Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
1.
J Proteome Res ; 22(1): 193-203, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36469742

RESUMO

The outbreak of Zika virus infection in 2016 led to the identification of its presence in several types of biofluids, including semen. Later discoveries associated Zika infection with sexual transmission and persistent replication in cells of the male reproductive tract. Prostate epithelial and carcinoma cells are favorable to virus replication, with studies pointing to transcriptomics alterations of immune and inflammation genes upon persistence. However, metabolome alterations promoted by the Zika virus in prostate cells are unknown. Given its chronic effects and oncolytic potential, we aim to investigate the metabolic alterations induced by the Zika virus in prostate epithelial (PNT1a) and adenocarcinoma (PC-3) cells using an untargeted metabolomics approach and high-resolution mass spectrometry. PNT1a cells were viable up to 15 days post ZIKV infection, in contrast to its antiproliferative effect in the PC-3 cell lineage. Remarkable alterations in the PNT1a cell metabolism were observed upon infection, especially regarding glycerolipids, fatty acids, and acylcarnitines, which could be related to viral cellular resource exploitation, in addition to the over-time increase in oxidative stress metabolites associated with carcinogenesis. The upregulation of FA20:5 at 5 dpi in PC-3 cells corroborates the antiproliferative effect observed since this metabolite was previously reported to induce PC-3 cell death. Overall, Zika virus promotes extensive lipid alterations on both PNT1a and PC-3 cells, promoting different outcomes based on the cellular metabolic state.


Assuntos
Adenocarcinoma , Infecção por Zika virus , Zika virus , Masculino , Humanos , Próstata , Células PC-3
2.
Am J Physiol Endocrinol Metab ; 324(3): E226-E240, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36724126

RESUMO

Obesity is one of the leading noncommunicable diseases in the world. Despite intense efforts to develop strategies to prevent and treat obesity, its prevalence continues to rise worldwide. A recent study has shown that the tricarboxylic acid intermediate succinate increases body energy expenditure by promoting brown adipose tissue thermogenesis through the activation of uncoupling protein-1; this has generated interest surrounding its potential usefulness as an approach to treat obesity. It is currently unknown how succinate impacts brown adipose tissue protein expression, and how exogenous succinate impacts body mass reduction promoted by a drug approved to treat human obesity, the glucagon-like-1 receptor agonist, liraglutide. In the first part of this study, we used bottom-up shotgun proteomics to determine the acute impact of exogenous succinate on the brown adipose tissue. We show that succinate rapidly affects the expression of 177 brown adipose tissue proteins, which are mostly associated with mitochondrial structure and function. In the second part of this study, we performed a short-term preclinical pharmacological intervention, treating diet-induced obese mice with a combination of exogenous succinate and liraglutide. We show that the combination was more efficient than liraglutide alone in promoting body mass reduction, food energy efficiency reduction, food intake reduction, and an increase in body temperature. Using serum metabolomics analysis, we showed that succinate, but not liraglutide, promoted a significant increase in the blood levels of several medium and long-chain fatty acids. In conclusion, exogenous succinate promotes rapid changes in brown adipose tissue mitochondrial proteins, and when used in association with liraglutide, increases body mass reduction.NEW & NOTEWORTHY Exogenous succinate induces major changes in brown adipose tissue protein expression affecting particularly mitochondrial respiration and structural proteins. When given exogenously in drinking water, succinate mitigates body mass gain in a rodent model of diet-induced obesity; in addition, when given in association with the glucagon-like peptide-1 receptor agonist, liraglutide, succinate increases body mass reduction promoted by liraglutide alone.


Assuntos
Tecido Adiposo Marrom , Liraglutida , Animais , Camundongos , Tecido Adiposo Marrom/metabolismo , Metabolismo Energético , Liraglutida/farmacologia , Liraglutida/uso terapêutico , Obesidade/metabolismo , Proteoma/metabolismo , Ácido Succínico/farmacologia , Ácido Succínico/metabolismo , Ácido Succínico/uso terapêutico , Termogênese , Proteína Desacopladora 1/metabolismo
3.
Int J Mol Sci ; 24(10)2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37240159

RESUMO

Glioblastoma (GB) is the most aggressive and frequent primary malignant tumor of the central nervous system and is associated with poor overall survival even after treatment. To better understand tumor biochemical alterations and broaden the potential targets of GB, this study aimed to evaluate differential plasma biomarkers between GB patients and healthy individuals using metabolomics analysis. Plasma samples from both groups were analyzed via untargeted metabolomics using direct injection with an electrospray ionization source and an LTQ mass spectrometer. GB biomarkers were selected via Partial Least Squares Discriminant and Fold-Change analyses and were identified using tandem mass spectrometry with in silico fragmentation, consultation of metabolomics databases, and a literature search. Seven GB biomarkers were identified, some of which were unprecedented biomarkers for GB, including arginylproline (m/z 294), 5-hydroxymethyluracil (m/z 143), and N-acylphosphatidylethanolamine (m/z 982). Notably, four other metabolites were identified. The roles of all seven metabolites in epigenetic modulation, energy metabolism, protein catabolism or folding processes, and signaling pathways that activate cell proliferation and invasion were elucidated. Overall, the findings of this study highlight new molecular targets to guide future investigations on GB. These molecular targets can also be further evaluated to derive their potential as biomedical analytical tools for peripheral blood samples.


Assuntos
Glioblastoma , Humanos , Metabolômica/métodos , Biomarcadores , Espectrometria de Massas em Tandem/métodos , Análise dos Mínimos Quadrados
4.
Int J Mol Sci ; 24(1)2022 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-36613836

RESUMO

Meningiomas (MGMs) are currently classified into grades I, II, and III. High-grade tumors are correlated with decreased survival rates and increased recurrence rates. The current grading classification is based on histological criteria and determined only after surgical tumor sampling. This study aimed to identify plasma metabolic alterations in meningiomas of different grades, which would aid surgeons in predefining the ideal surgical strategy. Plasma samples were collected from 51 patients with meningioma and classified into low-grade (LG) (grade I; n = 43), and high-grade (HG) samples (grade II, n = 5; grade III, n = 3). An untargeted metabolomic approach was used to analyze plasma metabolites. Statistical analyses were performed to select differential biomarkers among HG and LG groups. Metabolites were identified using tandem mass spectrometry along with database verification. Five and four differential biomarkers were identified for HG and LG meningiomas, respectively. To evaluate the potential of HG MGM metabolites to differentiate between HG and LG tumors, a receiving operating characteristic curve was constructed, which revealed an area under the curve of 95.7%. This indicates that the five HG MGM metabolites represent metabolic alterations that can differentiate between LG and HG meningiomas. These metabolites may indicate tumor grade even before the appearance of histological features.


Assuntos
Neoplasias Meníngeas , Meningioma , Humanos , Meningioma/patologia , Neoplasias Meníngeas/patologia , Gradação de Tumores , Estudos Retrospectivos
5.
Pharmacol Res ; 132: 33-46, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29653264

RESUMO

Intestinal helminths are prevalent in individuals who live in rural areas of developing countries, where obesity, type 2 diabetes, and metabolic syndrome are rare. In the present study, we analyzed the modulation of the gut microbiota in mice infected with the helminth Strongyloides venezuelensis, and fed either a standard rodent chow diet or high-fat diet (HFD). To investigate the effects of the microbiota modulation on the metabolism, we analyzed the expression of tight-junction proteins present in the gut epithelium, inflammatory markers in the serum and tissue and quantified glucose tolerance and insulin sensitivity and resistance. Additionally, the levels of lipids related to inflammation were evaluated in the feces and serum. Our results show that infection with Strongyloides venezuelensis results in a modification of the gut microbiota, most notably by increasing Lactobacillus spp. These modifications in the microbiota alter the host metabolism by increasing the levels of anti-inflammatory cytokines, switching macrophages from a M1 to M2 pattern in the adipose tissue, increasing the expression of tight junction proteins in the intestinal cells (thereby reducing the permeability) and decreasing LPS in the serum. Taken together, these changes correlate with improved insulin signaling and sensitivity, which could also be achieved with HFD mice treated with probiotics. Additionally, helminth infected mice produce higher levels of oleic acid, which participates in anti-inflammatory pathways. These results suggest that modulation of the microbiota by helminth infection or probiotic treatment causes a reduction in subclinical inflammation, which has a positive effect on the glucose metabolism of the host.


Assuntos
Ácidos Graxos/metabolismo , Microbioma Gastrointestinal , Resistência à Insulina , Estrongiloidíase/metabolismo , Estrongiloidíase/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Microbioma Gastrointestinal/genética , Masculino , Camundongos , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Strongyloides
6.
Reprod Fertil Dev ; 28(3): 293-301, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25228254

RESUMO

In the field of 'single cell analysis', many classical strategies like immunofluorescence and electron microscopy are the primary techniques of choice. However, these methodologies are time consuming and do not permit direct identification of specific molecular classes, such as lipids. In the present study, a novel mass spectrometry-based analytical approach was applied to bovine oocytes and embryos. This new metabolomics-based application uses mass spectrometry imaging (MSI), efficient data processing and multivariate data analysis. Metabolic fingerprinting (MF) was applied to the analysis of unfertilised oocytes, 2-, 4- and 8-cell embryos and blastocysts. A semiquantitative strategy for sphingomyelin [SM (16:0)+Na](+) (m/z 725) and phosphatidylcholine [PC (32:0)+Na](+) (m/z 756) was developed, showing that lipid concentration was useful for selecting the best metabolic biomarkers. This study demonstrates that a combination of MF, MSI features and chemometric analysis can be applied to discriminate cell stages, characterising specific biomarkers and relating them to developmental pathways. This information furthers our understanding of fertilisation and preimplantation events during bovine embryo development.


Assuntos
Blastocisto/metabolismo , Metabolômica/métodos , Oócitos/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Animais , Biomarcadores/metabolismo , Bovinos , Técnicas de Cultura Embrionária , Desenvolvimento Embrionário , Feminino , Fertilização in vitro , Técnicas de Maturação in Vitro de Oócitos , Análise Multivariada , Fosfatidilcolinas/metabolismo , Gravidez , Esfingomielinas/metabolismo , Fatores de Tempo
7.
Int J Food Microbiol ; 415: 110645, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38430687

RESUMO

This study aimed to assess the growth of Pseudomonas spp. and psychrotrophic bacteria in chilled Pacu (Piaractus mesopotamicus), a native South American fish, stored under chilling conditions (0 to 10 °C) through the use of predictive models under isothermal and non-isothermal conditions. Growth kinetic parameters, maximum growth rate (µmax, 1/h), lag time (tLag, h), and (Nmax, Log10 CFU/g) were estimated using the Baranyi and Roberts microbial growth model. Both kinetic parameters, growth rate and lag time, were significantly influenced by temperature (P < 0.05). The square root secondary model was used to describe the bacteria growth as a function of temperature. Secondary models, √µ = 0.016 (T + 10.13) and √µ =0.017 (T + 9.91) presented a linear correlation with R2 values >0.97 and were further validated under non-isothermal conditions. The model's performance was considered acceptable to predict the growth of Pseudomonas spp. and psychrotrophic bacteria in refrigerated Pacu fillets with bias and accuracy factors between 1.24 and 1.49 (fail-safe) and 1.45-1.49, respectively. Fish biomarkers and spoilage indicators were assessed during storage at 0, 4, and 10 °C. Volatile organic compounds, VOCs (1-hexanol, nonanal, octenol, and indicators 2-ethyl-1-hexanol) showed different behavior with storage time (P > 0.05). 1H NMR analysis confirmed increased enzymatic and microbial activity in Pacu fillets stored at 10 °C compared to 0 °C. The developed and validated models obtained in this study can be used as a tool for decision-making on the shelf-life and quality of refrigerated Pacu fillets stored under dynamic conditions from 0 to 10 °C.


Assuntos
Bactérias , Pseudomonas , Animais , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Prótons por Ressonância Magnética , Temperatura , Microbiologia de Alimentos , Conservação de Alimentos , Contagem de Colônia Microbiana , Armazenamento de Alimentos
8.
Cell Host Microbe ; 32(4): 606-622.e8, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38479396

RESUMO

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes acute, subacute, and chronic human arthritogenic diseases and, in rare instances, can lead to neurological complications and death. Here, we combined epidemiological, virological, histopathological, cytokine, molecular dynamics, metabolomic, proteomic, and genomic analyses to investigate viral and host factors that contribute to chikungunya-associated (CHIK) death. Our results indicate that CHIK deaths are associated with multi-organ infection, central nervous system damage, and elevated serum levels of pro-inflammatory cytokines and chemokines compared with survivors. The histopathologic, metabolite, and proteomic signatures of CHIK deaths reveal hemodynamic disorders and dysregulated immune responses. The CHIKV East-Central-South-African lineage infecting our study population causes both fatal and survival cases. Additionally, CHIKV infection impairs the integrity of the blood-brain barrier, as evidenced by an increase in permeability and altered tight junction protein expression. Overall, our findings improve the understanding of CHIK pathophysiology and the causes of fatal infections.


Assuntos
Febre de Chikungunya , Vírus Chikungunya , Animais , Humanos , Febre de Chikungunya/complicações , Proteômica , Vírus Chikungunya/genética , Citocinas/metabolismo
9.
Parkinsonism Relat Disord ; 116: 105847, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37844348

RESUMO

INTRODUCTION: Progressive Supranuclear Palsy (PSP) is a neurodegenerative tauopathy and, to date, the pathophysiological mechanisms in PSP that lead to Tau hyperphosphorylation and neurodegeneration are not clear. In some brain areas, Tau pathology in glial cells appears to precede Tau aggregation in neurons. The development of a model using astrocyte cell lines derived from patients has the potential to identify molecules and pathways that contribute to early events of neurodegeneration. We developed a model of induced pluripotent stem cells (iPSC)-derived astrocytes to investigate the pathophysiology of PSP, particularly early events that might contribute to Tau hyperphosphorylation, applying omics approach to detect differentially expressed genes, metabolites, and proteins, including those from the secretome. METHODS: Skin fibroblasts from PSP patients (without MAPT mutations) and controls were reprogrammed to iPSCs, further differentiated into neuroprogenitor cells (NPCs) and astrocytes. In the 5th passage, astrocytes were harvested for total RNA sequencing. Intracellular and secreted proteins were processed for proteomics experiments. Metabolomics profiling was obtained from supernatants only. RESULTS: We identified hundreds of differentially expressed genes. The main networks were related to cell cycle re-activation in PSP. Several proteins were found exclusively secreted by the PSP group. The cellular processes related to the cell cycle and mitotic proteins, TriC/CCT pathway, and redox signaling were enriched in the secretome of PSP. Moreover, we found distinct sets of metabolites between PSP and controls. CONCLUSION: Our iPSC-derived astrocyte model can provide distinct molecular signatures for PSP patients and it is useful to elucidate the initial stages of PSP pathogenesis.


Assuntos
Células-Tronco Pluripotentes Induzidas , Paralisia Supranuclear Progressiva , Tauopatias , Humanos , Paralisia Supranuclear Progressiva/diagnóstico , Astrócitos/metabolismo , Proteínas tau/genética , Tauopatias/patologia , Neurônios/metabolismo
10.
Metabolites ; 13(8)2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37623846

RESUMO

Cardiovascular disease is a leading cause of death worldwide. Heart failure is a cardiovascular disease with high prevalence, morbidity, and mortality. Several natural compounds have been studied for attenuating pathological cardiac remodeling. Orange juice has been associated with cardiovascular disease prevention by attenuating oxidative stress. However, most studies have evaluated isolated phytochemicals rather than whole orange juice and usually under pathological conditions. In this study, we evaluated plasma metabolomics in healthy rats receiving Pera or Moro orange juice to identify possible metabolic pathways and their effects on the heart. METHODS: Sixty male Wistar rats were allocated into 3 groups: control (C), Pera orange juice (PO), and Moro orange juice (MO). PO and MO groups received Pera orange juice or Moro orange juice, respectively, and C received water with maltodextrin (100 g/L). Echocardiogram and euthanasia were performed after 4 weeks. Plasma metabolomic analysis was performed by high-resolution mass spectrometry. Type I collagen was evaluated in picrosirius red-stained slides and matrix metalloproteinase (MMP)-2 activity by zymography. MMP-9, tissue inhibitor of metalloproteinase (TIMP)-2, TIMP-4, type I collagen, and TNF-α protein expression were evaluated by Western blotting. RESULTS: We differentially identified three metabolites in PO (N-docosahexaenoyl-phenylalanine, diglyceride, and phosphatidylethanolamine) and six in MO (N-formylmaleamic acid, N2-acetyl-L-ornithine, casegravol isovalerate, abscisic alcohol 11-glucoside, cyclic phosphatidic acid, and torvoside C), compared to controls, which are recognized for their possible roles in cardiac remodeling, such as extracellular matrix regulation, inflammation, oxidative stress, and membrane integrity. Cardiac function, collagen level, MMP-2 activity, and MMP-9, TIMP-2, TIMP-4, type I collagen, and TNF-α protein expression did not differ between groups. CONCLUSION: Ingestion of Pera and Moro orange juice induces changes in plasma metabolites related to the regulation of extracellular matrix, inflammation, oxidative stress, and membrane integrity in healthy rats. Moro orange juice induces a larger number of differentially expressed metabolites than Pera orange juice. Alterations in plasma metabolomics induced by both orange juice are not associated with modifications in cardiac extracellular matrix components. Our results allow us to postulate that orange juice may have beneficial effects on pathological cardiac remodeling.

11.
Rapid Commun Mass Spectrom ; 25(3): 449-52, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21213365

RESUMO

Fatty acid synthase (FASN) is the metabolic enzyme responsible for the endogenous synthesis of the saturated long-chain fatty acid palmitate. In contrast to most normal cells, FASN is overexpressed in a variety of human cancers including cutaneous melanoma, in which its levels of expression are associated with a poor prognosis and depth of invasion. Recently, we have demonstrated the mitochondrial involvement in FASN inhibition-induced apoptosis in melanoma cells. Herein we compare, via electrospray ionization mass spectrometry (ESI-MS), free fatty acids (FFA) composition of mitochondria isolated from control (EtOH-treated cells) and Orlistat-treated B16-F10 mouse melanoma cells. Principal component analysis (PCA) was applied to the ESI-MS data and found to separate the two groups of samples. Mitochondria from control cells showed predominance of six ions, that is, those of m/z 157 (Pelargonic, 9:0), 255 (Palmitic, 16:0), 281 (Oleic, 18:1), 311 (Arachidic, 20:0), 327 (Docosahexaenoic, 22:6) and 339 (Behenic, 22:0). In contrast, FASN inhibition with Orlistat changes significantly mitochondrial FFA composition by reducing synthesis of palmitic acid, and its elongation and unsaturation products, such as arachidic and behenic acids, and oleic acid, respectively. ESI-MS of mitochondria isolated from Orlistat-treated cells presented therefore three major ions of m/z 157 (Pelargonic, 9:0), 193 (unknown) and 199 (Lauric, 12:0). These findings demonstrate therefore that FASN inhibition by Orlistat induces significant changes in the FFA composition of mitochondria.


Assuntos
Ácido Graxo Sintases/antagonistas & inibidores , Espectrometria de Massas/métodos , Melanoma/enzimologia , Mitocôndrias/enzimologia , Animais , Linhagem Celular Tumoral , Etanol/química , Ácido Graxo Sintases/metabolismo , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Lactonas/farmacologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Orlistate , Análise de Componente Principal
12.
Anal Bioanal Chem ; 401(5): 1651-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21732042

RESUMO

Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) was used to interrogate the hepatic lipid profiles of hypertriglyceridemic and control normotriglyceridemic mice. The analyses of ex vivo complex lipid mixtures were made directly with EASI-MS without accompanying separation steps. Intense ions for phosphatidylcholines and triacylglycerols were observed in the positive ion mode whereas the spectra in the negative ion mode provided profiles of phosphatidylethanolamines and phosphatidylinositol. EASI-MS was coupled to high-performance thin-layer chromatography for analysis of free fatty acids. Fourier transform-ion cyclotron resonance-mass spectrometry was also employed to confirm the identity of the detected lipids. We demonstrated higher incorporation of oleic acid in phosphatidylcholine and triacylglycerol composition, higher relative abundance of arachidonic acid containing phosphatidylinositol, and overall distinct free fatty acid profile in the livers of genetic hypertriglyceridemic mice. We propose that these alterations in liver lipid composition are related to the higher tissue and body metabolic rates described in these hypertriglyceridemic mice.


Assuntos
Hipertrigliceridemia/metabolismo , Lipídeos/análise , Fígado/metabolismo , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Humanos , Metabolismo dos Lipídeos , Lipídeos/química , Fígado/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Triglicerídeos/análise
13.
J Photochem Photobiol B ; 223: 112297, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34482154

RESUMO

Lipid oxidation is ubiquitous in cell life under oxygen and essential for photodynamic therapy (PDT) of carcinomas. However, the mechanisms underlying lipid oxidation in rather complex systems such as plasma membranes remain elusive. Herein, Langmuir monolayers were assembled with the lipid extract of glandular breast cancer (MCF7) cells and used to probe the molecular interactions allowing adsorption of the photosensitizer (PS) erythrosine B and subsequent photooxidation outcomes. Surface pressure (π) versus area (cm2/mL) isotherms of MCF7 lipid extract shifted to larger areas upon erythrosine incorporation, driven by secondary interactions that affected the orientation of the carbonyl groups and lipid chain organization. Light-irradiation increased the surface area of the MCF7 lipid extract monolayer containing erythrosine owing to the lipid hydroperoxidation, which may further undergo decomposition, resulting in the chain cleavage of phospholipids and membrane permeabilization. Incorporation of erythrosine by MCF7 cells induced slight toxic effects on in vitro assays, differently of the severe phototoxicity caused by light-irradiation, which significantly decreased cell viability by more than 75% at 2.5 × 10-6 mol/L of erythrosine incubated for 3 and 24 h, reaching nearly 90% at 48 h of incubation. The origin of the phototoxic effects is in the rupture of the plasma membrane shown by the frontal (FSC) and side (SSC) light scattering of flow cytometry. Consistent with hydroperoxide decomposition, membrane permeabilization was also confirmed by cleaved lipids detected in mass spectrometry and subsidizes the necrotic pathway of cell death.


Assuntos
Membrana Celular/efeitos dos fármacos , Eritrosina/farmacologia , Luz , Fármacos Fotossensibilizantes/farmacologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Elasticidade , Eritrosina/química , Feminino , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Lipídeos/análise , Lipídeos/química , Microscopia Confocal , Fármacos Fotossensibilizantes/química , Análise de Componente Principal , Espectrometria de Massas por Ionização por Electrospray
14.
J Lipid Res ; 51(5): 1218-27, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19965589

RESUMO

Methods used for lipid analysis in embryos and oocytes usually involve selective lipid extraction from a pool of many samples followed by chemical manipulation, separation and characterization of individual components by chromatographic techniques. Herein we report direct analysis by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of single and intact embryos or oocytes from various species. Biological samples were simply moisturized with the matrix solution and characteristic lipid (represented by phosphatidylcholines, sphingomyelins and triacylglycerols) profiles were obtained via MALDI-MS. As representative examples, human, bovine, sheep and fish oocytes, as well as bovine and insect embryos were analyzed. MALDI-MS is shown to be capable of providing characteristic lipid profiles of gametes and embryos and also to respond to modifications due to developmental stages and in vitro culture conditions of bovine embryos. Investigation in developmental biology of the biological roles of structural and reserve lipids in embryos and oocytes should therefore benefit from these rapid MALDI-MS profiles from single and intact species.


Assuntos
Embrião de Mamíferos/química , Lipídeos/análise , Oócitos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Bovinos , Embrião de Mamíferos/embriologia , Desenvolvimento Embrionário , Feminino , Humanos , Especificidade da Espécie
15.
Analyst ; 135(4): 738-44, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20349539

RESUMO

A fast and reliable method is presented for the analysis of vegetable oils. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to efficiently desorb and ionize the main oil constituents from an inert surface under ambient conditions and to provide comprehensive triacylglyceride (TAG) and free fatty acid (FFA) profiles detected mainly as either [TAG + Na](+) or [FFA-H](-) ions. EASI(+/-)-MS analysis is simple, easily implemented, requires just a tiny droplet of the oil and is performed without any pre-separation or chemical manipulation. It also causes no fragmentation of TAG ions hence diacylglyceride (DAG) and monoacylglyceride (MAG) profiles and contents can also be measured. The EASI(+/-)-MS profiles of TAG and FFA permit authentication and quality control and can be used, for instance, to access levels of adulteration, acidity, oxidation or hydrolysis of vegetable oils in general.


Assuntos
Ácidos Graxos/química , Óleos de Plantas/química , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Triglicerídeos/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Ultrassom
16.
Inorg Chem ; 48(10): 4569-79, 2009 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-19425615

RESUMO

Herein, we report reactivity studies of the mononuclear water-soluble complex [Mn(II)(HPClNOL)(eta(1)-NO(3))(eta(2)-NO(3))] 1, where HPClNOL = 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol, toward peroxides (H(2)O(2) and tert-butylhydroperoxide). Both the catalase (in aqueous solution) and peroxidase (in CH(3)CN) activities of 1 were evaluated using a range of techniques including electronic absorption spectroscopy, volumetry (kinetic studies), pH monitoring during H(2)O(2) disproportionation, electron paramagnetic resonance (EPR), electrospray ionization mass spectrometry in the positive ion mode [ESI(+)-MS], and gas chromatography (GC). Electrochemical studies showed that 1 can be oxidized to Mn(III) and Mn(IV). The catalase-like activity of 1 was evaluated with and without pH control. The results show that the pH decreases when the reaction is performed in unbuffered media. Furthermore, the activity of 1 is greater in buffered than in unbuffered media, demonstrating that pH influences the activity of 1 toward H(2)O(2). For the reaction of 1 with H(2)O(2), EPR and ESI(+)-MS have led to the identification of the intermediate [Mn(III)Mn(IV)(mu-O)(2)(PClNOL)(2)](+). The peroxidase activity of 1 was also evaluated by monitoring cyclohexane oxidation, using H(2)O(2) or tert-butylhydroperoxide as the terminal oxidants. Low yields (<7%) were obtained for H(2)O(2), probably because it competes with 1 for the catalase-like activity. In contrast, using tert-butylhydroperoxide, up to 29% of cyclohexane conversion was obtained. A mechanistic model for the catalase activity of 1 that incorporates the observed lag phase in O(2) production, the pH variation, and the formation of a Mn(III)-(mu-O)(2)-Mn(IV) intermediate is proposed.


Assuntos
Materiais Biomiméticos/química , Catalase , Manganês/química , Compostos Organometálicos/química , Peroxidase , Catálise , Espectroscopia de Ressonância de Spin Eletrônica , Oxigênio/química , Espectrometria de Massas por Ionização por Electrospray
17.
Food Chem Toxicol ; 133: 110756, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31408721

RESUMO

Yeasts are able to reduce the levels of ochratoxin A in fermentative processes; and, through their enzymatic complex, these micro-organisms are also capable of forming modified mycotoxins. These mycotoxins are often underreported, and may increase health risks after ingestion of contaminated food. In this sense, this study aims to evaluate whether the presence of ochratoxin A influences yeast growth kinetic parameters and to elucidate the formation of modified ochratoxin by Saccharomyces cerevisiae strains during fermentation. Three S. cerevisiae strains (12 M, 01 PP, 41 PP) were exposed to OTA at the concentrations of 10, 20 and 30 µg/L. The Baranyi model was fitted to the growth data (Log CFU/mL), and the identification of modified ochratoxins was performed through High Resolution Mass Spectrometry. The presence of ochratoxin A did not influence the growth of S. cerevisiae strains. Four pathways were proposed for the metabolization of OTA: dechlorination, hydrolysis, hydroxylation, and conjugation. Among the elected targets, the following were identified: ochratoxin α, ochratoxin ß, ochratoxin α methyl ester, ochratoxin B methyl ester, ethylamide ochratoxin A, ochratoxin C, hydroxy-ochratoxin A, hydroxy-ochratoxin A methyl ester, and ochratoxin A cellobiose ester. These derivatives formed from yeast metabolism may contribute to the occurrence of underreporting levels of total mycotoxin in fermented products.


Assuntos
Ocratoxinas/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Biotransformação , Sobrevivência Celular/efeitos dos fármacos , Cinética , Modelos Biológicos , Ocratoxinas/análise
18.
Sci Rep ; 9(1): 6803, 2019 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-31028284

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

19.
Sci Rep ; 9(1): 13606, 2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31541139

RESUMO

Zika virus (ZIKV) has emerged as one of the most medically relevant viral infections of the past decades; the devastating effects of this virus over the developing brain are a major matter of concern during pregnancy. Although the connection with congenital malformations are well documented, the mechanisms by which ZIKV reach the central nervous system (CNS) and the causes of impaired cortical growth in affected fetuses need to be better addressed. We performed a non-invasive, metabolomics-based screening of saliva from infants with congenital Zika syndrome (CZS), born from mothers that were infected with ZIKV during pregnancy. We were able to identify three biomarkers that suggest that this population suffered from an important inflammatory process; with the detection of mediators associated with glial activation, we propose that microcephaly is a product of immune response to the virus, as well as excitotoxicity mechanisms, which remain ongoing even after birth.


Assuntos
Microcefalia/etiologia , Saliva/química , Infecção por Zika virus/diagnóstico , Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Biomarcadores , Feminino , Desenvolvimento Fetal , Feto , Humanos , Lactente , Recém-Nascido , Inflamação/complicações , Estudos Longitudinais , Masculino , Metabolômica/métodos , Microcefalia/virologia , Mães , Parto , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Viroses , Zika virus/patogenicidade , Infecção por Zika virus/virologia
20.
J Mass Spectrom ; 43(5): 594-9, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18200607

RESUMO

Fingerprinting by mass spectrometry has been increasingly used to study venom variations and for taxonomic analyses based on venom components. Most of these studies have concentrated on components heavier than 3 kDa, but Bothrops snake venoms contain many biologically active peptides, principally C-type natriuretic peptides and bradykinin-potentiating peptides (BPPs). In this work, we have examined the peptide profile of Bothrops venoms (B. alternatus, B. erythromelas, B. insularis, B. jararaca, B. jararacussu, B. leucurus and B. moojeni) using direct infusion nano-electrospray ionization mass spectrometry (nano-ESI-MS) subjecting the data further to principal components analysis (PCA) to assess whether the peptide distributions are reliable in distinguishing the venoms. ESI-MS of a low molar mass fraction obtained by ultrafiltration of each venom (5 kDa nominal cutoff filters) revealed that the venoms have a variety of peptides in common but that each venom also contains taxonomic marker peptides not shared with other venoms. One BPP peptide, QGGWPRPGPEIPP, was found to be common to the seven Bothrops species examined. This peptide may represent a specific marker for this genus since it was not found in the venom of the South American rattlesnake, Crotalus durissus terrificus. PCA on the ESI-MS data reveals a close relationship between B. jararaca, B. jararacussu and B. moojeni venoms, with B. leucurus and B. erythromelas being more distant from these three; B. alternatus and B. insularis were also located distant from these five species, as was C. d. terrificus. These results agree partially with established phylogenetic relationships among these species and suggest that ESI-MS peptide fingerprinting of snake venoms coupled with PCA is a useful tool for identifying venoms and for taxonomic analyses.


Assuntos
Análise de Injeção de Fluxo/métodos , Microquímica/métodos , Nanotecnologia/métodos , Mapeamento de Peptídeos/métodos , Peptídeos/química , Venenos de Serpentes/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Estudos de Viabilidade , Peptídeos/classificação , Venenos de Serpentes/classificação , Manejo de Espécimes/métodos
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa