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BACKGROUND: Sarcopenia is reported to be associated with neuroticism, but the mechanisms are not fully understood. Thus, it's of vital importance to elucidate the molecular mechanism of sarcopenia and neuroticism and to explore the potential molecular target of medical therapies for sarcopenia and neuroticism. METHODS: The expression datasets (sarcopenia: GSE111006 and neuroticism: GSE60491) were downloaded from the Gene Expression Omnibus. Weighted gene co-expression network analysis (WGCNA) was used to build the gene co-expression network, screen important modules, and filter the hub genes. Genes with significance over 0.2 and a module membership over 0.8 were hub genes. The overlapped hub genes between sarcopenia and neuroticism were defined as key genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed for the genes in modules with clinical interest. RESULTS: In this study, we identified 28 gene modules for sarcopenia and 7 for neuroticism by WGCNA. The key modules of sarcopenia and neuroticism were the tan and turquoise modules, respectively. Hub genes of sarcopenia and neuroticism were 20 genes and 107 genes, respectively. The function enrichment found that apoptosis was the common pathway for sarcopenia and neuroticism. Finally, LRRK2 was identified as key genes. LIMITATIONS: The sarcopenia dataset contained fewer samples. CONCLUSION: Based on WGCNA, our study identified apoptosis pathway and LRRK2 that acted as essential components in the etiology of sarcopenia and neuroticism, which may enhance our fundamental knowledge of the molecular mechanisms underlying the disease.
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Sarcopenia , Humanos , Neuroticismo , Sarcopenia/genética , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genéticaRESUMO
Background: Evidence from numerous observational studies and clinical trials has linked gut microbiota and metabolites to digestive tract cancer. However, the causal effect between these factors remains uncertain. Methods: Data for this study were obtained from the MiBioGen, TwinsUK Registry, and FinnGen (version R8). Two-sample Mendelian randomization analysis with inverse variance weighting method was primarily used, and the results were validated by heterogeneity analysis, pleiotropy test, and sensitivity analysis. Results: At P < 5 × 10-8, our analysis identified four gut microbiotas as risk factors for digestive tract cancer and six as risk factors for colorectal cancer. Conversely, one gut microbiota exhibited protection against bile duct cancer, and two showed protective effects against stomach cancer. At P < 1 × 10-5, our investigation revealed five, six, three, eight, eight, and eight gut microbiotas as risk factors for esophageal, stomach, bile duct, liver, pancreatic, and colorectal cancers, respectively. In contrast, four, two, eight, two, two, and five gut microbiotas exhibited protective effects against these cancers. Additionally, GABA, a metabolite of gut microbiota, displayed a significant protective effect against colorectal cancer. Conclusion: In conclusion, specific gut microbiota and metabolites play roles as risk factors or protective factors for digestive tract cancer, and a causal relationship between them has been established, offering novel insights into gut microbiota-mediated cancer development.
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Gemcitabine (GEM) is the gold-standard therapeutic regimen for patients with pancreatic cancer (PC); however, patients may receive limited benefits due to the drug resistance of GEM. LncRNA SNHG6 is reported to play key roles in drug resistance, but its role and molecular mechanism in PC remain incompletely understood. We found that LncRNA SNHG6 is drastically downregulated in GEM-resistant PC and is positively correlated with the survival of PC patients. With the help of bioinformatic analysis and molecular approaches, we show that LncRNA SNHG6 can sponge miR-944, therefore causing the upregulation of the target gene KPNA5. In vitro experiments showed that LncRNA SNHG6 and KPNA5 suppress PC cell proliferation and colony formation. The Upregulation of LncRNA SNHG6 and KPNA5 increases the response of GEM-resistant PANC-1 cells to GEM. We also show that the expression of KPNA5 is higher in patients without GEM resistance than in those who developed GEM resistance. In summary, our findings indicate that the LncRNA SNHG6/miR944/KPNA5 axis plays a pivotal role in overcoming GEM resistance, and targeting this axis may contribute to an increasing of the benefits of PC patients from GEM treatment.
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To investigate the chronic toxicity of cyadox, a growth promoting agent, five groups of Wistar rats (30 rats/group/sex) were fed with the diets containing cyadox (0, 100, 400 and 2000 mg/kg) or olaquindox (400 mg/kg) for 78weeks. There were significant decreases in body weights in both genders during most of the study period in 2000 mg/kg cyadox and 400 mg/kg olaquindox rats. Significant decreases in serum alkaline aminotransferase in the 2000 mg/kg cyadox rats at weeks 26, 52 and 78 were observed. Relative weights of liver and kidney were significantly increased in 2000 mg/kg cyadox and 400 mg/kg olaquindox rats at weeks 26, 52 and 78. A significant increase in relative brain and heart weights in 2000 mg/kg cyadox males was observed. The histopathological examinations revealed that 2000 mg/kg cyadox diet or 400 mg/kg olaquindox diet could induce proliferation of bile canaliculi in the portal area of liver and swelling and fatty degeneration of the proximal renal tubular epithelial cells in kidneys. In conclusion, the target organs of cyadox for rats were liver and kidney. The no-observed-adverse-effect level of cyadox in this study was estimated to be 400 mg/kg diet.
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Quinoxalinas/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Quinoxalinas/administração & dosagem , Distribuição Aleatória , Ratos , Ratos Wistar , Testes de Toxicidade Crônica/métodos , Transaminases/sangueRESUMO
Mequindox, 3-methyl-2-quinoxalinacetyl-1,4-dioxide, is a quinoxaline-N,N-dioxide used in veterinary medicine as a antibacterial in China. To gain an understanding of the interspecies differences in the metabolism of mequindox, comparative metabolite profiles were qualitatively and quantitatively carried out for the first time in rat, chicken and pig liver microsomes by high-performance liquid chromatography combined with hybrid ion trap/time-of-flight mass spectrometry. A total of 14 metabolites were characterized based on their accurate MS(2) spectra and known structure of mequindox. The in vitro metabolic pathways of mequindox in three species were proposed as N-->O group reduction, carbonyl reduction, N-->O group reduction followed by carbonyl reduction or methyl mono-hydroxylation. A metabolic pathway involving N-->O group reduction followed by acetyl group mono-hydroxylation in only chicken was also proposed. There was also quantitative species difference for mequindox metabolism in three species. 1-Desoxymequindox was the main metabolite in all species, but otherwise there were some qualitative interspecies differences in mequindox major metabolites. This work has revealed biotransformation characteristics of mequindox among different species, and moreover will further facilitate the explanations of the biological activities of mequindox in animals.
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Cromatografia Líquida de Alta Pressão/métodos , Microssomos Hepáticos/metabolismo , Quinoxalinas/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Galinhas , Feminino , Masculino , Redes e Vias Metabólicas , Microssomos Hepáticos/química , Quinoxalinas/química , Ratos , Ratos Wistar , Especificidade da Espécie , SuínosRESUMO
The application of electrospray ionization hybrid ion trap/time-of-flight mass spectrometry coupled with high-performance liquid chromatography (LC/MS-IT-TOF) in the rapid characterization of in vitro metabolites of quinocetone was developed. Metabolites formed in rat liver microsomes were separated using a VP-ODS column with gradient elution. Multiple scans of metabolites in MS and MS(2) modes and accurate mass measurements were automatically performed simultaneously through data-dependent acquisition in only a 30-min analysis. Most measured mass errors were less than 10 ppm for both protonated molecules and fragment ions using external mass calibration. The elemental compositions of all fragment ions of quinocetone and its metabolites could be rapidly assigned based upon the known compositional elements of protonated molecules. The structure of metabolites were elucidated based on the combination of three techniques: agreement between their proposed structure, the accurate masses, and the elemental composition of ions in their mass spectra; comparison of their changes in accurate molecular masses and fragment ions with those of parent drug or metabolite; and the elemental compositions of lost mass numbers in proposed fragmentation pathways. Twenty-seven phase I metabolites were identified as 11 reduction metabolites, three direct hydroxylation metabolites, and 13 metabolites with a combination of reduction and hydroxylation. All metabolites except the N-oxide reduction metabolite M6 are new metabolites of quinocetone, which were not previously reported. The ability to conduct expected biotransformation profiling via tandem mass spectrometry coupled with accurate mass measurement, all in a single experimental run, is one of the most attractive features of this methodology. The results demonstrate the use of LC/MS-IT-TOF approach appears to be rapid, efficient, and reliable in structural characterization of drug metabolites.
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Cromatografia Líquida de Alta Pressão/métodos , Microssomos Hepáticos/metabolismo , Quinoxalinas/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Cromatografia Líquida de Alta Pressão/economia , Masculino , Estrutura Molecular , Quinoxalinas/metabolismo , Ratos , Espectrometria de Massas por Ionização por Electrospray/economia , Espectrometria de Massas em Tandem/economia , Espectrometria de Massas em Tandem/métodos , Fatores de TempoRESUMO
A population pharmacokinetic (PPK) model for enrofloxacin and its metabolite ciprofloxacin in chicken based on retrospective data was developed. Plasma concentrations of enrofloxacin and its metabolite ciprofloxacin were determined in blood samples from chicken administered either enrofloxacin via oral and intravenous routes or ciprofloxacin via intravenous injection. The disposition of enrofloxacin and ciprofloxacin was described simultaneously by an integrated mathematic model. Two compartments were used to describe the enrofloxacin and ciprofloxacin disposition profiles. The formation of ciprofloxacin was through the central compartment of enrofloxacin. The integrated model was estimated with nonlinear mixed effects model (NONMEM). The total clearance of enrofloxacin (CLEN) and ciprofloxacin (CLCP) was 0.613 L/h and 1.15 L/h, respectively. Correlation between CLEN, the central compartment volume of distribution for enrofloxacin (V2) and CLCP was estimated. After intravenous administration of enrofloxacin, the transformation rate of enrofloxacin to ciprofloxacin was 0.429 L/h. The bioavailability factor after oral administration was 0.926, and 12.6% of enrofloxacin after oral administration was transformed to ciprofloxacin via first-pass effect. Pharmacodynamic (PD) evaluation was performed using area under concentration time curve of active moiety from 0 to 24 h and MIC collected from literature. This study is the first one to use PPK method to investigate parent drug and its metabolite disposition and PDs using an integrated model in veterinary medicine.
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Antibacterianos/farmacocinética , Galinhas/sangue , Ciprofloxacina/farmacocinética , Fluoroquinolonas/farmacocinética , Animais , Antibacterianos/sangue , Área Sob a Curva , Peso Corporal , Ciprofloxacina/sangue , Enrofloxacina , Fluoroquinolonas/sangue , Modelos Biológicos , Estudos RetrospectivosRESUMO
MicroRNAs (miRNAs) are short non-coding RNAs that regulate the expression of protein-coding genes by partially binding to specific target sites of mRNAs. miRNAs perform important functions in complicated cellular biological processes and their abnormal expression is involved in various disorders, including cancer. Among the miRNAs, differential expression of miR-139-5p serves a significant role in tumorigenesis, metastasis and recurrence, thus suggesting that it may potentially be used as a promising biomarker for cancer diagnosis, prognosis and therapy. miR-139-5p is expected to serve as a biomarker to eventually be implemented in a clinical setting. In the present review, we focus on the importance of miR-139-5p in cancer, summarize the association between miR-139-5p expression level and diagnosis and prognosis, and discuss the potential therapeutic implications for the future.
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Quinoxaline-1,4-dioxides (QdNOs) are the potent heterocyclic N-oxides with interesting biological properties such as antibacterial, anticandida, antitubercular, anticancer and antiprotozoal activities. Here, we tested and compared the mequindox (MEQ) for mutagenic abilities in a battery of different short term tests according to OECD guidelines. When compared with the controls, a strong mutagenicity of MEQ and carbadox (CBX) was observed with an approximate concentration-effect relationship in Salmonella reverse mutation test, chromosome aberration test, unscheduled DNA synthesis assay and HGPRT gene mutation test, in the absence and presence of S(9)-mix. In in vivo micronucleus test, CBX produced significant increase in the proportion of micronucleus formation than MEQ in mice bone marrow cells. From these results, we can conclude that MEQ had a strong genotoxic potential to mammalian cells in vitro as well as in vivo and its mutagenicity is slightly higher than CBX. Our results, for the 1st time, discuss the genotoxic potential of MEQ. These results not only confirm the earlier findings about CBX but also extend the knowledge and awareness about the genotoxic risk of QdNO derivatives.
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Testes de Mutagenicidade/métodos , Quinoxalinas/toxicidade , Animais , Células da Medula Óssea/efeitos dos fármacos , Carbadox/toxicidade , Aberrações Cromossômicas , Cricetinae , Relação Dose-Resposta a Droga , Humanos , Hipoxantina Fosforribosiltransferase/genética , Linfócitos/efeitos dos fármacos , Masculino , Camundongos , Testes para Micronúcleos , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genéticaRESUMO
To investigate the reproductive toxicity and teratogenic potential of quinocetone, a growth promoting agent, Wistar rats were fed different diets containing 0, 50, 300 and 1800 mg/kg quinocetone or 300 mg/kg olaquindox. Groups of 15 males and 30 females (F(0)) were fed through a 10-week prebreed period as well as during mating, gestation, parturition and lactation. At weaning, 12 males and 24 females of F(1) generation weanlings per group were selected randomly as parents for F(2) generation. Selected F(1) weanlings were exposed to the same diet and treatment as their parents. At the highest quinocetone group, body weights in F(0) and F(1) rats, fetal body weight on day 21 after birth and number of viable fetuses in F(0) and F(1) generation significantly decreased. In teratogenicity study, groups of 12 males and 24 females were fed with the same diets through a 12-week prebreed period and matting periods. Pregnant rats were subjected to cesarean section on GD 20 for teratogenic examination. At the highest quinocetone group, body weights and feed efficiency, fetal body lengths, tail lengths, litter weights and number of viable fetuses significantly decreased. The NOAEL for reproduction/development of quinocetone for rats was estimated to be 300 mg/kg diet.
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Quinoxalinas/toxicidade , Reprodução/efeitos dos fármacos , Teratogênicos/toxicidade , Ração Animal , Animais , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Comportamento Alimentar/efeitos dos fármacos , Feminino , Masculino , Quinoxalinas/administração & dosagem , Ratos , Ratos Wistar , Testes de ToxicidadeRESUMO
Bisdesoxyolaquindox is a reduced metabolite of olaquindox which is used as a medicinal feed additive in veterinary medicine. The relevant metabolism studies of bisdesoxyolaquindox have been carried out for the first time in rat, chicken, and pig liver subcellular fractions in order to understand the metabolic enzymes that are possibly responsible for the metabolism of olaquindox. The metabolites were characterized by high-performance liquid chromatography combined with hybrid ion trap/time-of-flight mass spectrometry. The major metabolic pathways of bisdesoxyolaquindox in the three species were the oxidation of hydroxyl to bisdesoxyolaquindox-2'-carboxyl acid (O10) and the N-dealkylation of the side chain to 3-methylquinoxaline 2-carboxamide (O12). Other metabolic pathways were also proposed which involved the direct methyl oxidation and N-oxide on the quinoxaline ring in the three species as well as N-hydroxylation only in rat. The intrinsic clearance values in the liver microsomes for O10 and O12 were ranked in the order of chicken>pigâ«rat and rat>pigâ«chicken, respectively. Inhibition studies indicated that 8-methoxypsoralen, 4-methylpyrazole and α-naphthoflavone could inhibit the formations of O10 and O12 in all species. Quinidine, troleandomycin, diethyldithiocarbamate, and disulfiram showed an interspecies difference in the inhibition of the formation of two metabolites. In rat and pig liver cytosol, 4-methylpyrazole, menadione and chlorpromazine strongly inhibited the formation of O10. Both diethyldithiocarbamate and disulfiram were found to inhibit O10 formation in rat cytosol but not in pig cytosol. These results indicated the following: In rat liver microsomes, CYP2A might be involved in the formation of O10, and CYP1A, CYP2A and CYP2E would be involved in the O12 formation. In pig liver microsomes, CYP1A and CYP2E might catalyze the formations of O10 and O12. In rat cytosol, alcohol dehydrogenase, aldehyde oxidase and aldehyde dehydrogenase should catalyze the O10 formation. In pig cytosol, alcohol dehydrogenase and aldehyde oxidase might be involved in the formation of O10. In chicken, it was found that various CYP isoenzymes were capable of catalyzing the two reactions; none of the inhibitors of cytosol enzymes inhibited O10 formation in chicken cytosol.
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Sistema Enzimático do Citocromo P-450/metabolismo , Fígado/metabolismo , Microssomos Hepáticos/metabolismo , Quinoxalinas/metabolismo , Animais , Galinhas , Cromatografia Líquida de Alta Pressão , Citosol/metabolismo , Remoção de Radical Alquila , Feminino , Isoenzimas , Fígado/enzimologia , Masculino , Espectrometria de Massas , Microssomos Hepáticos/enzimologia , Oxirredução , Ratos , Ratos Wistar , Especificidade da Espécie , SuínosRESUMO
Olaquindox is a growth-promoting feed additive for food-producing animals. Its toxicities were reported to be closely related to the metabolism. To provide the interpretation of toxicities in animals, this study explored the metabolism of olaquindox in rats, chickens and pigs of different genders by qualitative metabolite profiling. Animals were fed olaquindox in an oral dose, and then their urine, plasma, feces, liver, kidney and muscle were collected. Liquid chromatography combined with hybrid ion trap/time-of-flight mass spectrometry was used for structural investigation and identification of metabolites. The structures of metabolites were elucidated based on the accurate MS² spectra and comparison of their changes in accurate molecular masses and fragment ions with those of parent drug or metabolite. A total of 18, 18 and 16 metabolites of rats, chickens and pigs were identified, respectively. Among the identified metabolites, 8 known metabolites were confirmed as an early study had stated, and 15 metabolites were found for the first time in vivo. The major metabolic pathways of olaquindox were proposed to be N-O reduction and oxidation of hydroxyl to carboxylic acid followed by N-O reduction. The qualitative species difference on the metabolite profiles of olaquindox among the three species was observed. However, metabolite profiles of olaquindox appeared to be qualitatively similar between female and male for the same species. The proposed metabolic pathways of olaquindox in animals will provide comprehensive data to clarify the metabolism of olaquindox among different species, and will give scientific explanation for toxicities and residues of olaquindox.
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Quinoxalinas/farmacocinética , Animais , Antibacterianos/farmacocinética , Galinhas , Fezes/química , Feminino , Substâncias de Crescimento/farmacocinética , Rim/química , Fígado/química , Masculino , Músculo Esquelético/química , Quinoxalinas/análise , Quinoxalinas/sangue , Quinoxalinas/metabolismo , Quinoxalinas/urina , Ratos , Fatores Sexuais , Especificidade da Espécie , SuínosRESUMO
To investigate the teratogenic potential and reproductive toxicity of cyadox, a growth promoting agent, Wistar rats (F(0)) were fed with diets containing cyadox (0, 50, 150 and 2500 mg/kg) or olaquindox (150 mg/kg), approximately equivalent to cyadox 5, 15, 250 or olaquindox 15 mg/kg b.w./day across two generations. Half of the pregnant rats (F(0), F(1b)) were subjected to caesarean section on gestational day 20 for teratogenic examination and the other half produced pups F(1a) and F(2a), respectively. At the 250 mg/kg b.w./day cyadox group, body weights of F(1b) pregnant rats and F(2a) on day 21 after birth decreased; fetal body lengths and tail lengths decreased; the number of fetal resorptions increased significantly; litter weights, number of viable fetuses decreased; number of embryo resorptions increased significantly; number of liveborn F(1a), F(1b) and F(2a) decreased. No macroscopic or microscopic change of any significance was found in the reproductive organs. Significant increases in the incidence of cervical ribs or lumbar ribs in F(2a) pups and significant increases of relative organ weight of testis and epididymis in F(1b) were observed at the 250 mg/kg b.w./day cyadox group. The NOAEL for reproduction/development of cyadox for rats was estimated to be 150 mg/kg diet, which was equivalent to approximately 15 mg/kg b.w./day.
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Ração Animal , Reprodução/efeitos dos fármacos , Teratogênicos/toxicidade , Anormalidades Induzidas por Medicamentos/etiologia , Administração Oral , Análise de Variância , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Epididimo/efeitos dos fármacos , Epididimo/patologia , Feminino , Desenvolvimento Fetal , Masculino , Exposição Materna , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Quinoxalinas/toxicidade , Ratos , Ratos Wistar , Testículo/efeitos dos fármacos , Testículo/patologiaRESUMO
Mequindox (MEQ) is a novel synthetic quinoxaline 1,4-dioxides antibacterial agent and growth promoter in animal husbandry. This study was to investigate whether reactive oxygen species (ROS), the Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway, suppressors of cytokine signaling (SOCS) and inflammatory cytokines were involved in toxicities of MEQ. Our data demonstrated that high dose of MEQ (275 mg/kg) apparently led to tissue impairment combined with imbalance of redox in liver. In liver and spleen samples, hydroxylation metabolites and desoxymequindox were detected, directly confirming the potential link of NâO group reduction metabolism with its organ toxicity. Moreover, up-regulation of JAK/STAT, SOCS family, tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) were also observed in the high-dose group. Meanwhile, significant changes of oxidative stress indices in liver were observed in the high-dose group. As for NADPH subunit, the mRNA levels of many subunits were significantly up-regulated at low doses but down-regulated in a dose-dependent manner in liver and spleen, suggesting an involvement of NADPH in MEQ metabolism and ROS generation. In conclusion, we reported the dose-dependent long-term toxicity as well as the discussion of the potential mechanism and pathways of MEQ, which raised further awareness of its toxicity following with the dose change.
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Janus Quinases/metabolismo , Fígado/metabolismo , Quinoxalinas/toxicidade , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/fisiologia , Baço/metabolismo , Animais , Relação Dose-Resposta a Droga , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Quinoxalinas/administração & dosagem , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Baço/efeitos dos fármacos , Baço/patologiaRESUMO
Olaquindox, N-(2-hydroxyethyl)-3-methyl-2-quinoxalinecarboxamide-1,4-di-N-oxide, is one of the quinoxaline-dioxides used widely as an antimicrobial growth promoter in pig production. Its toxicities were reported to be closely related to the formation of N-oxide reductive metabolites. The present study presents the metabolism and N-oxide reduction of olaquindox incubated with liver microsomes and liver cytosol of rats, pigs and chicken. Metabolites were identified and characterized with a novel LC/MS-ITTOF. Thirteen metabolites were found in liver microsomes of rats, three of which were identified to be novel. Seven metabolites were found in liver microsomes of pigs and chicken. The N-oxide reduction was the major metabolic pathway of olaquindox in liver microsomes of the three species. The N1-reduction of olaquindox to metabolite O2 was found in not only liver microsomes but also cytosol of the three species in the presence of NAD(P)H under hypoxic conditions. The N1-reduction could be inhibited by air and carbon monoxide, and be significantly stimulated by riboflavin under various conditions. The N1-reduction in the liver cytosol of rats and pigs could be enhanced by menadione, but the reduction in liver cytosol of chicken could not be. The N1-reduction activities in all animals were not abolished when liver microsomes and cytosol were boiled. These findings suggested that the N1-reduction of olaquindox could be mediated by non-enzymatic and enzymatic conditions. This N1-reduction of olaquindox could also be catalyzed by a quinone-dependent reducing system in liver cytosol of rats and pigs. Moreover, liver cytosol of rats and pigs had an ability of N4-reduction that catalyzed olaquindox to metabolite O1 in the presence of benzaldehyde under hypoxic conditions, but the liver cytosol of chicken did not. The N4-reduction could be inhibited markedly in the cytosol rats and pigs by menadione, chlorpromazine and promethazine. In addition, 7-hydroxycoumarin was also found to inhibit the formation of O1 in the cytosol of rats. The inhibitory results suggested that the N4-reduction might be catalyzed by aldehyde oxidase in the cytosol of pigs, and by aldehyde oxidase and xanthine oxidase in the cytosol of rats. In conclusion, the N1-reduction and N4-reduction of olaquindox are mediated by multiple mechanisms and significant species differences are involved in both reductions. This work is a contribution to the understanding of toxicities and the relativities between toxicities and metabolism of olaquindox.
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Microssomos Hepáticos/metabolismo , Quinoxalinas/metabolismo , Animais , Galinhas , Citosol/metabolismo , Masculino , Estrutura Molecular , NAD , Quinoxalinas/química , Ratos , Ratos Wistar , SuínosRESUMO
Aims: Fibrodysplasia ossificans progressiva (FOP) is a rare and severely disabling autosomal dominant disorder characterized by congenital malformations of the great toes and progressive postnatal heterotopic ossification. A point mutation in the activin receptor IA (ACVR1) gene is the cause of FOP. Most of the reported cases of FOP are sporadic and caused by de novo mutations; however, some rare cases can also result from parental germline mosaicism associated with a greater risk of recurrence in successive pregnancies. Therefore, once the pathogenic mutation has been identified in the proband, it is relative cheaper and important to perform prenatal diagnostic tests to exclude the recurrence risk of FOP in subsequent pregnancies. In this study, we first investigated the mutation in the ACVR1 gene in a Chinese FOP patient and then performed prenatal tests to exclude the risk of recurrence in the patient's unborn sibling. Methods: A couple visited our clinic with their 4-year-old son, who was clinically diagnosed with FOP, for genetic counseling. Genetic testing was performed by amplifying all the nine exons of the ACVR1 gene using the conventional polymerase chain reaction. Further, DNA sequencing was used to determine the mutation based on the results of a mutation screening using denaturing high-performance liquid chromatography. Subsequently, a prenatal test was performed using the same technique as that used for the proband. Results: A recurrent single nucleotide mutation c.617 G>A (R206H) of the ACVR1 gene was identified in the patient; however, both the parents had a normal ACVR1 gene. Prenatal tests showed that the fetus did not carry the pathogenic mutation. Conclusion: The results confirmed that a recurrent single nucleotide mutation c.617 G>A (R206H) was the genetic cause of FOP and explored the utility of prenatal testing in excluding the risk of recurrence in the successive pregnancy.
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Quinoxaline 1,4-dioxides (QdNOs) derivatives, the potent synthetic antibacterial group used in food-producing animals, are assumed to have pro-oxidant properties. However, how oxidative stress mediated their adrenal toxicity is far from clear. The aim of this study was to assess the ability of three QdNOs, i.e. olaquindox (OLA), mequindox (MEQ), and cyadox (CYA), to produce reactive oxygen species (ROS) and oxidative cell damage in porcine adrenocortical cells. Multiple approaches such as cell activity assay, biochemical detectation, flow cytometry and fluorescent were used to study the integrated role of ROS homeostasis, mitochondrial redox metabolism and cell apoptosis as well as chemical stability of these drugs. The results showed that OLA and MEQ treatment evoked a significant dose and time-dependent cell damage in adrenocortical cells, well CYA displayed much less toxicity. As for the intracellular ROS production, OLA irritated a persistent and utmost release of ROS while MEQ made a similar but weaker reaction. CYA, however, had a short and unstable release of intracellular ROS. On the other hand, quinoxalinine-2-carboxylie acid (QCA), one of the metabolites of OLA and MEQ, did not cause any significant production of ROS and showed relatively lower toxicity than its parents. Moreover, an imbalance in the redox metabolism and mitochondrial membrane damage has been implicated in adrenal toxicity of QdNOs. ROS scavengers partially reversed QdNOs-induced mitochondrial damage, indicating that mitochondria may be a major target and critical for ROS-mediated cell death. In a word, these results suggested that ROS is a key mediator of QdNOs-induced cell death via mitochondria-dependent pathway in adrenocortical cells. The results provide a mechanism approach in understanding the characterize of adrenal damage caused by QdNOs in vitro, which would in turn, help in designing the appropriate therapeutic strategies of these kind of feed additives.