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1.
Int J Mol Sci ; 22(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200865

RESUMO

A novel cytoplasmic dye-decolorizing peroxidase from Dictyostelium discoideum was investigated that oxidizes anthraquinone dyes, lignin model compounds, and general peroxidase substrates such as ABTS efficiently. Unlike related enzymes, an aspartate residue replaces the first glycine of the conserved GXXDG motif in Dictyostelium DyPA. In solution, Dictyostelium DyPA exists as a stable dimer with the side chain of Asp146 contributing to the stabilization of the dimer interface by extending the hydrogen bond network connecting two monomers. To gain mechanistic insights, we solved the Dictyostelium DyPA structures in the absence of substrate as well as in the presence of potassium cyanide and veratryl alcohol to 1.7, 1.85, and 1.6 Å resolution, respectively. The active site of Dictyostelium DyPA has a hexa-coordinated heme iron with a histidine residue at the proximal axial position and either an activated oxygen or CN- molecule at the distal axial position. Asp149 is in an optimal conformation to accept a proton from H2O2 during the formation of compound I. Two potential distal solvent channels and a conserved shallow pocket leading to the heme molecule were found in Dictyostelium DyPA. Further, we identified two substrate-binding pockets per monomer in Dictyostelium DyPA at the dimer interface. Long-range electron transfer pathways associated with a hydrogen-bonding network that connects the substrate-binding sites with the heme moiety are described.


Assuntos
Corantes/química , Dictyostelium/enzimologia , Heme/química , Peróxido de Hidrogênio/química , Peroxidase/química , Peroxidase/metabolismo , Catálise , Domínio Catalítico , Cristalografia por Raios X , Heme/metabolismo , Ligação de Hidrogênio , Oxirredução
2.
Biosensors (Basel) ; 11(7)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201518

RESUMO

Metal-organic framework (MOF) nanozymes, as emerging members of the nanozymes, have received more and more attention due to their composition and structural characteristics. In this work, we report that mixed-valence state Ce-MOF (MVCM) has intrinsic haloperoxidase-mimicking activity. MVCM was synthesized by partial oxidation method using Ce-MOF as a precursor. In the presence of H2O2 and Br-, MVCM can catalyze oxidative bromination of chromogenic substrate phenol red (PR) to produce the blue product bromophenol blue (Br4PR), showing good haloperoxidase-like activity. Because of the special chromogenic substrate, we constructed a ratiometric colorimetric-sensing platform by detecting the absorbance of the MVCM-(PR, Br-) system at wavelengths of 590 and 430, for quantifying H2O2, where the detection limit of the H2O2 is 3.25 µM. In addition, the haloperoxidase-mimicking mechanism of the MVCM is proposed. Moreover, through enzyme kinetics monitoring, the Km (H2O2 and NH4Br) of the MVCM is lower than that of cerium oxide nanomaterials, indicating that the MVCM has a stronger binding affinity for H2O2 and NH4Br than other materials. This work provides more application prospects for the development of nanozymes in the field of biosensors in the future.


Assuntos
Colorimetria , Peróxido de Hidrogênio/análise , Materiais Biomiméticos , Técnicas Biossensoriais , Catálise , Cério , Limite de Detecção , Estruturas Metalorgânicas , Oxirredução
3.
Water Sci Technol ; 84(1): 159-171, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34280161

RESUMO

Magnetite nanoparticles (Fe3O4-NPs)/orange peel (MOP) composite was prepared via one-step in-situ co-precipitation method as magnetic heterogeneous Fenton-like catalyst. The properties of MOP were characterized by scanning electron microscopy, transmission electron microscopes, Brunauer-Emmett-Teller, X-ray diffraction, Fourier-transform infrared, thermogravimetric analysis and X-ray photoelectron spectroscopy technologies. Its Fenton-like catalytic responses towards removal of methyl orange (MO) were investigated, in which the effects of initial dye concentration, pH, temperature and hydrogen peroxide dosage were studied. The MO degradation ratio up to 98.0% was obtained within 20 min in optimized conditions. The catalyst showed excellent catalytic stability exhibiting nearly 90% degradation ratio in the 10th cycle within 20 min, whereas pure Fe3O4-NPs showed only 62.5% in this stage. Due to the stabilization of complexing orange peel hydroxyl to iron oxide in the composite and its magnetic separation property, MOP composite exhibits excellent Fenton-like catalytic performance, which offers great prospects for low-cost and high-efficiency organic dye wastewater treatment.


Assuntos
Citrus sinensis , Compostos Azo , Catálise , Peróxido de Hidrogênio , Ferro , Fenômenos Magnéticos
4.
Molecules ; 26(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199465

RESUMO

Hydrogen peroxide (H2O2) plays an important role in the human body and monitoring its level is meaningful due to the relationship between its level and diseases. A fluorescent sensor (CMB) based on coumarin was designed and its ability for detecting hydrogen peroxide by fluorescence signals was also studied. The CMB showed an approximate 25-fold fluorescence enhancement after adding H2O2 due to the interaction between the CMB and H2O2 and had the potential for detecting physiological H2O2. It also showed good biocompatibility and permeability, allowing it to penetrate cell membranes and zebrafish tissues, thus it can perform fluorescence imaging of H2O2 in living cells and zebrafish. This probe is a promising tool for monitoring the level of H2O2 in related physiological and pathological research.


Assuntos
Cumarínicos/química , Corantes Fluorescentes/química , Peróxido de Hidrogênio/análise , Animais , Membrana Celular , Humanos , Células MCF-7 , Imagem Óptica , Peixe-Zebra
5.
Molecules ; 26(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203560

RESUMO

A number of plants used in folk medicine in Thailand and Eastern Asia are attracting interest due to the high bioactivities of their extracts. The aim of this study was to screen the edible leaf extracts of 20 plants found in Thailand and investigate the potential neuroprotective effects of the most bioactive sample. The total phenol and flavonoid content and 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity were determined for all 20 leaf extracts. Based on these assays, Glochidion littorale leaf extract (GLE), which showed a high value in all tested parameters, was used in further experiments to evaluate its effects on neurodegeneration in Caenorhabditis elegans. GLE treatment ameliorated H2O2-induced oxidative stress by attenuating the accumulation of reactive oxygen species and protected the worms against 1-methyl-4-phenylpyridinium-induced neurodegeneration. The neuroprotective effects observed may be associated with the activation of the transcription factor DAF-16. The characterization of this extract by LC-MS identified several phenolic compounds, including myricetin, coumestrin, chlorogenic acid, and hesperidin, which may play a key role in neuroprotection. This study reports the novel neuroprotective activity of GLE, which may be used to develop treatments for neurodegenerative diseases such as Parkinson's syndrome.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Fármacos Neuroprotetores , Estresse Oxidativo/efeitos dos fármacos , Phyllanthus/química , Extratos Vegetais , Animais , Peróxido de Hidrogênio/farmacologia , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia
6.
Anal Chim Acta ; 1174: 338738, 2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34247736

RESUMO

Cysteine (Cys) is a critical amino acid that involves in many physiological and pathological processes in the human body, and it plays an important role in maintaining redox homeostasis in living systems. The concentration of intracellular Cys is abnormal under oxidative stress thus leading to many diseases. Therefore, it is significant to develop an effective method for detection of Cys under oxidative stress. In this work, we propose a new polymer-based ratiometric fluorescent probe with good selectivity and sensitivity for detecting Cys. The bioimaging experiments results show that the novel probe has a rapid ratiometric response to Cys, which can be used to monitor Cys level changes during LPS or H2O2 induced oxidative stress in living cells and zebrafish.


Assuntos
Cisteína , Corantes Fluorescentes , Animais , Cisteína/metabolismo , Células HeLa , Humanos , Peróxido de Hidrogênio/toxicidade , Lipopolissacarídeos/toxicidade , Estresse Oxidativo , Polímeros/toxicidade , Espectrometria de Fluorescência , Peixe-Zebra
7.
Molecules ; 26(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204227

RESUMO

Anneslea fragrans Wall., commonly known as "Pangpo Tea", is traditionally used as a folk medicine and healthy tea for the treatment of liver and intestine diseases. The aim of this study was to purify the antioxidative and cytoprotective polyphenols from A. fragrans leaves. After fractionation with polar and nonpolar organic solvents, the fractions of aqueous ethanol extract were evaluated for their total phenolic (TPC) and flavonoid contents (TFC) and antioxidant activities (DPPH, ABTS, and FRAP assays). The n-butanol fraction (BF) showed the highest TPC and TFC with the strongest antioxidant activity. The bio-guided chromatography of BF led to the purification of six flavonoids (1-6) and one benzoquinolethanoid (7). The structures of these compounds were determined by NMR and MS techniques. Compound 6 had the strongest antioxidant capacity, which was followed by 5 and 2. The protective effect of the isolated compounds on hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells revealed that the compounds 5 and 6 exhibited better protective effects by inhibiting ROS productions, having no significant difference with vitamin C (p > 0.05), whereas 6 showed the best anti-apoptosis activity. The results suggest that A. fragrans could serve as a valuable antioxidant phytochemical source for developing functional food and health nutraceutical products.


Assuntos
Ericales/química , Estresse Oxidativo/efeitos dos fármacos , Fenóis/isolamento & purificação , Antioxidantes/química , Antioxidantes/farmacologia , China , Flavonoides/farmacologia , Células Hep G2 , Humanos , Peróxido de Hidrogênio/farmacologia , Fenóis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Polifenóis/farmacologia
8.
Int J Mol Sci ; 22(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34204881

RESUMO

Mesenchymal stem cells (MSCs) are broadly applied in regenerative therapy to replace cells that are lost or impaired during disease. The low survival rate of MSCs after transplantation is one of the major limitations heavily influencing the success of the therapy. Unfavorable microenvironments with inflammation and oxidative stress in the damaged regions contribute to MSCs loss. Most of the strategies developed to overcome this obstacle are aimed to prevent stress-induced apoptosis, with little attention paid to senescence-another common stress reaction of MSCs. Here, we proposed the strategy to prevent oxidative stress-induced senescence of human endometrial stem cells (hMESCs) based on deferoxamine (DFO) application. DFO prevented DNA damage and stress-induced senescence of hMESCs, as evidenced by reduced levels of reactive oxygen species, lipofuscin, cyclin D1, decreased SA-ß-Gal activity, and improved mitochondrial function. Additionally, DFO caused accumulation of HIF-1α, which may contribute to the survival of H2O2-treated cells. Importantly, cells that escaped senescence due to DFO preconditioning preserved all the properties of the initial hMESCs. Therefore, once protecting cells from oxidative damage, DFO did not alter further hMESCs functioning. The data obtained may become the important prerequisite for development of a new strategy in regenerative therapy based on MSCs preconditioning using DFO.


Assuntos
Desferroxamina/farmacologia , Endométrio/efeitos dos fármacos , Inflamação/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Microambiente Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Ciclina D1/genética , Endométrio/citologia , Endométrio/crescimento & desenvolvimento , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/toxicidade , Inflamação/induzido quimicamente , Inflamação/patologia , Lipofuscina/genética , Células-Tronco Mesenquimais/efeitos dos fármacos , Espécies Reativas de Oxigênio , Medicina Regenerativa , Transdução de Sinais/efeitos dos fármacos
9.
Int J Mol Sci ; 22(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34205973

RESUMO

The Arabidopsis AtCRK5 protein kinase is involved in the establishment of the proper auxin gradient in many developmental processes. Among others, the Atcrk5-1 mutant was reported to exhibit a delayed gravitropic response via compromised PIN2-mediated auxin transport at the root tip. Here, we report that this phenotype correlates with lower superoxide anion (O2•-) and hydrogen peroxide (H2O2) levels but a higher nitric oxide (NO) content in the mutant root tips in comparison to the wild type (AtCol-0). The oxidative stress inducer paraquat (PQ) triggering formation of O2•- (and consequently, H2O2) was able to rescue the gravitropic response of Atcrk5-1 roots. The direct application of H2O2 had the same effect. Under gravistimulation, correct auxin distribution was restored (at least partially) by PQ or H2O2 treatment in the mutant root tips. In agreement, the redistribution of the PIN2 auxin efflux carrier was similar in the gravistimulated PQ-treated mutant and untreated wild type roots. It was also found that PQ-treatment decreased the endogenous NO level at the root tip to normal levels. Furthermore, the mutant phenotype could be reverted by direct manipulation of the endogenous NO level using an NO scavenger (cPTIO). The potential involvement of AtCRK5 protein kinase in the control of auxin-ROS-NO-PIN2-auxin regulatory loop is discussed.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Ácidos Indolacéticos/metabolismo , Proteínas Serina-Treonina Quinases/genética , Receptores de Superfície Celular/genética , Arabidopsis/crescimento & desenvolvimento , Transporte Biológico/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Gravitação , Gravitropismo/genética , Peróxido de Hidrogênio/farmacologia , Meristema/genética , Meristema/crescimento & desenvolvimento , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Paraquat/farmacologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo
10.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207072

RESUMO

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3-88.2% and 81.8-86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.


Assuntos
Cádmio/química , Cromo/química , Metais Pesados/química , Phoeniceae/química , Sementes/química , Água/química , Adsorção , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
11.
BMC Plant Biol ; 21(1): 326, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229625

RESUMO

BACKGROUND: Glycolate oxidase (GLO) is not only a key enzyme in photorespiration but also a major engine for H2O2 production in plants. Catalase (CAT)-dependent H2O2 decomposition has been previously reported to be involved in the regulation of IAA biosynthesis. However, it is still not known which mechanism contributed to the H2O2 production in IAA regulation. RESULTS: In this study, we found that in glo mutants of rice, as H2O2 levels decreased IAA contents significantly increased, whereas high CO2 abolished the difference in H2O2 and IAA contents between glo mutants and WT. Further analyses showed that tryptophan (Trp, the precursor for IAA biosynthesis in the Trp-dependent biosynthetic pathway) also accumulated due to increased tryptophan synthetase ß (TSB) activity. Moreover, expression of the genes involved in Trp-dependent IAA biosynthesis and IBA to IAA conversion were correspondingly up-regulated, further implicating that both pathways contribute to IAA biosynthesis as mediated by the GLO-dependent production of H2O2. CONCLUSION: We investigated the function of GLO in IAA signaling in different levels from transcription, enzyme activities to metabolic levels. The results suggest that GLO-dependent H2O2 signaling, essentially via photorespiration, confers regulation over IAA biosynthesis in rice plants.


Assuntos
Oxirredutases do Álcool/metabolismo , Peróxido de Hidrogênio/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/enzimologia , Oxirredutases do Álcool/genética , Vias Biossintéticas/efeitos da radiação , Respiração Celular/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Modelos Biológicos , Mutação/genética , Oryza/genética , Oryza/efeitos da radiação , Peroxissomos/metabolismo , Peroxissomos/efeitos da radiação , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Triptofano/metabolismo
12.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 37(8): 687-692, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34236028

RESUMO

Objective To investigate the effect of N-acetylcysteine (NAC) on the proliferation of fibroblast-like synoviocytes (FLS) treated with low concentration of hydrogen peroxide (H2O2) in rats with adjuvant arthritis (AA) and its mechanism. Methods Twenty SD rats were divided into a normal group and a model group (10 rats in each group). The model group was established by subcutaneous injection of Freund's complete adjuvant into the toe of rats, and the rats were sacrificed 28 days later. The contents of serum malondialdehyde (MDA) were detected by thiobarbituric acid method; the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined by hydroxylamine method and colorimetry respectively; and Nrf2 and Keap1 proteins in ankle synovial tissues of AA rats were detected by immunohistochemistry. AA-FLS were isolated, cultured, and identified by digestion of ankle joint slides of AA rats in vitro. The effects of NAC at different concentrations (final concentration 0, 0.3, 0.9, 3, 10, 30, 90, 180 µmol/L) on the activity of AA-FLS treated with H2O2 at low concentration (5 µmol/L) were detected by CCK-8 assay. The content of mitochondrial reactive oxygen species (ROS) in AA-FLS was detected by MitoSOX fluorescent probe. The effects of NAC (final concentration 0, 3, 10, 30 µmol/L) on Nrf2 and Keap1 protein expressions in AA-FLS treated with H2O2 at low concentration were detected by Western blotting. Results Compared with those in the control group, in AA model, the MDA level increased and SOD and GSH-Px levels decreased in serum, and the Nrf2 protein increased and the Keap1 protein decreased in synovial tissue. Immunocytochemical staining confirmed that the isolated and cultured cells were AA-FLS; NAC inhibited the proliferation of AA-FLS treated with H2O2 in a concentration-dependent manner, and the mitochondrial ROS content and the protein expressions of Nrf2 and Keap1 decreased. Conclusion NAC can inhibit the proliferation of AA-FLS treated with H2O2, which may be related to blocking Nrf2/Keap1 pathway.


Assuntos
Artrite Experimental , Sinoviócitos , Acetilcisteína/farmacologia , Animais , Artrite Experimental/tratamento farmacológico , Proliferação de Células , Fibroblastos/metabolismo , Peróxido de Hidrogênio , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Ratos , Ratos Sprague-Dawley , Sinoviócitos/metabolismo
13.
Molecules ; 26(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198860

RESUMO

In this study, the lactobacillus fermentation process of pomegranate (Punica granatum L.) peel and Schisandra chinensis (Turcz.) Baill (PP&SC) was optimized by using the response surface method (RSM) coupled with a Box-Behnken design. The optimum fermentation condition with the maximal yield of ellagic acid (99.49 ± 0.47 mg/g) was as follows: 1:1 (w:w) ratio of pomegranate peel to Schisandra chinensis, 1% (v:v) of strains with a 1:1 (v:v) ratio of Lactobacillus Plantarum to Streptococcus Thermophilus, a 37 °C fermentation temperature, 33 h of fermentation time, 1:20 (g:mL) of a solid-liquid ratio and 3 g/100 mL of a glucose dosage. Under these conditions, the achieved fermentation broth (FB) showed stronger free radical scavenging abilities than the water extract (WE) against the ABTS+, DPPH, OH- and O2- radicals. The cytotoxicity and the protective effect of FB on the intracellular ROS level in HaCaT cells were further detected by the Cell Counting Kit-8 (CCK-8) assay. The results showed that FB had no significant cytotoxicity toward HaCaT cells when its content was no more than 8 mg/mL. The FB with a concentration of 8 mg/mL had a good protective effect against oxidative damage, which can effectively reduce the ROS level to 125.94% ± 13.46% (p < 0.001) compared with 294.49% ± 11.54% of the control group in H2O2-damaged HaCaT cells. The outstanding antioxidant ability and protective effect against H2O2-induced oxidative damage in HaCaT cells promote the potential for the FB of PP&SC as a functional raw material of cosmetics.


Assuntos
Antioxidantes/farmacologia , Fatores Biológicos/farmacologia , Peróxido de Hidrogênio/efeitos adversos , Lactobacillus/fisiologia , Romã (Fruta)/microbiologia , Schisandra/microbiologia , Antioxidantes/química , Fatores Biológicos/química , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Ácido Elágico/química , Ácido Elágico/farmacologia , Fermentação , Células HaCaT , Humanos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Romã (Fruta)/química , Espécies Reativas de Oxigênio/metabolismo , Schisandra/química
14.
Biosensors (Basel) ; 11(6)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205541

RESUMO

A magnetic beads (MB)-involved amperometric immunosensor for the determination of ST2, a member of the IL1 receptor family, is reported in this work. The method utilizes a sandwich immunoassay and disposable screen-printed carbon electrodes (SPCEs). Magnetic immunoconjugates built on the surface of carboxylic acid-microsized magnetic particles (HOOC-MBs) were used to selectively capture ST2. A biotinylated secondary antibody further conjugated with a streptavidin peroxidase conjugate (Strep-HRP) was used to accomplish the sandwiching of the target protein. The immune platform exhibits great selectivity and a low limit of detection (39.6 pg mL-1) for ST2, allowing the determination of soluble ST2 (sST2) in plasma samples from healthy individuals and patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) in only 45 min once the immunoconjugates have been prepared. The good correlation of the obtained results with those provided by an ELISA kit performed using the same immunoreagents demonstrates the potential of the developed strategy for early diagnosis and/or prognosis of the fatal PDAC disease.


Assuntos
Técnicas Biossensoriais , Imunoensaio , Neoplasias/diagnóstico , Anticorpos , Carbono , Técnicas Eletroquímicas , Eletrodos , Ensaio de Imunoadsorção Enzimática , Humanos , Peróxido de Hidrogênio , Limite de Detecção , Magnetismo
15.
Nan Fang Yi Ke Da Xue Xue Bao ; 41(6): 953-959, 2021 Jun 20.
Artigo em Chinês | MEDLINE | ID: mdl-34238751

RESUMO

OBJECTIVE: To investigate the apoptosis- inducing effect of fucoxanthin in human prostate cancer PC-3 cells and the underlying mechanism. OBJECTIVE: The viability and apoptosis of PC-3 cells treated with fucoxanthin were analyzed using commercial kits, and the mitochondrial membrane potential, mitochondrial morphology and mitochondrial superoxide were detected using fluorescence probe staining. The contents of ATP, H2O2, malondialdehyde (MDA), superoxide and the total antioxidant capacity of PC-3 cells were determined. The protein expressions of Bcl-2, Bax and cytochrome c were detected with Western blotting, and the activity of caspase-9 and caspase- 3/7 was detected using corresponding kits. OBJECTIVE: Fucoxanthin significantly inhibited the viability of PC-3 cells in a time- and dose-dependent manner, and dose-dependently induced apoptosis of the cells (P < 0.05). Fucoxanthin-treated PC-3 cells showed significantly decreased mitochondrial membrane potential, mitochondrial fragmentation and increased superoxide level in the mitochondria (P < 0.05), and these effects of fucoxanthin were dose- dependent. Fucoxanthin dose-dependently decreased ATP level and the total antioxidant capacity of PC-3 cells, increased the contents of H2O2, MDA and superoxide (all P < 0.05), enhanced the protein expressions of Bax and cytochrome c in the cytoplasm, and lowered the protein expressions of Bcl-2 and cytochromes in the mitochondria (P < 0.05). OBJECTIVE: Fucoxanthin induces apoptosis of PC-3 cells by triggering mitochondrial dysfunction to cause oxidative stress and by activating mitochondria-mediated apoptotic signaling pathways, suggesting its potential in prostate cancer treatment.


Assuntos
Peróxido de Hidrogênio , Neoplasias da Próstata , Apoptose , Humanos , Peróxido de Hidrogênio/metabolismo , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Estresse Oxidativo , Células PC-3 , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Xantofilas , Proteína X Associada a bcl-2/metabolismo
16.
BMJ Open ; 11(7): e048687, 2021 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-34275864

RESUMO

OBJECTIVES: To compare the impact of respirator extended use and reuse strategies with regard to cost and sustainability during the COVID-19 pandemic. DESIGN: Cost analysis. SETTING: USA. PARTICIPANTS: All healthcare workers within the USA. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A model was developed to estimate usage, costs and waste incurred by several respirator usage strategies over the first 6 months of the pandemic in the USA. This model assumed universal masking of all healthcare workers. Estimates were taken from the literature, government databases and commercially available data from approved vendors. RESULTS: A new N95 respirator per patient encounter would require 7.41 billion respirators, cost $6.38 billion and generate 84.0 million kg of waste in the USA over 6 months. One respirator per day per healthcare worker would require 3.29 billion respirators, cost $2.83 billion and generate 37.22 million kg of waste. Decontamination by ultraviolet germicidal irradiation would require 1.64 billion respirators, cost $1.41 billion and accumulate 18.61 million kg of waste. H2O2 vapour decontamination would require 1.15 billion respirators, cost $1.65 billion and produce 13.03 million kg of waste. One reusable respirator with daily disposable filters would require 18 million respirators, cost $1.24 billion and generate 15.73 million kg of waste. Pairing a reusable respirator with H2O2 vapour-decontaminated filters would reduce cost to $831 million and generate 1.58 million kg of waste. The use of one surgical mask per healthcare worker per day would require 3.29 billion masks, cost $460 million and generate 27.92 million kg of waste. CONCLUSIONS: Decontamination and reusable respirator-based strategies decreased the number of respirators used, costs and waste generated compared with single-use or daily extended-use of disposable respirators. Future development of low-cost,simple technologies to enable respirator and/or filter decontamination is needed to further minimise the economic and environmental costs of masks.


Assuntos
COVID-19 , Pandemias , Descontaminação , Humanos , Peróxido de Hidrogênio , Máscaras , SARS-CoV-2 , Ventiladores Mecânicos
17.
Biosensors (Basel) ; 11(6)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200755

RESUMO

Prussian blue analogs (PBAs) are well-known artificial enzymes with peroxidase (PO)-like activity. PBAs have a high potential for applications in scientific investigations, industry, ecology and medicine. Being stable and both catalytically and electrochemically active, PBAs are promising in the construction of biosensors and biofuel cells. The "green" synthesis of PO-like PBAs using oxido-reductase flavocytochrome b2 is described in this study. When immobilized on graphite electrodes (GEs), the obtained green-synthesized PBAs or hexacyanoferrates (gHCFs) of transition and noble metals produced amperometric signals in response to H2O2. HCFs of copper, iron, palladium and other metals were synthesized and characterized by structure, size, catalytic properties and electro-mediator activities. The gCuHCF, as the most effective PO mimetic with a flower-like micro/nano superstructure, was used as an H2O2-sensitive platform for the development of a glucose oxidase (GO)-based biosensor. The GO/gCuHCF/GE biosensor exhibited high sensitivity (710 A M-1m-2), a broad linear range and good selectivity when tested on real samples of fruit juices. We propose that the gCuHCF and other gHCFs synthesized via enzymes may be used as artificial POs in amperometric oxidase-based (bio)sensors.


Assuntos
Técnicas Biossensoriais , Ferrocianetos/química , Peroxidase/análise , Fontes de Energia Bioelétrica , Eletroquímica , Eletrodos , Enzimas Imobilizadas , Glucose , Glucose Oxidase , Grafite , Peróxido de Hidrogênio , Oxirredutases , Paládio , Peroxidases
18.
Artigo em Inglês | MEDLINE | ID: mdl-34281105

RESUMO

To cope with the shortage of filtering facepiece respirators (FFRs) caused by the coronavirus disease (COVID-19), healthcare institutions have been forced to reuse FFRs using different decontamination methods, including vapor hydrogen peroxide (VHP). However, most healthcare institutions still struggle with evaluating the effect of VHP on filtration efficiency (FE) of the decontaminated FFRs. We developed a low-cost in-house FE assessment using a novel 3D-printed air duct. Furthermore, we assessed the FE of seven types of FFRs. Following 10 VHP cycles, we evaluated the FE of KN95 and 3M-N95 masks. The 3M-N95 and Benehal-N95 masks showed significant lower FE (80.4-91.8%) at fine particle sizes (0.3-1 µm) compared to other FFRs (FE ≥ 98.1%, p < 0.05). Following 10 VHP cycles, the FE of KN95 masks was almost stable (FE stability > 99.1%) for all particle sizes, while 3M-N95 masks were stable only at 2 and 5 µm (FE stability > 98.0%). Statistically, FE stability of 3M-N95 masks at 0.3, 0.5, and 0.7 µm was significantly lower (p ≤ 0.006) than 2 and 5 µm. The in-house FE assessment may be used as an emergency procedure to validate the decontaminated FFRs, as well as a screening option for production control of FFRs. Following VHP cycles, both masks showed high stability at 5 µm, the size of the most suspected droplets implicated in COVID-19 transmission.


Assuntos
COVID-19 , Dispositivos de Proteção Respiratória , Descontaminação , Reutilização de Equipamento , Filtração , Humanos , Peróxido de Hidrogênio , SARS-CoV-2 , Ventiladores Mecânicos
19.
Appl Microbiol Biotechnol ; 105(13): 5419-5431, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34244814

RESUMO

In recent years, an increasing number of studies have shown that fibroblast growth factor 12 (FGF12) plays important roles in regulating neural development and function. Importantly, changes of FGF12 expression are thought to be related to the pathophysiology of many neurological diseases. However, little research has been performed to explore the protective effect of FGF12 on nerve damage. This study aims to explore its neuroprotective effects using our recombinant humanized FGF12 (rhFGF12). The hFGF12 gene was cloned and ligated into an expression vector to construct a recombinant plasmid pET-3a-hFGF12. Single colonies were screened to obtain high expression engineering strains, and fermentation and purification protocols for rhFGF12 were designed and optimized. The biological activities and related mechanisms of rhFGF12 were investigated by MTT assay using NIH3T3 and PC12 cell lines. The in vitro neurotoxicity model of H2O2-induced oxidative injury in PC12 cells was established to explore the protective effects of rhFGF12. The results indicate that the beneficial effects of rhFGF12 were most likely achieved by promoting cell proliferation and reducing apoptosis. Moreover, a transgenic zebrafish (islet) with strong GFP fluorescence in the motor neurons of the hindbrain was used to establish a central injury model caused by mycophenolate mofetil (MMF). The results suggested that rhFGF12 could ameliorate central injury induced by MMF in zebrafish. In conclusion, we have established an efficient method to express and purify active rhFGF12 using an Escherichia coli expression system. Besides, rhFGF12 plays a protective effect of on nerve damage, and it provides a promising therapeutic approach for nerve injury. KEY POINTS: • Effective expression and purification of bioactive rhFGF12 protein in E. coli. • ERK/MAPK pathway is involved in rhFGF12-stimulated proliferation on PC12 cells. • The rhFGF12 has the neuroprotective effects by inhibiting apoptosis.


Assuntos
Fármacos Neuroprotetores , Animais , Escherichia coli/genética , Fatores de Crescimento de Fibroblastos/genética , Humanos , Peróxido de Hidrogênio , Camundongos , Células NIH 3T3 , Fármacos Neuroprotetores/farmacologia , Ratos , Peixe-Zebra
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 262: 120134, 2021 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-34271238

RESUMO

Studies have shown that changes in the redox state of cells might be closely related to pathological and physiological processes. Sulfur dioxide and hydrogen peroxide, as a significant redox couple in living cells, are endogenously produced by cells. Here, we report a long-wavelength fluorescent probe to reversibly monitor sulfur dioxide and hydrogen peroxide. This probe (NBD) displayed high selectivity and sensitivity, which could be accumulated in mitochondria for real-time imaging of SO2/H2O2. These results indicated that NBD would be an ideal tool for monitoring the redox cycle state in living cells.


Assuntos
Corantes Fluorescentes , Peróxido de Hidrogênio , Células HeLa , Humanos , Mitocôndrias , Imagem Óptica , Dióxido de Enxofre
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