bcl-2,Bax,Bid,Bad,Fas and FasL,as well as corresponding encoding genes were assessed by Western Blotting and real-time PCR.The results showed that triptolide treatment promoted the generation of a great amount of ROS,up-regulated the expression of Bax,Bid,Bad,Fas and FasL at both protein and mRNA levels,as well as the ratio of Bax to Bcl-2,and caused the apoptosis of renal tubular cells and renal injury.However,pretreatment with an antioxidant,vitamin C,significantly reduced the generation of ROS and effectively inhibited the triptolide-induced apoptosis of renal tubular cells and renal injury.It was concluded that ROS plays a critical role in triptolide-induced apoptosis of renal tubular cells and renal injury.The protective administration of vitamin C may help alleviate triptolide-induced renal injury and nephrotoxicity.
基金supported by the National 863 Program of China (2002AA2Z4011)the Foundation for Personnel of Henan University of Science and Technology China.
文摘Rice is one of the main staple food crops in the world, but it may suffer serious water stress during growth period. Water stress during grain filling results in decreased grain yeild, but its mechanism generating and scavenging the active oxygen is unclear under continuance of the water stress. The experiment was carried out in growth chamber to investigate the effects of water stress on the production of superoxide free radical (O2), hydrogen peroxide (H202), malondialdehyde (MDA), reduced glutathione (GSH), ascorbic acid (AsA), and antioxidative enzyme activities in three rice hybrids with differing drought resistant under both normal and drought conditions during grain-filling stage. The results showed that water stress aggravated the membrane lipid peroxidation in rice leaves, which was more severe in less drought resistant hybrids than that in more tolerant ones. Also O2' and H2O2 accumulated more rapidly in less drought resistant hybrids than that in more tolerant ones. During water stress, decreases of GSH, AsA, chlorophyll, and relative water contents in more drought resistant hybrids were obvious less than those in less tolerant ones. Activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in/eaves increased obviously in 0-14 d after heading and subsequently decreased rapidly, and those in more drought resistant hybrids were more than those in less tolerant ones. The results showed that changes of O2, H2O2, MDA, GSH, and AsA contents and antioxidative enzyme activities correlated significantly to drought resistance of rice hybrids, and more drought resistant hybrids possessed high ant oxidation capacity.
基金Supported by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(No.KZCX2-EWQ215)
文摘Different amounts of vitamin C were added to diets fed to juveniles (2.5+0.15 g) of sea cucumber Apostichopus japonicus (Selenka) in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels (0.5, 1.0, and 1.5 mg/L) of nitrite stress for 4, 8, and 12 h at four time intervals (0, 15, 30, and 45 d). Growth of the animals was recorded during the experiment. Reactive oxygen species (ROS) (i.e. hydroxyl free radical (-OH), malondialdehyde (MDA) and total antioxidant capacity (T-AOC)) and antioxidant enzyme activities (i.e., superoxide dismutase (SOD) and eatalase (CAT)) were measured. Response surface methodology (RSM) was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain (WG) and special growth rate (SGR) of vitamin C supplementation groups were significantly higher than those of control group (P〈0.05). The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.
基金financially supported by a grant sanctioned to Prof. A.R. Khuda-Bukhsh, Department of Zoology,University of Kalyani, by Boiron Laboratories, Lyon, France
文摘OBJECTIVE: Preventive measures against skin melanoma like chemotherapy are useful but suffer from chronic side effects and drug resistance. Ethanolic extract of Phytolacca decandra (PD), used in homeopathy for the treatment of various ailments like chronic rheumatism, regular conjunctivitis, psoriasis, and in some skin diseases was tested for its possible anticancer potential. METHODS: Cytotoxicity of the drug was tested by conducting 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay on both normal (peripheral blood mononuclear cells) and A375 cells. Fluorescence microscopic study of 4',6-diamidino-2-phenylindole dihydrochloride-stained cells was conducted for DNA fragmentation assay, and changes in cellular morphology, if any, were also recorded. Lactate dehydrogenase activity assay was done to evaluate the percentages of apoptosis and necrosis. Reactive oxygen species (ROS) accumulation, if any, and expression study of apoptotic genes also were evaluated to pin-point the actual events of apoptosis. RESULTS: Results showed that PD administration caused a remarkable reduction in proliferation of A375 cells, without showing much cytotoxicity on peripheral blood mononuclear cells. Generation of ROS and DNA damage, which made the cancer cells prone to apoptosis, were found to be enhanced in PD-treated cells. These results were duly supported by the analytical data on expression of different cellular and nuclear proteins, as for example, by down- regulation of Akt and Bcl-2, up-regulation of p53, Bax and caspase 3, and an increase in number of cell deaths by apoptosis in A375 cells. CONCLUSION: Overall results demonstrate anticancer potentials of PD on A375 cells through activation of caspase-mediated signaling and ROS generation.
文摘The combinative effects of applied zinc (Zn) and soil moisture on the plant growth, Zn uptake, and the metabolism of reactive oxygen species (ROS) in maize (Zea mays L.) plants were examined through two pot experiments under greenhouse conditions. Maize variety Zhongdan 9409 was used. In experiment 1, maize plants were grown in cumulic cinnamon soil with five Zn treatments (0, 3.0, 9.0, 27.0, and 81.0 mg Zn kg^-1 soil). Three treatments of soil moisture including serious drought, mild drought, and adequate water supply were set at 30-35%, 40-45%, and 70-75% (w/w) of soil saturated water content, respectively. Soil saturated water content was 36% (w/w). The dry matter weights of shoots were enhanced by Zn application and adequate water supply. There was no apparent difference in plant growth among Zn application rates from 3.0 to 81.0 mg Zn kg^-1 soil. The increases of plant growth and Zn uptake due to Zn application were found more significant under well-watered condition than under drying condition. In experiment 2, two levels of Zn (0 and 5.0 mg Zn kg^-1 soil) and soil moisture regimen (40-45% and 70-75% of soil saturated water content, respectively) were set. Zn deficiency or water stress resulted in higher concentrations of O2^- and malondiadehyde in the first fully expanded leaves. Zn deficiency lowered the activity of superoxide dismutase (SOD, EC 1.15.1.1) in leaves. Drought stress increased SOD activity in leaves regardless of Zn supply. The activity of guaiacol peroxidase (POD, ECI.11.1.11) was found to be enhanced by Zn supply only in well-watered leaves. Zinc deficiency or water stress had little effect on the activity of catalase (CAT, EC 1.11.1.6). The higher ROS level in early maize leaves due to water stress seemed not to be alleviated or lowered partially by Zn application. However, Zn fertilizer was recommended to apply to maize plants irrigated or supplied with adequate water, otherwise Zn deficiency would reduce the water use for plant biomass production.