Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study...Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.展开更多
BACKGROUND Sepsis-associated liver injury(SALI)refers to secondary liver function impairment caused by sepsis,patients with SALI often have worse clinical outcomes.The early identification and assessment of the occurr...BACKGROUND Sepsis-associated liver injury(SALI)refers to secondary liver function impairment caused by sepsis,patients with SALI often have worse clinical outcomes.The early identification and assessment of the occurrence and progression of SALI are pressing issues that urgently need to be resolved.AIM To investigate the relationship between iron metabolism and SALI.METHODS In this prospective study,139 patients were recruited,with 53 assigned to the SALI group.The relationships between SALI and various iron metabolism-related biomarkers were examined.These biomarkers included serum iron(SI),total iron-binding capacity(TIBC),serum ferritin,transferrin,and transferrin saturation.To identify independent risk factors for SALI,both univariate and multivariate logistic regression analyses were performed.Additionally,receiver operating characteristic curve analysis was utilized to assess the predictive value of these biomarkers for the occurrence of SALI.RESULTS There were no statistically significant differences in age,sex,body mass index,Sequential Organ Failure Assessment scores(excluding liver function),or APACHE II scores between the two groups of patients.Compared with the sepsis group,the SALI group presented significantly higher SI(P<0.001),TIBC(P<0.001),serum ferritin(P=0.001),transferrin(P=0.005),and transferrin saturation levels(P<0.001).Multivariate logistic regression analysis revealed that SI(odds ratio=1.24,95%confidence interval:1.11-1.40,P<0.001)and TIBC levels(odds ratio=1.13,95%confidence interval:1.05-1.21,P<0.001)were independent predictors of SALI.Receiver operating characteristic curve analysis revealed that SI and TIBC had areas under the curve of 0.816 and 0.757,respectively,indicating moderate predictive accuracy for SALI.CONCLUSION Iron metabolism disorders are closely associated with the development of SALI,and SI and TIBC may serve as potential predictive biomarkers.The combined use of SI and TIBC has superior diagnostic efficacy for SALI.These findings provide valuable insights for the early identification and management of SALI among patients with sepsis.展开更多
This letter offered commentary on the recently published article by Wang et al that investigated the relationship between iron metabolism disorders and sepsis-associated liver injury(SALI).The original study identifie...This letter offered commentary on the recently published article by Wang et al that investigated the relationship between iron metabolism disorders and sepsis-associated liver injury(SALI).The original study identified serum iron and total iron-binding capacity as potential predictive markers of SALI,contributing important insights to critical care hepatology.In this correspondence several methodological considerations that may influence the interpretation and general-izability of the findings were discussed.These include the limitations of a single-center design,the lack of serial biomarker measurements,the omission of hepcidin(a central iron regulatory hormone)as a measured variable,and the exclusive reliance on biochemical criteria for diagnosing liver injury.The potential value of incorporating imaging modalities and additional iron-related markers such as ferritin and transferrin saturation were also highlighted.The aim was to reinforce the importance of a comprehensive approach to iron metabolism in sepsis and to suggest future directions for clinical research that may enhance the diagnostic and prognostic utility of iron-related biomarkers in SALI.展开更多
The development of gastrointestinal diseases has been found to be associated with Helicobacter pylori (H. pylori) infection and various biochemical stresses in stomach and intestine. These stresses, such as oxidative,...The development of gastrointestinal diseases has been found to be associated with Helicobacter pylori (H. pylori) infection and various biochemical stresses in stomach and intestine. These stresses, such as oxidative, osmotic and acid stresses, may bring about bi-directional effects on both hosts and H. pylori, leading to changes of protein expression in their proteomes. Therefore, proteins differentially expressed in H. pylori under various stresses not only reflect gastrointestinal environment but also provide useful biomarkers for disease diagnosis and prognosis. In this regard, proteomic technology is an ideal tool to identify potential biomarkers as it can systematically monitor proteins and protein variation on a large scale of cell’s translational landscape, permitting in-depth analyses of host and pathogen interactions. By performing two-dimensional polyacrylamide gel electrophoresis (2-DE) followed by liquid chromatography-nanoESI-mass spectrometry (nanoLC-MS/MS), we have successfully pinpointed alkylhydroperoxide reductase (AhpC), neutrophil-activating protein and non-heme iron-binding ferritin as three prospective biomarkers showing up-regulation in H. pylori under oxidative, osmotic and acid stresses, respectively. Further biochemical characterization reveals that various environmental stresses can induce protein structure change and functional conversion in the identified biomarkers. Especially salient is the antioxidant enzyme AhpC, an abundant antioxidant protein present in H. pylori. It switches from a peroxide reductase of low-molecular-weight (LMW) oligomers to a molecular chaperone of high-molecular-weight (HMW) complexes under oxidative stress. Different seropositivy responses against LMW or HMW AhpC in H. pylori-infected patients faithfully match the disease progression from disease-free healthy persons to patients with gastric ulcer and cancer. These results has established AhpC of H. pylori as a promising diagnostic marker for gastrointestinal maladies, and highlight the utility of clinical proteomics for identifying disease biomarkers that can be uniquely applied to disease-oriented translational medicine.展开更多
AIM: To elucidate the sequential transfer of iron amongst ferritin, transferrin and transferrin receptor under various iron status conditions. METHODS: Incorporation of 59Fe into mucosal and luminal proteins was carri...AIM: To elucidate the sequential transfer of iron amongst ferritin, transferrin and transferrin receptor under various iron status conditions. METHODS: Incorporation of 59Fe into mucosal and luminal proteins was carried out in control WKY rats. The sequential transfer of iron amongst ferritin, transferrin and transferrin receptor was carried out in iron deficient, control and iron overloaded rats. The duodenal proteins were subjected to immunoprecipitation and quantitation by specific ELISA and in situ localization by microautoradiography and immunohistochemistry in tandem duodenal sections. Human duodenal biopsy (n = 36) collected from subjects with differing iron status were also stained for these proteins. RESULTS: Ferritin was identified as the major protein that incorporated iron in a time-dependent manner in the duodenal mucosa. The concentration of mucosal ferritin was significantly higher in the iron excess group compared to control, iron deficient groups (731.5 ± 191.96 vs 308.3 ± 123.36, 731.5 ± 191.96 vs 256.0 ± 1.19, P < 0.005), while that of luminal transferrin which was significantly higher than the mucosal did not differ among the groups (10.9 ± 7.6 vs 0.87 ± 0.79, 11.1 ± 10.3 vs 0.80 ± 1.20, 6.8 ± 4.7 vs 0.61 ± 0.63, P < 0.001). In situ grading of proteins and iron, and their superimposition, suggested the occurrence of a sequential transfer of iron. This was demonstrated to occur through the initial binding of iron to luminal transferrin then to absorptive cell surface transferrin receptors. The staining intensity of these proteins variedaccording to the iron nutrition in humans, with intense staining of transferrin receptor observed in iron deficient subjects. CONCLUSION: It is concluded that the intestine takes up iron through a sequential transfer involving interaction of luminal transferrin, transferrin-transferrin receptor and ferritin.展开更多
Members belonging to the siderophilin family are iron-binding and iron-transporting proteins, which includes transferrin and lactoferrin. They have only been found in animals previously. If siderophilin could be found...Members belonging to the siderophilin family are iron-binding and iron-transporting proteins, which includes transferrin and lactoferrin. They have only been found in animals previously. If siderophilin could be found in and isolated from a plant, its production and subsequent extensive application could be increased. The present study is the first to report the discovery of a homolog of siderophilin in a plant. In order to purify antifreeze proteins from Ammopiptanthus mongolicus （Maxim.） Cheng f., the authors processed the proteins from the leaves using techniques such as column chromatography using DEAE-Cellulose-52, gel filtration via Sephacryl S-100 HR medium, hydrophobic interaction chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mass spectroscopy was performed on the three proteins purified and the sequence of one of the proteins （containing 32 amino acids） was found to have 97% homology with the corresponding part of one type of human lactoferrin. Moreover, one of the two peptides belongs to an iron-binding domain. So, it is possible that siderophilin also exists in plants and plays a role as an antibacterial and antifungal, among other actions.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52170156,52250056,and 52293443)the Shenzhen Science and Technology Program(No.KQTD20190929172630447).
文摘Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.
基金Supported by the National Science Foundation of Jiangsu Province,No.BK20221280the National Natural Science Foundation of China,No.82371336+2 种基金the Chinese Postdoctoral Science Foundation,No.2022M711426the Special Fund for Social Key Research and Development Plan of Yangzhou City,No.YZ2022097Yangzhou Municipal Science and Technology Bureau,No.YZ2024091 and No.YZ2022098.
文摘BACKGROUND Sepsis-associated liver injury(SALI)refers to secondary liver function impairment caused by sepsis,patients with SALI often have worse clinical outcomes.The early identification and assessment of the occurrence and progression of SALI are pressing issues that urgently need to be resolved.AIM To investigate the relationship between iron metabolism and SALI.METHODS In this prospective study,139 patients were recruited,with 53 assigned to the SALI group.The relationships between SALI and various iron metabolism-related biomarkers were examined.These biomarkers included serum iron(SI),total iron-binding capacity(TIBC),serum ferritin,transferrin,and transferrin saturation.To identify independent risk factors for SALI,both univariate and multivariate logistic regression analyses were performed.Additionally,receiver operating characteristic curve analysis was utilized to assess the predictive value of these biomarkers for the occurrence of SALI.RESULTS There were no statistically significant differences in age,sex,body mass index,Sequential Organ Failure Assessment scores(excluding liver function),or APACHE II scores between the two groups of patients.Compared with the sepsis group,the SALI group presented significantly higher SI(P<0.001),TIBC(P<0.001),serum ferritin(P=0.001),transferrin(P=0.005),and transferrin saturation levels(P<0.001).Multivariate logistic regression analysis revealed that SI(odds ratio=1.24,95%confidence interval:1.11-1.40,P<0.001)and TIBC levels(odds ratio=1.13,95%confidence interval:1.05-1.21,P<0.001)were independent predictors of SALI.Receiver operating characteristic curve analysis revealed that SI and TIBC had areas under the curve of 0.816 and 0.757,respectively,indicating moderate predictive accuracy for SALI.CONCLUSION Iron metabolism disorders are closely associated with the development of SALI,and SI and TIBC may serve as potential predictive biomarkers.The combined use of SI and TIBC has superior diagnostic efficacy for SALI.These findings provide valuable insights for the early identification and management of SALI among patients with sepsis.
文摘This letter offered commentary on the recently published article by Wang et al that investigated the relationship between iron metabolism disorders and sepsis-associated liver injury(SALI).The original study identified serum iron and total iron-binding capacity as potential predictive markers of SALI,contributing important insights to critical care hepatology.In this correspondence several methodological considerations that may influence the interpretation and general-izability of the findings were discussed.These include the limitations of a single-center design,the lack of serial biomarker measurements,the omission of hepcidin(a central iron regulatory hormone)as a measured variable,and the exclusive reliance on biochemical criteria for diagnosing liver injury.The potential value of incorporating imaging modalities and additional iron-related markers such as ferritin and transferrin saturation were also highlighted.The aim was to reinforce the importance of a comprehensive approach to iron metabolism in sepsis and to suggest future directions for clinical research that may enhance the diagnostic and prognostic utility of iron-related biomarkers in SALI.
基金Supported by(in part) Kaohsiung Medical University,Academia Sinica,and the National Science Council,Taipei,Taiwan,No.96-2311-B-037-005-MY3,No.99-2314-B-037-042,and No.99-2745-B-037-005 to Chiou SH
文摘The development of gastrointestinal diseases has been found to be associated with Helicobacter pylori (H. pylori) infection and various biochemical stresses in stomach and intestine. These stresses, such as oxidative, osmotic and acid stresses, may bring about bi-directional effects on both hosts and H. pylori, leading to changes of protein expression in their proteomes. Therefore, proteins differentially expressed in H. pylori under various stresses not only reflect gastrointestinal environment but also provide useful biomarkers for disease diagnosis and prognosis. In this regard, proteomic technology is an ideal tool to identify potential biomarkers as it can systematically monitor proteins and protein variation on a large scale of cell’s translational landscape, permitting in-depth analyses of host and pathogen interactions. By performing two-dimensional polyacrylamide gel electrophoresis (2-DE) followed by liquid chromatography-nanoESI-mass spectrometry (nanoLC-MS/MS), we have successfully pinpointed alkylhydroperoxide reductase (AhpC), neutrophil-activating protein and non-heme iron-binding ferritin as three prospective biomarkers showing up-regulation in H. pylori under oxidative, osmotic and acid stresses, respectively. Further biochemical characterization reveals that various environmental stresses can induce protein structure change and functional conversion in the identified biomarkers. Especially salient is the antioxidant enzyme AhpC, an abundant antioxidant protein present in H. pylori. It switches from a peroxide reductase of low-molecular-weight (LMW) oligomers to a molecular chaperone of high-molecular-weight (HMW) complexes under oxidative stress. Different seropositivy responses against LMW or HMW AhpC in H. pylori-infected patients faithfully match the disease progression from disease-free healthy persons to patients with gastric ulcer and cancer. These results has established AhpC of H. pylori as a promising diagnostic marker for gastrointestinal maladies, and highlight the utility of clinical proteomics for identifying disease biomarkers that can be uniquely applied to disease-oriented translational medicine.
基金Supported by Council of Scientific and Industrial research, India: schemes no (812) 93EMR11 to KMN
文摘AIM: To elucidate the sequential transfer of iron amongst ferritin, transferrin and transferrin receptor under various iron status conditions. METHODS: Incorporation of 59Fe into mucosal and luminal proteins was carried out in control WKY rats. The sequential transfer of iron amongst ferritin, transferrin and transferrin receptor was carried out in iron deficient, control and iron overloaded rats. The duodenal proteins were subjected to immunoprecipitation and quantitation by specific ELISA and in situ localization by microautoradiography and immunohistochemistry in tandem duodenal sections. Human duodenal biopsy (n = 36) collected from subjects with differing iron status were also stained for these proteins. RESULTS: Ferritin was identified as the major protein that incorporated iron in a time-dependent manner in the duodenal mucosa. The concentration of mucosal ferritin was significantly higher in the iron excess group compared to control, iron deficient groups (731.5 ± 191.96 vs 308.3 ± 123.36, 731.5 ± 191.96 vs 256.0 ± 1.19, P < 0.005), while that of luminal transferrin which was significantly higher than the mucosal did not differ among the groups (10.9 ± 7.6 vs 0.87 ± 0.79, 11.1 ± 10.3 vs 0.80 ± 1.20, 6.8 ± 4.7 vs 0.61 ± 0.63, P < 0.001). In situ grading of proteins and iron, and their superimposition, suggested the occurrence of a sequential transfer of iron. This was demonstrated to occur through the initial binding of iron to luminal transferrin then to absorptive cell surface transferrin receptors. The staining intensity of these proteins variedaccording to the iron nutrition in humans, with intense staining of transferrin receptor observed in iron deficient subjects. CONCLUSION: It is concluded that the intestine takes up iron through a sequential transfer involving interaction of luminal transferrin, transferrin-transferrin receptor and ferritin.
文摘Members belonging to the siderophilin family are iron-binding and iron-transporting proteins, which includes transferrin and lactoferrin. They have only been found in animals previously. If siderophilin could be found in and isolated from a plant, its production and subsequent extensive application could be increased. The present study is the first to report the discovery of a homolog of siderophilin in a plant. In order to purify antifreeze proteins from Ammopiptanthus mongolicus （Maxim.） Cheng f., the authors processed the proteins from the leaves using techniques such as column chromatography using DEAE-Cellulose-52, gel filtration via Sephacryl S-100 HR medium, hydrophobic interaction chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mass spectroscopy was performed on the three proteins purified and the sequence of one of the proteins （containing 32 amino acids） was found to have 97% homology with the corresponding part of one type of human lactoferrin. Moreover, one of the two peptides belongs to an iron-binding domain. So, it is possible that siderophilin also exists in plants and plays a role as an antibacterial and antifungal, among other actions.
