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1.
J Chromatogr A ; 1665: 462819, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35038613

RESUMO

Loblolly fruit (LBF) is mainly used as raw material for beverage, but there are few researches on its quality evaluation or control. The aim of this study was to develop comprehensive evaluation methods for the quality control of Loblolly fruit. firstly, double wavelength coefficient ratio spectrum was used to identify the purity of chromatographic fingerprint peak. It is very important to identify the purity of fingerprint peaks because only the quantitative determination of pure chromatographic peaks is meaningful for its efficient quality control. Then, multi-wavelength fusion fingerprint was established to avoid one-sidedness of a single wavelength for further evaluation by systematically quantified fingerprint method (SQFM). According to the outcome of Pm, 25 batches of LBF were classified into two classifications by hierarchical cluster analysis, which was consistent with the SQFM evaluation results. Two active components, gallic acid (GAC) and ethyl gallate (EGA) in LBF, were quantitatively determined by quantitative analysis of multi-components by single marker (QAMS). In addition, the fingerprint efficacy relationship was established using an off-line antioxidant system and partial least-squares model to explore the connection between chemical components and antioxidant activities. Finally, the evaluation results of high-performance liquid chromatography and gas chromatography were integrated by the mean algorithm, which could reduce the error caused by single method. The results showed that the proposed strategy could provide a method for quality evaluation of LBF and even other traditional Chinese medicines (TCMs).

2.
Sci Total Environ ; 803: 149910, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500266

RESUMO

As an important pollutant, perfluorooctane acid (PFOA) has been widely concerned and reported by thousands of times, while less is known about the concentration-response pathway of PFOA. The aim of the present work was to reveal the concentration-response mechanism of PFOA in human cells. Omics results showed that calcium-related pathways play key roles in PFOA injury mechanisms. The results of GO and KEGG analyses showed that the cAMP signaling pathway was presented as the top one in all of the regulatory patterns and concentrations groups of PFOA. In the cAMP signaling pathway, the adenosine A1 receptor (ADORA1) recognized the low concentration of PFOA and induced pathway "Gi-cAMP-PKA" to decrease the concentration of cAMP. This indicated that the low concentration of PFOA may promote breast hyperplasia and inhibit lactation. While adenosine A2A receptor (ADORA2A) recognized the high concentration of PFOA and induced pathway "GS-AC-cAMP-RKA" to increase the concentration of cAMP, induce cell damage and may lead to the deterioration of breast cancer. The results of molecular dynamics simulation showed that PFOA could bind to ADORA1 and ADORA2A, thus cause subsequent signal transduction. Furthermore, considering the strong binding ability of PFOA with ADORA1, PFOA tends to bind to ADORA1 at a low concentration. On the other side, PFOA at high concentration will continue to bind to another receptor protein, ADORA2A, and activate subsequent signaling pathways. Combined analyses of transcriptomic and proteomic revealed that different concentrations of PFOA regulate cellular calcium-related pathways. The cAMP pathway showed a concentration-response effect of PFOA. After treatment with different concentrations of PFOA, ADORA1 and ADORA2A were activated respectively, showing opposite cellular effects, leading to kinds of breast lesions. In the nervous system, PFOA might induce a variety of nervous system diseases. The present work was an exploration on the toxicological mechanism of PFOA, providing important information on the health impacts of PFOA in humans.


Assuntos
Fluorcarbonetos , Proteômica , Feminino , Fluorcarbonetos/toxicidade , Humanos , Simulação de Dinâmica Molecular , Receptor A1 de Adenosina
3.
Int J Radiat Biol ; 97(12): 1731-1740, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34597255

RESUMO

BACKGROUND: Ionizing radiation, especially heavy ion (HI) beams, has been widely used in biology and medicine. However, the mechanism of membrane damage by such radiation remains primarily uncharacterized. PURPOSE: Transcriptomic profiles of Escherichia coli (E. coli) treated with HI illustrated the response mechanisms of the membrane, mainly ABC transporters, related genes regulated by antibiotics treatment through enrichment analyses of GO and KEGG. The networks of protein-protein interactions indicated that LsrB was the crucial one among the ABC transporters specially regulated by HI through the calculation of plugins MCODE and cytoHubba of Cytoscape. Finally, the expression pattern, GO/KEGG enrichment terms, and the interaction between nine LuxS/AI-2 quorum sensing system members were investigated. CONCLUSIONS: Above all, results suggested that HI might perform membrane damage through regulated material transport, inhibited LuxS/AI-2 system, finally impeded biofilm formation. This work provides further evidence for the role of ABC transporters, especially LsrB, in membrane damage of E. coli to HI. It will provide new strategies for improving the precise application of HI.

4.
J Clin Pharm Ther ; 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34668203

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Like many countries in the world, China is also facing growing drug expenditures year by year. In particular, the rising cost of prescription drugs has been one of the critical factors leading to the serious burden on health insurance programs. The high cost of prescription drugs not only threatens the health budget but also limits the nation's investment in other public sectors. China implemented the National Centralized Drug Procurement (NCDP) policy, also known as the "4 + 7" policy, in tertiary hospitals in various provinces and cities across the country on 18 December 2019, aiming to lessen personal and national health insurance burdens by reducing drug procurement prices. The aim of this study is to explore the impact of the implementation of the NCDP policy on the drug expenditures of patients treated in outpatient and emergency departments and on national health insurance expenditures. METHODS: This study adopts interrupted time series (ITS) to evaluate the impact of China's implementation of the NCDP policy on the drug expenditures of patients treated in outpatient and emergency departments in a tertiary hospital. The NCDP policy was officially implemented on 18 December 2019. A segmented regression model is utilized to analyse the average monthly drug expenditures of patients treated in outpatient and emergency departments from January 2018 to June 2021, including the average monthly per-visit drug expenditures of all patients and the average monthly per-visit drug expenditures of patients who paid for drugs with health insurance and those who did not use health insurance. RESULTS: After the implementation of the NCDP policy, the overall average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments were immediately reduced by 233.954 CNY (p < 0.01). Compared with the continued downward trend for drug expenditures before the implementation of the NCDP policy, the long-term trend after policy implementation was not obvious (p = 0.051973>0.05). Similarly, the average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments who use health insurance to procure drugs also immediately decreased by 505.287 CNY (p < 0.01), but the long-term trends before (p = 0.469>0.05) and after policy implementation (p = 0.51>0.05) did not exhibit obvious change. For the average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments who did not use health insurance, the implementation of the NCDP policy did not produce an immediate reduction in drug expenditures (p = 0.3603>0.05). Although the average monthly per-visit drug expenditures decreased by 9.078 CNY (p < 0.01) before policy implementation, this trend ended after the policy was implemented (p = 0.0735>0.05), and no other changes were triggered. WHAT IS NEW AND CONCLUSION: This study reviews the data for a period of time before and after the implementation of the NCDP policy. The policy is shown to significantly decrease the average monthly per-visit drug expenditures of patients treated in outpatient and emergency departments.

5.
Genomics ; 113(6): 3681-3695, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34509619

RESUMO

The storage quality of Hylocereus undatus was significantly improved by trypsin, a novel preservative. The transcriptomic results revealed that antioxidant signal pathways were induced, while lignin catabolic process was impeded by trypsin. In addition, the results of protein-protein interaction (PPI) network networks suggested that flavone 3'-O-methyltransferase 1 (OMT1), ferulic acid 5-hydroxylase 1 (CYP84A1), cellulose synthase isomer (CEV1), and 4-coumarate-CoA ligase 3 (4CL3) act as hubs of peroxidases, lignin related proteins, and proteins involved in the phenylpropanoid metabolism (PLPs) induced by trypsin. Trypsin also regulated the biosynthesis of lignin, chlorogenic acid, and flavonoids. Caffeic acid might be the hub in the metabolic network of the early pathways of phenylpropanoid biosynthesis. It has been hypothesized that trypsin might quickly induce lignin biosynthesis and then up-regulated bioactive metabolites to enhance storage quality of H. undatus.

6.
Plant Physiol Biochem ; 158: 497-507, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33257230

RESUMO

Trypsin is a novel superoxide scavenger. The storage quality of H. undatus was significantly improved by trypsin. To investigate the mechanism of flavonoid metabolism regulated by trypsin, combined analysis of widely targeted metabolomic and transcriptome were performed. GO and KEGG enrichment analyses of the transcriptome profiles of H. undatus revealed that some of the flavonoid related biosynthesis pathways were regulated by up or down patterns with the treatment of trypsin. Correlation analysis of flavonoid related genes expression in H. undatus provided a rationale for the functional significance of them. Furthermore, it has been revealed that the most significantly regulated flavonoid was catechin gallate in metabolomic profiles of H. undatus. The major route of flavonoid biosynthesis regulated by trypsin was also illustrated by both transcriptomic and metabolomic data. Finally, the results of PPI network revealed that C4H, HCT, and CYP75B1 acted as hub proteins involved in flavonoid metabolism regulated by trypsin.


Assuntos
Cactaceae , Catequina/análogos & derivados , Tripsina/farmacologia , Cactaceae/genética , Cactaceae/metabolismo , Catequina/metabolismo , Metaboloma , Transcriptoma
7.
J Pharm Biomed Anal ; 193: 113719, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33220654

RESUMO

Quantified profiling and quantitative analysis of multi-components by single marker (QAMS) method were combined to control the quality consistency of Rong'e Yishen oral liquid (REYS) in this paper. Firstly, High Performance Liquid Chromatography (HPLC) with diode array detection (DAD) was applied to collect fingerprints and establish a content determination method. Then, two methods of QAMS and the external standard method (ESM) were used for comparative study to investigate the feasibility of the former to accurately control the quality of individual marker. The results showed that there was no significant difference in quantitative determination between QAMS and ESM (t test, P>0.05). Sodium benzoate, as an internal reference standard (IRS), can be used to simultaneously quantify Icariin, Echinacoside, and Acteoside three components of the oral liquid. Finally, the fingerprint of 15 batches of REYSs was assessed by SQFM with Hierarchical clustering analysis (HCA). The result of the quality evaluation demonstrated that 15 batches were divided into 3 levels and had good quality consistency. What's more, the content percentage of the dominant three medicinal markers and their total amount presented a close correlation with the macro quantitative similarity (Pm) of samples. Thus, quantified profiling combined with QAMS, which is systematic, simple, rigorous, and objective, could be a novel method to evaluate the quality consistency of REYS or even other traditional Chinese medicine (TCM).


Assuntos
Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão , Medicina Tradicional Chinesa , Padrões de Referência
8.
BMC Genomics ; 21(1): 437, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32590938

RESUMO

BACKGROUND: It was demonstrated in our previous research that trypsin scavenges superoxide anions. In this study, the mechanisms of storage quality improvement by trypsin were evaluated in H. undatus. RESULTS: Trypsin significantly delayed the weight loss and decreased the levels of ROS and membrane lipid peroxidation. Transcriptome profiles of H. undatus treated with trypsin revealed the pathways and regulatory mechanisms of ROS genes that were up- or downregulated following trypsin treatment by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses. The current results showed that through the regulation of the expression of hub redox enzymes, especially thioredoxin-related proteins, trypsin can maintain low levels of endogenous active oxygen species, reduce malondialdehyde content and delay fruit aging. In addition, the results of protein-protein interaction networks suggested that the downregulated NAD(P) H and lignin pathways might be the key regulatory mechanisms governed by trypsin. CONCLUSIONS: Trypsin significantly prolonged the storage life of H. undatus through regulatory on the endogenous ROS metabolism. As a new biopreservative, trypsin is highly efficient, safe and economical. Therefore, trypsin possesses technical feasibility for the quality control of fruit storage.


Assuntos
Cactaceae/crescimento & desenvolvimento , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Tripsina/farmacologia , Cactaceae/efeitos dos fármacos , Cactaceae/metabolismo , Qualidade dos Alimentos , Armazenamento de Alimentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala , Malondialdeído/análise , Anotação de Sequência Molecular , Proteínas de Plantas/genética , Mapas de Interação de Proteínas/efeitos dos fármacos , Análise de Sequência de RNA
9.
Antioxidants (Basel) ; 9(2)2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32079316

RESUMO

It has been revealed by us that superoxide scavenging is a new activity of trypsin. In this study, the synergistic mechanisms of trypsin and superoxide dismutases (SODs) were evaluated in Hylocereus undatus (pitaya). Trypsin significantly improved the storage quality of H. undatus, including weight loss impediment and decrease of cellular injury. The regulatory mechanisms of 16 SOD genes by trypsin were revealed using transcriptomic analysis on H. undatus. Results revealed that important physiological metabolisms, such as antioxidant activities or metal ion transport were induced, and defense responses were inhibited by trypsin. Furthermore, the results of protein-protein interaction (PPI) networks showed that besides the entire ROS network, the tiny SODs sub-network was also a scale-free network. Cu/Zn SODs acted as the hub that SODs synergized with trypsin during the storage of H. undatus.

10.
Food Funct ; 10(12): 8116-8128, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31746888

RESUMO

It has been revealed in our previous studies that trypsin scavenges superoxide anions. In the current study, the mechanisms of storage quality improvement by trypsin were evaluated in H. undatus. Strikingly, the improvement is due not to its antibacterial or antifungal activity but to its superoxide scavenging activity. Moreover, trypsin significantly decreased the levels of ROS, cell permeability and membrane lipid peroxidation. The activities of major antioxidant enzymes were significantly improved by trypsin treatment. Transcriptome profiles of H. undatus treated with trypsin revealed the pathways and regulatory mechanisms of antioxidant genes up or down-regulated following trypsin treatment by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses. The results of protein-protein interaction networks indicated that CAT is the key among the enzymes of the complicated antioxidant system. In addition, the current results showed that the synergistic effect of trypsin with antioxidant enzymes can regulate the levels of endogenous active oxygen species, reduce malondialdehyde content, improve cell membrane integrity, alleviate cell damage and delay fruit ageing.


Assuntos
Antioxidantes/metabolismo , Cactaceae/química , Cactaceae/genética , Frutas/química , Proteínas de Plantas/genética , Tripsina/química , Antioxidantes/análise , Cactaceae/metabolismo , Conservação de Alimentos/métodos , Armazenamento de Alimentos , Frutas/genética , Frutas/metabolismo , Perfilação da Expressão Gênica , Ontologia Genética , Malondialdeído/análise , Malondialdeído/metabolismo , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Transcriptoma
11.
Genet Mol Biol ; 42(3): 624-634, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31424071

RESUMO

Drought and cold are the primary factors limiting plant growth worldwide. The Ammopiptanthus mongolicus NAC11 (AmNAC11) gene encodes a stress-responsive transcription factor. Expression of the AmNAC11 gene was induced by drought, cold and high salinity. The AmNAC11 protein was localized in the nucleus and plays an important role in tolerance to drought, cold and salt stresses. We also found that differential expression of AmNAC11 was induced in the early stages of seed germination and was related to root growth. When the AmNAC11 gene was introduced into Arabidopsis thaliana by an Agrobacterium-mediated method, the transgenic lines expressing AmNAC11 displayed significantly enhanced tolerance to drought and freezing stresses compared to wild-type Arabidopsis thaliana plants. These results indicated that over-expression of the AmNAC11 gene in Arabidopsis could significantly enhance its tolerance to drought and freezing stresses. Our study provides a promising approach to improve the tolerance of crop cultivars to abiotic stresses through genetic engineering.

12.
Chemosphere ; 216: 524-532, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30388688

RESUMO

Decabromodiphenyl ethane (DBDPE) is widely used in industry as an alternative to the decabromodiphenyl ether (BDEs). The large-scale use of DBDPE could lead to rapid growth of the human accumulation level of DBDPE. However, the biophysics of accumulation of DBDPE in cell membranes, as one of determinants of DBDPE metabolism is not clear. In the present study, detailed observations of cell lactate dehydrogenase (LDH) and reactive oxygen species (ROS) levels measurements proved that the DBDPE exposure to cell could result in significant cell membrane damage by concentration-dependent manners. The fluorescence anisotropy analysis supported the evidence that high concentration DBDPE bound decreased membrane fluidity significantly. Besides it, a detailed molecular dynamic (MD) simulation was approached to investigate the effects of DBDPE on the DPPC (dipalmitoyl phosphatidylcholine) phospholipid bilayer, which was constructed as the model of cell membrane. The molecular dynamic simulation revealed that DBDPE molecules can easily enter the membrane from the aqueous phase. Under the concentration of a threshold, the DBDPE molecules tended to aggregate inside the DPPC bilayer and caused pore formation. The bound of high concentration of DBDPE could result in significant variations in DPPC bilayer with a less dense, more disorder and rougher layer. The knowledge about DBDPEs interactions with lipid membranes is fundamentally essential to understand the in vivo process of DBDPE and the physical basis for the toxicity of DBDPE in cell membranes.


Assuntos
Bromobenzenos/química , Membrana Celular/química , Lipídeos/química , Humanos , Simulação de Dinâmica Molecular
13.
Appl Biochem Biotechnol ; 181(4): 1549-1560, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27796872

RESUMO

Trypsin is an endogenous enzyme that is generally used as a proteinase. Intriguingly, we found that trypsin had superoxide scavenging activity. In the current study, our results showed that trypsin scavenges superoxide in either intracorporal or extracorporal systems. In the light of the porcupine plots of trypsin compounds generated by ProDy, the copper ion binds to trypsin and accelerates the superoxide scavenging activity of trypsin by increasing the stability of the structure. Furthermore, the data on the age-related parameters showed that the aging of mice could be slowed by trypsin, at least in part, due to its superoxide scavenging activity. These results suggested that trypsin is an effective superoxide scavenger and has potential as a novel agent to promote health and improve aging-associated pathologies.


Assuntos
Envelhecimento/efeitos dos fármacos , Sequestradores de Radicais Livres/farmacologia , Superóxidos/metabolismo , Tripsina/farmacologia , Envelhecimento/metabolismo , Animais , Cobre/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/metabolismo , Técnicas de Inativação de Genes , Masculino , Camundongos , Camundongos Endogâmicos ICR , Modelos Moleculares , Conformação Proteica , Superóxido Dismutase/deficiência , Superóxido Dismutase/genética , Tripsina/química , Tripsina/metabolismo , Inibidores da Tripsina/farmacologia
14.
BMC Genomics ; 15: 671, 2014 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-25108399

RESUMO

BACKGROUND: The molecular mechanisms involved in plant tolerance to either drought or cold have been extensively studied in many plant species. However, few studies have focused on their comparisons especially using non-model plants with strong tolerance to both stresses. Ammopiptanthus mongolicus (Maxim. ex Kom.) Cheng f. is the only evergreen broadleaf shrub grown in the central Asian desert and it has very strong cold and drought tolerance. To provide further insights into plant tolerance, the transcriptome profiles of drought- and cold-treated A. mongolicus seedlings were analyzed using Illumina technology and differentially expressed genes (DEGs) were compared. RESULTS: A comprehensive transcriptome of A. mongolicus was sequenced using pooled mRNA extracted from drought-, cold-stressed and unstressed seedlings as well as leaves from naturally grown shrub. These sequences were assembled into 86058 unigenes, of which 51014 unigenes had an annotated function and 2440 encoded transcription factors (TFs). Transcriptome profiles were analyzed in A. mongolicus seedlings after drought and cold treatments at three time points (2, 8 and 24 h). Between 3917 and 6102 unigenes were identified as DEGs at a single time point in both stresses. Among these DEGs 2028 and 2026 DEGs were common across the three time points of drought and cold treatments respectively, and 971 DEGs were co-regulated by both stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The most pronounced findings are that flavonoid biosynthesis genes were enriched in the DEGs co-up-regulated by both stresses; while membrane protein genes and genes related to chloroplast were abundant in the DEGs specifically up-regulated by drought or cold, respectively. Furthermore, the DREB, ERF, NAC and WRKY TFs were predominantly co-up-regulated by both stresses. CONCLUSIONS: The present study provides the most comprehensive transcriptome resource and the first dynamic transcriptome profiles of A. mongolicus under drought and cold stresses. This information will deepen our understanding of plant tolerance to drought and cold. The up-regulated DEGs will be valuable for further investigations of key genes and molecular mechanisms involved in the adaptation of A. mongolicus to harsh environments.


Assuntos
Resposta ao Choque Frio/genética , Clima Desértico , Secas , Fabaceae/genética , Fabaceae/fisiologia , Perfilação da Expressão Gênica , Anotação de Sequência Molecular
15.
Res Microbiol ; 165(8): 605-11, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25084557

RESUMO

Hydrogen peroxide (H2O2) is usually generated by normal aerobic respiration of pathogens and by the host defense response during plant-pathogen interactions. In this study, histochemical localization of H2O2 accumulation in rice inoculated with the wild-type strain (PXO99(A)) and the gene deletion mutant (ΔahpC) of alkyl hydroperoxide reductase subunit C (AhpC) of Xanthomonas oryzae pv. oryzae (Xoo), the bacterial blight pathogen of rice, was analyzed. The ΔahpC mutant displayed a significant decrease in endogenous H2O2 accumulation which was induced by the compensatory increase in H2O2 scavenging activity. The change in the bacterial endogenous H2O2 level affected the total amount of H2O2 accumulation during the interaction with rice plants. These results suggested that Xoo contributes to H2O2 accumulation in rice in a compatible interaction, and pathogen-driving H2O2 is in association with cell collapse of rice.


Assuntos
Interações Hospedeiro-Patógeno , Peróxido de Hidrogênio/metabolismo , Mutação , Oryza/microbiologia , Peroxirredoxinas/metabolismo , Xanthomonas/enzimologia , Xanthomonas/fisiologia , Deleção de Genes , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Peroxirredoxinas/genética , Doenças das Plantas/microbiologia , Xanthomonas/genética
16.
Microsc Res Tech ; 76(2): 121-5, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23161475

RESUMO

The bacterial endogenous hydrogen peroxide (H(2)O(2)) was detected cytochemically by its reaction with cerium chloride (CeCl(3)) to produce electron-dense deposits of cerium perhydroxides. The sequence of fixation and CeCl(3) staining of H(2)O(2) in the processing of transmission electron microscope (TEM) sample preparation is crucial to the localization of endogenous H(2)O(2) in Escherichia coli. In this study, results confirmed that the process that fixation simultaneously with CeCl(3) staining provided optimum effects for H(2)O(2) localization in E. coli. The modified process of TEM provides very efficient protection for H(2)O(2) localization and more accurate quantization for the H(2)O(2) accumulation in bacterial cells.


Assuntos
Escherichia coli/química , Escherichia coli/ultraestrutura , Peróxido de Hidrogênio/análise , Microscopia Eletrônica de Transmissão/métodos , Preservação Biológica/métodos , Manejo de Espécimes/métodos , Coloração e Rotulagem/métodos , Cério/metabolismo
17.
Wei Sheng Wu Xue Bao ; 50(7): 876-84, 2010 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-20815233

RESUMO

OBJECTIVE: Ultrastructural alteration and hydrogen peroxide (H2O2) localization were examined in Xanthomonas under cellular injury using transmission electron microscopy. METHODS: Histochemical methods were used in the present study. RESULTS: Intriguingly, the injury led to presence of an additional location of H2O2 accumulation within the cells. There was an association between the frequency and size of the additional location of H2O2 accumulation and the degrees of injury. Furthermore, an additional ultrastructure, mesosomes, was also present in injured cells. The frequency and size of mesosomes also increased with the increasing degrees of injury. CONCLUSION: Result of multiple linear regression showed that the size of mesosome plays as a key factor in the quantity of excess H2O2 accumulation in bacteria under cellular injury. Linear correlation was confirmed between quantity of excess H2O2 accumulation and the size of mesosome in injured cells. This finding intensely indicated that mesosomes are just the additional location of H2O2 accumulation in cells under cellular injury. The excess H2O2 accumulation in mesosomes should be a positive regulatory mechanism in bacteria under cellular injury.


Assuntos
Peróxido de Hidrogênio/metabolismo , Organelas/metabolismo , Xanthomonas/metabolismo , Mutação , Organelas/genética , Organelas/ultraestrutura , Xanthomonas/genética , Xanthomonas/ultraestrutura
18.
Can J Microbiol ; 55(2): 110-6, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19295642

RESUMO

Endogenous superoxide anion production was determined by electron spin resonance in wild-type strains and avrXa7 mutants of Xanthomonas oryzae pv. oryzae. The localization of superoxide anion was carried out in the intra- and extra-cellular fractions. Results showed the presence of superoxide anion in multi-locations of X. oryzae pv. oryzae cells. The extracellular fraction was the major location of superoxide anion production. Furthermore, a positive relationship was shown between the levels of endogenous superoxide anion and the virulence of strains. These indubitable results suggested that the superoxide anion contributes to the virulence of X. oryzae pv. oryzae.


Assuntos
Espaço Extracelular/metabolismo , Oryza/microbiologia , Doenças das Plantas/microbiologia , Superóxidos/metabolismo , Xanthomonas/metabolismo , Xanthomonas/patogenicidade , Transporte Biológico , Espaço Extracelular/química , Virulência , Xanthomonas/química , Xanthomonas/genética
19.
Mol Cell Biochem ; 311(1-2): 241-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18163201

RESUMO

Ultrastructural alteration and hydrogen peroxide localization were examined in Xanthomonas campestris pv. phaseoli during rifampicin effect using transmission electron microscopy. Bacterial cells were treated with rifampicin and then were examined by electron microscopy to observe the changes of ultrastructure or hydrogen peroxide accumulation in living cells that took place before lysis. Intriguingly, rifampicin treatment led to presence of an additional location of hydrogen peroxide accumulation within the cells. There was an association between the frequency and size of the additional location of hydrogen peroxide accumulation and the concentration of rifampicin. Furthermore, an additional ultrastructure, mesosomes, was also present in cells during rifampicin effect. The frequency and size of mesosome increased with the increasing concentration of rifampicin. Result of multiple linear regression showed that the size of mesosome plays as a key factor in the quantity of excess hydrogen peroxide accumulation in cells during rifampicin effect. Linear correlation was confirmed between quantity of excess hydrogen peroxide accumulation and the size of mesosome in cells during rifampicin effect. This finding intensely indicated that mesosomes are just the additional location of hydrogen peroxide accumulation in cells under cellular injury caused by rifampicin treatment. The mesosome formation is always accompanied by excess hydrogen peroxide accumulation in X. campestris pv. phaseoli during rifampicin effect.


Assuntos
Antibióticos Antituberculose/farmacologia , Peróxido de Hidrogênio/metabolismo , Oxidantes/metabolismo , Rifampina/farmacologia , Xanthomonas campestris/ultraestrutura , Xanthomonas campestris/efeitos dos fármacos , Xanthomonas campestris/metabolismo
20.
Mol Cell Biochem ; 300(1-2): 207-13, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17375266

RESUMO

Production and localization of endogenous hydrogen peroxide (H2O2) were investigated in strains of Xanthomonas by histochemical analysis under electron microscopy. Even though the levels of endogenous H2O2 production were different among various strains, the produced H2O2 was localized in the cell wall of all Xanthomonas strains tested. The impairment of the level of endogenous H2O2 accumulation resulted in a significantly decreased growth rate of bacteria, regardless if the difference of the H2O2 level is originally present between wild type strains or caused by mutation of the ahpC gene of Xanthomonas. The endogenous accumulation of H2O2 positively correlates with the cell division. Interestingly, the accumulated H2O2 was also localized in the mesosome-like structure and nucleoids during the cell division cycle. Furthermore, results revealed quantitative and dimensional changes of H2O2 accumulation in the two additional locations. These findings indicated that the additional locations of the accumulated H2O2 were closely associated with the process of cell division. Together, these results suggest that the endogenous H2O2 production plays an important role in cell proliferation of Xanthomonas.


Assuntos
Ciclo Celular , Peróxido de Hidrogênio/metabolismo , Xanthomonas/citologia , Xanthomonas/metabolismo , Divisão Celular , Mutação/genética , Coloração e Rotulagem , Xanthomonas/crescimento & desenvolvimento
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