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1.
Gut ; 72(6): 1115-1128, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36175116

RESUMO

OBJECTIVE: In the management of patients with IBD, there is a need to identify prognostic markers and druggable biological pathways to improve mucosal repair and probe the efficacy of tumour necrosis factor alpha biologics. Vnn1 is a pantetheinase that degrades pantetheine to pantothenate (vitamin B5, a precursor of coenzyme A (CoA) biosynthesis) and cysteamine. Vnn1 is overexpressed by inflamed colonocytes. We investigated its contribution to the tolerance of the intestinal mucosa to colitis-induced injury. DESIGN: We performed an RNA sequencing study on colon biopsy samples from patients with IBD stratified according to clinical severity and modalities of treatment. We generated the VIVA mouse transgenic model, which specifically overexpresses Vnn1 on intestinal epithelial cells and explored its susceptibility to colitis. We developed a pharmacological mimicry of Vnn1 overexpression by administration of Vnn1 derivatives. RESULTS: VNN1 overexpression on colonocytes correlates with IBD severity. VIVA mice are resistant to experimentally induced colitis. The pantetheinase activity of Vnn1 is cytoprotective in colon: it enhances CoA regeneration and metabolic adaptation of colonocytes; it favours microbiota-dependent production of short chain fatty acids and mostly butyrate, shown to regulate mucosal energetics and to be reduced in patients with IBD. This prohealing phenotype is recapitulated by treating control mice with the substrate (pantethine) or the products of pantetheinase activity prior to induction of colitis. In severe IBD, the protection conferred by the high induction of VNN1 might be compromised because its enzymatic activity may be limited by lack of available substrates. In addition, we identify the elevation of indoxyl sulfate in urine as a biomarker of Vnn1 overexpression, also detected in patients with IBD. CONCLUSION: The induction of Vnn1/VNN1 during colitis in mouse and human is a compensatory mechanism to reinforce the mucosal barrier. Therefore, enhancement of vitamin B5-driven metabolism should improve mucosal healing and might increase the efficacy of anti-inflammatory therapy.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Humanos , Camundongos , Animais , Colite/metabolismo , Colo/patologia , Mucosa Intestinal/metabolismo , Doenças Inflamatórias Intestinais/genética , Ácidos Graxos Voláteis/metabolismo , Vitaminas , Sulfato de Dextrana , Modelos Animais de Doenças
2.
Mol Microbiol ; 117(4): 907-920, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35066935

RESUMO

Desulfovibrio fructosovorans, a sulfate-reducing bacterium, possesses six gene clusters encoding six hydrogenases catalyzing the reversible oxidation of H2 into protons and electrons. Among them, Hnd is an electron-bifurcating hydrogenase, coupling the exergonic reduction of NAD+ to the endergonic reduction of a ferredoxin with electrons derived from H2 . It was previously hypothesized that its biological function involves the production of NADPH necessary for biosynthetic purposes. However, it was subsequently demonstrated that Hnd is instead a NAD+ -reducing enzyme, thus its specific function has yet to be established. To understand the physiological role of Hnd in D. fructosovorans, we compared the hnd deletion mutant with the wild-type strain grown on pyruvate. Growth, metabolite production and consumption, and gene expression were compared under three different growth conditions. Our results indicate that hnd is strongly regulated at the transcriptional level and that its deletion has a drastic effect on the expression of genes for two enzymes, an aldehyde ferredoxin oxidoreductase and an alcohol dehydrogenase. We demonstrated here that Hnd is involved in ethanol metabolism when bacteria grow fermentatively and proposed that Hnd might oxidize part of the H2 produced during fermentation generating both NADH and reduced ferredoxin for ethanol production via its electron bifurcation mechanism.


Assuntos
Hidrogenase , Desulfovibrio , Elétrons , Etanol , Ferredoxinas/metabolismo , Hidrogênio/metabolismo , Hidrogenase/genética , Hidrogenase/metabolismo , NAD/metabolismo , Oxirredução , Ácido Pirúvico
3.
Anal Chem ; 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34133140

RESUMO

Nuclear magnetic resonance (NMR)-based metabolomic studies commonly involve the use of T2 filter pulse sequences to eliminate or attenuate the broad signals from large molecules and improve spectral resolution. In this paper, we demonstrate that the T1ρ filter-based pulse sequence represents an interesting alternative because it allows the stability and the reproducibility needed for statistical analysis. The integrity of the samples and the stability of the instruments were assessed for different filter durations and amplitudes. We showed that the T1ρ filter pulse sequence did not induce sample overheating for a filter duration of up to 500 ms. The reproducibility was evaluated and compared with the T2 filter in serum and liver samples. The implementation is relatively simple and provides the same statistical and analytical results as those obtained with the standard filters. Regarding tissues analysis, because the duration of the filter is the same as that of the spin-lock, the synchronization of the echo delays with the magic angle spinning (MAS) rate is no longer necessary as for T2 filter-based sequences. The results presented in this article aim at establishing a new protocol to improve metabolomic studies and pave the way for future developments on T1ρ alternative filters, in liquid and HR-MAS NMR experiments.

4.
Molecules ; 26(8)2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33919750

RESUMO

Breast cancer (BC) is the most common form of cancer among women worldwide. Despite the huge advancements in its treatment, the exact etiology of breast cancer still remains unresolved. There is an increasing interest in the role of the gut microbiome in modulating the anti-cancer therapeutic response. It seems that alteration of the microbiome-derived metabolome potentially promotes carcinogenesis. Taken together, metabolomics has arisen as a fascinating new omics field to screen promising metabolic biomarkers. In this study, fecal metabolite profiling was performed using NMR spectroscopy, to identify potential biomarker candidates that can predict response to neoadjuvant chemotherapy (NAC) for breast cancer. Metabolic profiles of feces from patients (n = 8) following chemotherapy treatment cycles were studied. Interestingly, amino acids were found to be upregulated, while lactate and fumaric acid were downregulated in patients under the second and third cycles compared with patients before treatment. Furthermore, short-chain fatty acids (SCFAs) were significantly differentiated between the studied groups. These results strongly suggest that chemotherapy treatment plays a key role in modulating the fecal metabolomic profile of BC patients. In conclusion, we demonstrate the feasibility of identifying specific fecal metabolic profiles reflecting biochemical changes that occur during the chemotherapy treatment. These data give an interesting insight that may complement and improve clinical tools for BC monitoring.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Fezes/química , Metabolômica , Terapia Neoadjuvante , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Análise Discriminante , Ácidos Graxos Voláteis/metabolismo , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Redes e Vias Metabólicas , Metaboloma , Pessoa de Meia-Idade , Análise de Componente Principal , Espectroscopia de Prótons por Ressonância Magnética , Curva ROC
5.
Faraday Discuss ; 218(0): 459-480, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31173013

RESUMO

Analytical methods for mixtures of small molecules require specificity (is a certain molecule present in the mix?) and speciation capabilities. NMR spectroscopy has been a tool of choice for both of these issues since its early days, due to its quantitative (linear) response, sufficiently high resolving power and capabilities of inferring molecular structures from spectral features (even in the absence of a reference database). However, the analytical performances of NMR spectroscopy are being stretched by the increased complexity of the samples, the dynamic range of the components, and the need for a reasonable turnover time. One approach that has been actively pursued for disentangling the composition complexity is the use of 2D NMR spectroscopy. While any of the many experiments from this family will increase the spectral resolution, some are more apt for mixtures, as they are capable of unveiling signals belonging to whole molecules or fragments of it. Among the most popular ones, one can enumerate HSQC-TOCSY, DOSY and Maximum-Quantum (MaxQ) NMR spectroscopy. For multicomponent samples, the development of robust mathematical methods of signal decomposition would provide a clear edge towards identification. We have been pursuing, along these lines, Blind Source Separation (BSS). Here, the un-mixing of the spectra is achieved relying on correlations detected on a series of datasets. The series could be associated with samples of different relative composition or in a classically acquired 2D experiment by the mathematical laws underlying the construction of the indirect dimension, the one not recorded by the spectrometer. Many algorithms have been proposed for BSS in NMR spectroscopy since the seminal work of Nuzillard. In this paper, we use rather standard algorithms in BSS in order to disentangle NMR spectra. We show on simulated data (both 1D and 2D HSQC) that these approaches enable us to accurately disentangle multiple components, and provide good estimates for the concentrations of compounds. Furthermore, we show that after proper realignment of the signals, the same algorithms are able to disentangle real 1D NMR spectra. We obtain similar results on 2D HSQC spectra, where the BSS algorithms are able to successfully disentangle components, and provide even better estimates for concentrations.

6.
Metabolomics ; 14(10): 141, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30830426

RESUMO

INTRODUCTION: Ultrasound examination coupled with fine-needle aspiration (FNA) cytology is the gold standard for the diagnosis of thyroid cancer. However, about 10-40% of these analyses cannot be conclusive on the malignancy of the lesions and lead to surgery. The cytological indeterminate FNA biopsies are mainly constituted of follicular-patterned lesions, which are benign in 80% of the cases. OBJECTIVES: The development of a FNAB classification approach based on the metabolic phenotype of the lesions, complementary to cytology and other molecular tests in order to limit the number of patients undergoing unnecessary thyroidectomy. METHODS: We explored the potential of a NMR-based metabolomics approach to improve the quality of the diagnosis from FNABs, using thyroid tissues collected post-surgically. RESULTS: The NMR-detected metabolites were used to produce a robust OPLSDA model to discriminate between benign and malignant tumours. Malignancy was correlated with amino acids such as tyrosine, serine, alanine, leucine and phenylalanine and anti-correlated with myo-inositol, scyllo-inositol and citrate. Diagnosis accuracy was of 84.8% when only indeterminate lesions were considered. CONCLUSION: These results on model FNAB indicate that there is a clear interest in exploring the possibility to export NMR metabolomics to pre-surgical diagnostics.


Assuntos
Metabolômica , Ressonância Magnética Nuclear Biomolecular , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/metabolismo , Nódulo da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/metabolismo , Biópsia por Agulha Fina , Feminino , Humanos , Masculino , Análise Multivariada , Neoplasias da Glândula Tireoide/cirurgia , Nódulo da Glândula Tireoide/cirurgia
7.
Anal Chem ; 86(21): 10749-54, 2014 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-25286333

RESUMO

High-resolution magic-angle spinning (HR-MAS) nuclear magnetic resonance (NMR) is an essential tool to characterize a variety of semisolid systems, including biological tissues, with virtually no sample preparation. The "non-destructive" nature of NMR is typically compromised, however, by the extreme centrifugal forces experienced under conventional HR-MAS frequencies of several kilohertz. These features limit the usefulness of current HR-MAS approaches for fragile samples. Here, we introduce a full protocol for acquiring high-quality HR-MAS NMR spectra of biological tissues at low spinning rates (down to a few hundred hertz). The protocol first consists of a carefully designed sample preparation, which yields spectra without significant spinning sidebands at low spinning frequency for several types of sample holders, including the standard disposable inserts classically used in HR-MAS NMR-based metabolomics. Suppression of broad spectral features is then achieved using a modified version of the recently introduced PROJECT experiment with added water suppression and rotor synchronization, which deposits limited power in the sample and which can be suitably rotor-synchronized at low spinning rates. The performance of the slow HR-MAS NMR procedure is demonstrated on conventional (liver tissue) and very delicate (fish eggs) samples, for which the slow-spinning conditions are shown to preserve the structural integrity and to minimize intercompartmental leaks of metabolites. Taken together, these results expand the applicability and reliability of HR-MAS NMR spectroscopy. These results have been obtained at 400 and 600 MHz and suggest that high-quality slow HR-MAS spectra can be expected at higher magnetic fields using the described protocol.


Assuntos
Fígado/química , Espectroscopia de Ressonância Magnética/métodos , Animais , Bovinos , Feminino
9.
Naturwissenschaften ; 101(8): 623-35, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24925357

RESUMO

Staining and histochemistry of volatile organic compounds (VOCs) were performed at different inflorescence developmental stages on nine aroid species; one temperate, Arum italicum and eight tropical from the genera Caladium, Dieffenbachia and Philodendron. Moreover, a qualitative and quantitative analysis of VOCs constituting the scent of A. italicum, depending on the stage of development of inflorescences was also conducted. In all nine species, vesicles were observed in the conical cells of either the appendix or the stamens (thecae) and the staminodes. VOCs were localised in intracellular vesicles from the early stages of inflorescence development until their release during receptivity of gynoecium. This localisation was observed by the increase of both number and diameter of the vesicles during 1 week before receptivity. Afterwards, vesicles were fewer and smaller but rarely absent. In A. italicum, staining and gas chromatography analyses confirmed that the vesicles contained terpenes. The quantitatively most important ones were the sesquiterpenes, but monoterpenes were not negligible. Indeed, the quantities of terpenes matched the vesicles' size evolution during 1 week. Furthermore, VOCs from different biosynthetic pathways (sesquiterpenes and alkanes) were at their maximum quantity 2 days before gynoecium receptivity (sesquiterpenes and alkanes) or during receptivity (isobutylamine, monoterpenes, skatole and p-cresol). VOCs seemed to be emitted during gynoecium receptivity and/or during thermogenesis, and FADs are accumulated after thermogenesis in the spadix. These complex dynamics of the different VOCs could indicate specialisation of some VOCs and cell machinery to attract pollinators on the one hand and to repulse/protect against phytophagous organisms and pathogens after pollination on the other hand.


Assuntos
Araceae/química , Arum/química , Polinização , Compostos Orgânicos Voláteis/análise , Araceae/crescimento & desenvolvimento , Arum/crescimento & desenvolvimento , Cromatografia Gasosa , Folhas de Planta/química , Terpenos/análise
10.
Curr Genomics ; 15(3): 178-83, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24955025

RESUMO

We review the progress and state-of-the-art applications of studies in Magnetic Resonance Spectroscopy (MRS) and Imaging as an aid for diagnosis of thyroid lesions of different nature, especially focusing our attention to those lesions that are cytologically undetermined. It appears that the high-resolution of High-Resolution Magic-Angle-Spinning (HRMAS) MRS improves the overall accuracy of the analysis of thyroid lesions to a point that a significant improvement in the diagnosis of cytologically undetermined lesions can be expected. This analysis, in the meantime, allows a more precise comprehension of the alterations in the metabolic pathways induced by the development of the different tumors. Although these results are promising, at the moment, a clinical application of the method to the common workup of thyroid nodules cannot be used, due to both the limitation in the availability of this technology and the wide range of techniques, that are not uniformly used. The coming future will certainly see a wider application of these methods to the clinical practice in patients affected with thyroid nodules and various other neoplastic diseases.

11.
Magn Reson Chem ; 52(11): 694-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25103092

RESUMO

The detailed characterization of complex mixtures by NMR is often hampered by the presence of signals from uninformative compounds, the resonances of which overlap with those of the molecules of interest. We provide here a proof of principle for an approach to NMR signal suppression in complex samples using Molecularly Imprinted Polymers (MIPS). Addition of a few milligrams of polymer to a solution traps the target molecule in typical micromolar to millimolar concentration, thus achieving in situ signal suppression, without altering any other spectral features. This method minimized any manipulation or perturbation of the spectrum and was applied to a complex mixture of known compounds and to a plant extract, in both cases spiked with a compound (bisphenol A), which was subsequently removed by selective binding to a complementary MIP. What is described in this report is comparable with microextraction and may in due course be applied to a large number of analytical challenges.


Assuntos
Compostos de Anilina/análise , Compostos Benzidrílicos/análise , Compostos de Benzil/análise , Compostos de Bifenilo/análise , Impressão Molecular , Fenóis/análise , Microextração em Fase Sólida , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Polímeros/química
12.
Anal Bioanal Chem ; 405(28): 9093-100, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24057027

RESUMO

In this paper, we present for the first time the use of high-resolution magic angle spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy combined with chemometrics as an alternative tool for the characterization of tobacco products from different commercial international brands as well as for the identification of counterfeits. Although cigarette filling is a very complex chemical mixture, we were able to discriminate between dark, bright, and additive-free cigarette blends belonging to six different filter-cigarette brands, commercially available, using an approach for which no extraction procedure is required. Second, we focused our study on a specific worldwide-distributed brand for which established counterfeits were available. We discriminated those from their genuine counterparts with 100% accuracy using unsupervised multivariate statistical analysis. The counterfeits that we analyzed showed a higher amount of nicotine and solanesol and a lower content of sugars, all endogenous tobacco leaf metabolites. This preliminary study demonstrates the great potential of HRMAS NMR spectroscopy to help in controlling cigarette authenticity.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Nicotina/análise , Terpenos/análise , Produtos do Tabaco/análise , Espectroscopia de Ressonância Magnética/instrumentação , Controle de Qualidade
13.
Microbiol Res ; 268: 127279, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36592576

RESUMO

Solidesulfovibrio fructosivorans (formely Desulfovibrio fructosovorans), an anaerobic sulfate-reducing bacterium, possesses six gene clusters encoding six hydrogenases catalyzing the reversible oxidation of hydrogen gas (H2) into protons and electrons. One of these, named Hnd, was demonstrated to be an electron-bifurcating hydrogenase Hnd (Kpebe et al., 2018). It couples the exergonic reduction of NAD+ to the endergonic reduction of a ferredoxin with electrons derived from H2 and whose function has been recently shown to be involved in ethanol production under pyruvate fermentation (Payne 2022). To understand further the physiological role of Hnd in S. fructosivorans, we compared the mutant deleted of part of the hnd gene with the wild-type strain grown on pyruvate without sulfate using NMR-based metabolomics. Our results confirm that Hnd is profoundly involved in ethanol metabolism, but also indirectly intervenes in global carbon metabolism and additional metabolic processes such as the biosynthesis of branched-chain amino acids. We also highlight the metabolic reprogramming induced by the deletion of hndD that leads to the upregulation of several NADP-dependent pathways.


Assuntos
Hidrogenase , Elétrons , Fermentação , Hidrogênio/metabolismo , Hidrogenase/genética , Hidrogenase/química , Hidrogenase/metabolismo , Oxirredução , Ácido Pirúvico , Desulfovibrionaceae/química , Desulfovibrionaceae/metabolismo
14.
Front Microbiol ; 14: 1139276, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37051519

RESUMO

The tetrameric cytoplasmic FeFe hydrogenase Hnd from Solidesulfovibrio fructosivorans (formely Desulfovibrio fructosovorans) catalyses H2 oxidation and couples the exergonic reduction of NAD+ to the endergonic reduction of a ferredoxin by using a flavin-based electron-bifurcating mechanism. Regarding its implication in the bacterial physiology, we previously showed that Hnd, which is non-essential when bacteria grow fermentatively on pyruvate, is involved in ethanol metabolism. Under these conditions, it consumes H2 to produce reducing equivalents for ethanol production as a fermentative product. In this study, the approach implemented was to compare the two S. fructosivorans WT and the hndD deletion mutant strains when grown on ethanol as the sole carbon and energy source. Based on the determination of bacterial growth, metabolite consumption and production, gene expression followed by RT-q-PCR, and Hnd protein level followed by mass spectrometry, our results confirm the role of Hnd hydrogenase in the ethanol metabolism and furthermore uncover for the first time an essential function for a Desulfovibrio hydrogenase. Hnd is unequivocally required for S. fructosivorans growth on ethanol, and we propose that it produces H2 from NADH and reduced ferredoxin generated by an alcohol dehydrogenase and an aldehyde ferredoxin oxidoreductase catalyzing the conversion of ethanol into acetate. The produced H2 could then be recycled and used for sulfate reduction. Hnd is thus a reversible hydrogenase that operates in H2-consumption by an electron-bifurcating mechanism during pyruvate fermentation and in H2-production by an electron-confurcating mechanism when the bacterium uses ethanol as electron donor.

15.
Life Sci Alliance ; 6(12)2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37833072

RESUMO

The tumor microenvironment is a dynamic network of stromal, cancer, and immune cells that interact and compete for resources. We have previously identified the Vanin1 pathway as a tumor suppressor of sarcoma development via vitamin B5 and coenzyme A regeneration. Using an aggressive sarcoma cell line that lacks Vnn1 expression, we showed that the administration of pantethine, a vitamin B5 precursor, attenuates tumor growth in immunocompetent but not nude mice. Pantethine boosts antitumor immunity, including the polarization of myeloid and dendritic cells towards enhanced IFNγ-driven antigen presentation pathways and improved the development of hypermetabolic effector CD8+ T cells endowed with potential antitumor activity. At later stages of treatment, the effect of pantethine was limited by the development of immune cell exhaustion. Nevertheless, its activity was comparable with that of anti-PD1 treatment in sensitive tumors. In humans, VNN1 expression correlates with improved survival and immune cell infiltration in soft-tissue sarcomas, but not in osteosarcomas. Pantethine could be a potential therapeutic immunoadjuvant for the development of antitumor immunity.


Assuntos
Linfócitos T CD8-Positivos , Sarcoma , Humanos , Camundongos , Animais , Coenzima A/farmacologia , Ácido Pantotênico/farmacologia , Sarcoma/tratamento farmacológico , Microambiente Tumoral
16.
J Proteome Res ; 11(6): 3317-25, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22509853

RESUMO

Cytological analysis of thyroid nodules detected using ultrasound-guided fine-needle aspiration technique is an efficient method for the diagnosis of well-differenciated tumors such as papillary thyroid carcinoma. However, for between 10 to 30% of all the nodules, the cytological analysis based on fine-needle aspiration biopsies leads to an "indeterminated" identification. Consequently, a surgical excision is then necessary for a definite histological diagnosis of the lesions, resulting in 85% of the patient with indeterminated nodules undergoing unnecessary surgery since their tumor is finally diagnosed as benign. In this work, we discuss how HRMAS (1)H NMR-based metabolomics could be a complementary tool for the diagnosis of these elusive cases. We first showed that our approach was able to discriminate clearly any types of thyroid lesions from healthy tissues. Then we proceeded to demonstrate that the information produced by (1)H HRMAS NMR spectra differentiate tumors according to their malignancy grade, even when they belong to the "indeterminate" category. Analysis of the discriminating spectral area in this last case points out toward a possible increase of phenylalanine, taurine, and lactate and a decrease of choline and choline derivatives, myo- and scyllo-inositol in the malignant tumors compared to the benign ones.


Assuntos
Adenocarcinoma Folicular/diagnóstico , Adenoma/diagnóstico , Biomarcadores Tumorais/metabolismo , Metaboloma , Neoplasias da Glândula Tireoide/diagnóstico , Adenocarcinoma Folicular/metabolismo , Adenoma/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Diagnóstico Diferencial , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Componente Principal , Curva ROC , Reprodutibilidade dos Testes , Neoplasias da Glândula Tireoide/metabolismo , Adulto Jovem
17.
Anal Chem ; 84(4): 1840-8, 2012 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-22242722

RESUMO

The world faces complex challenges for chemical hazard assessment. Microfluidic bioartificial organs enable the spatial and temporal control of cell growth and biochemistry, critical for organ-specific metabolic functions and particularly relevant to testing the metabolic dose-response signatures associated with both pharmaceutical and environmental toxicity. Here we present an approach combining a microfluidic system with (1)H NMR-based metabolomic footprinting, as a high-throughput small-molecule screening approach. We characterized the toxicity of several molecules: ammonia (NH(3)), an environmental pollutant leading to metabolic acidosis and liver and kidney toxicity; dimethylsulfoxide (DMSO), a free radical-scavenging solvent; and N-acetyl-para-aminophenol (APAP, or paracetamol), a hepatotoxic analgesic drug. We report organ-specific NH(3) dose-dependent metabolic responses in several microfluidic bioartificial organs (liver, kidney, and cocultures), as well as predictive (99% accuracy for NH(3) and 94% for APAP) compound-specific signatures. Our integration of microtechnology, cell culture in microfluidic biochips, and metabolic profiling opens the development of so-called "metabolomics-on-a-chip" assays in pharmaceutical and environmental toxicology.


Assuntos
Acetaminofen/toxicidade , Amônia/toxicidade , Órgãos Bioartificiais , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Metabolômica , Microfluídica/instrumentação , Microfluídica/métodos , Analgésicos não Narcóticos/toxicidade , Animais , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas , Cães , Células Hep G2 , Humanos , Rim/citologia , Rim/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Curva ROC
18.
Sci Rep ; 11(1): 14782, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285254

RESUMO

Deep-sea hydrothermal vents are extreme and complex ecosystems based on a trophic chain. We are still unsure of the identities of the first colonizers of these environments and their metabolism, but they are thought to be (hyper)thermophilic autotrophs. Here we investigate whether the electric potential observed across hydrothermal chimneys could serve as an energy source for these first colonizers. Experiments were performed in a two-chamber microbial electrochemical system inoculated with deep-sea hydrothermal chimney samples, with a cathode as sole electron donor, CO2 as sole carbon source, and nitrate, sulfate, or oxygen as electron acceptors. After a few days of culturing, all three experiments showed growth of electrotrophic biofilms consuming the electrons (directly or indirectly) and producing organic compounds including acetate, glycerol, and pyruvate. Within the biofilms, the only known autotroph species retrieved were members of Archaeoglobales. Various heterotrophic phyla also grew through trophic interactions, with Thermococcales growing in all three experiments as well as other bacterial groups specific to each electron acceptor. This electrotrophic metabolism as energy source driving initial microbial colonization of conductive hydrothermal chimneys is discussed.

19.
Microorganisms ; 9(12)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34946077

RESUMO

Recent studies have shown the presence of an abiotic electrical current across the walls of deep-sea hydrothermal chimneys, allowing the growth of electroautotrophic microbial communities. To understand the role of the different phylogenetic groups and metabolisms involved, this study focused on electrotrophic enrichment with nitrate as electron acceptor. The biofilm density, community composition, production of organic compounds, and electrical consumption were monitored by FISH confocal microscopy, qPCR, metabarcoding, NMR, and potentiostat measurements. A statistical analysis by PCA showed the correlation between the different parameters (qPCR, organic compounds, and electron acceptors) in three distinct temporal phases. In our conditions, the Archaeoglobales have been shown to play a key role in the development of the community as the first colonizers on the cathode and the first producers of organic compounds, which are then used as an organic source by heterotrophs. Finally, through subcultures of the community, we showed the development of a greater biodiversity over time. This observed phenomenon could explain the biodiversity development in hydrothermal contexts, where energy sources are transient and unstable.

20.
J Proteome Res ; 9(9): 4513-20, 2010 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-20590164

RESUMO

The development of Statistical Total Correlation Spectroscopy (STOCSY), a representation of the autocorrelation matrix of a spectral data set as a 2D pseudospectrum, has allowed more reliable assignment of one- and two-dimensional NMR spectra acquired from the complex mixtures that are usually used in metabolomics/metabonomics studies, thus, improving precise identification of candidate biomarkers contained in metabolic signatures computed by multivariate statistical analysis. However, the correlations obtained cannot always be interpreted in terms of connectivities between metabolites. In this study, we combine statistical recoupling of variables (SRV) and STOCSY to identify perturbed metabolite systems. The resulting Recoupled-STOCSY (R-STOCSY) method provides a 2D correlation landscape based on the SRV clusters representing physical, chemical, and biological entities. This enables the identification of correlations between distant clusters and extends the recoupling scheme of SRV, which was previously limited to the association of neighboring clusters. This allows the recovery of only meaningful correlations between metabolic signals and significantly enhances the interpretation of STOCSY. The method is validated through the measurement of the distances between the metabolites involved in these correlations, within the whole metabolic network, which shows that the average shortest path length is significantly shorter for the correlations detected in this new way compared to metabolite couples randomly selected from within the entire KEGG metabolic network. This enables the identification without any a priori knowledge of the perturbed metabolic network. The R-STOCSY completes the recoupling procedure between distant clusters, further reducing the high dimensionality of metabolomics/metabonomics data set and finally allows the identification of composite biomarkers, highlighting disruption of particular metabolic pathways within a global metabolic network. This allows the perturbed metabolic network to be extracted through NMR based metabolomics/metabonomics in an automated, and statistical manner.


Assuntos
Biologia Computacional/métodos , Redes e Vias Metabólicas , Metabolômica/métodos , Ressonância Magnética Nuclear Biomolecular/métodos , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Análise por Conglomerados , Bases de Dados Factuais , Análise Multivariada , Reprodutibilidade dos Testes , Biologia de Sistemas
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