Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
1.
PLoS Genet ; 13(10): e1007068, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29084269

RESUMO

The coronary vasculature is an essential vessel network providing the blood supply to the heart. Disruptions in coronary blood flow contribute to cardiac disease, a major cause of premature death worldwide. The generation of treatments for cardiovascular disease will be aided by a deeper understanding of the developmental processes that underpin coronary vessel formation. From an ENU mutagenesis screen, we have isolated a mouse mutant displaying embryonic hydrocephalus and cardiac defects (EHC). Positional cloning and candidate gene analysis revealed that the EHC phenotype results from a point mutation in a splice donor site of the Myh10 gene, which encodes NMHC IIB. Complementation testing confirmed that the Myh10 mutation causes the EHC phenotype. Characterisation of the EHC cardiac defects revealed abnormalities in myocardial development, consistent with observations from previously generated NMHC IIB null mouse lines. Analysis of the EHC mutant hearts also identified defects in the formation of the coronary vasculature. We attribute the coronary vessel abnormalities to defective epicardial cell function, as the EHC epicardium displays an abnormal cell morphology, reduced capacity to undergo epithelial-mesenchymal transition (EMT), and impaired migration of epicardial-derived cells (EPDCs) into the myocardium. Our studies on the EHC mutant demonstrate a requirement for NMHC IIB in epicardial function and coronary vessel formation, highlighting the importance of this protein in cardiac development and ultimately, embryonic survival.


Assuntos
Vasos Coronários/crescimento & desenvolvimento , Desenvolvimento Embrionário/genética , Cadeias Pesadas de Miosina/genética , Miosina não Muscular Tipo IIB/genética , Pericárdio/crescimento & desenvolvimento , Animais , Diferenciação Celular/genética , Vasos Coronários/metabolismo , Embrião de Mamíferos , Transição Epitelial-Mesenquimal/genética , Humanos , Hidrocefalia/genética , Hidrocefalia/metabolismo , Hidrocefalia/patologia , Camundongos , Camundongos Knockout , Mutação , Miocárdio/metabolismo , Pericárdio/metabolismo
2.
Genesis ; 52(8): 713-37, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24866031

RESUMO

Genes required for an organism to develop to maturity (for which no other gene can compensate) are considered essential. The continuing functional annotation of the mouse genome has enabled the identification of many essential genes required for specific developmental processes including cardiac development. Patterns are now emerging regarding the functional nature of genes required at specific points throughout gestation. Essential genes required for development beyond cardiac progenitor cell migration and induction include a small and functionally homogenous group encoding transcription factors, ligands and receptors. Actions of core cardiogenic transcription factors from the Gata, Nkx, Mef, Hand, and Tbx families trigger a marked expansion in the functional diversity of essential genes from midgestation onwards. As the embryo grows in size and complexity, genes required to maintain a functional heartbeat and to provide muscular strength and regulate blood flow are well represented. These essential genes regulate further specialization and polarization of cell types along with proliferative, migratory, adhesive, contractile, and structural processes. The identification of patterns regarding the functional nature of essential genes across numerous developmental systems may aid prediction of further essential genes and those important to development and/or progression of disease.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/genética , Genes Essenciais/genética , Coração/crescimento & desenvolvimento , Mamíferos/genética , Animais , Diferenciação Celular , Movimento Celular , Coração/embriologia , Mamíferos/embriologia , Mamíferos/crescimento & desenvolvimento , Camundongos , Células-Tronco
3.
J Proteome Res ; 12(12): 5775-90, 2013 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-24161236

RESUMO

Non-genotoxic carcinogens (NGCs) promote tumor growth by altering gene expression, which ultimately leads to cancer without directly causing a change in DNA sequence. As a result NGCs are not detected in mutagenesis assays. While there are proposed biomarkers of carcinogenic potential, the definitive identification of non-genotoxic carcinogens still rests with the rat and mouse long-term bioassay. Such assays are expensive and time-consuming and require a large number of animals, and their relevance to human health risk assessments is debatable. Metabolomics and lipidomics in combination with pathology and clinical chemistry were used to profile perturbations produced by 10 compounds that represented a range of rat non-genotoxic hepatocarcinogens (NGC), non-genotoxic non-hepatocarcinogens (non-NGC), and a genotoxic hepatocarcinogen. Each compound was administered at its maximum tolerated dose level for 7, 28, and 91 days to male Fisher 344 rats. Changes in liver metabolite concentration differentiated the treated groups across different time points. The most significant differences were driven by pharmacological mode of action, specifically by the peroxisome proliferator activated receptor alpha (PPAR-α) agonists. Despite these dominant effects, good predictions could be made when differentiating NGCs from non-NGCs. Predictive ability measured by leave one out cross validation was 87% and 77% after 28 days of dosing for NGCs and non-NGCs, respectively. Among the discriminatory metabolites we identified free fatty acids, phospholipids, and triacylglycerols, as well as precursors of eicosanoid and the products of reactive oxygen species linked to processes of inflammation, proliferation, and oxidative stress. Thus, metabolic profiling is able to identify changes due to the pharmacological mode of action of xenobiotics and contribute to early screening for non-genotoxic potential.


Assuntos
Carcinógenos/toxicidade , Neoplasias Hepáticas Experimentais/metabolismo , Fígado/efeitos dos fármacos , Metabolômica , Mutagênicos/toxicidade , Animais , Biomarcadores/metabolismo , Carcinógenos/classificação , Dano ao DNA , Eicosanoides/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Expressão Gênica , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/patologia , Masculino , Mutagênicos/classificação , PPAR alfa/agonistas , PPAR alfa/genética , PPAR alfa/metabolismo , Fosfolipídeos/metabolismo , Ratos , Ratos Endogâmicos F344 , Espécies Reativas de Oxigênio/metabolismo , Triglicerídeos/metabolismo
4.
Infect Drug Resist ; 16: 5511-5522, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37638071

RESUMO

Background: Drug resistance in tuberculosis poses challenges to both the control and prevention of the disease. The extent of resistance is not well known in developing countries, including Ethiopia. This study was conducted to determine the drug resistance patterns and mutation characteristics of Mycobacterium tuberculosis among extra pulmonary tuberculosis patients in selected health facilities in Addis Ababa. Material and Methods: A cross-sectional study was conducted from February 2022 to August 2022 in selected hospitals in Addis Ababa. Socio-demographic and clinical data were collected using structured questionnaire. Mycobacterium tuberculosis complex (MTBC) isolates were tested for phenotypic drug susceptibility patterns using the Mycobacterium growth indicator tube (MGIT) method for first-line drugs and mutation characteristics using the Line Probe Assay (LPA) method. The data were analyzed using: SPSS version 23, and a P-value ≤ 0.05 was considered statistically significant. Results: From a total of 308 patient samples from presumptive extra pulmonary patients, 44 (14.3%) were positive for MTBC. Any drug resistance was discovered in 25% of 44 MTBC isolates evaluated for five first-line drugs phenotypically, with isoniazid (INH) and pyrazinamide (PZA) resistance accounting for a greater proportion with 13.6% and 11.4% of the isolates, respectively. Two (4.5%) of the isolates were MDR-TB. Out of 44 isolates tested using the Geno Type MTBDRplus assay, 5 (11.4%) showed mutations at katG and 2 (4.5%) showed mutations in the rpoB genes. Conclusion: Both the phenotypic and genotypic drug susceptibility test results showed a high proportion of INH resistance. All INH resistance-conferring mutations were identified from katG gene. The overall prevalence of MDR-TB was also high. For early case detection and treatment, expanding diagnostic capacity for first-line DST is a vital step to limit further spread of drug resistant TB strains in the study area.

5.
IJID Reg ; 7: 199-205, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37114203

RESUMO

Background: Extra pulmonary tuberculosis (EPTB) accounts for a significant proportion of tuberculosis (TB), a devastating disease of public health concern. The complexity of the cases, the involvement of many organs, resource constraints, and concerns regarding drug resistance make disease diagnosis and treatment difficult. This study aimed to determine the burden of tuberculosis and associated factors among presumptive EPTB patients in selected hospitals in Addis Ababa. Material and methods: A cross-sectional study was conducted from February to August 2022 in selected public hospitals in Addis Ababa. Those who attended the hospitals and were presumptively diagnosed as EPTB patient were included in the study. Sociodemographic and clinical data were collected using a semistructured questionnaire. The GeneXpert MTB/RIF assay, Mycobacterium Growth Indicator Tube (MGIT) culture, and solid culture using Löwenstein-Jensen (LJ) medium were used. The data were entered and analyzed using SPSS version 23, and a p-value ≤ 0.05 was considered as statistically significant. Results: From a total of 308 participants enrolled in this study, the measured burdens of extrapulmonary tuberculosis using the Xpert MTB/RIF assay, liquid culture, and solid culture were 54 (17.5%), 45 (14.6%), and 39 (12.7%), respectively. In this study, sex, contact history with known TB cases, having a purulent type of aspirate, and being HIV positive had statistically significant associations with EPTB. Conclusions: The burden of extrapulmonary tuberculosis among presumptive extrapulmonary tuberculosis cases was found to be significant. Sex, contact history with a known TB case, having apurulent type of aspirate, and being HIV positive were found to be associated with extrapulmonary tuberculosis infection. Strict adherence to the national tuberculosis diagnosis and treatment guidelines is important, while the true burden of the disease should be ascertained using standard diagnostic tests for better prevention and control interventions.

6.
Toxicol Rep ; 8: 155-161, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33473352

RESUMO

Species differences in hepatic metabolism of thyroxine (T4) by uridine diphosphate glucuronosyl transferase (UGT) and susceptibility to thyroid hormone imbalance could underlie differences in thyroid carcinogenesis caused by hepatic enzyme inducers in rats and humans. To investigate this hypothesis we examined profiles of hepatic UGT induction by the prototypical CAR activator phenobarbital (PB) in rat and human liver 3D microtissues. The rationale for this approach was that 3D microtissues would generate data more relevant to humans. Rat and human liver 3D microtissues were exposed to PB over a range of concentrations (500 u M - 2000 u M) and times (24-96 hr). Microarray and proteomics analyses were performed on parallel samples to generate integrated differentially expressed gene (DEG) datasets. Bioinformatics analysis of DEG data, including CAR response element (CRE) sequence analysis of UGT promoters, was used to assess species differences in UGT induction relative to CAR-mediated transactivation potential. A higher proportion of human UGT promoters were found to contain consensus CREs compared to the rat homologs. UGTs 1a6, 2b17 and 2b37 were upregulated by PB in rat liver 3D microtissues, but unaltered in human liver 3D microtissues. By contrast, human UGTs 1A8, 1A10 and 2B10 showed higher levels of induction (RNA and /or protein) compared to the rat homologs. There was general concordance between the presence of CREs and the induction of UGT RNA. As UGT1A and 2B isoforms metabolise T4, these results suggest that differences in UGT induction could contribute to differential susceptibility to CAR-mediated thyroid carcinogenesis in rats and humans.

7.
BMC Genomics ; 11: 9, 2010 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-20053287

RESUMO

BACKGROUND: Non-genotoxic carcinogens are notoriously difficult to identify as they do not damage DNA directly and have diverse modes of action, necessitating long term in vivo studies. The early effects of the classic rodent non-genotoxic hepatocarcinogen phenobarbital have been investigated in the Fisher rat using a combination of metabolomics and transcriptomics, to investige early stage mechanistic changes that are predictive of longer term pathology. RESULTS: Liver and blood plasma were profiled across 14 days, and multivariate statistics used to identify perturbed pathways. Both metabolomics and transcriptomics detected changes in the liver which were dose dependent, even after one day of exposure. Integration of the two datasets associated perturbations with specific pathways. Hepatic glycogen was decreased due to a decrease in synthesis, and plasma triglycerides were decreased due to an increase in fatty acid uptake by the liver. Hepatic succinate was increased and this was associated with increased heme biosynthesis. Glutathione synthesis was also increased, presumably in response to oxidative stress. Liquid Chromatography Mass Spectrometry demonstrated a remodeling of lipid species, possibly resulting from proliferation of the smooth endoplasmic reticulum. CONCLUSIONS: The data fusion of metabolomic and transcriptomic changes proved to be a highly sensitive approach for monitoring early stage changes in altered hepatic metabolism, oxidative stress and cytochrome P450 induction simultaneously. This approach is particularly useful in interpreting changes in metabolites such as succinate which are hubs of metabolism.


Assuntos
Perfilação da Expressão Gênica , Fígado/efeitos dos fármacos , Metaboloma , Fenobarbital/toxicidade , Animais , Análise por Conglomerados , Sistema Enzimático do Citocromo P-450/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Fígado/metabolismo , Fígado/patologia , Espectroscopia de Ressonância Magnética , Masculino , Análise Multivariada , Estresse Oxidativo , Plasma/efeitos dos fármacos , Plasma/metabolismo , Análise de Componente Principal , Ratos , Ratos Endogâmicos F344
8.
Anal Chem ; 82(11): 4479-85, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20446676

RESUMO

High-resolution (1)H NMR spectroscopy is frequently used in the field of metabolomics to assess the metabolites found in biofluids or tissue extracts to define a metabolic profile that describes a given biological process. In this study, we aimed to increase the utility of NMR-based metabolomics by using advanced Bayesian modeling of the time-domain high-resolution 1D NMR free induction decay (FID). The improvement over traditional nonparametric binning is twofold and associated with enhanced resolution of the analysis and automation of the signal processing stage. The automation is achieved by using a Bayesian formalism for all parameters of the model including the number of components. The approach is illustrated with a study of early markers of acute exposure to different doses of a well-characterized nongenotoxic hepatocarcinogen, phenobarbital, in rats. The results demonstrate that Bayesian deconvolution produces a better model for the NMR spectra that allows the identification of subtle changes in metabolic concentrations and a decrease in the expected false discovery rate compared with approaches based on "binning". These properties suggest that Bayesian deconvolution could facilitate the biomarker discovery process and improve information extraction from high-resolution NMR spectra.


Assuntos
Fígado/citologia , Fígado/efeitos dos fármacos , Espectroscopia de Ressonância Magnética/estatística & dados numéricos , Metabolômica/métodos , Fenobarbital/toxicidade , Animais , Teorema de Bayes , Biomarcadores/metabolismo , Reações Falso-Positivas , Glicina/metabolismo , Fígado/metabolismo , Masculino , Análise Multivariada , Ratos
9.
Toxicol Pathol ; 37(6): 714-32, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19700658

RESUMO

The two-year cancer bioassay in rodents remains the primary testing strategy for in-life screening of compounds that might pose a potential cancer hazard. Yet experimental evidence shows that cancer is often secondary to a biological precursor effect, the mode of action is sometimes not relevant to humans, and key events leading to cancer in rodents from nongenotoxic agents usually occur well before tumorigenesis and at the same or lower doses than those producing tumors. The International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) hypothesized that the signals of importance for human cancer hazard identification can be detected in shorter-term studies. Using the National Toxicology Program (NTP) database, a retrospective analysis was conducted on sixteen chemicals with liver, lung, or kidney tumors in two-year rodent cancer bioassays, and for which short-term data were also available. For nongenotoxic compounds, results showed that cellular changes indicative of a tumorigenic endpoint can be identified for many, but not all, of the chemicals producing tumors in two-year studies after thirteen weeks utilizing conventional endpoints. Additional endpoints are needed to identify some signals not detected with routine evaluation. This effort defined critical questions that should be explored to improve the predictivity of human carcinogenic risk.


Assuntos
Testes de Carcinogenicidade/métodos , Carcinógenos/toxicidade , Bases de Dados Factuais , Neoplasias Experimentais/induzido quimicamente , Animais , Feminino , Humanos , Fenômenos do Sistema Imunitário/efeitos dos fármacos , Masculino , Camundongos , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Neoplasias Experimentais/prevenção & controle , Ratos , Ratos Endogâmicos F344 , Medição de Risco/métodos
10.
Worldviews Evid Based Nurs ; 6(1): 27-35, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19207560

RESUMO

AIM: To test the psychometric properties of the Context Assessment Index (CAI). BACKGROUND: We used the Promoting Action on Research Implementation in Health Services Framework (PARIHS) as the theoretical framework for the study. The framework shows the successful implementation of evidence in practice as dependent on the inter-relationship of the nature of the evidence, the quality of the context, and expert facilitation. However, a comprehensive method of assessing context has not yet been available. METHODS: A five-stage instrument development and testing methodology was used. Principal components analysis, exploratory factor analysis, and expert panel feedback were used to develop and refine the CAI model. The model was further tested for psychometric properties of internal consistency and test-retest scores. Telephone interviews were conducted with expert nurses to gauge the usability of the instrument. These stages of development and testing resulted in a final 37-item, five-factor CAI model. FINDINGS: This 37-item model was accepted as a reasonable explanation of the data. The measures of homogeneity were calculated for each of the five factors to measure internal reliability. The Cronbach's alpha score for the complete questionnaire was estimated at 0.93. All five factors achieved a satisfactory estimated level of internal consistency in scoring, ranging from 0.78 to 0.91. Test-retest scores indicate reliability of the findings, and the feedback from focus group participants suggests that the instrument has practical utility. CONCLUSIONS: The CAI provides clinicians with the means to assess and understand the context in which they work and the effect this has on using evidence in practice.


Assuntos
Competência Clínica , Enfermagem Baseada em Evidências/métodos , Enfermagem Baseada em Evidências/normas , Psicometria/métodos , Psicometria/normas , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Reprodutibilidade dos Testes
11.
Toxicol Rep ; 6: 998-1005, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31673501

RESUMO

Characterisation of the mode of action (MOA) of constitutive androstane receptor (CAR)-mediated rodent liver tumours involves measurement 5 key events including activation of the CAR receptor, altered gene expression, hepatocellular proliferation, clonal expansion and increased hepatocellular adenomas/carcinomas. To test whether or not liver 3D microtissues (LiMTs) recapitulate CAR- mediated procarcinogenic key events in response to the prototypical CAR activator phenobarbital (PB) we performed hepatocyte proliferation (LI%) analysis in rat and human LiMTs using a microTMA technology in conjunction with integrated transcriptomics (microarray) and proteomics analysis. The rationale for this approach was that LiMTs containing parenchymal and non-parenchymal cells (NPCs) are more physiologically representative of liver and thus would generate data more relevant to the in vivo situation. Rat and human LiMTs were treated with PB over a range of concentrations (500 uM - 2000 uM) and times (24 h - 96 h) in a dose-response/time-course analysis. There was a dose-dependent induction of LI% in rat LiMTs, however there was little or no effect of PB on LI% in human LiMTs. ATP levels in the rat and human LiMTs were similar to control in all of the PB treatments. There was also a dose- and time-dependent PB-mediated RNA induction of CAR regulated genes CYP2B6/Cyp2b2, CYP3A7/Cyp3a9 and UGT1A6/Ugt1a6 in human and rat LiMTs, respectively. These CAR regulated genes were also upregulated at the protein level. Ingenuity pathways analysis (IPA) indicated that there was a significant (Z score >2.0;-log p value >) activation of CAR by PB in both human and rat LiMTs. These results indicate that human and rat LiMTs showed the expected responses at the level of PB-induced hepatocyte proliferation and enzyme induction with rat LiMTs showing significant dose-dependent effects while human LiMTs showed no proliferation response but did show dose-dependent enzyme induction at the RNA and protein levels. In conclusion LiMTs serve as a model to provide mechanistic data for 3 of the 5 key events considered necessary to establish a CAR-mediated MOA for liver tumourigenesis and thus can potentially reduce the use of animals when compiling mechanistic data packages.

12.
Redox Biol ; 14: 198-210, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28942197

RESUMO

There is a need for robust in vitro models to sensitively capture skeletal muscle adverse toxicities early in the research and development of novel xenobiotics. To this end, an in vitro rat skeletal muscle model (L6) was used to study the translation of transcriptomics data generated from an in vivo rat model. Novel sulfonyl isoxazoline herbicides were associated with skeletal muscle toxicity in an in vivo rat model. Gene expression pathway analysis on skeletal muscle tissues taken from in vivo repeat dose studies identified enriched pathways associated with mitochondrial dysfunction, oxidative stress, energy metabolism, protein regulation and cell cycle. Mitochondrial dysfunction and oxidative stress were further explored using in vitro L6 metabolic models. These models demonstrated that the sulfonyl isoxazoline compounds induced mitochondrial dysfunction, mitochondrial superoxide production and apoptosis. These in vitro findings accurately concurred with the in vivo transcriptomics data, thereby confirming the ability of the L6 skeletal muscle models to identify relevant in vivo mechanisms of xenobiotic-induced toxicity. Moreover, these results highlight the sensitivity of the L6 galactose media model to study mitochondrial perturbation associated with skeletal muscle toxicity; this model may be utilised to rank the potency of novel xenobiotics upon further validation.


Assuntos
Mitocôndrias/efeitos dos fármacos , Músculo Esquelético/metabolismo , Xenobióticos/toxicidade , Trifosfato de Adenosina/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 7/metabolismo , Linhagem Celular , Feminino , Isoxazóis/química , Isoxazóis/toxicidade , Mitocôndrias/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Transcriptoma/efeitos dos fármacos
13.
Toxicol Sci ; 99(1): 315-25, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17557908

RESUMO

Cyproconazole, a triazole fungicide, causes hepatocellular adenomas and carcinomas in CD-1 mice at dose levels of 100 and 200 ppm. The constitutive androstane receptor (CAR) has been shown to play a significant role in the overall mode of action for several nongenotoxic rodent carcinogens such as phenobarbital. The liver effects of dietary cyproconazole or phenobarbital were investigated after 2, 7, or 14 days in male CD-1, C57BL/6J, and C3H/HeNClrBR mice. Cyproconazole produced similar, dose-responsive effects in all three strains of mice, and the response was similar to that of phenobarbital. Subsequently, Car-null and wild-type male mice on a C3H/HeNClrBR background were administered 200 or 450 ppm cyproconazole, or 850 ppm phenobarbital for up to 7 days. In wild-type mice, 200 ppm cyproconazole caused liver hypertrophy, increased liver weight and cell proliferation, single-cell necrosis and fat vacuolation, effects generally similar to those caused by 850 ppm phenobarbital. Plasma cholesterol was decreased by both compounds, but cyproconazole had a greater effect. The higher dose (450 ppm) of cyproconazole caused similar changes, but greater evidence of liver damage was observed, including a large increase in plasma transaminases. Induction of CAR target genes Cyp2b10 and Gadd45beta was observed with both compounds, whereas the cell cycle regulatory gene Mdm2 was unaffected. In Car-null mice, the effects noted with either cyproconazole or phenobarbital were absent or greatly diminished. These experiments demonstrate that short-term liver effects of cyproconazole in mice are CAR-dependent and similar to those of phenobarbital, a known nongenotoxic rodent liver carcinogen.


Assuntos
Fungicidas Industriais/toxicidade , Fígado/efeitos dos fármacos , Receptores Androgênicos/metabolismo , Triazóis/toxicidade , Administração Oral , Animais , Antígenos de Diferenciação/biossíntese , Antígenos de Diferenciação/genética , Hidrocarboneto de Aril Hidroxilases/biossíntese , Hidrocarboneto de Aril Hidroxilases/genética , Proliferação de Células/efeitos dos fármacos , Família 2 do Citocromo P450 , Dieta , Relação Dose-Resposta a Droga , Indução Enzimática/efeitos dos fármacos , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/patologia , Regulação da Expressão Gênica , Inativação Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Hipertrofia , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Tamanho do Órgão/efeitos dos fármacos , Fenobarbital/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/biossíntese , Proteínas Proto-Oncogênicas c-mdm2/genética , Receptores Androgênicos/genética , Especificidade da Espécie , Esteroide Hidroxilases/biossíntese , Esteroide Hidroxilases/genética , Vacúolos/efeitos dos fármacos
18.
Data Brief ; 8: 196-202, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27331087

RESUMO

This article contains mass spectrometry (MS) data investigating small molecule changes as an effect of a triple peroxisome proliferator-activated receptor (PPAR-pan) agonist GW625019 in the liver as described in the manuscript (Ament et al., 2016) [1]. Samples were measured using gas chromatography-mass spectrometry (GC-MS) for total fatty acid content, and liquid chromatography-mass spectrometry (LC-MS) to measure intact lipids, carnitines and selected aqueous metabolites and eicosanoids. Data files comprise of Excel (Microsoft, WA, USA) spreadsheets of identified metabolites and their area ratio values for total fatty acids, carnitines, aqueous metabolites, and eicosanoids where the intensity of the analytes were normalised to the intensity of the internal standard. In the case of open profiling intact lipid data, the Excel file contains area ratio values of retention time and mass to charge ratio pairs; again, the area ratio values were calculated by normalising to the intensity of the internal standard. It should be noted that several metabolic changes are potentially indirect (secondary, tertiary and ensuing changes).

19.
Free Radic Biol Med ; 95: 357-68, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26654758

RESUMO

The peroxisome proliferator-activated receptors (PPARs) are ligand activated nuclear receptors that regulate cellular homoeostasis and metabolism. PPARs control the expression of genes involved in fatty-acid and lipid metabolism. Despite evidence showing beneficial effects of their activation in the treatment of metabolic diseases, particularly dyslipidaemias and type 2 diabetes, PPAR agonists have also been associated with a variety of side effects and adverse pathological changes. Agonists have been developed that simultaneously activate the three PPAR receptors (PPARα, γ and δ) in the hope that the beneficial effects can be harnessed while avoiding some of the negative side effects. In this study, the hepatic effects of a discontinued PPAR-pan agonist (a triple agonist of PPAR-α, -γ, and -δ), was investigated after dietary treatment of male Sprague-Dawley (SD) rats. The agonist induced liver enlargement in conjunction with metabolomic and lipidomic remodelling. Increased concentrations of several metabolites related to processes of oxidation, such as oxo-methionine, methyl-cytosine and adenosyl-methionine indicated increased stress and immune status. These changes are reflected in lipidomic changes, and increased energy demands as determined by free fatty acid (decreased 18:3 n-3, 20:5 n-3 and increased ratios of n-6/n-3 fatty acids) triacylglycerol, phospholipid (decreased and increased bulk changes respectively) and eicosanoid content (increases in PGB2 and 15-deoxy PGJ2). We conclude that the investigated PPAR agonist, GW625019, induces liver enlargement, accompanied by lipidomic remodelling, oxidative stress and increases in several pro-inflammatory eicosanoids. This suggests that such pathways should be monitored in the drug development process and also outline how PPAR agonists induce liver proliferation.


Assuntos
Fígado/efeitos dos fármacos , Estresse Oxidativo/genética , PPAR alfa/genética , PPAR gama/genética , PPAR beta/genética , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/patologia , Ácidos Graxos não Esterificados/metabolismo , Metabolismo dos Lipídeos/genética , Lipídeos/biossíntese , Lipídeos/genética , Fígado/metabolismo , Fígado/patologia , PPAR alfa/agonistas , PPAR gama/agonistas , PPAR beta/agonistas , Ratos , Ratos Sprague-Dawley
20.
Toxicol Lett ; 235(3): 189-98, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25865432

RESUMO

ABC transporters play an important role in the disposition of avermectins in several animal species. In this study the interactions of three key avermectins, abamectin, emamectin and ivermectin, with human and mouse homologues of MDR1 (ABCB1/Abcb1a) and MRP (ABCC/Abcc), transporters endogenously expressed by human SH-SY5Y and mouse N2a neuroblastoma cells were investigated. In both cell lines, retention of the fluorescent dye H33342 was found to be significantly increased in the presence of avermectins and cyclosporin A. These effects were shown to be unresponsive to the BCRP inhibitor Ko-143 and therefore MDR1/Mdr1-dependent. Avermectins inhibited MDR1/Mdr1a-mediated H33342 dye efflux, with apparent Ki values of 0.24±0.08 and 0.18±0.02µM (ivermectin); 0.60±0.07 and 0.56±0.02µM (emamectin) and 0.95±0.08 and 0.77±0.25µM (abamectin) in SH-SY5Y and N2a cells, respectively. There were some apparent affinity differences for MDR1 and Mdr1a within each cell line (affinity for ivermectin>emamectin≥abamectin, P<0.05 by One-Way ANOVA), but importantly, the Ki values for individual avermectins for human MDR1 or mouse Mdr1a were not significantly different. MK571-sensitive retention of GSMF confirmed the expression of MRP/Mrp efflux transporters in both cell lines. Avermectins inhibited MRP/Mrp-mediated dye efflux with IC50 values of 1.58±0.51 and 1.94±0.72µM (ivermectin); 1.87±0.57 and 2.74±1.01µM (emamectin) and 2.25±0.01 and 1.68±0.63µM (abamectin) in SH-SY5Y and N2a cells, respectively. There were no significant differences in IC50 values between individual avermectins or between human MRP and mouse Mrp. Kinetic data for endogenous human MDR1/MRP isoforms in SH-SY5Y cells and mouse Mdr1a/b/Mrp isoforms in N2a cells are comparable for the selected avermectins. All are effluxed at concentrations well above 0.05-0.1µM ivermectin detected in plasma (Ottesen and Campbell, 1994; Ottesen and Campbell, 1994) This is an important finding in the light of toxicity seen in the Mdr1-deficient animal models CF-1 mice, Mdr1ab (-/-) double knockout mice and Collie dogs. We also confirm MRP/Mrp-mediated avermectin transport in both N2a and SH-SY5Y cell lines.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Genes MDR/fisiologia , Ivermectina/análogos & derivados , Neuroblastoma/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Regulação da Expressão Gênica , Humanos , Ivermectina/metabolismo , Camundongos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa