Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.848
Filtrar
1.
Toxicol Lett ; 318: 86-91, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31669099

RESUMO

Proton pump inhibitors (PPIs) have been used worldwide to treat gastrointestinal disorders. A recent study showed that long-term use of PPIs caused iron deficiency; however, it is unclear whether PPIs affect iron metabolism directly. We investigated the effect of PPIs on the peptide hepcidin, an important iron regulatory hormone. First, we used the FDA Adverse Event Reporting System database and analyzed the influence of PPIs. We found that PPIs, as well as H2 blockers, increased the odds ratio of iron-deficient anemia. Next, HepG2 cells were used to examine the action of PPIs and H2 blockers on hepcidin. PPIs augmented hepcidin expression, while H2 blockers did not. In fact, the PPI omeprazole increased hepcidin secretion, and omeprazole-induced hepcidin upregulation was inhibited by gene silencing or the pharmacological inhibition of the aryl hydrocarbon receptor. In mouse experiments, omeprazole also increased hepatic hepcidin mRNA expression and blood hepcidin levels. In mice treated with omeprazole, protein levels of duodenal and splenic ferroportin decreased. Taken together, PPIs directly affect iron metabolism by suppressing iron absorption through the inhibition of duodenal ferroportin via hepcidin upregulation. These findings provide a new insight into the molecular mechanism of PPI-induced iron deficiency.


Assuntos
Anemia Ferropriva/induzido quimicamente , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Duodeno/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepcidinas/metabolismo , Absorção Intestinal/efeitos dos fármacos , Ferro/sangue , Inibidores da Bomba de Prótons/toxicidade , Receptores de Hidrocarboneto Arílico/metabolismo , Anemia Ferropriva/sangue , Anemia Ferropriva/fisiopatologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Transporte de Cátions/metabolismo , Duodeno/metabolismo , Duodeno/fisiopatologia , Células Hep G2 , Hepatócitos/metabolismo , Antagonistas dos Receptores Histamínicos H2/toxicidade , Humanos , Ferro/deficiência , Masculino , Camundongos Endogâmicos C57BL , Receptores de Hidrocarboneto Arílico/genética
2.
Cancer Invest ; 37(8): 367-375, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31462083

RESUMO

The aryl hydrocarbon receptor (AhR) is activated by the ligand, benzo[a]pyrene (B[a]P), a component of smoke that is implicated in lung carcinogenesis in humans. However, the role of B[a]P and AhR in lung cancer malignancy is not well known. In this study, we analyzed the effects of B[a]P and AhR in the 3 D spheroids of human lung cancer cells in vitro. In these spheroids, B[a]P and AhR enhanced cancer cell proliferation. These results suggest that the AhR-dependent effects of B[a]P on cell proliferation may contribute to the adverse effects of continuous smoking with respect to lung cancer malignancy.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/agonistas , Benzo(a)pireno/toxicidade , Proliferação de Células/efeitos dos fármacos , Neoplasias Pulmonares/metabolismo , Receptores de Hidrocarboneto Arílico/agonistas , Células A549 , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais , Esferoides Celulares
3.
Plant Physiol Biochem ; 142: 490-499, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31442880

RESUMO

ICE1 (inducer of CBF expression 1) encodes a typical MYC-like basic helix-loop- helix (bHLH) transcription factor that acts as a pivotal component in the cold signalling pathway. In this study, DlICE1, a novel ICE1-like gene, was isolated from the southern subtropical fruit tree longan (Dimocarpus longan Lour.). DlICE1 encodes a nuclear protein with a highly conserved bHLH domain. DlICE1 expression was slightly upregulated under cold stress. Overexpression of DlICE1 in Arabidopsis conferred enhanced cold tolerance via increased proline content, decreased ion leakage, and reduced malondialdehyde (MDA) and reactive oxygen species (ROS) accumulation. Expression of the ICE1-CBF cold signalling pathway genes, including AtCBF1/2/3 and cold-responsive genes (AtRD29A, AtCOR15A, AtCOR47 and AtKIN1), was also significantly higher in DlICE1-overexpressing lines than in wild-type (WT) plants under cold stress. In conclusion, these findings indicate that DlICE1 is a member of the bHLH gene family and positively regulates cold tolerance in D. longan.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Genes de Plantas/genética , Proteínas de Plantas/genética , Sapindaceae/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Clonagem Molecular , Resposta ao Choque Frio , Regulação da Expressão Gênica de Plantas , Genes de Plantas/fisiologia , Malondialdeído/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas , Prolina/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sapindaceae/fisiologia , Análise de Sequência de DNA
4.
Anticancer Res ; 39(8): 4165-4170, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366501

RESUMO

AIM: To examine the influence of hypoxia on the in vitro growth of leukaemia cells and the activity of signalling proteins to better understand the pathophysiology of leukaemia cells in human bone marrow. MATERIALS AND METHODS: Six human leukaemia cell lines were cultured under normoxic or hypoxic conditions. Cell growth, recovery of clonogenic cells, and the expression and activation of various signalling proteins were examined. RESULTS: Hypoxia suppressed cell growth and the recovery of clonogenic cells. Moreover, hypoxia up-regulated hypoxia-inducible factor (HIF) 1α and HIF2α expression while suppressing the expression and activation of NOTCH1, mechanistic target of rapamycin kinase (mTOR) activation, and nuclear factor-kappa B (NF-κB) phosphorylation. CONCLUSION: We found that hypoxia up-regulated HIF expression while it suppressed the self-renewal capacity of leukaemia cells, NOTCH activity, and expression of its down-stream signalling molecules, which differs from previous reports mentioning that HIF activates NOTCH signalling. Our findings serve to further elucidate the in vivo pathophysiology of leukaemia cells.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Leucemia/genética , Receptor Notch1/genética , Ciclo Celular/genética , Hipóxia Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Leucêmica da Expressão Gênica/genética , Humanos , Leucemia/patologia , NF-kappa B/genética , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética
5.
Science ; 365(6454): 658-664, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31416957

RESUMO

Increased planting densities have boosted maize yields. Upright plant architecture facilitates dense planting. Here, we cloned UPA1 (Upright Plant Architecture1) and UPA2, two quantitative trait loci conferring upright plant architecture. UPA2 is controlled by a two-base sequence polymorphism regulating the expression of a B3-domain transcription factor (ZmRAVL1) located 9.5 kilobases downstream. UPA2 exhibits differential binding by DRL1 (DROOPING LEAF1), and DRL1 physically interacts with LG1 (LIGULELESS1) and represses LG1 activation of ZmRAVL1 ZmRAVL1 regulates brd1 (brassinosteroid C-6 oxidase1), which underlies UPA1, altering endogenous brassinosteroid content and leaf angle. The UPA2 allele that reduces leaf angle originated from teosinte, the wild ancestor of maize, and has been lost during maize domestication. Introgressing the wild UPA2 allele into modern hybrids and editing ZmRAVL1 enhance high-density maize yields.


Assuntos
Grão Comestível/anatomia & histologia , Grão Comestível/genética , Regulação da Expressão Gênica de Plantas , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Zea mays/anatomia & histologia , Zea mays/genética , Alelos , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Brassinosteroides/metabolismo , Quimera , Clonagem Molecular , Domesticação , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Edição de Genes , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polimorfismo Genético , Locos de Características Quantitativas
6.
Gastroenterology ; 157(4): 1093-1108.e11, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31325428

RESUMO

BACKGROUND & AIMS: Inflammation, injury, and infection up-regulate expression of the tryptophan metabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) in the intestinal epithelium. We studied the effects of cell-specific IDO1 expression in the epithelium at baseline and during intestinal inflammation in mice. METHODS: We generated transgenic mice that overexpress fluorescence-tagged IDO1 in the intestinal epithelium under control of the villin promoter (IDO1-TG). We generated intestinal epithelial spheroids from mice with full-length Ido1 (controls), disruption of Ido1 (knockout mice), and IDO1-TG and analyzed them for stem cell and differentiation markers by real-time polymerase chain reaction, immunoblotting, and immunofluorescence. Some mice were gavaged with enteropathogenic Escherichia coli (E2348/69) to induce infectious ileitis, and ileum contents were quantified by polymerase chain reaction. Separate sets of mice were given dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid to induce colitis; intestinal tissues were analyzed by histology. We utilized published data sets GSE75214 and GDS2642 of RNA expression data from ilea of healthy individuals undergoing screening colonoscopies (controls) and patients with Crohn's disease. RESULTS: Histologic analysis of small intestine tissues from IDO1-TG mice revealed increases in secretory cells. Enteroids derived from IDO1-TG intestine had increased markers of stem, goblet, Paneth, enteroendocrine, and tuft cells, compared with control enteroids, with a concomitant decrease in markers of absorptive cells. IDO1 interacted non-enzymatically with the aryl hydrocarbon receptor to inhibit activation of NOTCH1. Intestinal mucus layers from IDO1-TG mice were 2-fold thicker than mucus layers from control mice, with increased proportions of Akkermansia muciniphila and Mucispirillum schaedleri. Compared to controls, IDO1-TG mice demonstrated an 85% reduction in ileal bacteria (P = .03) when challenged with enteropathogenic E coli, and were protected from immune infiltration, crypt dropout, and ulcers following administration of dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid. In ilea of Crohn's disease patients, increased expression of IDO1 correlated with increased levels of MUC2, LYZ1, and aryl hydrocarbon receptor, but reduced levels of SLC2A5. CONCLUSIONS: In mice, expression of IDO1 in the intestinal epithelial promotes secretory cell differentiation and mucus production; levels of IDO1 are positively correlated with secretory cell markers in ilea of healthy individuals and Crohn's disease patients. We propose that IDO1 contributes to intestinal homeostasis.


Assuntos
Bactérias/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular , Microbioma Gastrointestinal , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Doenças Inflamatórias Intestinais/enzimologia , Doenças Inflamatórias Intestinais/microbiologia , Mucosa Intestinal/enzimologia , Mucosa Intestinal/microbiologia , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores Notch/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Estudos de Casos e Controles , Linhagem Celular , Linhagem da Célula , Modelos Animais de Doenças , Células Epiteliais/enzimologia , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Genótipo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/deficiência , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/patologia , Camundongos Knockout , Fenótipo , Receptores de Hidrocarboneto Arílico/genética , Receptores Notch/genética , Via Secretória , Transdução de Sinais , Células-Tronco/enzimologia , Células-Tronco/microbiologia , Células-Tronco/patologia
7.
Plant Cell Physiol ; 60(8): 1633-1645, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31292642

RESUMO

Plants respond to a rise in ambient temperature by increasing the growth of petioles and hypocotyls. In this work, we show that Arabidopsis thaliana class I TEOSINTE BRANCHED 1, CYCLOIDEA, PCF (TCP) transcription factors TCP14 and TCP15 are required for optimal petiole and hypocotyl elongation under high ambient temperature. These TCPs influence the levels of the DELLA protein RGA and the expression of growth-related genes, which are induced in response to an increase in temperature. However, the class I TCPs are not required for the induction of the auxin biosynthesis gene YUCCA8 or for auxin-dependent gene expression responses. TCP15 directly targets the gibberellin biosynthesis gene GA20ox1 and the growth regulatory genes HBI1 and PRE6. Several of the genes regulated by TCP15 are also targets of the growth regulator PIF4 and show an enrichment of PIF4- and TCP-binding motifs in their promoters. PIF4 binding to GA20ox1 and HBI1 is enhanced in the presence of the TCPs, indicating that TCP14 and TCP15 directly participate in the induction of genes involved in gibberellin biosynthesis and cell expansion by high temperature functionally interacting with PIF4. In addition, overexpression of HBI1 rescues the growth defects of tcp14 tcp15 double mutants, suggesting that this gene is a major outcome of regulation by both class I TCPs during thermomorphogenesis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Giberelinas/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação da Expressão Gênica de Plantas , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Complexo de Endopeptidases do Proteassoma/genética , Temperatura Ambiente , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
8.
Toxicol Lett ; 313: 188-195, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31284022

RESUMO

Brucine is one of the main bioactive and toxic constituents of the herb drug Semen Strychni. Here we aimed to determine dosing time-dependent hepatotoxicity of brucine, and to investigate the role of metabolism in generation of brucine chronotoxicity. Brucine was administered to wild-type or Npas2-/- (a clock disrupted model) mice at different circadian time points for toxicity and pharmacokinetic characterization. The hepatotoxicity was evaluated by plasma alanine aminotransferase and aspartate aminotransferase measurements and histopathological analysis. The role of Cyp3a11 in brucine metabolism was determined by chemical inhibition assays and Cyp3a11-overexpressing HEK293 cells. Hepatic circadian Cyp3a11 mRNA and protein levels were determined by qPCR and Western blotting, respectively. The toxicity of brucine was more severe in the light phase [Zeitgeber time (ZT) 2 and ZT8] than in the dark phase (ZT14 and ZT20). Chemical inhibition and substrate metabolism assays suggested Cyp3a11 as a significant contributor to brucine metabolism. The Cyp3a11 mRNA, protein and activity in the livers of wild-type mice displayed significant circadian fluctuations. Npas2 ablation markedly down-regulated Cyp3a11 mRNA, protein and activity, and abrogated their circadian rhythms. The circadian time differences in brucine pharmacokinetics and liver distribution were lost in Npas2-/- mice, so were the time differences in brucine hepatotoxicity. In conclusion, chronotoxicity of brucine was determined by circadian variations in Cyp3a11 metabolism. The findings have implications in improving brucine (and possibly Semen Strychni) efficacy via dosing time optimization.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Ritmo Circadiano , Citocromo P-450 CYP3A/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Proteínas de Membrana/metabolismo , Fotoperíodo , Estricnina/análogos & derivados , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/patologia , Ritmo Circadiano/genética , Cronoterapia Farmacológica , Células HEK293 , Humanos , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Estricnina/administração & dosagem , Estricnina/metabolismo , Estricnina/farmacocinética , Estricnina/toxicidade
9.
Life Sci ; 232: 116635, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31283925

RESUMO

AIMS: The pathological cardiac hypertrophy will develop into heart failure, which has no effective treatment currently. Previous studies have proved that microRNAs (miRNAs) participate in the development of cardiac hypertrophy and regulate the pathological progress. In this study, we want to investigate the role of microRNA-92b-3p (miR-92b-3p) in cardiomyocyte hypertrophy and the mechanisms involved. MATERIALS AND METHODS: Neonatal mouse ventricular cells (NMVCs) were isolated from the hearts of 1-3-d-old newborn C57BL6 mice. The isolated NMVCs were induced hypertrophic phenotype by Angiotensin-II (Ang-II) and the cell size was examined by FITC-phalloidin staining assay. The expression of miR-92b-3p was determined by quantitative real-time PCR (qRT-qPCR). MRNA and protein level of ß-MHC, ACTA1 and HAND2 in NMVCs transfected with miR-92b-3p mimic and inhibition were assessed by RT-qPCR assay and western blot assay, respectively. Dual luciferase assay was used to verify the interaction between miR-92b-3p and the 3'-untranslated region (UTR) of HAND2 gene. KEY FINDINGS: MiR-92b-3p and HAND2 were significantly increased in Ang-II-induced NMVCs. Overexpression of miR-92b-3p can ameliorate Ang-II-induced cardiomyocyte hypertrophy. MiR-92b-3p negatively regulated HAND2 expression at the transcriptional level. Both miR-92b-3p mimic and HAND2 siRNA could efficiently inhibit Ang-II-induced hypertrophy in mouse cardiomyocytes. SIGNIFICANCE: MiR-92b-3p inhibits Ang-II-induced cardiomyocyte hypertrophy via targeting HAND2.


Assuntos
Angiotensina II/farmacologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Cardiomiopatia Hipertrófica/tratamento farmacológico , Cardiomiopatia Hipertrófica/metabolismo , MicroRNAs/metabolismo , Miócitos Cardíacos/patologia , Regiões 3' não Traduzidas , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/patologia , Modelos Animais de Doenças , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Cardiopatias Congênitas/patologia , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Ventrículos do Coração/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima
10.
Nature ; 572(7767): 120-124, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31341279

RESUMO

Organogenesis involves integration of diverse cell types; dysregulation of cell-type-specific gene networks results in birth defects, which affect 5% of live births. Congenital heart defects are the most common malformations, and result from disruption of discrete subsets of cardiac progenitor cells1, but the transcriptional changes in individual progenitors that lead to organ-level defects remain unknown. Here we used single-cell RNA sequencing to interrogate early cardiac progenitor cells as they become specified during normal and abnormal cardiogenesis, revealing how dysregulation of specific cellular subpopulations has catastrophic consequences. A network-based computational method for single-cell RNA-sequencing analysis that predicts lineage-specifying transcription factors2,3 identified Hand2 as a specifier of outflow tract cells but not right ventricular cells, despite the failure of right ventricular formation in Hand2-null mice4. Temporal single-cell-transcriptome analysis of Hand2-null embryos revealed failure of outflow tract myocardium specification, whereas right ventricular myocardium was specified but failed to properly differentiate and migrate. Loss of Hand2 also led to dysregulation of retinoic acid signalling and disruption of anterior-posterior patterning of cardiac progenitors. This work reveals transcriptional determinants that specify fate and differentiation in individual cardiac progenitor cells, and exposes mechanisms of disrupted cardiac development at single-cell resolution, providing a framework for investigating congenital heart defects.


Assuntos
Cardiopatias Congênitas/embriologia , Cardiopatias Congênitas/patologia , Coração/embriologia , Análise de Célula Única , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular , Movimento Celular , Análise por Conglomerados , Feminino , Cardiopatias Congênitas/genética , Masculino , Camundongos , Análise de Sequência de RNA , Tretinoína/metabolismo
11.
J Agric Food Chem ; 67(28): 7898-7907, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31282664

RESUMO

This study aimed to explore the effects of silencing HB12 and TT8 genes on protein utilization characteristics of alfalfa. Ground samples of 11 HB12-silenced (HB12i), 5 TT8-silenced (TT8i) and 4 wild type (WT) were incubated in a Daisy II incubator with N15 labeled ammonium sulfate for 0, 4, 8, 12, and 24 h. CP degradation and degradational kinetics, microbial nitrogen fractions, and protein metabolic profiles were determined. Moreover, relationships between protein profiles and FTIR spectral parameters were estimated. Results showed that transgenic alfalfa had lower CP degradation, microbial protein, and total available protein compared with WT, especially for HB12i. In addition, CP degradation and protein metabolic profiles were closely correlated with FTIR spectral parameters and thereby could be predicted from spectral parameters. In conclusion, silencing of HB12 and TT8 genes in alfalfa decreased protein degradational and metabolic profiles, which were predictable with FTIR spectral parameters.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Inativação Gênica , Proteínas de Homeodomínio/genética , Medicago sativa/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Rúmen/metabolismo , Ração Animal/análise , Animais , Bactérias/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Bovinos , Digestão , Proteínas de Homeodomínio/metabolismo , Cinética , Medicago sativa/química , Medicago sativa/metabolismo , Proteínas de Plantas/química , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Proteólise , Rúmen/química , Rúmen/microbiologia
12.
Toxicol Lett ; 314: 142-152, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31319114

RESUMO

Cadmium (Cd), an established carcinogen, is a risk factor for oral squamous cell carcinoma (OSCC). Macroautophagy/autophagy is proposed to play a pivotal role in Cd-mediated carcinogenic activity. However, the mechanisms underlying Cd-induced autophagy are poorly understood. In the present study, a CAL27 OSCC cell line exposed to 10-6 M Cd for 8 weeks was used as a model system. Repeated Cd exposure induced significant migration and invasion of CAL27 cells. Furthermore, we showed that Cd increased the autophagic flux in CAL27 cells, as evidenced by the upregulation of LC3-II and the downregulation of P62/SQSTM1. The genetic blocking of autophagy inhibited Cd-induced migration and invasion, indicating a carcinogenic role of autophagy in Cd-treated CAL27 cells. Cd-induced NUPR1 expression, which contributes to lysosomal biogenesis and expression of autophagy-related gene, was found to mechanistically initiate autophagy in CAL27 cells. Of note, NUPR1 shRNA abolished Cd-induced autophagy both in vitro and in vivo. We also found that Cd triggered the generation of MDA in a xenograft tumour model and that N-acetyl-l-cysteine, a reactive oxygen species (ROS) scavenger, abrogated the effects of Cd on NUPR1-dependent autophagy in vivo. Taken together, these results demonstrate that ROS-dependent NUPR1-mediated autophagy plays an important role in repeated Cd exposure -induced cell growth, migration and invasion in OSCC cells.


Assuntos
Acetilcisteína/farmacologia , Antioxidantes/farmacologia , Autofagia/efeitos dos fármacos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Cloreto de Cádmio/toxicidade , Movimento Celular/efeitos dos fármacos , Neoplasias Bucais/tratamento farmacológico , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Animais , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Masculino , Camundongos Nus , Proteínas Associadas aos Microtúbulos/metabolismo , Neoplasias Bucais/genética , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Proteína Sequestossoma-1/metabolismo , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Nat Med ; 25(8): 1280-1289, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31359001

RESUMO

In response to various stimuli, vascular smooth muscle cells (SMCs) can de-differentiate, proliferate and migrate in a process known as phenotypic modulation. However, the phenotype of modulated SMCs in vivo during atherosclerosis and the influence of this process on coronary artery disease (CAD) risk have not been clearly established. Using single-cell RNA sequencing, we comprehensively characterized the transcriptomic phenotype of modulated SMCs in vivo in atherosclerotic lesions of both mouse and human arteries and found that these cells transform into unique fibroblast-like cells, termed 'fibromyocytes', rather than into a classical macrophage phenotype. SMC-specific knockout of TCF21-a causal CAD gene-markedly inhibited SMC phenotypic modulation in mice, leading to the presence of fewer fibromyocytes within lesions as well as within the protective fibrous cap of the lesions. Moreover, TCF21 expression was strongly associated with SMC phenotypic modulation in diseased human coronary arteries, and higher levels of TCF21 expression were associated with decreased CAD risk in human CAD-relevant tissues. These results establish a protective role for both TCF21 and SMC phenotypic modulation in this disease.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Doença da Artéria Coronariana/prevenção & controle , Miócitos de Músculo Liso/fisiologia , Análise de Célula Única/métodos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Células Cultivadas , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Osteoprotegerina/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de RNA
15.
Eur J Endocrinol ; 181(2): 103-119, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31200363

RESUMO

Context: Congenital hypogonadotropic hypogonadism (CHH) is a rare condition caused by GnRH deficiency. Several genes have been associated with the pathogenesis of CHH, but most cases still remain without a molecular diagnosis. The advent of next-generation sequencing (NGS) has allowed the simultaneous genotyping of several regions, faster, making possible the extension of the genetic knowledge of CHH. Objective: Genetic characterization of a large cohort of Brazilian CHH patients. Design and patients: A cohort of 130 unrelated patients (91 males, 39 females) with CHH (75 normosmic CHH, 55 Kallmann syndrome) was studied using a panel containing 36 CHH-associated genes. Results: Potential pathogenic or probably pathogenic variants were identified in 43 (33%) CHH patients. The genes ANOS1, FGFR1 and GNRHR were the most frequently affected. A novel homozygous splice site mutation was identified in the GNRH1 gene and a deletion of the entire coding sequence was identified in SOX10. Deleterious variants in the IGSF10 gene were identified in two patients with reversible normosmic CHH. Notably, 6.9% of the patients had rare variants in more than one gene. Rare variants were also identified in SPRY4, IL17RD, FGF17, IGSF1 and FLRT3 genes. Conclusions: This is a large study of the molecular genetics of CHH providing new genetic findings for this complex and heterogeneous genetic condition. NGS has been shown to be a fast, reliable and effective tool in the molecular diagnosis of congenital CHH and being able to targeting clinical genetic testing in the future.


Assuntos
Hipogonadismo/congênito , Hipogonadismo/genética , Mutação , Adulto , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Brasil/epidemiologia , Proteínas de Transporte/genética , Estudos de Coortes , Análise Mutacional de DNA , Feminino , Predisposição Genética para Doença , Testes Genéticos , Glicoproteínas/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Hipogonadismo/diagnóstico , Hipogonadismo/epidemiologia , Imunoglobulinas/genética , Síndrome de Kallmann/diagnóstico , Síndrome de Kallmann/epidemiologia , Síndrome de Kallmann/genética , Fator de Transcrição MSX1/genética , Masculino , Proteínas de Membrana/genética , Fatores de Transcrição Otx/genética , Linhagem , Receptores de Grelina/genética , Ribonucleoproteínas/genética , Adulto Jovem
16.
Dokl Biochem Biophys ; 485(1): 150-152, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201638

RESUMO

A hybrid 6XRE-hTERT promoter consisting of the hTERT tumor-specific promoter and six copies of the XRE element from the CYP1A1 human gene promoter was created. Using a human lung cancer cells as a model, we showed that XRE elements in the hybrid promoter greatly increase the activity of the hTERT promoter and ensure the reporter gene transcriptional activation in response to the treatment of the cells with the AhR ligand benzo(a)pyrene. However, similar effects were also observed in normal human bronchial epithelial cells HBEpC, which indicates the loss of the tumor-specific activity by the 6XRE-hTERT hybrid promoter. XRE elements can be used for nonspecific transcription enhancement but are unsuitable for the creation of tumor-specific promoters with enhanced activity.


Assuntos
Citocromo P-450 CYP1A1 , Elementos de Resposta , Telomerase , Ativação Transcricional/efeitos dos fármacos , Células A549 , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Benzo(a)pireno/toxicidade , Brônquios/metabolismo , Brônquios/patologia , Citocromo P-450 CYP1A1/biossíntese , Citocromo P-450 CYP1A1/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Mucosa Respiratória/metabolismo , Mucosa Respiratória/patologia , Telomerase/biossíntese , Telomerase/genética
17.
Gene ; 710: 399-405, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31200088

RESUMO

Iron-responsive elements (IREs) are ~35-nucleotide (nt) stem-loop RNA structures located in 5' or 3' untranslated regions (UTRs) of mRNAs that mediate post-transcriptional regulation by their association with IRE-binding proteins (IRPs). IREs are characterized by their apical 6-nt loop motif 5'-CAGWGH-3' (W = A or U and H = A, C or U), the so-called pseudotriloop, of which the loop nts C1 and G5 are paired, and the none-paired C between the two stem regions. In this study, the yeast three-hybrid (Y3H) system was used to investigate the relevance of the pseudotriloop structure of ferritin light chain (FTL) for the IRE-IRP interaction and the binding affinities between variant IRE(-like) structures and the two IRP isoforms, IRP1 and 2. Destabilization of the pseudotriloop structure by a G5-to-A mutation reduced binding of IRP1 and 2, while restoring the pseudotriloop conformation by the compensatory C1-to-U mutation, restored binding to both IRPs. In particular, IRP1 showed even stronger binding to the C1U-G5A mutant than to the wildtype FTL IRE. On the other hand, deletion of the bulged-out U6 of the pseudotriloop did not significantly affect its binding to either IRP1 or 2, but substitution with C particularly enhanced the binding to IRP1. In comparison to FTL IRE, IRE-like structures of 5'-aminolevulinate synthase 2 (ALAS2) and SLC40A1 (also known as ferroportin-1) showed similar or, in the case of endothelial PAS domain protein 1 (EPAS1) IRE, slightly weaker binding affinity to IRPs. SLC11A2 (a.k.a. divalent metal transporter-1) IRE exhibited relatively weak binding to IRP1 and medium binding to IRP2. Notably, the IRE-like structure of α-synuclein showed no detectable binding to either IRP under the conditions used in this Y3H assay. Our results indicate that Y3H can be used to characterize binding between IRPs and various IRE-like structures in vivo.


Assuntos
Apoferritinas/química , Apoferritinas/genética , Proteína 1 Reguladora do Ferro/metabolismo , Proteína 2 Reguladora do Ferro/metabolismo , 5-Aminolevulinato Sintetase/química , 5-Aminolevulinato Sintetase/genética , 5-Aminolevulinato Sintetase/metabolismo , Animais , Apoferritinas/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Proteína 1 Reguladora do Ferro/genética , Proteína 2 Reguladora do Ferro/genética , Mutação , Conformação de Ácido Nucleico , Técnicas do Sistema de Duplo-Híbrido , Regiões não Traduzidas
18.
Sheng Wu Gong Cheng Xue Bao ; 35(5): 766-774, 2019 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-31222995

RESUMO

Iron is one of the essential mineral micronutrients for plants. Low concentrations of effective iron in soil can easily increase risk of plant iron deficiency. Several members of bHLH transcription factors family participate in the response to iron deficiency and play an important role in iron regulation of plants. In order to better understand the mechanism of iron deficiency response, an overview of the structure, classification, function and regulatory mechanism of bHLH transcription factors was given in this review as well as signaling pathway triggered by iron deficiency. It will provide theoretical basis and design strategies for cultivating iron deficiency tolerant or iron-rich crops using bHLH transcription factors.


Assuntos
Arabidopsis , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Regulação da Expressão Gênica de Plantas , Ferro , Arabidopsis/genética , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ferro/deficiência , Transdução de Sinais/fisiologia
19.
Toxicol Lett ; 313: 108-119, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31251971

RESUMO

Polychlorinated biphenyls (PCBs) are classic persistent organic pollutants (POPs) and are associated with the progression of many cancers, including liver cancer. The present study investigated the effect of 2,3'4,4',5-pentachlorobiphenyl (PCB118) on hepatocellular carcinoma cell proliferation and its underlying mechanisms. The results indicated that PCB118 exposure promotes the proliferation and glycolysis of hepatocellular carcinoma SMMC-7721 cells. Moreover, PCB118 exposure increased the expression level of pyruvate kinase M2 (PKM2) and its nuclear translocation, whereas treatment with PKM2 shRNA suppressed the induction of cell proliferation and glycolysis by PCB118. PCB118 stimulated reactive oxygen species (ROS) production by activating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Treatment with the antioxidants N-acetyl-L-cysteine (NAC) and superoxide dismutase (SOD) prevented PCB118-induced effects on PKM2, cell proliferation and glycolysis. Furthermore, we found that PCB118 activated NADPH oxidase through the aryl hydrocarbon receptor (AhR) in SMMC-7721 cells. Consistently, treatment with AhR shRNA suppressed PCB118-induced effects on PKM2, cell proliferation and glycolysis. Overall, these results indicated that PCB118 promotes HCC cell proliferation via PKM2-dependent upregulation of glycolysis, which is mediated by AhR/NADPH oxidase-induced ROS production.


Assuntos
Carcinógenos Ambientais/toxicidade , Carcinoma Hepatocelular/enzimologia , Proteínas de Transporte/metabolismo , Proliferação de Células/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Neoplasias Hepáticas/enzimologia , Proteínas de Membrana/metabolismo , Bifenilos Policlorados/toxicidade , Hormônios Tireóideos/metabolismo , Transporte Ativo do Núcleo Celular , Fatores de Transcrição Hélice-Alça-Hélice Básicos/agonistas , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/patologia , Proteínas de Membrana/genética , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de Hidrocarboneto Arílico/agonistas , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Hormônios Tireóideos/genética
20.
Gastroenterology ; 157(3): 793-806.e14, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31170413

RESUMO

BACKGROUND & AIMS: The role of aryl hydrocarbon receptor (AhR) in liver fibrosis is controversial because loss and gain of AhR activity both lead to liver fibrosis. The goal of this study was to investigate how the expression of AhR by different liver cell types, hepatic stellate cells (HSCs) in particular, affects liver fibrosis in mice. METHODS: We studied the effects of AhR on primary mouse and human HSCs, measuring their activation and stimulation of fibrogenesis using RNA-sequencing analysis. C57BL/6J mice were given the AhR agonists 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE); were given carbon tetrachloride (CCl4); or underwent bile duct ligation. We also performed studies in mice with disruption of Ahr specifically in HSCs, hepatocytes, or Kupffer cells. Liver tissues were collected from mice and analyzed by histology, immunohistochemistry, and immunoblotting. RESULTS: AhR was expressed at high levels in quiescent HSCs, but the expression decreased with HSC activation. Activation of HSCs from AhR-knockout mice was accelerated compared with HSCs from wild-type mice. In contrast, TCDD or ITE inhibited spontaneous and transforming growth factor ß-induced activation of HSCs. Mice with disruption of Ahr in HSCs, but not hepatocytes or Kupffer cells, developed more severe fibrosis after administration of CCl4 or bile duct ligation. C57BL/6J mice given ITE did not develop CCl4-induced liver fibrosis, whereas mice without HSC AhR given ITE did develop CCl4-induced liver fibrosis. In studies of mouse and human HSCs, we found that AhR prevents transforming growth factor ß-induced fibrogenesis by disrupting the interaction of Smad3 with ß-catenin, which prevents the expression of genes that mediate fibrogenesis. CONCLUSIONS: In studies of human and mouse HSCs, we found that AhR prevents HSC activation and expression of genes required for liver fibrogenesis. Development of nontoxic AhR agonists or strategies to activate AhR signaling in HSCs might be developed to prevent or treat liver fibrosis.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Senescência Celular , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Células Estreladas do Fígado/metabolismo , Cirrose Hepática Experimental/prevenção & controle , Fígado/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/agonistas , Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proliferação de Células , Células Cultivadas , Senescência Celular/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Regulação da Expressão Gênica , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/patologia , Indóis/farmacologia , Fígado/efeitos dos fármacos , Fígado/patologia , Cirrose Hepática Experimental/genética , Cirrose Hepática Experimental/metabolismo , Cirrose Hepática Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Receptores de Hidrocarboneto Arílico/agonistas , Receptores de Hidrocarboneto Arílico/deficiência , Receptores de Hidrocarboneto Arílico/genética , Transdução de Sinais , Proteína Smad3/metabolismo , Tiazóis/farmacologia , beta Catenina/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA