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1.
Anal Chim Acta ; 1221: 340143, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35934375

RESUMO

Damaging the structure of the G-quadruplex (G4) to prevent the formation of the G4/hemin complex is presently the only available method to inhibit the activity of the peroxidase-mimic DNAzyme. In this study, a unique intramolecular inhibitory effect of the adjacent base-pair (InE(N:N)), by installing a rationally adjacent base-pair of the G4 core sequence, is proposed for the inhibition of the DNAzyme activity, which eliminates the need to damage the entire G4 structure. Various base pairs show different abilities to inhibit DNAzyme activity. The adjacent adenine: thymine pair possesses the best inhibitory efficiency (17 times). Through detailed investigations of the InE(N:N), it was revealed that the adjacent adenine: thymine pair downregulated the formation of compound I in the catalytic process, thus inhibiting the G4 DNAzyme activity. The mechanism of inhibition indicated that the carbonyl group on the hexatomic ring of the complementary base played an important role. To further reflect the advantages of the proposed strategy, two InE(N:N)-based biosensors were developed for DNA analysis and Uracil-DNA glycosylase (UDG) detection. Compared with existing DNAzyme-based methods, the application of InE(N: N) facilitates the real-time assay and simplifies the design difficulty. Therefore, InE(N:N) provides new insights into the regulation of the DNAzyme activity and offers an efficient approach for the future application of DNAzyme.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , Quadruplex G , Adenina , Técnicas Biossensoriais/métodos , Corantes , DNA Catalítico/química , Hemina/química , Peroxidase/metabolismo , Peroxidases/química , Timina
2.
Nat Commun ; 13(1): 4658, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35945238

RESUMO

The mechanisms linking systemic infection to hyperinflammation and immune dysfunction in sepsis are poorly understood. Extracellular histones promote sepsis pathology, but their source and mechanism of action remain unclear. Here, we show that by controlling fungi and bacteria captured by splenic macrophages, neutrophil-derived myeloperoxidase attenuates sepsis by suppressing histone release. In systemic candidiasis, microbial capture via the phagocytic receptor SIGNR1 neutralizes myeloperoxidase by facilitating marginal zone infiltration and T cell death-dependent histone release. Histones and hyphae induce cytokines in adjacent CD169 macrophages including G-CSF that selectively depletes mature Ly6Ghigh neutrophils by shortening their lifespan in favour of immature Ly6Glow neutrophils with a defective oxidative burst. In sepsis patient plasma, these mediators shorten mature neutrophil lifespan and correlate with neutrophil mortality markers. Consequently, high G-CSF levels and neutrophil lifespan shortening activity are associated with sepsis patient mortality. Hence, by exploiting phagocytic receptors, pathogens degrade innate and adaptive immunity through the detrimental impact of downstream effectors on neutrophil lifespan.


Assuntos
Neutrófilos , Sepse , Fator Estimulador de Colônias de Granulócitos/metabolismo , Histonas/metabolismo , Humanos , Longevidade , Macrófagos/metabolismo , Peroxidase/metabolismo , Linfócitos T/metabolismo
3.
Redox Biol ; 54: 102385, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35803124

RESUMO

Peroxidasin (PXDN) is involved in the crosslinking of collagen IV, a major constituent of basement membranes. Disruption of basement membrane integrity as observed in genetic alterations of collagen IV or PXDN can result in developmental defects and diverse pathologies. Hence, the study of PXDN activity in (patho)physiological contexts is highly relevant. So far, measurements of PXDN activity have been reported from purified proteins, cell lysates and de-cellularized extracellular matrix. Here, for the first time we report the measurement of PXDN activity in live cells using the Amplex Red assay with a signal amplifying modification. We observe that bromide addition enhances the obtained signal, most likely due to formation of HOBr. Abrogation of signal amplification by the HOBr scavenger carnosine supports this hypothesis. Both, pharmacological inhibition as well as complementary genetic approaches confirm that the obtained signal is indeed related to PXDN activity. We validate the modified assay by investigating the effect of Brefeldin A, to inhibit the secretory pathway and thus the access of PXDN to the extracellular Amplex Red dye. Our method opens up new possibilities to investigate the activity of PXDN in (patho)physiological contexts.


Assuntos
Brometos , Proteínas da Matriz Extracelular , Colágeno Tipo IV/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Peroxidase/metabolismo
4.
Nat Plants ; 8(7): 828-839, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35851622

RESUMO

At present, a cooperative process hypothesis is used to explain the supply of enzyme (class III peroxidases and/or laccases) and substrates during lignin polymerization. However, it remains elusive how xylem cells meet the needs of early lignin rapid polymerization during secondary cell wall formation. Here we provide evidence that a mitochondrial ascorbate peroxidase (PtomtAPX) is responsible for autonomous lignification during the earliest stage of secondary cell wall formation in Populus tomentosa. PtomtAPX was relocated to cell walls undergoing programmed cell death and catalysed lignin polymerization in vitro. Aberrant phenotypes were caused by altered PtomtAPX expression levels in P. tomentosa. These results reveal that PtomtAPX is crucial for catalysing lignin polymerization during the early stages of secondary cell wall formation and xylem development, and describe how xylem cells provide autonomous enzymes needed for lignin polymerization during rapid formation of the secondary cell wall by coupling with the programmed cell death process.


Assuntos
Populus , Regulação da Expressão Gênica de Plantas , Lignina , Peroxidase/genética , Peroxidase/metabolismo , Peroxidases/genética , Peroxidases/metabolismo , Xilema/metabolismo
5.
Mikrochim Acta ; 189(8): 290, 2022 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-35879483

RESUMO

The pathway from the advanced electrocatalyst to nanozymes defeating natural enzyme is reviewed. Prussian blue, being the most advantageous electrocatalyst for hydrogen peroxide reduction, is obviously the best candidate for mimicking peroxidase activity. Indeed, catalytically synthesized Prussian blue nanoparticles are characterized by the catalytic rate constants, which are significantly (up to 4 orders of magnitude) higher than for enzyme peroxidase. Displaying in addition the enzymatic specificity in terms of an absence of oxidase-like activity, catalytically synthesized Prussian blue nanoparticles can be referred to as nanozymes. The latter provide the most versatile method for surface covering with the electrocatalyst, allowing to modify non-traditional materials like boron-doped diamond. For stabilization, Prussian blue core can be covered with nickel hexacyanoferrate shell; the resulting core-shell nanozymes still defeat natural enzyme in terms of activity. Discovering the catalytic pathway of nanozymes "artificial peroxidase" action, we have found the novel advantage of nanozymes over the corresponding biological catalysts: their dramatically (100 times) improved bimolecular rate constants.


Assuntos
Nanopartículas , Peroxidase , Catálise , Ferrocianetos , Peroxidase/metabolismo , Peroxidases
6.
Int J Mol Sci ; 23(15)2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35897821

RESUMO

Macrophages are present in every tissue in the body and play essential roles in homeostasis and host defense against microorganisms. Some tissue macrophages derive from the yolk sac/fetal liver that populate tissues for life. Other tissue macrophages derive from monocytes that differentiate in the bone marrow and circulate through tissues via the blood and lymphatics. Circulating monocytes are very plastic and differentiate into macrophages with specialized functions upon entering tissues. Specialized monocyte/macrophage subsets have been difficult to differentiate based on cell surface markers. Here, using a combination of "pan" monocyte/macrophage markers and flow cytometry, we asked whether myeloperoxidase (MPO) could be used as a marker of pro-inflammatory monocyte/macrophage subsets. MPO is of interest because of its potent microbicidal activity. In wild-type SPF housed mice, we found that MPO+ monocytes/macrophages were present in peripheral blood, spleen, small and large intestines, and mesenteric lymph nodes, but not the central nervous system. Only monocytes/macrophages that expressed cell surface F4/80 and/or Ly6C co-expressed MPO with the highest expression in F4/80HiLy6CHi subsets regardless of tissue. These cumulative data indicate that MPO expression can be used as an additional marker to differentiate between monocyte/macrophage subsets with pro-inflammatory and microbicidal activity in a variety of tissues.


Assuntos
Monócitos , Peroxidase , Animais , Biomarcadores/metabolismo , Contagem de Leucócitos , Macrófagos/metabolismo , Camundongos , Monócitos/metabolismo , Peroxidase/metabolismo
7.
Biochem Biophys Res Commun ; 622: 108-114, 2022 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-35843089

RESUMO

Apolipoprotein A-I (apoA-I), the main protein component of High-Density Lipoprotein (HDL), is modified in plasma and the arterial wall by various enzymes. Myeloperoxidase (MPO), a leukocyte-derived peroxidase, is highly expressed during inflammation and associates with HDL reducing its functionality and contributing to atherosclerosis. In the present study we sought to explore further the effect of MPO on HDL structure and functionality in vivo using adenovirus-mediated gene transfer of human MPO combined with human apoA-I forms containing substitutions at MPO-sensitive sites or wild type apoA-I. We found that overexpression of MPO in mice significantly increased plasma apoA-I and HDL levels without affecting the expression of genes involved in HDL biogenesis or catabolism in the liver. Overexpression of MPO in the liver reduced the expression of pro-inflammatory genes and increased or did not affect the expression of anti-inflammatory genes suggesting that MPO had no toxic effects in this organ. In the plasma of mice overexpressing MPO, no significant alterations in HDL size or electrophoretic mobility was observed with the exception of mice expressing apoA-I (M148A) which showed enriched pre-ß relative to α HDL particles, suggesting that the apoA-I (M148A) mutation may interfere with HDL remodelling. Overexpression of MPO was associated with reduced anti-oxidant capacity of HDL particles in all mice. Interestingly, HDL particles bearing apoA-I (Y192A) showed enhanced ABCA1-dependent cholesterol efflux from macrophages which was not affected by MPO and these mice had reduced levels of LDL-c. These findings provide new insights on the role of specific amino acid residues of apoA-I in HDL structure and function following modification by MPO. This knowledge may facilitate the development of novel therapies based on improved HDL forms for patients with chronic diseases that are characterized by dysfunctional HDL.


Assuntos
Infecções por Adenoviridae , Apolipoproteína A-I , Transportador 1 de Cassete de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Adenoviridae/genética , Adenoviridae/metabolismo , Animais , Apolipoproteína A-I/metabolismo , Humanos , Lipoproteínas HDL , Camundongos , Peroxidase/genética , Peroxidase/metabolismo
8.
Cells ; 11(11)2022 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-35681467

RESUMO

Peroxiredoxins are multifunctional enzymes that play a key role in protecting cells from stresses and maintaining the homeostasis of many cellular processes. Peroxiredoxins were firstly identified as antioxidant enzymes that can be found in all living organisms. Later studies demonstrated that peroxiredoxins also act as redox signaling regulators, chaperones, and proinflammatory factors and play important roles in oxidative defense, redox signaling, protein folding, cycle cell progression, DNA integrity, inflammation, and carcinogenesis. The versatility of peroxiredoxins is mainly based on their unique active center cysteine with a wide range of redox states and the ability to switch between low- and high-molecular-weight species for regulating their peroxidase and chaperone activities. Understanding the molecular mechanisms of peroxiredoxin in these processes will allow the development of new approaches to enhance longevity and to treat various cancers. In this article, we briefly review the history of peroxiredoxins, summarize recent advances in our understanding of peroxiredoxins in aging- and cancer-related biological processes, and discuss the future perspectives of using peroxiredoxins in disease diagnostics and treatments.


Assuntos
Neoplasias , Peroxirredoxinas , Antioxidantes/metabolismo , Humanos , Neoplasias/metabolismo , Oxirredução , Peroxidase/metabolismo , Peroxirredoxinas/metabolismo
9.
Free Radic Biol Med ; 188: 162-174, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35718304

RESUMO

Myeloperoxidase (MPO) mediates pathogen destruction by generating the bactericidal oxidant hypochlorous acid (HOCl). Formation of this oxidant is however associated with host tissue damage and disease. MPO also utilizes H2O2 to oxidize other substrates, and we hypothesized that mixtures of other plasma anions, including bromide (Br-), iodide (I-), thiocyanate (SCN-) and nitrite (NO2-), at normal or supplemented concentrations, might modulate MPO-mediated HOCl damage. For the (pseudo)halide anions, only SCN- significantly modulated HOCl formation (IC50 ∼33 µM), which is within the normal physiological range, as judged by damage to human plasma fibronectin or extracellular matrix preparations detected by ELISA and LC-MS. NO2- modulated HOCl-mediated damage, in a dose-dependent manner, at physiologically-attainable anion concentrations. However, this was accompanied by increased tyrosine and tryptophan nitration (detected by ELISA and LC-MS), and the overall extent of damage remained approximately constant. Increasing NO2- concentrations (0.5-20 µM) diminished HOCl-mediated modification of tyrosine and methionine, whereas tryptophan loss was enhanced. At higher NO2- concentrations, enhanced tyrosine and methionine loss was detected. These analytical data were confirmed in studies of cell adhesion and metabolic activity. Together, these data indicate that endogenous plasma levels of SCN- (but not Br- or I-) can modulate protein modification induced by MPO, including the extent of chlorination. In contrast, NO2- alters the type of modification, but does not markedly decrease its extent, with chlorination replaced by nitration. These data also indicate that MPO could be a major source of nitration in vivo, and particularly at inflammatory sites where NO2- levels are often elevated.


Assuntos
Nitritos , Peroxidase , Matriz Extracelular/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Ácido Hipocloroso/metabolismo , Metionina , Nitritos/farmacologia , Dióxido de Nitrogênio , Oxidantes/metabolismo , Peroxidase/metabolismo , Triptofano , Tirosina/metabolismo
10.
Leukemia ; 36(8): 2086-2096, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35761024

RESUMO

Myeloperoxidase (MPO) gene alterations with variable clinical penetrance have been found in hereditary MPO deficiency, but their leukemia association in patients and carriers has not been established. Germline MPO alterations were found to be significantly enriched in myeloid neoplasms: 28 pathogenic/likely pathogenic variants were identified in 100 patients. The most common alterations were c.2031-2 A > C, R569W, M519fs* and Y173C accounting for about half of the cases. While functional experiments showed that the marrow stem cell pool of Mpo-/- mice was not increased, using competitive repopulation demonstrated that Mpo-/- grafts gained growth advantage over MPO wild type cells. This finding also correlated with increased clonogenic potential after serial replating in the setting of H2O2-induced oxidative stress. Furthermore, we demonstrated that H2O2-induced DNA damage and activation of error-prone DNA repair may result in secondary genetic damage potentially predisposing to leukemia leukemic evolution. In conclusion, our study for the first time demonstrates that germline MPO variants may constitute risk alleles for MN evolution.


Assuntos
Leucemia , Transtornos Mieloproliferativos , Neoplasias , Animais , Células Germinativas/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Leucemia/genética , Camundongos , Peroxidase/genética , Peroxidase/metabolismo
11.
Methods Mol Biol ; 2506: 281-295, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35771479

RESUMO

Neutrophil extracellular traps (NETs) have the ability to regulate many aspects of asthma pathology. NETs can be detected either in bronchoalveolar lavage fluids (BALF) or in lung biopsies. Here, we describe methods to quantify NETs in BALF, namely the quantification of cell-free DNA, or of myeloperoxidase (MPO) or neutrophil elastase (NE) complexed with cell-free DNA. We also explain how to detect NETs in lung biopsies by two distinct techniques. The first technique is based on quantification of the citrullinated form of histone 3 (Cit-H3 , a specific component of NET) by western blot on tissue protein extracts. The second technique is based on the visualization of extracellular structures composed of MPO co-localizing with Cit-H3 in tissue sections by confocal microscopy. Finally, we describe a method allowing for quantification of NET volume in lung sections.


Assuntos
Asma , Ácidos Nucleicos Livres , Armadilhas Extracelulares , Asma/diagnóstico , Asma/metabolismo , Líquido da Lavagem Broncoalveolar , Ácidos Nucleicos Livres/metabolismo , Armadilhas Extracelulares/metabolismo , Humanos , Neutrófilos/metabolismo , Peroxidase/metabolismo
12.
AAPS PharmSciTech ; 23(6): 170, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35729366

RESUMO

UV radiation can cause damages, such as erythema, skin photoaging, and carcinogenesis. The adoption of protective measures against sun exposure is essential to prevent these damages, and the interest in using natural substances as an alternative for photoprotection is growing. Thus, hesperetin with antioxidant, anti-inflammatory, and anticancer properties is a promising substance to be used with photochemopreventive action and to protect the skin from damage induced by UV radiation. Therefore, the present study aimed to develop a topical formulation based on AAMVPC gel containing hesperetin and evaluate its photoprotective effect on the skin of rats exposed to UVA-UVB radiation. The animals were submitted to the irradiation protocol UVA-UVB, and at the end, erythema, lipid peroxidation, and activity of the antioxidant enzyme catalase and superoxide dismutase were evaluated. Additionally, it evaluated the activity of myeloperoxidase and histological changes. The formulation presented a rheological and spreadability profile suitable for cutaneous application. In vivo results demonstrated that the topical formulation of AAMVPC gel containing hesperetin at a concentration of 10% protected the skin from damage induced by UVA-UVB radiation, with the absence of erythema, lipid lipoperoxidation, and inflammation (low myeloperoxidase activity), and increased catalase and superoxide dismutase activities. The morphology and architecture of the dermo-epidermal tissue of these animals were like those observed under normal conditions (non-irradiated animals). Thus, the results showed that hesperetin was able to protect the animals' skin against UV radiation-induced skin damage and the protection mechanisms may be related to the antioxidant and anti-inflammatory properties of this natural product.


Assuntos
Peroxidase , Raios Ultravioleta , Animais , Anti-Inflamatórios/metabolismo , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Catalase , Hesperidina , Hidrogéis/metabolismo , Estresse Oxidativo , Peroxidase/metabolismo , Peroxidase/farmacologia , Ratos , Pele/metabolismo , Superóxido Dismutase/metabolismo , Superóxido Dismutase/farmacologia , Raios Ultravioleta/efeitos adversos
13.
J Hazard Mater ; 436: 129165, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35739705

RESUMO

Nanozyme-based dye degradation methods are promising for the remediation of water pollution. Though Pd nanoparticles (PdNPs) are known to act as nanozymes, their dye degradation capability has not been investigated. Low nanozyme activities, easy aggregation, difficulties in recovery and reuse are the major challenges in achieving this. For the first time, cellulose nanofibrils-supported PdNPs (PdNPs/PCNF) as a novel nanozyme with good peroxidase and oxidase-mimicking activities and easy recyclability is explored for dye degradation. An efficient and rapid method of PdNPs/PCNF preparation was demonstrated by adjusting the pH and microwave irradiation. Enzyme kinetic studies revealed good kinetic parameters and specific activities of 415 and 277 U/g for peroxidase and oxidase, respectively. PdNPs/PCNF offered 99.64% degradation of methylene blue within 12 min (0.468 min-1) with 0.4 M H2O2 at pH 5.0. Mechanistic studies revealed the involvement of hydroxyl and superoxide radicals. Owing to the network-like structure of PCNF, films and foams were prepared, their dye degradation potentials were compared, and recyclability was tested. Successful degradation of mixed dye solutions and spiked real water samples was achieved and a continuous flow method was demonstrated using a foam-packed column.


Assuntos
Nanopartículas , Peroxidase , Celulose , Corantes/química , Peróxido de Hidrogênio , Cinética , Nanopartículas/química , Oxirredutases/metabolismo , Peroxidase/metabolismo
14.
Nutrients ; 14(9)2022 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-35565934

RESUMO

Fermented camel's milk has various health beneficial prebiotics and probiotics. This study aimed to evaluate the preventive efficacy of Bacillus amyloliquefaciens enriched camel milk (BEY) in 2-, 4- and 6-Trinitrobenzenesulfonic acid (TNBS)-induced colitis mice models. To this end, the immune modulatory effects of Bacillus amyloliquefaciens (BA) on TNF-α challenged HT29 colon cells were estimated using the cell proliferation and cytokines ELISA method. BEY was prepared using the incubation method and nutritional value was quantified by comparing it to commercial yogurt. Furthermore, TNBS-induced colitis was established and the level of disease index, pathological scores, and inflammatory markers of BEY-treated mice using macroscopic and microscopic examinations, qPCR and immunoblot were investigated. The results demonstrate that BA is non-toxic to HT29 colon cells and balanced the inflammatory cytokines. BEY reduced the colitis disease index, and improved the body weight and colon length of the TNBS-induced mice. Additionally, Myeloperoxidase (MPO) and pro-inflammatory cytokines (IL1ß, IL6, IL8 and TNF-α) were attenuated by BEY treatment. Moreover, the inflammatory progress mRNA and protein markers nuclear factor kappa B (NFκB), phosphatase and tensin homolog (PTEN), proliferating cell nuclear antigen (PCNA), cyclooxygenase-2 (COX-2) and occludin were significantly down-regulated by BEY treatment. Interestingly, significant suppression of PCNA was observed in colonic tissues using the immunohistochemical examination. Treatment with BEY increased the epigenetic (microRNA217) interactions with PCNA. In conclusion, the BEY clearly alleviated the colitis symptoms and in the future could be used to formulate a probiotic-based diet for the host gut health and control the inflammatory bowel syndrome in mammals.


Assuntos
Bacillus amyloliquefaciens , Colite , Animais , Bacillus amyloliquefaciens/metabolismo , Camelus/metabolismo , Colite/induzido quimicamente , Colite/prevenção & controle , Colo/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Camundongos , Leite/metabolismo , Peroxidase/metabolismo , Antígeno Nuclear de Célula em Proliferação , Ácido Trinitrobenzenossulfônico/toxicidade , Fator de Necrose Tumoral alfa/metabolismo
15.
Molecules ; 27(9)2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35566036

RESUMO

Antioxidative peptides that inhibit myeloperoxidase (MPO) enzyme activity can effectively defend against oxidative stress damage. The antioxidant peptides from tuna protein were produced using alcalase hydrolysis and purified by ultrafiltration and Sephadex G-15, and the fractions with the highest free radicals scavenging ability and oxygen radical absorbance capacity (ORAC) values were sequenced using HPLC-MS/MS. Fifty-five peptide sequences were identified, 53 of which were successfully docked into MPO. The representative peptide ACGSDGK had better antioxidant activity and inhibition of MPO chlorination and peroxidation than the reference peptide hLF1-11. The docking model further showed intense molecular interactions between ACGSDGK and MPO, including hydrogen bonds, charge, and salt bridge interactions, which occluded the active site and blocked the catalytic activity of MPO. These results suggested that the antioxidant peptide ACGSDGK has the potential to inhibit oxidative stress and alleviate inflammation in vivo because of its inhibitory effect on the MPO enzyme.


Assuntos
Antioxidantes , Hidrolisados de Proteína , Animais , Antioxidantes/química , Hidrólise , Peptídeos/química , Peroxidase/metabolismo , Hidrolisados de Proteína/química , Espectrometria de Massas em Tandem , Atum/metabolismo
16.
Molecules ; 27(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35566122

RESUMO

Inflammatory bowel diseases (IBDs) such as ulcerative colitis (UC) and Crohn's disease (CD) are diseases of the gastrointestinal system involving genetic and environmental factors attributed to oxidative stress and inflammation. Targeting oxidative stress and inflammation by novel dietary compounds of natural origin convincingly appears to be one of the important therapeutic strategies to keep the disease in remission. As there is no permanent cure for IBD except for chronic long-term treatment or surgery, it is therefore imperative to investigate plant-based agents that are receiving attention for their therapeutic benefits to overcome the debilitating clinical conditions of IBD. Lycopodium (LYCO), a plant of tropical and subtropical origin and known by numerous names such as ground pine, club moss, or devil's claw, has been popularly used for centuries in traditional medicine including Chinese and Indian medicines. In the present study, the effect of LYCO has been investigated in an acetic acid (AA)-induced colitis model in Wistar rats. LYCO was orally administered at the dose of 50 mg/kg/day either 3 days before or 30 min after the induction of IBD and continued for 7 days by intrarectal administration of AA. The changes in body weight and macroscopic and microscopic analysis of the colon of rats of different experimental groups were observed on days 0, 2, 4, and 7. The levels of myeloperoxidase (MPO), reduced glutathione (GSH), and malondialdehyde (MDA) were measured. AA caused a significant reduction in body weight and increased macroscopic and microscopic ulcer scores along with a significant decline in antioxidant enzymes, superoxide dismutase (SOD), and catalase and antioxidant substrate, glutathione (GSH). There was a concomitant increased formation of malondialdehyde (MDA), a marker of lipid peroxidation, and raised myeloperoxidase (MPO) activity, a marker of neutrophil activation. Treatment with LYCO significantly improved IBD-induced reduction in body weight, improved histology, inhibited MDA formation, and restored antioxidants along with reduced MPO activity. AA also caused the release of proinflammatory cytokines such as interleukin-1ß (IL-1ß) and interleukin-23 (IL-23). Furthermore, AA also increased the levels of calprotectin, a protein released by neutrophils under inflammatory conditions of the gastrointestinal tract. LYCO treatment significantly reduced the release of calprotectin and proinflammatory cytokines. The results demonstrate that LYCO treatment has the potential to improve disease activity by inhibiting oxidative stress, lipid peroxidation, and inflammation along with histological preservation of colonic tissues.


Assuntos
Colite Ulcerativa , Colite , Doenças Inflamatórias Intestinais , Lycopodium , Ácido Acético/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Antioxidantes/metabolismo , Peso Corporal , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Citocinas/metabolismo , Glutationa/metabolismo , Inflamação/metabolismo , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/metabolismo , Complexo Antígeno L1 Leucocitário/metabolismo , Complexo Antígeno L1 Leucocitário/farmacologia , Complexo Antígeno L1 Leucocitário/uso terapêutico , Malondialdeído/metabolismo , Estresse Oxidativo , Peroxidase/metabolismo , Ratos , Ratos Wistar
17.
Front Immunol ; 13: 879157, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35619694

RESUMO

During the COVID-19 pandemic, vaccination is the most important countermeasure. Pharmacovigilance concerns however emerged with very rare, but potentially disastrous thrombotic complications following vaccination with ChAdOx1. Platelet factor-4 antibody mediated vaccine-induced immune thrombotic thrombocytopenia (VITT) was described as an underlying mechanism of these thrombotic events. Recent work moreover suggests that mechanisms of immunothrombosis including neutrophil extracellular trap (NET) formation might be critical for thrombogenesis during VITT. In this study, we investigated blood and thrombus specimens of a female patient who suffered severe stroke due to VITT after vaccination with ChAdOx1 in comparison to 13 control stroke patients with similar clinical characteristics. We analyzed cerebral thrombi using histological examination, staining of complement factors, NET-markers, DNase and LL-37. In blood samples at the hyper-acute phase of stroke and 7 days later, we determined cell-free DNA, myeloperoxidase-histone complexes, DNase activity, myeloperoxidase activity, LL-37 and inflammatory cytokines. NET markers were identified in thrombi of all patients. Interestingly, the thrombus of the VITT-patient exclusively revealed complement factors and high amounts of DNase and LL-37. High DNase activity was also measured in blood, implying a disturbed NET-regulation. Furthermore, serum of the VITT-patient inhibited reactive oxygen species-dependent NET-release by phorbol-myristate-acetate to a lesser degree compared to controls, indicating either less efficient NET-inhibition or enhanced NET-induction in the blood of the VITT-patient. Additionally, the changes in specific cytokines over time were emphasized in the VITT-patient as well. In conclusion, insufficient resolution of NETs, e.g. by endogenous DNases or protection of NETs against degradation by embedded factors like the antimicrobial peptide LL-37 might thus be an important factor in the pathology of VITT besides increased NET-formation. On the basis of these findings, we discuss the potential implications of the mechanisms of disturbed NETs-degradation for diagnostic and therapeutic approaches in VITT-related thrombogenesis, other auto-immune disorders and beyond.


Assuntos
COVID-19 , Armadilhas Extracelulares , Púrpura Trombocitopênica Idiopática , Acidente Vascular Cerebral , Trombocitopenia , Trombose , Vacinas , Desoxirribonuclease I/metabolismo , Desoxirribonucleases , Feminino , Humanos , Neutrófilos , Pandemias , Peroxidase/metabolismo , Fator Plaquetário 4/metabolismo , Púrpura Trombocitopênica Idiopática/metabolismo , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/metabolismo , Trombocitopenia/induzido quimicamente , Trombocitopenia/metabolismo , Trombose/etiologia , Trombose/metabolismo , Vacinas/metabolismo
18.
Int J Mol Sci ; 23(9)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35563357

RESUMO

Although the molecular response of bacteria exposed to metal nanoparticles (NPs) is intensively studied, many phenomena related to their survival, metal uptake, gene expression and protein production are not fully understood. Therefore, this work aimed to study Ag-NPs, Cu-NPs, ZnO-NPs and TiO2-NPs-induced alterations in the expression level of selected oxidative stress-related genes in connection with the activity of antioxidant enzymes: catalase (CAT), peroxidase (PER) and superoxide dismutase (SOD) in Escherichia coli, Bacillus cereus and Staphylococcus epidermidis. The methodology used included: the extraction of total RNA and cDNA synthesis, the preparation of primers for selected housekeeping and oxidative stress genes, RT-qPCR reaction and the measurements of CAT, PER and SOD activities. It was established that the treatment of E. coli and S. epidermidis with NPs resulted mainly in the down-regulation of targeted genes, whilst the up-regulation of genes was confirmed in B. cereus. The greatest differences in the relative expression levels of tested genes occurred in B. cereus and S. epidermidis treated with TiO2-NPs, while in E. coli, they were observed under ZnO-NPs exposure. The changes found were mostly related to the expression of genes encoding proteins with PER and CAT-like activity. Among NPs, ZnO-NPs and Cu-NPs increased the activity of antioxidants in E. coli and B. cereus. In turn, TiO2-NPs had a major effect on enzymes activity in S. epidermidis. Considering all of the collected results for tested bacteria, it can be emphasised that the impact of NPs on the antioxidant system functioning was dependent on their type and concentration.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Estresse Oxidativo , Antioxidantes/metabolismo , Bacillus cereus/genética , Bacillus cereus/metabolismo , Cobre/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Estresse Oxidativo/genética , Peroxidase/metabolismo , Prata/química , Prata/farmacologia , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/metabolismo , Superóxido Dismutase/metabolismo , Titânio/farmacologia , Óxido de Zinco/farmacologia
19.
Microbiol Spectr ; 10(3): e0049322, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35510858

RESUMO

Antibiotic-producing microorganisms usually require one or more self-resistance determinants to survive antibiotic production. The effectors of these mechanisms are proteins that inactivate the antibiotic, facilitate its transport, or modify the target to render it insensitive to the molecule. Streptomyces bacteria biosynthesize various bioactive natural products and possess resistance systems for most metabolites, which are coregulated with antibiotic biosynthesis genes. Streptomyces olindensis strain DAUFPE 5622 produces the antitumor antibiotic cosmomycin D (COSD), a member of the anthracycline family. In this study, we propose three self-resistance mechanisms, anchored or based in the COSD biosynthetic gene cluster. These include cosIJ (an ABC transporter), cosU (a UvrA class IIa protein), and a new self-resistance mechanism encoded by cosP, which shows response against peroxides by the enzyme mycothiol peroxidase (MPx). Activity-based investigations of MPx and its mutant enzyme confirmed peroxidation during the production of COSD. Overexpression of the ABC transporter, the UvrA class IIa protein, and the MPx led to an effective response against toxic anthracyclines, such as cosmomycins. Our findings help to understand how thiol peroxidases play an antioxidant role in the anthracycline producer S. olindensis DAUFPE 5622, a mechanism which has been reported for neoplastic cells that are resistant to doxorubicin (DOX). IMPORTANCE Anthracycline compounds are DNA intercalating agents widely used in cancer chemotherapeutic protocols. This work focused on the self-resistance mechanisms developed by the cosmomycin-producing bacterium Streptomyces olindensis. Our findings showed that cysteine peroxidases, such as mycothiol peroxidase, encoded by the gene cosP, protected S. olindensis against peroxidation during cosmomycin production. This observation can contribute to much better understanding of resistance both in the producers, eventually enhancing production, and in some tumoral cell lines.


Assuntos
Antioxidantes , Cisteína , Transportadores de Cassetes de Ligação de ATP , Antraciclinas/metabolismo , Antibacterianos/farmacologia , Cisteína/metabolismo , Glicopeptídeos , Inositol , Oxirredutases/metabolismo , Peroxidase/metabolismo , Peroxidases/metabolismo , Streptomyces
20.
Mol Microbiol ; 117(6): 1447-1463, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35578788

RESUMO

Teg49 is a Staphylococcus aureus trans-acting regulatory sRNA derived from cleavage of the sarA P3 transcript. We showed by RNA-Seq here that the 5' trident-like structure in Teg49 regulates transcriptionally (direct and indirect) 22 genes distinct from sarA. Among these, Teg49 was noted to repress spn, encoding a 102 residue preprotein which yields the mature 73 residue peptide which inhibits the catalytic activity of myeloperoxidase in human neutrophils. Teg49 was found to regulate spn mRNA post-transcriptionally in strain SH1000 through 9-nt base-pairing between hairpin loop 2 of Teg49 and an exposed bulge of the spn mRNA. Mutations of the Teg49 binding site disrupted the repression of spn, leading to reduced degradation, and increased half-life of spn mRNA in the Teg49 mutant. The spn-Teg49 interaction was also confirmed with a synonymous spn mutation to yield enhanced spn expression in the mutant vs. the parent. The Teg49 mutant with increased spn expression exhibited enhanced resistance to MPO activity in vitro. Killing assays with human neutrophils showed that the Teg49 mutant was more resistant to killing after phagocytosis. Altogether, this study shows that Teg49 in S. aureus has a distinct and important regulatory profile whereby this sRNA modulates resistance to myeloperoxidase-mediated killing by human neutrophils.


Assuntos
Pequeno RNA não Traduzido , Infecções Estafilocócicas , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/genética , Humanos , Neutrófilos , Peroxidase/genética , Peroxidase/metabolismo , RNA Mensageiro/metabolismo , Pequeno RNA não Traduzido/genética , Pequeno RNA não Traduzido/metabolismo , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo
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