Ferroptosis is a form of regulated cell death, characterized by excessive membrane lipid peroxidation in an iron-and ROS-dependent manner. Celastrol, a natural bioactive triterpenoid extracted from Tripterygium wilfor...Ferroptosis is a form of regulated cell death, characterized by excessive membrane lipid peroxidation in an iron-and ROS-dependent manner. Celastrol, a natural bioactive triterpenoid extracted from Tripterygium wilfordii, shows effective anti-fibrotic and anti-inflammatory activities in multiple hepatic diseases. However, the exact molecular mechanisms of action and the direct protein targets of celastrol in the treatment of liver fibrosis remain largely elusive. Here, we discover that celastrol exerts anti-fibrotic effects via promoting the production of reactive oxygen species(ROS) and inducing ferroptosis in activated hepatic stellate cells(HSCs). By using activity-based protein profiling(ABPP) in combination with bio-orthogonal click chemistry reaction and cellular thermal shift assay(CETSA), we show that celastrol directly binds to peroxiredoxins(PRDXs), including PRDX1, PRDX2, PRDX4 and PRDX6,through the active cysteine sites, and inhibits their anti-oxidant activities. Celastrol also targets to heme oxygenase 1(HO-1) and upregulates its expression in activated-HSCs. Knockdown of PRDX1, PRDX2,PRDX4, PRDX6 or HO-1 in HSCs, to varying extent, elevated cellular ROS levels and induced ferroptosis. Taken together, our findings reveal the direct protein targets and molecular mechanisms via which celastrol ameliorates hepatic fibrosis, thus supporting the further development of celastrol as a promising therapeutic agent for liver fibrosis.展开更多
Reactive oxygen species (ROS) are produced under oxidative stress, such as high oxygen concentration and during the metabolic consumption of oxygen molecules. Male reproductive tissues appear to be continuously expose...Reactive oxygen species (ROS) are produced under oxidative stress, such as high oxygen concentration and during the metabolic consumption of oxygen molecules. Male reproductive tissues appear to be continuously exposed to ROS produced by active metabolism. In addition, spermatozoa must pass through a high oxygen environment during the mating process. Thus, to maintain viable reproductive ability, a protective mechanism against oxidative stress is of importance. Here, we overview our current understanding of the cooperative function of antioxidative and redox systems that are involved in male fertility. Superoxide dismutase and glutathione peroxidase are major enzymes that scavenge harmful ROS in male reproductive organs. In turn, glutathione and thioredoxin systems constitute the main redox systems that repair oxidized and damaged molecules and also play a role in regulating a variety of cellular functions. While glutathione functions as an antioxidant by donating electrons to glutathione peroxidase and thioredoxin donates electrons to peroxiredoxin as a counterpart of glutathione peroxidase. In addition, aldo-keto reductases, which detoxify carbonyl compounds produced by oxidative stress, are present at high levels in the epithelia of the genital tract and Sertoli cells of the testis. Since these systems are involved in cross-talk, a comprehensive understanding will be required to maintain the physiological functions of male reproductive system.展开更多
Background β2-adrenoceptor （β2AR） desensitization is a common problem in clinical practice, β2AR desensitization proceeds by at least such three mechanisms as heterologous desensitization, homologous desensitizat...Background β2-adrenoceptor （β2AR） desensitization is a common problem in clinical practice, β2AR desensitization proceeds by at least such three mechanisms as heterologous desensitization, homologous desensitization and a kind of agonist-induced rapid phosphorylation by a variety of serine/threonine kinases. It is not clear whether there are other mechanisms, This study aimed to investigate potential mechanisms of β2AR desensitization.Methods Twenty-four BALB/c （6-8 weeks old） mice were divided into three groups, which is, group A, phosphate buffered saline （PBS）-treated; group B, ovalbumin （OVA）-induced; and group C, salbutamol-treated. Inflammatory cell counts, cytokine concentrations of bronchoalveolar lavage fluid （BALF）, pathological sections, total serum IgE, airway responsiveness, membrane receptor numbers and total amount of β2AR were observed. Asthmatic mouse model and β2AR desensitization asthmatic mouse model were established. Groups B and C were selected for two-dimensional gel electrophoresis （2DE） analysis so as to find key protein spots related to β2AR desensitization.Results Asthmatic mouse model and β2AR desensitization asthmatic mouse model were verified by inflammatory cell count, cytokine concentration of BALF, serum IgE level, airway hyperreactivity measurement, radioligand receptor binding assay, Western blot analysis, and pathologic examination. Then the two groups （groups B and C） were subjected to 2DE. Two key protein spots associated with β2AR desensitization, Rho GDP-dissociation inhibitor 2 （RhoGDl2） and peroxiredoxin 5, were found by comparative proteomics （2DE and mass spectrum analysis）.Conclusion Oxidative stress and small G protein regulators may play an important role in the process of β2AR desensitization.v展开更多
Oxidative stress is one of the major causes of male infertility; it damages spermatogenic cells, the spermatogenic process and sperm function. Recent advances in redox biology have revealed the signalling role of reac...Oxidative stress is one of the major causes of male infertility; it damages spermatogenic cells, the spermatogenic process and sperm function. Recent advances in redox biology have revealed the signalling role of reactive oxygen species （ROS） that are generated by cells. While highly reactive oxidants, such as the hydroxyl radical, exert largely deleterious effects, hydrogen peroxide can feasibly serve as a signal mediator because it is moderately reactive and membrane permeable and because it can oxidize only limited numbers of functional groups of biological molecules. The amino acid side chain most sensitive to oxidation is cysteine sulphydryl, which is commonly involved in the catalysis of some enzymes. Although the reactivity of cysteine sulphhydryl is not very high in ordinary proteins, some phosphatases possess a highly reactive sulphydryl group at their catalytic centre and are thereby oxidatively inactivated by transiently elevated hydrogen peroxide levels after extracellular stimuli and under certain environmental conditions. Peroxiredoxins, in turn, show moderate hydrogen peroxide-reducing activity, and their role in the modulation of ROS-mediated signal transduction in ordinary cells, mediated by protecting phosphatases from oxidative inactivation, has attracted much attention. Although knowledge of the signalling role of ROS in the male reproductive system is limited at present, its significance is becoming a focal issue. Here, we present a review of the emerging signalling role of hydrogen peroxide in testes.展开更多
In plants, the highly abundant 2-cysteine peroxiredoxin （2-CysPrx） is associated with the chloroplast and involved in protecting photosynthesis. This work addresses the multiple interactions of the 2-CysPrx in the c...In plants, the highly abundant 2-cysteine peroxiredoxin （2-CysPrx） is associated with the chloroplast and involved in protecting photosynthesis. This work addresses the multiple interactions of the 2-CysPrx in the chloroplast, which depend on its redox state. Transcript co-regulation analysis showed a strong linkage to the peptidyl-prolyl-cis/trans isomerase Cyclophilin 20-3 （Cyp20-3） and other components of the photosynthetic apparatus. Co-expression in protoplasts and quantification of fluorescence resonance energy transfer （FRET） efficiency in vivo confirmed protein interactions of 2-CysPrx with Cyp20-3 as well as NADPH-dependent thioredoxin reductase C （NTRC）, while thioredoxin x （Trx-x） did not form complexes that could enable FRET. Likewise, changes in FRET of fluorescently labeled 2-CysPrx in vitro and in vivo proved redox dependent dynamics of 2-CysPrx. Addition of Cyp20-3 to an in vitro peroxidase assay with 2-CysPrx had no significant effect on peroxide reduction. Also, in the presence of NTRC, addition of Cyp20-3 did not further enhance peroxide reduction. In addition, 2-CysPrx functioned as chaperone and inhibited aggregation of citrate synthase during heat treatment. This activity was partly inhibited by Cyp20-3. As a new interaction partner of decameric 2-CysPrx, photosystem Ⅱ could be identified after chloroplast fractionation and in pull-down assays after reconstitution. In summary, the data indicate a dynamic function of plant 2-CysPrx as redox sensor, chaperone, and regulator in the chloroplast with diverse functions beyond its role as thiol peroxidase.展开更多
Hepatic stellate cells(HSCs)are essential drivers of fibrogenesis.Inducing activated-HSC apoptosis is a promising strategy for treating hepatic fibrosis.18beta-glycyrrhetinic acid(18b-GA)is a natural compound that exi...Hepatic stellate cells(HSCs)are essential drivers of fibrogenesis.Inducing activated-HSC apoptosis is a promising strategy for treating hepatic fibrosis.18beta-glycyrrhetinic acid(18b-GA)is a natural compound that exists widely in herbal medicines,such as Glycyrrhiza uralensis Fisch,which is used for treating multiple liver diseases,especially in Asia.In the present study,we demonstrated that 18b-GA decreased hepatic fibrosis by inducing the apoptosis in activated HSCs.18b-GA inhibited the expression of a-smooth muscle actin and collagen type Ⅰ alpha-1.Using a chemoproteomic approach derived from activity-based protein profiling,together with cellular thermal shift assay and surface plasmon resonance,we found that 18b-GA covalently targeted peroxiredoxin 1(PRDX1)and peroxiredoxin 2(PRDX2)proteins via binding to active cysteine residues and thereby inhibited their enzymatic activities.18b-GA induced the elevation of reactive oxygen species(ROS),resulting in the apoptosis of activated HSCs.PRDX1 knockdown also led to ROS-mediated apoptosis in activated HSCs.Collectively,our findings revealed the target proteins and molecular mechanisms of 18b-GA in ameliorating hepatic fibrosis,highlighting the future development of 18b-GA as a novel therapeutic drug for hepatic fibrosis.展开更多
This study observes the therapeutic detoxification of quercetin, a well-known flavonoid, against carbon tetrachlodde （CCI4） induced acute liver injury in vivo and explores its mechanism. QuerceUn decreased CCI4-incr...This study observes the therapeutic detoxification of quercetin, a well-known flavonoid, against carbon tetrachlodde （CCI4） induced acute liver injury in vivo and explores its mechanism. QuerceUn decreased CCI4-increased serum activities of alanine and aspartate aminotransferases （ALT/AST） when orally taken 30 min after CCI4 intoxica- tion. The results of a histological evaluation further evidenced the ability of quercetin to protect against CCI4-induced liver injury. Quercetin decreased the CCI4-increased malondialdehyde （MDA） and reduced the glutathione （GSH） amounts in the liver. It also reduced the enhanced immunohistochemical staining of the 4-hydroxynonenal （4-HNE） in the liver induced by CCI4. Peroxiredoxin （Prx） 1, 2, 3, 5, 6, thioredoxin reductase 1 and 2 （TrxRl/2）, thioredoxin 1 and 2 （Trxl/2）, nuclear factor erythroid 2-related factor 2 （Nrf2）, and heme oxygenase-1 （HO-1） all play critical roles in maintaining cellular redox homeostasis. Real-time polymerase chain reaction （PCR） results demonstrated that quercetin reversed the decreased mRNA expression of all those genes induced by CCI4. In conclusion, our results demonstrate that quercetin ameliorates CCI4-induced acute liver injury in vivo via alleviating oxidative stress injuries when orally taken after CCI4 intoxication. This protection may be caused by the elevation of the antioxidant capacity induced by quercetin.展开更多
基金supported by the National Key Research and Development Program of China (2020YFA0908000)the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine (ZYYCXTD-C-202002,China)+1 种基金the National Natural Science Foundation of China(81903588,81803456,82074098 and 81841001,China)the Fundamental Research Funds for the Central Public Welfare Research Institutes (ZXKT18003 and ZZ15-YQ-063,China)。
文摘Ferroptosis is a form of regulated cell death, characterized by excessive membrane lipid peroxidation in an iron-and ROS-dependent manner. Celastrol, a natural bioactive triterpenoid extracted from Tripterygium wilfordii, shows effective anti-fibrotic and anti-inflammatory activities in multiple hepatic diseases. However, the exact molecular mechanisms of action and the direct protein targets of celastrol in the treatment of liver fibrosis remain largely elusive. Here, we discover that celastrol exerts anti-fibrotic effects via promoting the production of reactive oxygen species(ROS) and inducing ferroptosis in activated hepatic stellate cells(HSCs). By using activity-based protein profiling(ABPP) in combination with bio-orthogonal click chemistry reaction and cellular thermal shift assay(CETSA), we show that celastrol directly binds to peroxiredoxins(PRDXs), including PRDX1, PRDX2, PRDX4 and PRDX6,through the active cysteine sites, and inhibits their anti-oxidant activities. Celastrol also targets to heme oxygenase 1(HO-1) and upregulates its expression in activated-HSCs. Knockdown of PRDX1, PRDX2,PRDX4, PRDX6 or HO-1 in HSCs, to varying extent, elevated cellular ROS levels and induced ferroptosis. Taken together, our findings reveal the direct protein targets and molecular mechanisms via which celastrol ameliorates hepatic fibrosis, thus supporting the further development of celastrol as a promising therapeutic agent for liver fibrosis.
文摘Reactive oxygen species (ROS) are produced under oxidative stress, such as high oxygen concentration and during the metabolic consumption of oxygen molecules. Male reproductive tissues appear to be continuously exposed to ROS produced by active metabolism. In addition, spermatozoa must pass through a high oxygen environment during the mating process. Thus, to maintain viable reproductive ability, a protective mechanism against oxidative stress is of importance. Here, we overview our current understanding of the cooperative function of antioxidative and redox systems that are involved in male fertility. Superoxide dismutase and glutathione peroxidase are major enzymes that scavenge harmful ROS in male reproductive organs. In turn, glutathione and thioredoxin systems constitute the main redox systems that repair oxidized and damaged molecules and also play a role in regulating a variety of cellular functions. While glutathione functions as an antioxidant by donating electrons to glutathione peroxidase and thioredoxin donates electrons to peroxiredoxin as a counterpart of glutathione peroxidase. In addition, aldo-keto reductases, which detoxify carbonyl compounds produced by oxidative stress, are present at high levels in the epithelia of the genital tract and Sertoli cells of the testis. Since these systems are involved in cross-talk, a comprehensive understanding will be required to maintain the physiological functions of male reproductive system.
基金This study was supported by grants from the National Youth Natural Science Foundation of China （No. 30400191）, the National Natural Science Foundation China （No. 30570797）, and the Key Subject of＂135＂ Project of Jiangsu Province （No. 20013102）.
文摘Background β2-adrenoceptor （β2AR） desensitization is a common problem in clinical practice, β2AR desensitization proceeds by at least such three mechanisms as heterologous desensitization, homologous desensitization and a kind of agonist-induced rapid phosphorylation by a variety of serine/threonine kinases. It is not clear whether there are other mechanisms, This study aimed to investigate potential mechanisms of β2AR desensitization.Methods Twenty-four BALB/c （6-8 weeks old） mice were divided into three groups, which is, group A, phosphate buffered saline （PBS）-treated; group B, ovalbumin （OVA）-induced; and group C, salbutamol-treated. Inflammatory cell counts, cytokine concentrations of bronchoalveolar lavage fluid （BALF）, pathological sections, total serum IgE, airway responsiveness, membrane receptor numbers and total amount of β2AR were observed. Asthmatic mouse model and β2AR desensitization asthmatic mouse model were established. Groups B and C were selected for two-dimensional gel electrophoresis （2DE） analysis so as to find key protein spots related to β2AR desensitization.Results Asthmatic mouse model and β2AR desensitization asthmatic mouse model were verified by inflammatory cell count, cytokine concentration of BALF, serum IgE level, airway hyperreactivity measurement, radioligand receptor binding assay, Western blot analysis, and pathologic examination. Then the two groups （groups B and C） were subjected to 2DE. Two key protein spots associated with β2AR desensitization, Rho GDP-dissociation inhibitor 2 （RhoGDl2） and peroxiredoxin 5, were found by comparative proteomics （2DE and mass spectrum analysis）.Conclusion Oxidative stress and small G protein regulators may play an important role in the process of β2AR desensitization.v
文摘Oxidative stress is one of the major causes of male infertility; it damages spermatogenic cells, the spermatogenic process and sperm function. Recent advances in redox biology have revealed the signalling role of reactive oxygen species （ROS） that are generated by cells. While highly reactive oxidants, such as the hydroxyl radical, exert largely deleterious effects, hydrogen peroxide can feasibly serve as a signal mediator because it is moderately reactive and membrane permeable and because it can oxidize only limited numbers of functional groups of biological molecules. The amino acid side chain most sensitive to oxidation is cysteine sulphydryl, which is commonly involved in the catalysis of some enzymes. Although the reactivity of cysteine sulphhydryl is not very high in ordinary proteins, some phosphatases possess a highly reactive sulphydryl group at their catalytic centre and are thereby oxidatively inactivated by transiently elevated hydrogen peroxide levels after extracellular stimuli and under certain environmental conditions. Peroxiredoxins, in turn, show moderate hydrogen peroxide-reducing activity, and their role in the modulation of ROS-mediated signal transduction in ordinary cells, mediated by protecting phosphatases from oxidative inactivation, has attracted much attention. Although knowledge of the signalling role of ROS in the male reproductive system is limited at present, its significance is becoming a focal issue. Here, we present a review of the emerging signalling role of hydrogen peroxide in testes.
文摘In plants, the highly abundant 2-cysteine peroxiredoxin （2-CysPrx） is associated with the chloroplast and involved in protecting photosynthesis. This work addresses the multiple interactions of the 2-CysPrx in the chloroplast, which depend on its redox state. Transcript co-regulation analysis showed a strong linkage to the peptidyl-prolyl-cis/trans isomerase Cyclophilin 20-3 （Cyp20-3） and other components of the photosynthetic apparatus. Co-expression in protoplasts and quantification of fluorescence resonance energy transfer （FRET） efficiency in vivo confirmed protein interactions of 2-CysPrx with Cyp20-3 as well as NADPH-dependent thioredoxin reductase C （NTRC）, while thioredoxin x （Trx-x） did not form complexes that could enable FRET. Likewise, changes in FRET of fluorescently labeled 2-CysPrx in vitro and in vivo proved redox dependent dynamics of 2-CysPrx. Addition of Cyp20-3 to an in vitro peroxidase assay with 2-CysPrx had no significant effect on peroxide reduction. Also, in the presence of NTRC, addition of Cyp20-3 did not further enhance peroxide reduction. In addition, 2-CysPrx functioned as chaperone and inhibited aggregation of citrate synthase during heat treatment. This activity was partly inhibited by Cyp20-3. As a new interaction partner of decameric 2-CysPrx, photosystem Ⅱ could be identified after chloroplast fractionation and in pull-down assays after reconstitution. In summary, the data indicate a dynamic function of plant 2-CysPrx as redox sensor, chaperone, and regulator in the chloroplast with diverse functions beyond its role as thiol peroxidase.
基金the Innovation Team and Talents Cultivation Program of the National Administration of Traditional Chinese Medicine,China(Grant No.:ZYYCXTD-C-202002)the National Key Research and Development Program of China,China(Grant No.:2020YFA0908000)+1 种基金the National Natural Science Foundation of China,China(Grant Nos.:81803389,81903588,32101219,81702580,82074098,81903866,and 81803456)the Fundamental Research Funds for the Central Public Welfare Research Institutes,China(Grant Nos.:ZZ14-YQ-050,ZZ14-YQ-059,ZZ15-ND-10,ZZ15-YQ-063,ZZ14-ND-010,and ZZ14-FL-002).
文摘Hepatic stellate cells(HSCs)are essential drivers of fibrogenesis.Inducing activated-HSC apoptosis is a promising strategy for treating hepatic fibrosis.18beta-glycyrrhetinic acid(18b-GA)is a natural compound that exists widely in herbal medicines,such as Glycyrrhiza uralensis Fisch,which is used for treating multiple liver diseases,especially in Asia.In the present study,we demonstrated that 18b-GA decreased hepatic fibrosis by inducing the apoptosis in activated HSCs.18b-GA inhibited the expression of a-smooth muscle actin and collagen type Ⅰ alpha-1.Using a chemoproteomic approach derived from activity-based protein profiling,together with cellular thermal shift assay and surface plasmon resonance,we found that 18b-GA covalently targeted peroxiredoxin 1(PRDX1)and peroxiredoxin 2(PRDX2)proteins via binding to active cysteine residues and thereby inhibited their enzymatic activities.18b-GA induced the elevation of reactive oxygen species(ROS),resulting in the apoptosis of activated HSCs.PRDX1 knockdown also led to ROS-mediated apoptosis in activated HSCs.Collectively,our findings revealed the target proteins and molecular mechanisms of 18b-GA in ameliorating hepatic fibrosis,highlighting the future development of 18b-GA as a novel therapeutic drug for hepatic fibrosis.
基金Project supported by the "Shu Guang" Project from Shanghai Municipal Education Commission and Shanghai Education Development Foundation(No.13SG43)the National Natural Science Foundation of China(No.81322053)the Program for New Century Excellent Talents in University(No.NCET-11-1054),China
文摘This study observes the therapeutic detoxification of quercetin, a well-known flavonoid, against carbon tetrachlodde （CCI4） induced acute liver injury in vivo and explores its mechanism. QuerceUn decreased CCI4-increased serum activities of alanine and aspartate aminotransferases （ALT/AST） when orally taken 30 min after CCI4 intoxica- tion. The results of a histological evaluation further evidenced the ability of quercetin to protect against CCI4-induced liver injury. Quercetin decreased the CCI4-increased malondialdehyde （MDA） and reduced the glutathione （GSH） amounts in the liver. It also reduced the enhanced immunohistochemical staining of the 4-hydroxynonenal （4-HNE） in the liver induced by CCI4. Peroxiredoxin （Prx） 1, 2, 3, 5, 6, thioredoxin reductase 1 and 2 （TrxRl/2）, thioredoxin 1 and 2 （Trxl/2）, nuclear factor erythroid 2-related factor 2 （Nrf2）, and heme oxygenase-1 （HO-1） all play critical roles in maintaining cellular redox homeostasis. Real-time polymerase chain reaction （PCR） results demonstrated that quercetin reversed the decreased mRNA expression of all those genes induced by CCI4. In conclusion, our results demonstrate that quercetin ameliorates CCI4-induced acute liver injury in vivo via alleviating oxidative stress injuries when orally taken after CCI4 intoxication. This protection may be caused by the elevation of the antioxidant capacity induced by quercetin.
