BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple b...BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple biological processes,including cellular senescence,apoptosis,sugar and lipid metabolism,oxidative stress,and inflammation.AIM To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms.METHODS This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)testing.C57BL/6 mice were also intraperitoneally pretreated with SIRT1,p53,or glutathione peroxidase 4(GPX4)inducers and inhibitors and injected with lipopolysaccharide(LPS)/D-galactosamine(D-GalN)to induce ALF.Gasdermin D(GSDMD)^(-/-)mice were used as an experimental group.Histological changes in liver tissue were monitored by hematoxylin and eosin staining.ALT,AST,glutathione,reactive oxygen species,and iron levels were measured using commercial kits.Ferroptosis-and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction.SIRT1,p53,and GSDMD were assessed by immunofluorescence analysis.RESULTS Serum AST and ALT levels were elevated in patients with ALF.SIRT1,solute carrier family 7a member 11(SLC7A11),and GPX4 protein expression was decreased and acetylated p5,p53,GSDMD,and acyl-CoA synthetase long-chain family member 4(ACSL4)protein levels were elevated in human ALF liver tissue.In the p53 and ferroptosis inhibitor-treated and GSDMD^(-/-)groups,serum interleukin(IL)-1β,tumour necrosis factor alpha,IL-6,IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated.In mice with GSDMD knockout,p53 was reduced,GPX4 was increased,and ferroptotic events(depletion of SLC7A11,elevation of ACSL4,and iron accumulation)were detected.In vitro,knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels,the cytostatic rate,and GSDMD expression,restoring SLC7A11 depletion.Moreover,SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group,accompanied by reduced p53,GSDMD,and ACSL4,and increased SLC7A11 and GPX4.Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalNinduced in vitro and in vivo models.CONCLUSION SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF.展开更多
This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2...This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2 and GPX4 in peripheral blood of patients with PHC was determined to analyze the diagnostic value of the two combined for PHC.The prognostic significance of NRF2 and GPX4 was evaluated by 3-year followup.Human liver epithelial cells THLE-2 and human hepatocellular carcinoma cells HepG2 were purchased,and the expression of NRF2 and GPX4 in the cells was determined.NRF2 and GPX4 aberrant expression vectors were constructed and transfected into HepG2,and changes in cell proliferation and invasion capabilities were observed.Results:The expression of NRF2 and GPX4 in patients with PHC was higher than that in patients with LC or VH(p<0.05),and the two indicators combined was excellent in diagnosing PHC.Moreover,patients with high expression of NRF2 and GPX4 had a higher risk of death(p<0.05).In in vitro experiments,both NRF2 and GPX4 expression was elevated in HepG2(p<0.05).HepG2 activity was enhanced by increasing the expression of the two,vice versa(p<0.05).Conclusion:NRF2 and GPX4 combined is excellent in diagnosing PHC,and promotes the malignant development of PHC.展开更多
Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organ...Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organoselenium whose GPx mimetic property has been suggested to rely on the oxidation of non-protein or protein thiols critical to the activities of some sulfhydryl enzymes.This study,therefore investigated the GPx mimic/antioxidant property of DPDS as well as the role of thiols of two key sulfhydryl enzymes,cerebral Na^(+)/K^(+)-ATPase(sodium pump)and hepatic delta-aminolevulinic acid dehydratase(δ-ALAD)in the GPx mimicry of DPDS.Albino Wistar rats were euthanized,and the liver and brain were removed and used to assay for the effect of DPDS on lipid peroxidation induced by two prooxidants[Fe2^(+)(10μM)and H2O2,(1 mM)]as well as the activities of the sulfhydryl enzymes.The results revealed that DPDS profoundly(P<0.05)counteracted Fe2^(+)and H2O2-induced lipid peroxidation in the rats’hepatic and cerebral tissues.Furthermore,the results of assay systems for lipid peroxidation and sodium pump revealed that DPDS inhibited Na^(+)/K^(+)-ATPase and lipid peroxidation in the brain tissue homogenates in the same reaction system.A similar result was obtained in the assay system for lipid peroxidation and hepaticδ-ALAD as DPDS simultaneously inhibited the enzyme’s activity and lipid peroxidation.This suggests that the GPx mimetic property of DPDS may be linked to the enzymes’loss of activity,which further validates the suggestions that the enzymes’inhibition,as well as the antioxidant action of DPDS,rely on the oxidation of critical thiols of the enzymes.However,the GPx mimicry of DPDS should be investigated in the presence of thiol-blocking or oxidizing agents in biological systems in order to further ascertain the role of protein thiols.展开更多
Glutathione peroxidase (GPx) is an antioxidant that plays an important role in the maintenance of male fertility. The aim of this study was to compare the profile of enzymatic activity of glutathione peroxidase in the...Glutathione peroxidase (GPx) is an antioxidant that plays an important role in the maintenance of male fertility. The aim of this study was to compare the profile of enzymatic activity of glutathione peroxidase in the seminal plasma of normozoosperm and those of pathological sperm. Thus, the activity of glutathione peroxidase was determined in the seminal plasma of 20 normozoosperms, 9 azoosperms and 31 oligoasthenoteratozoosperms. It was 37.58 ± 3.14 U/L in normozoosperms, 39.39 ± 2.27 U/L in oligoasthenoteratozoosperms, and 29.77 ± 2.62 U/L in azoosperms. The mean GPx enzyme activity of normozoosperms did not differ significantly from that of oligoasthenoteratozoosperms and azoosperms. In contrast, comparison of enzyme activity between abnormal sperms gave a significant difference. This study showed that glutathione peroxidase enzymatic activity is not related to sperm quality.展开更多
OBJECTIVE Intracellular aggre⁃gation ofα-synuclein(SNCA)is one of the core pathological features of neurodegenerative disor⁃ders including Parkinson disease,whilst the detailed mechanism for consequently neuron loss ...OBJECTIVE Intracellular aggre⁃gation ofα-synuclein(SNCA)is one of the core pathological features of neurodegenerative disor⁃ders including Parkinson disease,whilst the detailed mechanism for consequently neuron loss has not been fully illustrated.Since the altered phospholipid homeostasis has been suggested to play a role in synucleinopathy,this study aims to depict the fully-featured status of phospholip⁃ids and the targets reposingα-synuclein-related neurotoxicity.METHODS SNCAA53T transgenic mice were utilized as the model of Parkinson disease.Behavioral tests including pole test,rotarod test and gait analysis were conducted to assess the motor features of Parkinsonism.Tyro⁃sine hydroxylase were determined by immunohis⁃tochemistry.Glutathione,dopamine,3,4-dihy⁃droxyphenylacetic acid and homovanillic acid were determined by HPLC-ECD analysis.Assess⁃ment of lipid peroxidation included MDA assay and Liperfluo staining.Phospholipid-omics was analyzed based on LC-MS/MS.Investigation on mechanism was relied on Western blotting and qPCR assay.The injection of AAV into midbrain was achieved by ultra-micro injection pump to obtain the target genotype.RESULTS SNCAA53T transgenic mice displayed progres⁃sively deteriorated motor coordination functions and the mechanisms were related with lipid per⁃oxidation and ferroptosis,which might help to explain the parkinsonism.These hydroperoxides were observed on plasm membrane and were further characterized by LC-MS/MS-based phos⁃pholipid-omics analysis.α-synucleinA53T trans⁃genic mice displayed distinct patterns of phos⁃pholipid peroxidation in midbrain regions com⁃pared to wild type littermates.Among different subtypes of oxidized phospholipids,oxidative phosphatidylcholine(PC-ox)was more promi⁃nently elevated.Phospholipid peroxidation is believed as a biomarker of ferroptosis,which is largely a specialized death program caused by insufficiency of glutathione peroxidase-4(GPX4),the only known enzyme that can reduce lipid hydroperoxides within biological membranes.The deficiency of Gpx4 was demonstrated to be responsible forα-synuclein-induced lipid peroxi⁃dation,and the cell lines and mouse models underwent genetic Gpx4 downregulation showed exacerbated dopaminergic neuron loss and par⁃kinsonism.On the other hand,the potentiation of Gpx4 expression remarkably inhibited dopami⁃nergic ferroptotic death and behavioral deficits in a mouse model with synucleinopathy.CONCLU⁃SION A cellular pathway that Gpx4 deficit-medi⁃ated phospholipid peroxidation and behavioral consequence participated in synucleinopathy,suggesting a potential strategy targeting Gpx4 to alleviate PD symptoms.展开更多
The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severit...The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severity of hepatic injury. We aimed to study the oxidative stress state in children with chronic hepatitis by using indirect approach in which antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) are determined in the liver tissue. The present study included 21 children and adolescents (12 males, 9 females) suffering from chronic hepatitis. Patients were selected from the Hepatology Clinic, New Children’s Hospital, Cairo University from November 2006 till 2009 and compared with a group of 7 children who happened to have incidental normal liver biopsy. Children with chronic hepatitis had mean age 8.12 ± 1.15 years. It was further subdivided into 2 subgroups: chronic viral heaptitis (n = 13) and cryptogenic hepatitis (n = 8). GPX, SOD and CAT levels were measured in fresh liver tissue (cell free homogenates) using ELISA. In chronic hepatitis group;there was a significant increase in the hepatic GPX activity (38.59 ± 35.82 nmol/min/ml) as compared to the control group (10.62 ± 6.68 nmol/min/ml). Also a significant correlation was observed between SOD and both ALT (r = 0.87, p < 0.05) and AST (r = 0.74, p < 0.05). GPX correlated with ALT (r = 0.80, p < 0.05) level in the chronic viral hepatitis subgroup. Our findings suggest that oxidative stress could play a role in the pathogenesis of chronic hepatitis. These preliminary results are encouraging to conduct more extensive clinical studies combining antioxidant therapy with various treatments.展开更多
Catalase(CAT) and selenium-dependent glutathione peroxidase(Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H2O2. The objective of this paper is to evaluate the role...Catalase(CAT) and selenium-dependent glutathione peroxidase(Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H2O2. The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawn Exopalaemon carinicauda in response to low salinity stress. A complementary DNA(cDNA) containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction(RT-PCR) and rapid amplification of cDNA ends. The full-length cDNA of CAT(2 649 bp) contains a 5'-untranslated region(UTR) of 78 bp, a 3'- UTR of1 017 bp, with a poly(A) tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature(60FDRERIPERVVHAKGAG76), proximal heme-ligand signature sequence(350RLFSYPDTH358) and three catalytic amino acid residues(His71, Asn144 and Tyr354). Sequence comparison showed that the CAT deduced amino acid sequence of E. carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT m RNA was widely expressed in the hepatopancreas(highest), hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress,CAT and GPx m RNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response in E. carinicauda. All these results indicate that E. carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress.展开更多
Aim: To study the secretory activity and androgen regulation of glutathione peroxidase (GPx) in epithelial cell cultures from human epididymis. Methods: Tissue was obtained from patients undergoing therapeutic orchide...Aim: To study the secretory activity and androgen regulation of glutathione peroxidase (GPx) in epithelial cell cultures from human epididymis. Methods: Tissue was obtained from patients undergoing therapeutic orchidectomy for prostatic cancer. Epithelial cell cultures were obtained from the caput, corpus and cauda epididymides. Enzymatic activity was measured in conditioned media by colorimetric methods in absence or presence of 1, 10 or 100 nmol·L^-1 testosterone. The effect of 1 μmol·L^-1 flutamide was also evaluated. Results: GPx activity was higher in cultures from corpus and cauda than caput epididymidis. The presence of different concentrations of testosterone increase enzyme activity in cell cultures from all epididymal regions. Addition of flutamide reverses the androgen dependent increase of GPx activity. Conclusion: GPx activity is secreted from human epididymal cells in a region dependent manner and is regulated by androgens.展开更多
In order to enhance the glutathione peroxidase(GPX) catalytic activity of the selenium-containing single-chain variable fragments(Se-scFv), a novel human scFv was designed on the basis of the structure of human antibo...In order to enhance the glutathione peroxidase(GPX) catalytic activity of the selenium-containing single-chain variable fragments(Se-scFv), a novel human scFv was designed on the basis of the structure of human antibody and optimized via bioinformatics methods such as homologous sequence analysis, three-dimensional(3D) model building, binding-site analysis and docking. The DNA sequence of the new human scFv was synthesized and cloned into the expression vector pET22b(+), then the scFv protein was expressed in soluble form in Escherichia coli BL21(DE3) and purified by Ni2+-immobilized metal affinity chromatography(IMAC). The serine residue of scFv in the active site was converted into selenocysteine(Sec) with the chemical modification method, thus, the human Se-scFv with GPX activity was obtained. The GPX activity of the Se-scFv protein was characterized. Compared with other Se-scFv, the new human Se-scFv showed similar efficiency for catalyzing the reduction of hydrogen peroxide by glutathione. It exhibited pH and temperature dependent catalytic activity and a typical ping-pong kinetic mechanism.展开更多
To investigate the treatment effect of 2-selenium bridged β -cyclodextrin(2-SeCD),a GPX mimic,on the stroke of stroke-prone spontaneously hypertensive rats(SHRSP),fifty-two SHRSP of 8-week old were randomly divided i...To investigate the treatment effect of 2-selenium bridged β -cyclodextrin(2-SeCD),a GPX mimic,on the stroke of stroke-prone spontaneously hypertensive rats(SHRSP),fifty-two SHRSP of 8-week old were randomly divided into four groups A,B,C and control group D. The rats of groups A,B,C and D were given 1.0%-1.5% NaCl mass fraction as drinking fluid. After onset of stroke,groups A,B and C were given \{orally\} 16.05,160.5 and 1605 mg·kg -1 ·day -1 of 2-SeCD,respectively,and group D was given water for \{2 weeks.\} The clinical score of stroke,systolic blood pressure(SBP),survival time of rats were recorded and the histopathologic examinations of their brain and carotid artery were made after decapitation. The clinical scores of stroke after treatment with 160.5 mg·kg -1 ·day -1 (Group B) and 1605 mg·kg -1 ·day -1 (Group C) of 2-SeCD are 2.55±0.98 and 1.98±0.79,respectively,those are obviously lower than that of group D(3.41±0.83,p<0.01). The survival days in group B(10.0±8.6) and group C(14.4±7.9) are longer than that for group D(4.7±2.9,p<0.01). The electron microscope study showed that the endothelium of carotid artery was near to normal in group B and group C,while it was seriously injured in control group D and mildly injured in group A. 2-SeCD may effectively be used to treat the stroke for SHRSP.展开更多
The changes of sclenium metabolism, glutathione peroxidase activity and lipid peroxidescontent in the tissues of rats suffering from 30% TBSA full thickness scalding were observed in thefirst 7 days after injury. It w...The changes of sclenium metabolism, glutathione peroxidase activity and lipid peroxidescontent in the tissues of rats suffering from 30% TBSA full thickness scalding were observed in thefirst 7 days after injury. It was found that selenium content in the rat tissues decreased remarkably af-ter injury, which in turn resulted in serious reduction of glutathione peroxidasc activity and significantincrease of lipid peroxides in the scrum, crythrocytcs and liver. However the muscular tissue showedno significant changes. These facts imply that after burn injury, the body is in a state of selenium deficiency, the lossof selenium might be responsible for the reduction of anti - peroxidation ability of glutathioneperoxidase, and conscqucntly there is an increase of lipid peroxides in the tissues. Only the musculartissue is insensitive to lipid peroxidation. It is believed that the reduction of anti-peroxidation abilityof glutathione peroxidasc after bum injury might be one of the main causes to intensify, the injury re-suiting from free radicals.展开更多
Objective To oberve the change in blood glutathione peroxidase (GSH-Px) protein levels of residents in the low-selenium (Se) area by contrasting the blood GSH-Px protein level of the children in the Keshan disease are...Objective To oberve the change in blood glutathione peroxidase (GSH-Px) protein levels of residents in the low-selenium (Se) area by contrasting the blood GSH-Px protein level of the children in the Keshan disease area with those in the Kashin-Beck disease and non-endemic areas. Methods GSH-Px protein levels were measured by enzyme-linked immunosorbent assays (ELISA). The Se content and GSH-Px activity were assayed by the 2,3-diaminonaphthalene spectrofluorimetric method and glutathione reductase-coupled method respectively. Results ①The blood Se content and GSH-Px protein level of children in Keshan disease area (Moding) were significantly lower than those in Xi’an non-endemic area, however, there was no significant difference when compared with the low-Se non-endemic area; ②The blood Se content, GSH-Px activity and GSH-Px protein level of children in the Kashin-Beck disease area (Yulin) were significantly lower than those of children in two non-endemic areas and in the Keshan disease area; ③The blood Se content and GSH-Px activity were positively correlated to the GSH-Px protein level respectively. Conclusion These results indicate that the blood GSH-Px protein level is decreased in the low-Se residents. The Se status not only affects the GSH-Px activity but also regulate the GSH-Px protein level.展开更多
Background: Oxidative stress plays a crucial role in the pathogenesis and progression of many diseases, including cardiovascular disease (CVD) and diabetes mellitus. Oxidative stress results from an imbalance between ...Background: Oxidative stress plays a crucial role in the pathogenesis and progression of many diseases, including cardiovascular disease (CVD) and diabetes mellitus. Oxidative stress results from an imbalance between free radical formation and the protective antioxidant mechanisms. The latter mechanisms include superoxide dismutases (SODs) and glutathione peroxidases (GPx) that scavenge excessive ROS and protect cells against excess ROS production. The aim of current study was to determine the serum levels of SOD and serum GPx mRNA as well as the serum prooxidant-antioxidant balance in CVD patients. Method: A total of 103 subjects were recruited, with ≥50% stenosis (Angio+) or –). The expression levels of SOD and GPx in serum were measured using real time PCR. Biochemical-analyses (e.g., triglycerides;high-density lipo-protein cholesterol;low-density lipoprotein cholesterol;fasting-blood-glucose) were determined in all the subjects. Associations of SOD and GPx levels with biochemical and anthropometric characteristics were assessed together with evaluation of the serum pro-oxidant-antioxidant balance (PAB). Results: CVD subjects had a significantly higher level of fasting blood glucose (FBG), TC, LDL-C, TG and hs-CRP levels, as compared to control subjects. The level of serum PAB was significantly higher in the CVD group, 117.92 ± 35.51 and 110.65 ± 27.65 μg/dl in the angio– and angio+ groups, respectively compared to the control group (54.26 + 23.25). Additionally we observed that the SOD-3 level was higher in angio+ group versus control subjects. Conclusion: We have found that patients with CVD had a significantly higher prooxidant-antioxidant and SOD-3 levels. Further studies in larger multi-center setting are warranted to explore the value of emerging biomarker in CVD patients.展开更多
A novel mimic was synthesized by modifying hyaluronic acid (HA) with tellurium,whose function is similar to that of glutathione peroxidase (GPX). The structure of TeHA was characterized by means of IR and NMR,the targ...A novel mimic was synthesized by modifying hyaluronic acid (HA) with tellurium,whose function is similar to that of glutathione peroxidase (GPX). The structure of TeHA was characterized by means of IR and NMR,the target-Te was located at -CH2OH of the N-acetyl-D-glucosamine of HA. The H2O2 reducing activity of TeHA,by glutathione (GSH),was 163.6 U/μmol according to Wilson’s method. In contrast to other mimics,TeHA displayed the highest activity. Moreover,TeHA accepted many hydroperoxides as its substrates,such as H2O2,cumenyl hydroperoxide (CuOOH) and tert-butyl hydroperoxide (t-BuOOH),and CuOOH was the optimal substrate of TeHA. A ping-pong mechanism was observed in the steady-state kinetic studies of the reactions catalyzed by TeHA.展开更多
Phospholipid hydroperoxide glutathione peroxidase is an antioxidant enzyme that has the highest capability of reducing membrane-bound hydroperoxy lipids as compared to free organic and inorganic hydroperoxides amongst...Phospholipid hydroperoxide glutathione peroxidase is an antioxidant enzyme that has the highest capability of reducing membrane-bound hydroperoxy lipids as compared to free organic and inorganic hydroperoxides amongst the glutathione peroxidases.In this study,urea-induced effects on the inactivation and unfolding of a recombinant phospholipid hydroperoxide glutathione peroxidase(PHGPx)from Oryza sativa were investigated by means of circular dichroism and fluorescence spectroscopy.With the increase of urea concentration,the residual activity of OsPHGPx decreases correspondingly.When the urea concentration is above 5.0 mol/L,there was no residual activity.In addition,the observed changes in intrinsic tryptophan fluorescence,the binding of the hydrophobic fluorescence probe ANS,and the far UV CD describe a common dependence on the concentration of urea suggesting that the conformational features of the native OsPHGPx are lost in a highly cooperative single transition.The unfolding process comprises of three zones:the native base-line zone between 0 and 2.5 mol/L urea,the transition zone between 2.5 and 5.5 mol/L urea,and the denatured base-line zone above 5.5 mol/L urea.The transition zone has a midpoint at about 4.0 mol/L urea.展开更多
BACKGROUND:Several studies have demonstrated that low molecular weight heparin-superoxide dismutase (LMWH-SOD) conjugate may exhibit good neuroprotective effects on cerebral ischemia/reperfusion injury though anticoag...BACKGROUND:Several studies have demonstrated that low molecular weight heparin-superoxide dismutase (LMWH-SOD) conjugate may exhibit good neuroprotective effects on cerebral ischemia/reperfusion injury though anticoagulation,decreasing blood viscosity,having anti-inflammatory activity,and scavenging oxygen free radicals. OBJECTIVE: To investigate the intervention effects of LMWH-SOD conjugate on serum levels of nitric oxide (NO),glutathione peroxidase (GSH-Px),and myeloperoxidase (MPO) following cerebral ischemia/reperfusion injury. DESIGN,TIME AND SETTING: A randomized,controlled,and neurobiochemical experiment was performed at the Institute of Biochemical Pharmacy,School of Pharmaceutical Sciences,Shandong University between April and July 2004. MATERIALS: A total of 60 Mongolian gerbils of either gender were included in this study. Total cerebral ischemia/reperfusion injury was induced in 50 gerbils by occluding bilateral common carotid arteries. The remaining 10 gerbils received a sham-operation (sham-operated group). Kits of SOD,NO,and MPO were sourced from Nanjing Jiancheng Bioengineering Institute,China. LMWH,SOD,and LMWH-SOD conjugates were provided by Institute of Biochemistry and Biotechnique,Shandong University,China. METHODS: Fifty successful gerbil models of total cerebral ischemia/reperfusion injury were evenly randomized to five groups: physiological saline,LMWH-SOD,SOD,LMWH + SOD,and LMWH. At 2 minutes prior to ischemia,0.5 mL/65 g physiological saline,20 000 U/kg LMWH-SOD conjugate,20 000 U/kg SOD,a mixture of SOD (20 000 U/kg) and LMWH (LMWH dose calculated according to weight ratio,LMWH: SOD=23.6:51),and LMWH (dose as in the LMWH + SOD group) were administered through the femoral artery in each above-mentioned group,respectively. MAIN OUTCOME MEASURES: Serum levels of NO,MPO,and GSH-Px. RESULTS: Compared with 10 sham-operated gerbils,the cerebral ischemia/reperfusion injury gerbils exhibited decreased serum levels of GSH-Px and increased serum levels of NO and MPO (P<0.01). The serum level of GSH-Px was significantly upregulated in all groups,in particular in the LMWH-SOD group (P<0.01),compared with the physiological saline group (P<0.05-0.01). Following medical treatment,serum levels of NO and MPO were significantly downregulated in all groups,in particular in the LMWH-SOD group (P<0.01). Serum levels of GSH-Px,NO,and MPO in the LMWH-SOD group were close to those in the sham-operated group (P > 0.05). CONCLUSION: In cerebral ischemia/reperfusion injury,LMWH-SOD conjugate exhibits stronger neuroprotective effects on free radical scavenging,inflammation inhibition,and cytotoxicity inhibition than simple or combined application of LMWH and SOD by downregulating NO and MPO levels and upregulating the GSH-Px level.展开更多
Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial ac...Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial activity, resistance to insect attack, stress tolerance, and human anti-cancer effects. As a sulfur-containing compound, glutathione has a strong connection with GSLs biosynthesis as a sulfur donor or redox system, and exists in reduced(glutathione;GSH) and oxidized(glutathione disulfide;GSSG) forms. However, the mechanism of GSH regulating GSLs biosynthesis remainds unclear. Hence, the exogenous therapy to pakchoi under normal growth condition and sulfur deficiency condition were conducted in this work to explore the relevant mechanism. The results showed that exogenous application of buthionine sulfoximine, an inhibitor of GSH synthesis, decreased the transcript levels of GSLs synthesis-related genes and transcription factors, as well as sulfur assimilation-related genes under the normal growth condition. Application of exogenous GSH inhibited the expression of GSLs synthesis-and sulfur assimilation-related genes under the normal condition, while the GSLs biosynthesis and the sulfur assimilation pathway were activated by exogenous application of GSH when the content of GSH in vivo of plants decreased owing to sulfur deficiency. Moreover,exogenous application of GSSG increased the transcript levels of GSLs synthesis-and sulfur assimilation-related genes under the normal growth condition and under sulfur deficiency. The present work provides new insights into the molecular mechanisms of GSLs biosynthesis underlying glutathione regulation.展开更多
The molecular basis for adaptations to extreme environments can now be understood by interrogating the everincreasing number of sequenced genomes.Mammals such as cetaceans,bats,and highland species can protect themsel...The molecular basis for adaptations to extreme environments can now be understood by interrogating the everincreasing number of sequenced genomes.Mammals such as cetaceans,bats,and highland species can protect themselves from oxidative stress,a disruption in the balance of reactive oxygen species,which results in oxidative injury and cell damage.Here,we consider the evolution of the glutathione peroxidase(GPX)family of antioxidant enzymes by interrogating publicly available genome data from 70 mammalian species from all major clades.We identified 8 GPX subclasses ubiquitous to all mammalian groups.Mammalian GPX gene families resolved into the GPX4/7/8 and GPX1/2/3/5/6 groups and are characterized by several instances of gene duplication and loss,indicating a dynamic process of gene birth and death in mammals.Seven of the eight GPX subfamilies(all but GPX7)were under positive selection,with the residues under selection located at or close to active sites or at the dimer interface.We also reveal evidence of a correlation between ecological niches(e.g.high oxidative stress)and the divergent selection and gene copy number of GPX subclasses.Notably,a convergent expansion of GPX1 was observed in several independent lineages of mammals under oxidative stress and may be important for avoiding oxidative damage.Collectively,this study suggests that the GPX gene family has shaped the adaption of mammals to stressful environments.展开更多
Selenium is an essential nutritional element for human,animal and some microorganisms.In human and animal bodies it acts as a component of glutathione peroxidase (GSH-Px) to break chain reaction of lipid peroxidation ...Selenium is an essential nutritional element for human,animal and some microorganisms.In human and animal bodies it acts as a component of glutathione peroxidase (GSH-Px) to break chain reaction of lipid peroxidation by catalyzing perox-展开更多
基金Supported by National Natural Science Foundation of China,No.82060123Doctoral Start-up Fund of Affiliated Hospital of Guizhou Medical University,No.gysybsky-2021-28+1 种基金Fund Project of Guizhou Provincial Science and Technology Department,No.[2020]1Y299Guizhou Provincial Health Commission,No.gzwjk2019-1-082。
文摘BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple biological processes,including cellular senescence,apoptosis,sugar and lipid metabolism,oxidative stress,and inflammation.AIM To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms.METHODS This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)testing.C57BL/6 mice were also intraperitoneally pretreated with SIRT1,p53,or glutathione peroxidase 4(GPX4)inducers and inhibitors and injected with lipopolysaccharide(LPS)/D-galactosamine(D-GalN)to induce ALF.Gasdermin D(GSDMD)^(-/-)mice were used as an experimental group.Histological changes in liver tissue were monitored by hematoxylin and eosin staining.ALT,AST,glutathione,reactive oxygen species,and iron levels were measured using commercial kits.Ferroptosis-and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction.SIRT1,p53,and GSDMD were assessed by immunofluorescence analysis.RESULTS Serum AST and ALT levels were elevated in patients with ALF.SIRT1,solute carrier family 7a member 11(SLC7A11),and GPX4 protein expression was decreased and acetylated p5,p53,GSDMD,and acyl-CoA synthetase long-chain family member 4(ACSL4)protein levels were elevated in human ALF liver tissue.In the p53 and ferroptosis inhibitor-treated and GSDMD^(-/-)groups,serum interleukin(IL)-1β,tumour necrosis factor alpha,IL-6,IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated.In mice with GSDMD knockout,p53 was reduced,GPX4 was increased,and ferroptotic events(depletion of SLC7A11,elevation of ACSL4,and iron accumulation)were detected.In vitro,knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels,the cytostatic rate,and GSDMD expression,restoring SLC7A11 depletion.Moreover,SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group,accompanied by reduced p53,GSDMD,and ACSL4,and increased SLC7A11 and GPX4.Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalNinduced in vitro and in vivo models.CONCLUSION SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF.
文摘This study aims to analyze the clinical significance and mechanism of nuclear factor erythroid 2-related factor 2(NRF2)and glutathione peroxidase 4(GPX4)in primary hepatic carcinoma(PHC).Methods:The expression of NRF2 and GPX4 in peripheral blood of patients with PHC was determined to analyze the diagnostic value of the two combined for PHC.The prognostic significance of NRF2 and GPX4 was evaluated by 3-year followup.Human liver epithelial cells THLE-2 and human hepatocellular carcinoma cells HepG2 were purchased,and the expression of NRF2 and GPX4 in the cells was determined.NRF2 and GPX4 aberrant expression vectors were constructed and transfected into HepG2,and changes in cell proliferation and invasion capabilities were observed.Results:The expression of NRF2 and GPX4 in patients with PHC was higher than that in patients with LC or VH(p<0.05),and the two indicators combined was excellent in diagnosing PHC.Moreover,patients with high expression of NRF2 and GPX4 had a higher risk of death(p<0.05).In in vitro experiments,both NRF2 and GPX4 expression was elevated in HepG2(p<0.05).HepG2 activity was enhanced by increasing the expression of the two,vice versa(p<0.05).Conclusion:NRF2 and GPX4 combined is excellent in diagnosing PHC,and promotes the malignant development of PHC.
文摘Organoseleniums are a class of compounds attracting attention across the globe owing to their Glutathione peroxidase(GPx)mimicry,which confers on them a strong antioxidant activity.Diphenyl diselenide(DPDS)is an Organoselenium whose GPx mimetic property has been suggested to rely on the oxidation of non-protein or protein thiols critical to the activities of some sulfhydryl enzymes.This study,therefore investigated the GPx mimic/antioxidant property of DPDS as well as the role of thiols of two key sulfhydryl enzymes,cerebral Na^(+)/K^(+)-ATPase(sodium pump)and hepatic delta-aminolevulinic acid dehydratase(δ-ALAD)in the GPx mimicry of DPDS.Albino Wistar rats were euthanized,and the liver and brain were removed and used to assay for the effect of DPDS on lipid peroxidation induced by two prooxidants[Fe2^(+)(10μM)and H2O2,(1 mM)]as well as the activities of the sulfhydryl enzymes.The results revealed that DPDS profoundly(P<0.05)counteracted Fe2^(+)and H2O2-induced lipid peroxidation in the rats’hepatic and cerebral tissues.Furthermore,the results of assay systems for lipid peroxidation and sodium pump revealed that DPDS inhibited Na^(+)/K^(+)-ATPase and lipid peroxidation in the brain tissue homogenates in the same reaction system.A similar result was obtained in the assay system for lipid peroxidation and hepaticδ-ALAD as DPDS simultaneously inhibited the enzyme’s activity and lipid peroxidation.This suggests that the GPx mimetic property of DPDS may be linked to the enzymes’loss of activity,which further validates the suggestions that the enzymes’inhibition,as well as the antioxidant action of DPDS,rely on the oxidation of critical thiols of the enzymes.However,the GPx mimicry of DPDS should be investigated in the presence of thiol-blocking or oxidizing agents in biological systems in order to further ascertain the role of protein thiols.
文摘Glutathione peroxidase (GPx) is an antioxidant that plays an important role in the maintenance of male fertility. The aim of this study was to compare the profile of enzymatic activity of glutathione peroxidase in the seminal plasma of normozoosperm and those of pathological sperm. Thus, the activity of glutathione peroxidase was determined in the seminal plasma of 20 normozoosperms, 9 azoosperms and 31 oligoasthenoteratozoosperms. It was 37.58 ± 3.14 U/L in normozoosperms, 39.39 ± 2.27 U/L in oligoasthenoteratozoosperms, and 29.77 ± 2.62 U/L in azoosperms. The mean GPx enzyme activity of normozoosperms did not differ significantly from that of oligoasthenoteratozoosperms and azoosperms. In contrast, comparison of enzyme activity between abnormal sperms gave a significant difference. This study showed that glutathione peroxidase enzymatic activity is not related to sperm quality.
基金National Key Research and Development Program of China(2017YFC1700404)Natural Science Foundation of China(81873209)+8 种基金Natural Science Foundation of China(U1801284)Natural Science Foundation of China(81903821)Natural Science Foundation of China(81973718)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Y036)GDUPS(2019),Fun⁃damental Research Funds for the Central Univer⁃sities(21620448)Natural Science Foundation of Guangdong Province(2019A 1515010909)Nat⁃ural Science Foundation of Guangdong Prov⁃ince(2021A1515011297)Science and Tech⁃nology Program of Guangzhou(201903010062)Science and Technology Program of Guang⁃zhou(907158833068),and the Innovation Team Project of Guangdong Provincial Department of Education(2020KCXT D003)。
文摘OBJECTIVE Intracellular aggre⁃gation ofα-synuclein(SNCA)is one of the core pathological features of neurodegenerative disor⁃ders including Parkinson disease,whilst the detailed mechanism for consequently neuron loss has not been fully illustrated.Since the altered phospholipid homeostasis has been suggested to play a role in synucleinopathy,this study aims to depict the fully-featured status of phospholip⁃ids and the targets reposingα-synuclein-related neurotoxicity.METHODS SNCAA53T transgenic mice were utilized as the model of Parkinson disease.Behavioral tests including pole test,rotarod test and gait analysis were conducted to assess the motor features of Parkinsonism.Tyro⁃sine hydroxylase were determined by immunohis⁃tochemistry.Glutathione,dopamine,3,4-dihy⁃droxyphenylacetic acid and homovanillic acid were determined by HPLC-ECD analysis.Assess⁃ment of lipid peroxidation included MDA assay and Liperfluo staining.Phospholipid-omics was analyzed based on LC-MS/MS.Investigation on mechanism was relied on Western blotting and qPCR assay.The injection of AAV into midbrain was achieved by ultra-micro injection pump to obtain the target genotype.RESULTS SNCAA53T transgenic mice displayed progres⁃sively deteriorated motor coordination functions and the mechanisms were related with lipid per⁃oxidation and ferroptosis,which might help to explain the parkinsonism.These hydroperoxides were observed on plasm membrane and were further characterized by LC-MS/MS-based phos⁃pholipid-omics analysis.α-synucleinA53T trans⁃genic mice displayed distinct patterns of phos⁃pholipid peroxidation in midbrain regions com⁃pared to wild type littermates.Among different subtypes of oxidized phospholipids,oxidative phosphatidylcholine(PC-ox)was more promi⁃nently elevated.Phospholipid peroxidation is believed as a biomarker of ferroptosis,which is largely a specialized death program caused by insufficiency of glutathione peroxidase-4(GPX4),the only known enzyme that can reduce lipid hydroperoxides within biological membranes.The deficiency of Gpx4 was demonstrated to be responsible forα-synuclein-induced lipid peroxi⁃dation,and the cell lines and mouse models underwent genetic Gpx4 downregulation showed exacerbated dopaminergic neuron loss and par⁃kinsonism.On the other hand,the potentiation of Gpx4 expression remarkably inhibited dopami⁃nergic ferroptotic death and behavioral deficits in a mouse model with synucleinopathy.CONCLU⁃SION A cellular pathway that Gpx4 deficit-medi⁃ated phospholipid peroxidation and behavioral consequence participated in synucleinopathy,suggesting a potential strategy targeting Gpx4 to alleviate PD symptoms.
文摘The advantages of measuring hepatic oxidative status in liver biopsy are that it helps in diagnosis of hepatic dysfunction, reflects the degree of deterioration in the liver tissues, and helps to determine the severity of hepatic injury. We aimed to study the oxidative stress state in children with chronic hepatitis by using indirect approach in which antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) are determined in the liver tissue. The present study included 21 children and adolescents (12 males, 9 females) suffering from chronic hepatitis. Patients were selected from the Hepatology Clinic, New Children’s Hospital, Cairo University from November 2006 till 2009 and compared with a group of 7 children who happened to have incidental normal liver biopsy. Children with chronic hepatitis had mean age 8.12 ± 1.15 years. It was further subdivided into 2 subgroups: chronic viral heaptitis (n = 13) and cryptogenic hepatitis (n = 8). GPX, SOD and CAT levels were measured in fresh liver tissue (cell free homogenates) using ELISA. In chronic hepatitis group;there was a significant increase in the hepatic GPX activity (38.59 ± 35.82 nmol/min/ml) as compared to the control group (10.62 ± 6.68 nmol/min/ml). Also a significant correlation was observed between SOD and both ALT (r = 0.87, p < 0.05) and AST (r = 0.74, p < 0.05). GPX correlated with ALT (r = 0.80, p < 0.05) level in the chronic viral hepatitis subgroup. Our findings suggest that oxidative stress could play a role in the pathogenesis of chronic hepatitis. These preliminary results are encouraging to conduct more extensive clinical studies combining antioxidant therapy with various treatments.
基金The Modern Agro-industry Technology Research System under contract No.CARS-47the National High-tech R&D Program(863 Program) of China under contract No.2012AA10A409+1 种基金the Special Fund for Independent Innovation of Shandong Province under contract No.2013CX80202the Special Fund for Agro-scientific Research in the Public Interest under contract No.201103034
文摘Catalase(CAT) and selenium-dependent glutathione peroxidase(Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H2O2. The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawn Exopalaemon carinicauda in response to low salinity stress. A complementary DNA(cDNA) containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction(RT-PCR) and rapid amplification of cDNA ends. The full-length cDNA of CAT(2 649 bp) contains a 5'-untranslated region(UTR) of 78 bp, a 3'- UTR of1 017 bp, with a poly(A) tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature(60FDRERIPERVVHAKGAG76), proximal heme-ligand signature sequence(350RLFSYPDTH358) and three catalytic amino acid residues(His71, Asn144 and Tyr354). Sequence comparison showed that the CAT deduced amino acid sequence of E. carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT m RNA was widely expressed in the hepatopancreas(highest), hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress,CAT and GPx m RNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response in E. carinicauda. All these results indicate that E. carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress.
文摘Aim: To study the secretory activity and androgen regulation of glutathione peroxidase (GPx) in epithelial cell cultures from human epididymis. Methods: Tissue was obtained from patients undergoing therapeutic orchidectomy for prostatic cancer. Epithelial cell cultures were obtained from the caput, corpus and cauda epididymides. Enzymatic activity was measured in conditioned media by colorimetric methods in absence or presence of 1, 10 or 100 nmol·L^-1 testosterone. The effect of 1 μmol·L^-1 flutamide was also evaluated. Results: GPx activity was higher in cultures from corpus and cauda than caput epididymidis. The presence of different concentrations of testosterone increase enzyme activity in cell cultures from all epididymal regions. Addition of flutamide reverses the androgen dependent increase of GPx activity. Conclusion: GPx activity is secreted from human epididymal cells in a region dependent manner and is regulated by androgens.
基金Supported by the National Natural Science Foundation of China(No.30970608)the Applicative Technological Project of Bureau of Science and Technology of Changchun City, China(No.2009045)+1 种基金the Development and Planning Major Program of Jilin Provincial Science and Technology Department, China(No.20100948)the Innovation Method Fund of China (No.2008IM040800)
文摘In order to enhance the glutathione peroxidase(GPX) catalytic activity of the selenium-containing single-chain variable fragments(Se-scFv), a novel human scFv was designed on the basis of the structure of human antibody and optimized via bioinformatics methods such as homologous sequence analysis, three-dimensional(3D) model building, binding-site analysis and docking. The DNA sequence of the new human scFv was synthesized and cloned into the expression vector pET22b(+), then the scFv protein was expressed in soluble form in Escherichia coli BL21(DE3) and purified by Ni2+-immobilized metal affinity chromatography(IMAC). The serine residue of scFv in the active site was converted into selenocysteine(Sec) with the chemical modification method, thus, the human Se-scFv with GPX activity was obtained. The GPX activity of the Se-scFv protein was characterized. Compared with other Se-scFv, the new human Se-scFv showed similar efficiency for catalyzing the reduction of hydrogen peroxide by glutathione. It exhibited pH and temperature dependent catalytic activity and a typical ping-pong kinetic mechanism.
文摘To investigate the treatment effect of 2-selenium bridged β -cyclodextrin(2-SeCD),a GPX mimic,on the stroke of stroke-prone spontaneously hypertensive rats(SHRSP),fifty-two SHRSP of 8-week old were randomly divided into four groups A,B,C and control group D. The rats of groups A,B,C and D were given 1.0%-1.5% NaCl mass fraction as drinking fluid. After onset of stroke,groups A,B and C were given \{orally\} 16.05,160.5 and 1605 mg·kg -1 ·day -1 of 2-SeCD,respectively,and group D was given water for \{2 weeks.\} The clinical score of stroke,systolic blood pressure(SBP),survival time of rats were recorded and the histopathologic examinations of their brain and carotid artery were made after decapitation. The clinical scores of stroke after treatment with 160.5 mg·kg -1 ·day -1 (Group B) and 1605 mg·kg -1 ·day -1 (Group C) of 2-SeCD are 2.55±0.98 and 1.98±0.79,respectively,those are obviously lower than that of group D(3.41±0.83,p<0.01). The survival days in group B(10.0±8.6) and group C(14.4±7.9) are longer than that for group D(4.7±2.9,p<0.01). The electron microscope study showed that the endothelium of carotid artery was near to normal in group B and group C,while it was seriously injured in control group D and mildly injured in group A. 2-SeCD may effectively be used to treat the stroke for SHRSP.
文摘The changes of sclenium metabolism, glutathione peroxidase activity and lipid peroxidescontent in the tissues of rats suffering from 30% TBSA full thickness scalding were observed in thefirst 7 days after injury. It was found that selenium content in the rat tissues decreased remarkably af-ter injury, which in turn resulted in serious reduction of glutathione peroxidasc activity and significantincrease of lipid peroxides in the scrum, crythrocytcs and liver. However the muscular tissue showedno significant changes. These facts imply that after burn injury, the body is in a state of selenium deficiency, the lossof selenium might be responsible for the reduction of anti - peroxidation ability of glutathioneperoxidase, and conscqucntly there is an increase of lipid peroxides in the tissues. Only the musculartissue is insensitive to lipid peroxidation. It is believed that the reduction of anti-peroxidation abilityof glutathione peroxidasc after bum injury might be one of the main causes to intensify, the injury re-suiting from free radicals.
文摘Objective To oberve the change in blood glutathione peroxidase (GSH-Px) protein levels of residents in the low-selenium (Se) area by contrasting the blood GSH-Px protein level of the children in the Keshan disease area with those in the Kashin-Beck disease and non-endemic areas. Methods GSH-Px protein levels were measured by enzyme-linked immunosorbent assays (ELISA). The Se content and GSH-Px activity were assayed by the 2,3-diaminonaphthalene spectrofluorimetric method and glutathione reductase-coupled method respectively. Results ①The blood Se content and GSH-Px protein level of children in Keshan disease area (Moding) were significantly lower than those in Xi’an non-endemic area, however, there was no significant difference when compared with the low-Se non-endemic area; ②The blood Se content, GSH-Px activity and GSH-Px protein level of children in the Kashin-Beck disease area (Yulin) were significantly lower than those of children in two non-endemic areas and in the Keshan disease area; ③The blood Se content and GSH-Px activity were positively correlated to the GSH-Px protein level respectively. Conclusion These results indicate that the blood GSH-Px protein level is decreased in the low-Se residents. The Se status not only affects the GSH-Px activity but also regulate the GSH-Px protein level.
文摘Background: Oxidative stress plays a crucial role in the pathogenesis and progression of many diseases, including cardiovascular disease (CVD) and diabetes mellitus. Oxidative stress results from an imbalance between free radical formation and the protective antioxidant mechanisms. The latter mechanisms include superoxide dismutases (SODs) and glutathione peroxidases (GPx) that scavenge excessive ROS and protect cells against excess ROS production. The aim of current study was to determine the serum levels of SOD and serum GPx mRNA as well as the serum prooxidant-antioxidant balance in CVD patients. Method: A total of 103 subjects were recruited, with ≥50% stenosis (Angio+) or –). The expression levels of SOD and GPx in serum were measured using real time PCR. Biochemical-analyses (e.g., triglycerides;high-density lipo-protein cholesterol;low-density lipoprotein cholesterol;fasting-blood-glucose) were determined in all the subjects. Associations of SOD and GPx levels with biochemical and anthropometric characteristics were assessed together with evaluation of the serum pro-oxidant-antioxidant balance (PAB). Results: CVD subjects had a significantly higher level of fasting blood glucose (FBG), TC, LDL-C, TG and hs-CRP levels, as compared to control subjects. The level of serum PAB was significantly higher in the CVD group, 117.92 ± 35.51 and 110.65 ± 27.65 μg/dl in the angio– and angio+ groups, respectively compared to the control group (54.26 + 23.25). Additionally we observed that the SOD-3 level was higher in angio+ group versus control subjects. Conclusion: We have found that patients with CVD had a significantly higher prooxidant-antioxidant and SOD-3 levels. Further studies in larger multi-center setting are warranted to explore the value of emerging biomarker in CVD patients.
文摘A novel mimic was synthesized by modifying hyaluronic acid (HA) with tellurium,whose function is similar to that of glutathione peroxidase (GPX). The structure of TeHA was characterized by means of IR and NMR,the target-Te was located at -CH2OH of the N-acetyl-D-glucosamine of HA. The H2O2 reducing activity of TeHA,by glutathione (GSH),was 163.6 U/μmol according to Wilson’s method. In contrast to other mimics,TeHA displayed the highest activity. Moreover,TeHA accepted many hydroperoxides as its substrates,such as H2O2,cumenyl hydroperoxide (CuOOH) and tert-butyl hydroperoxide (t-BuOOH),and CuOOH was the optimal substrate of TeHA. A ping-pong mechanism was observed in the steady-state kinetic studies of the reactions catalyzed by TeHA.
基金Supported by the National Basic Research Program of China(No.2006CB101706)the Hi-tech Research and DevelopmentProgram of China(No.2007AA100604)the National Natural Science Foundation of China(Nos.30170080and39770078).
文摘Phospholipid hydroperoxide glutathione peroxidase is an antioxidant enzyme that has the highest capability of reducing membrane-bound hydroperoxy lipids as compared to free organic and inorganic hydroperoxides amongst the glutathione peroxidases.In this study,urea-induced effects on the inactivation and unfolding of a recombinant phospholipid hydroperoxide glutathione peroxidase(PHGPx)from Oryza sativa were investigated by means of circular dichroism and fluorescence spectroscopy.With the increase of urea concentration,the residual activity of OsPHGPx decreases correspondingly.When the urea concentration is above 5.0 mol/L,there was no residual activity.In addition,the observed changes in intrinsic tryptophan fluorescence,the binding of the hydrophobic fluorescence probe ANS,and the far UV CD describe a common dependence on the concentration of urea suggesting that the conformational features of the native OsPHGPx are lost in a highly cooperative single transition.The unfolding process comprises of three zones:the native base-line zone between 0 and 2.5 mol/L urea,the transition zone between 2.5 and 5.5 mol/L urea,and the denatured base-line zone above 5.5 mol/L urea.The transition zone has a midpoint at about 4.0 mol/L urea.
文摘BACKGROUND:Several studies have demonstrated that low molecular weight heparin-superoxide dismutase (LMWH-SOD) conjugate may exhibit good neuroprotective effects on cerebral ischemia/reperfusion injury though anticoagulation,decreasing blood viscosity,having anti-inflammatory activity,and scavenging oxygen free radicals. OBJECTIVE: To investigate the intervention effects of LMWH-SOD conjugate on serum levels of nitric oxide (NO),glutathione peroxidase (GSH-Px),and myeloperoxidase (MPO) following cerebral ischemia/reperfusion injury. DESIGN,TIME AND SETTING: A randomized,controlled,and neurobiochemical experiment was performed at the Institute of Biochemical Pharmacy,School of Pharmaceutical Sciences,Shandong University between April and July 2004. MATERIALS: A total of 60 Mongolian gerbils of either gender were included in this study. Total cerebral ischemia/reperfusion injury was induced in 50 gerbils by occluding bilateral common carotid arteries. The remaining 10 gerbils received a sham-operation (sham-operated group). Kits of SOD,NO,and MPO were sourced from Nanjing Jiancheng Bioengineering Institute,China. LMWH,SOD,and LMWH-SOD conjugates were provided by Institute of Biochemistry and Biotechnique,Shandong University,China. METHODS: Fifty successful gerbil models of total cerebral ischemia/reperfusion injury were evenly randomized to five groups: physiological saline,LMWH-SOD,SOD,LMWH + SOD,and LMWH. At 2 minutes prior to ischemia,0.5 mL/65 g physiological saline,20 000 U/kg LMWH-SOD conjugate,20 000 U/kg SOD,a mixture of SOD (20 000 U/kg) and LMWH (LMWH dose calculated according to weight ratio,LMWH: SOD=23.6:51),and LMWH (dose as in the LMWH + SOD group) were administered through the femoral artery in each above-mentioned group,respectively. MAIN OUTCOME MEASURES: Serum levels of NO,MPO,and GSH-Px. RESULTS: Compared with 10 sham-operated gerbils,the cerebral ischemia/reperfusion injury gerbils exhibited decreased serum levels of GSH-Px and increased serum levels of NO and MPO (P<0.01). The serum level of GSH-Px was significantly upregulated in all groups,in particular in the LMWH-SOD group (P<0.01),compared with the physiological saline group (P<0.05-0.01). Following medical treatment,serum levels of NO and MPO were significantly downregulated in all groups,in particular in the LMWH-SOD group (P<0.01). Serum levels of GSH-Px,NO,and MPO in the LMWH-SOD group were close to those in the sham-operated group (P > 0.05). CONCLUSION: In cerebral ischemia/reperfusion injury,LMWH-SOD conjugate exhibits stronger neuroprotective effects on free radical scavenging,inflammation inhibition,and cytotoxicity inhibition than simple or combined application of LMWH and SOD by downregulating NO and MPO levels and upregulating the GSH-Px level.
基金funded by the National Natural Science Foundation of China (Grant Nos.31972394 and 31501748)。
文摘Glucosinolates(GSLs) are a group of nitrogen-and sulfur-containing secondary metabolites, synthesized primarily in members of the Brassicaceae family, that play an important role in food flavor, plant antimicrobial activity, resistance to insect attack, stress tolerance, and human anti-cancer effects. As a sulfur-containing compound, glutathione has a strong connection with GSLs biosynthesis as a sulfur donor or redox system, and exists in reduced(glutathione;GSH) and oxidized(glutathione disulfide;GSSG) forms. However, the mechanism of GSH regulating GSLs biosynthesis remainds unclear. Hence, the exogenous therapy to pakchoi under normal growth condition and sulfur deficiency condition were conducted in this work to explore the relevant mechanism. The results showed that exogenous application of buthionine sulfoximine, an inhibitor of GSH synthesis, decreased the transcript levels of GSLs synthesis-related genes and transcription factors, as well as sulfur assimilation-related genes under the normal growth condition. Application of exogenous GSH inhibited the expression of GSLs synthesis-and sulfur assimilation-related genes under the normal condition, while the GSLs biosynthesis and the sulfur assimilation pathway were activated by exogenous application of GSH when the content of GSH in vivo of plants decreased owing to sulfur deficiency. Moreover,exogenous application of GSSG increased the transcript levels of GSLs synthesis-and sulfur assimilation-related genes under the normal growth condition and under sulfur deficiency. The present work provides new insights into the molecular mechanisms of GSLs biosynthesis underlying glutathione regulation.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant no.31900310 to R.T.)the Key Project of the National Natural Science Foundation of China(NSFC)(Grant no.31630071 to G.Y.)+1 种基金the National Natural Science Foundation of China(NSFC)(Grant no.31950410545 to I.S.)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘The molecular basis for adaptations to extreme environments can now be understood by interrogating the everincreasing number of sequenced genomes.Mammals such as cetaceans,bats,and highland species can protect themselves from oxidative stress,a disruption in the balance of reactive oxygen species,which results in oxidative injury and cell damage.Here,we consider the evolution of the glutathione peroxidase(GPX)family of antioxidant enzymes by interrogating publicly available genome data from 70 mammalian species from all major clades.We identified 8 GPX subclasses ubiquitous to all mammalian groups.Mammalian GPX gene families resolved into the GPX4/7/8 and GPX1/2/3/5/6 groups and are characterized by several instances of gene duplication and loss,indicating a dynamic process of gene birth and death in mammals.Seven of the eight GPX subfamilies(all but GPX7)were under positive selection,with the residues under selection located at or close to active sites or at the dimer interface.We also reveal evidence of a correlation between ecological niches(e.g.high oxidative stress)and the divergent selection and gene copy number of GPX subclasses.Notably,a convergent expansion of GPX1 was observed in several independent lineages of mammals under oxidative stress and may be important for avoiding oxidative damage.Collectively,this study suggests that the GPX gene family has shaped the adaption of mammals to stressful environments.
文摘Selenium is an essential nutritional element for human,animal and some microorganisms.In human and animal bodies it acts as a component of glutathione peroxidase (GSH-Px) to break chain reaction of lipid peroxidation by catalyzing perox-
