Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 128
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
Int J Cancer ; 155(3): 582-594, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38380807

RESUMO

The proto-oncogene MYCN expression marked a cancer stem-like cell population in hepatocellular carcinoma (HCC) and served as a therapeutic target of acyclic retinoid (ACR), an orally administered vitamin A derivative that has demonstrated promising efficacy and safety in reducing HCC recurrence. This study investigated the role of MYCN as a predictive biomarker for therapeutic response to ACR and prognosis of HCC. MYCN gene expression in HCC was analyzed in the Cancer Genome Atlas and a Taiwanese cohort (N = 118). Serum MYCN protein levels were assessed in healthy controls (N = 15), patients with HCC (N = 116), pre- and post-surgical patients with HCC (N = 20), and a subset of patients from a phase 3 clinical trial of ACR (N = 68, NCT01640808). The results showed increased MYCN gene expression in HCC tumors, which positively correlated with HCC recurrence in non-cirrhotic or single-tumor patients. Serum MYCN protein levels were higher in patients with HCC, decreased after surgical resection of HCC, and were associated with liver functional reserve and fibrosis markers, as well as long-term HCC prognosis (>4 years). Subgroup analysis of a phase 3 clinical trial of ACR identified serum MYCN as the risk factor most strongly associated with HCC recurrence. Patients with HCC with higher serum MYCN levels after a 4-week treatment of ACR exhibited a significantly higher risk of recurrence (hazard ratio 3.27; p = .022). In conclusion, serum MYCN holds promise for biomarker-based precision medicine for the prevention of HCC, long-term prognosis of early-stage HCC, and identification of high-response subgroups for ACR-based treatment.


Assuntos
Biomarcadores Tumorais , Carcinoma Hepatocelular , Neoplasias Hepáticas , Proteína Proto-Oncogênica N-Myc , Recidiva Local de Neoplasia , Proto-Oncogene Mas , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/prevenção & controle , Neoplasias Hepáticas/patologia , Proteína Proto-Oncogênica N-Myc/genética , Recidiva Local de Neoplasia/prevenção & controle , Recidiva Local de Neoplasia/sangue , Prognóstico
2.
Plant Physiol ; 191(3): 1561-1573, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36652387

RESUMO

Genome-wide association studies (GWASs) are used to detect quantitative trait loci (QTL) using genomic and phenotypic data as inputs. While genomic data are obtained with high throughput and low cost, obtaining phenotypic data requires a large amount of effort and time. In past breeding programs, researchers and breeders have conducted a large number of phenotypic surveys and accumulated results as legacy data. In this study, we conducted a GWAS using phenotypic data of temperate japonica rice (Oryza sativa) varieties from a public database. The GWAS using the legacy data detected several known agriculturally important genes, indicating reliability of the legacy data for GWAS. By comparing the GWAS using legacy data (L-GWAS) and a GWAS using phenotypic data that we measured (M-GWAS), we detected reliable QTL for agronomically important traits. These results suggest that an L-GWAS is a strong alternative to replicate tests to confirm the reproducibility of QTL detected by an M-GWAS. In addition, because legacy data have often been accumulated for many traits, it is possible to evaluate the pleiotropic effect of the QTL identified for the specific trait that we focused on with respect to various other traits. This study demonstrates the effectiveness of using legacy data for GWASs and proposes the use of legacy data to accelerate genomic breeding.


Assuntos
Oryza , Locos de Características Quantitativas , Locos de Características Quantitativas/genética , Estudo de Associação Genômica Ampla/métodos , Oryza/genética , Reprodutibilidade dos Testes , Melhoramento Vegetal , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
3.
Nature ; 543(7644): 199-204, 2017 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-28241135

RESUMO

Long non-coding RNAs (lncRNAs) are largely heterogeneous and functionally uncharacterized. Here, using FANTOM5 cap analysis of gene expression (CAGE) data, we integrate multiple transcript collections to generate a comprehensive atlas of 27,919 human lncRNA genes with high-confidence 5' ends and expression profiles across 1,829 samples from the major human primary cell types and tissues. Genomic and epigenomic classification of these lncRNAs reveals that most intergenic lncRNAs originate from enhancers rather than from promoters. Incorporating genetic and expression data, we show that lncRNAs overlapping trait-associated single nucleotide polymorphisms are specifically expressed in cell types relevant to the traits, implicating these lncRNAs in multiple diseases. We further demonstrate that lncRNAs overlapping expression quantitative trait loci (eQTL)-associated single nucleotide polymorphisms of messenger RNAs are co-expressed with the corresponding messenger RNAs, suggesting their potential roles in transcriptional regulation. Combining these findings with conservation data, we identify 19,175 potentially functional lncRNAs in the human genome.


Assuntos
Bases de Dados Genéticas , RNA Longo não Codificante/química , RNA Longo não Codificante/genética , Transcriptoma/genética , Células Cultivadas , Sequência Conservada/genética , Conjuntos de Dados como Assunto , Elementos Facilitadores Genéticos/genética , Epigênese Genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Genoma Humano/genética , Estudo de Associação Genômica Ampla , Genômica , Humanos , Internet , Anotação de Sequência Molecular , Especificidade de Órgãos/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Locos de Características Quantitativas/genética , Estabilidade de RNA , RNA Mensageiro/genética
4.
Plant J ; 107(6): 1616-1630, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34216173

RESUMO

Glutamine is a product of ammonium (NH4+ ) assimilation catalyzed by glutamine synthetase (GS) and glutamate synthase (GOGAT). The growth of NH4+ -preferring paddy rice (Oryza sativa L.) depends on root NH4+ assimilation and the subsequent root-to-shoot allocation of glutamine; however, little is known about the mechanism of glutamine storage in roots. Here, using transcriptome and reverse genetics analyses, we show that the rice amino acid transporter-like 6 (OsATL6) protein exports glutamine to the root vacuoles under NH4+ -replete conditions. OsATL6 was expressed, along with OsGS1;2 and OsNADH-GOGAT1, in wild-type (WT) roots fed with sufficient NH4 Cl, and was induced by glutamine treatment. We generated two independent Tos17 retrotransposon insertion mutants showing reduced OsATL6 expression to determine the function of OsATL6. Compared with segregants lacking the Tos17 insertion, the OsATL6 knock-down mutant seedlings exhibited lower root glutamine content but higher glutamine concentration in the xylem sap and greater shoot growth under NH4+ -replete conditions. The transient expression of monomeric red fluorescent protein-fused OsATL6 in onion epidermal cells confirmed the tonoplast localization of OsATL6. When OsATL6 was expressed in Xenopus laevis oocytes, glutamine efflux from the cell into the acidic bath solution increased. Under sufficient NH4+ supply, OsATL6 transiently accumulated in sclerenchyma and pericycle cells, which are located adjacent to the Casparian strip, thus obstructing the apoplastic solute path, and in vascular parenchyma cells of WT roots before the peak accumulation of GS1;2 and NADH-GOGAT1 occurred. These findings suggest that OsATL6 temporarily stores excess glutamine, produced by NH4+ assimilation, in root vacuoles before it can be translocated to the shoot.


Assuntos
Sistemas de Transporte de Aminoácidos/metabolismo , Glutamina/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Sistemas de Transporte de Aminoácidos/genética , Amônia/metabolismo , Cloreto de Amônio/farmacologia , Animais , Feminino , Regulação da Expressão Gênica de Plantas , Homeostase , Mutação , Cebolas/citologia , Cebolas/genética , Oócitos/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Vacúolos/metabolismo , Xenopus laevis
5.
Plant Physiol ; 182(4): 1894-1909, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32024696

RESUMO

Nitrogen (N) is an essential macronutrient, and the final form of endogenous inorganic N is ammonium, which is assimilated by Gln synthetase (GS) into Gln. However, how the multiple isoforms of cytosolic GSs contribute to metabolic systems via the regulation of ammonium assimilation remains unclear. In this study, we compared the effects of two rice (Oryza sativa) cytosolic GSs, namely OsGS1;1 and OsGS1;2, on central metabolism in roots using reverse genetics, metabolomic and transcriptomic profiling, and network analyses. We observed (1) abnormal sugar and organic N accumulation and (2) significant up-regulation of genes associated with photosynthesis and chlorophyll biosynthesis in the roots of Osgs1;1 but not Osgs1;2 knockout mutants. Network analysis of the Osgs1;1 mutant suggested that metabolism of Gln was coordinated with the metabolic modules of sugar metabolism, tricarboxylic acid cycle, and carbon fixation. Transcript profiling of Osgs1;1 mutant roots revealed that expression of the rice sigma-factor (OsSIG) genes in the mutants were transiently upregulated. GOLDEN2-LIKE transcription factor-encoding genes, which are involved in chloroplast biogenesis in rice, could not compensate for the lack of OsSIGs in the Osgs1;1 mutant. Microscopic analysis revealed mature chloroplast development in Osgs1;1 roots but not in the roots of Osgs1;2, Osgs1;2-complemented lines, or the wild type. Thus, organic N assimilated by OsGS1;1 affects a broad range of metabolites and transcripts involved in maintaining metabolic homeostasis and plastid development in rice roots, whereas OsGS1;2 has a more specific role, affecting mainly amino acid homeostasis but not carbon metabolism.


Assuntos
Glutamato-Amônia Ligase/metabolismo , Oryza/metabolismo , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Glutamato-Amônia Ligase/genética , Nitrogênio/metabolismo , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
6.
Bioorg Med Chem Lett ; 43: 128065, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915257

RESUMO

New chemotherapeutics are needed to treat hepatocellular carcinoma (HCC), and menaquinones, homologs of vitamin K consisting of a 1,4-naphthoquinone core and a (poly)isoprene chain, are potential candidates. In this study, we designed and synthesized a series of phthalazine-1,4-dione-based menaquinone analogs. Among them, compounds bearing the intact isoprene chain exhibited selective antiproliferative activity towards HCC cell line JHH7, as compared with normal hepatocytes. The geranyl derivative 10 showed submicromolar potency, and might be a promising lead compound for anticancer agents.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Ftalazinas/farmacologia , Vitamina K 2/análogos & derivados , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Ftalazinas/síntese química , Ftalazinas/química , Relação Estrutura-Atividade , Vitamina K 2/síntese química , Vitamina K 2/química , Vitamina K 2/farmacologia
7.
Physiol Plant ; 171(4): 802-808, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33280129

RESUMO

Urea is the most used nitrogenous fertilizer worldwide and an important nitrogen-containing plant metabolite. Despite its major use as fertilizer, its direct uptake is limited due to the ubiquitous presence of bacterial urease, which leads to the formation of ammonium. In this review, we will focus mainly on the more recent research about the high-affinity urea transporter function in nitrogen-deficient conditions. The effective use of nitrogenous compounds is essential for plants to be able to deal with nitrogen-deficient conditions. Leaf senescence, either induced by development and/or by nitrogen deficiency, plays an important role in the efficient use of already assimilated nitrogen. Proteinaceous nitrogen is set free through catabolic reactions: the released amino acids from protein catabilization are in turn catabolized leading to an accumulation of ammonium and urea. The concentration and conversion to transportable forms of nitrogen, e.g. amino acids like glutamine and asparagine, are coordinated around the vascular tissue. Urea itself can be translocated directly over the phloem by a mechanism that involves DUR3, or it is converted by urease to ammonium and assimilated again into amino acids. The details of the high-affinity transporter function in this physiological context and the implications for crop yield are explained.


Assuntos
Arabidopsis , Transporte Biológico , Fertilizantes , Nitrogênio , Ureia
8.
Bioorg Med Chem ; 46: 116375, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492592

RESUMO

Hypoxia-inducible factor 1 (HIF-1) is a promising drug target for cancer chemotherapy. In our screening program aimed at identifying new HIF-1 inhibitors by using a hypoxia-responsive luciferase reporter gene assay, KUSC-5001 containing the 1-alkyl-1H-pyrazole-3-carboxamide moiety was found as a potential hit molecule. During an extensive structure-activity relationship (SAR) study, we developed a more effective HIF-1 inhibitor KUSC-5037 (IC50 = 1.2 µM). Under hypoxic conditions, KUSC-5037 suppressed the HIF-1α (a regulatory subunit of HIF-1) mRNA, causing decreases in the gene expression of HIF-1 target genes such as carbonic anhydrase 9 (CA9) and vascular endothelial growth factor (VEGF) genes. Furthermore, by applying our fluorescent and bifunctional probes, ATP5B, a catalytic ß subunit of mitochondrial FoF1-ATP synthase, was identified as a target protein of KUSC-5037. These results indicate that the derivatives of KUSC-5037 containing the 1-alkyl-1H-pyrazole-3-carboxamide moiety are promising lead molecules for the inhibition of HIF-1 signaling via FoF1-ATP synthase suppression.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Pirazóis/farmacologia , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Anidrase Carbônica IX/antagonistas & inibidores , Anidrase Carbônica IX/genética , Anidrase Carbônica IX/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
9.
Proc Natl Acad Sci U S A ; 115(19): 4969-4974, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29686061

RESUMO

Hepatocellular carcinoma (HCC) is a highly lethal cancer that has a high rate of recurrence, in part because of cancer stem cell (CSC)-dependent field cancerization. Acyclic retinoid (ACR) is a synthetic vitamin A-like compound capable of preventing the recurrence of HCC. Here, we performed a genome-wide transcriptome screen and showed that ACR selectively suppressed the expression of MYCN, a member of the MYC family of basic helix-loop-helix-zipper transcription factors, in HCC cell cultures, animal models, and liver biopsies obtained from HCC patients. MYCN expression in human HCC was correlated positively with both CSC and Wnt/ß-catenin signaling markers but negatively with mature hepatocyte markers. Functional analysis showed repressed cell-cycle progression, proliferation, and colony formation, activated caspase-8, and induced cell death in HCC cells following silencing of MYCN expression. High-content single-cell imaging analysis and flow cytometric analysis identified a MYCN+ CSC subpopulation in the heterogeneous HCC cell cultures and showed that these cells were selectively killed by ACR. Particularly, EpCAM+ cells isolated using a cell-sorting system showed increased MYCN expression and sensitivity to ACR compared with EpCAM- cells. In a long-term (>10 y) follow-up study of 102 patients with HCC, MYCN was expressed at higher levels in the HCC tumor region than in nontumor regions, and there was a positive correlation between MYCN expression and recurrence of de novo HCC but not metastatic HCC after curative treatment. In summary, these results suggest that MYCN serves as a prognostic biomarker and therapeutic target of ACR for liver CSCs in de novo HCC.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Hepatocelular/prevenção & controle , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Hepáticas/prevenção & controle , Proteína Proto-Oncogênica N-Myc/biossíntese , Células-Tronco Neoplásicas/metabolismo , Tretinoína/análogos & derivados , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Molécula de Adesão da Célula Epitelial/metabolismo , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Metástase Neoplásica , Células-Tronco Neoplásicas/patologia , Prognóstico , Tretinoína/farmacologia
10.
Cancer Sci ; 111(3): 869-880, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31883160

RESUMO

Primary hepatic tumors mainly include hepatocellular carcinoma (HCC), which is one of the most frequent causes of cancer-related deaths worldwide. Thus far, HCC prognosis has remained extremely poor given the lack of effective treatments. Numerous studies have described the roles played by microRNAs (miRNAs) in cancer progression and the potential of these small noncoding RNAs for diagnostic or therapeutic applications. The current consensus supports the idea that direct repression of a wide range of oncogenes by a single key miRNA could critically affect the malignant properties of cancer cells in a synergistic manner. In this study, we aimed to investigate the oncogenes controlled by miR-493-5p, a major tumor suppressor miRNA that inactivates miR-483-3p oncomir in hepatic cancer cells. Using global gene expression analysis, we highlighted a set of candidate genes potentially regulated by miR-493-5p. In particular, the canonical MYCN protooncogene (MYCN) appeared to be an attractive target of miR-493-5p given its significant inhibition through 3'-UTR targeting in miR-493-5p-rescued HCC cells. We showed that MYCN was overexpressed in liver cancer cell lines and clinical samples from HCC patients. Notably, MYCN expression levels were inversely correlated with miR-493-5p in tumor tissues. We confirmed that MYCN knockdown mimicked the anticancer effect of miR-493-5p by inhibiting HCC cell growth and invasion, whereas MYCN rescue hindered miR-493-5p activity. In summary, miR-493-5p is a pivotal miRNA that modulates various oncogenes after its reexpression in liver cancer cells, suggesting that tumor suppressor miRNAs with a large spectrum of action could provide valuable tools for miRNA replacement therapies.


Assuntos
Carcinoma Hepatocelular/genética , Proliferação de Células/genética , Neoplasias Hepáticas/genética , Proteína Proto-Oncogênica N-Myc/genética , Oncogenes/genética , Regiões 3' não Traduzidas/genética , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Genes Supressores de Tumor/fisiologia , Células Hep G2 , Humanos , Neoplasias Hepáticas/patologia , Masculino , MicroRNAs , Pessoa de Meia-Idade , Prognóstico , Proto-Oncogenes/genética
11.
Anal Biochem ; 597: 113654, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32142762

RESUMO

Sepsis is the leading cause of death in hospitalized patients and is characterized by a dysregulated inflammatory response to infection and multiple organ failure, including the liver. Transglutaminase 2 (TG2) is a multifunctional enzyme that exhibits transamidase, GTPase, and integrin-binding activities and has opposing roles in the regulation of cell growth, differentiation, and apoptosis. TG2 plays both pathogenic and protective roles in liver diseases, revealing the need to examine the activities of TG2. Here, we introduced an ex vivo imaging approach to examine the in vivo transamidase activity of TG2 based on the combination of intraperitoneal injection of 5-biotinamidopentylamine (5BAPA), a biotinylated substrate for TG2, and fluorescent streptavidin staining in frozen liver sections. Increased 5BAPA signals was observed in the livers of lipopolysaccharide (LPS) and cecal ligation and puncture (CLP)-induced sepsis mice. Pharmacological inhibition of TG2 activity ameliorated LPS-induced liver injury. 5BAPA signals were observed in TG2-expressing and F4/80-positive midzonal macrophages, providing direct evidence that activated macrophages are the major cellular source of active TG2 in the livers of sepsis mice. Further studies focusing on the activation of 5BAPA-stained midzonal macrophages may improve understanding of the molecular pathophysiology and the development of therapeutic strategies for sepsis.


Assuntos
Proteínas de Ligação ao GTP/metabolismo , Fígado/enzimologia , Macrófagos/enzimologia , Sepse/metabolismo , Transglutaminases/metabolismo , Animais , Proteínas de Ligação ao GTP/análise , Injeções Intraperitoneais , Lipopolissacarídeos/administração & dosagem , Fígado/patologia , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Imagem Óptica , Proteína 2 Glutamina gama-Glutamiltransferase , Sepse/induzido quimicamente , Sepse/patologia , Transglutaminases/análise
12.
Med Mycol ; 58(5): 679-689, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31642483

RESUMO

NADPH oxidases (Nox) generate reactive oxygen species (ROS) such as superoxide anion radical (O2-) and hydrogen peroxide (H2O2). The pathogenic fungi Candida albicans and Candida glabrata enhance cellular transglutaminase 2 (TG2) activity levels in co-cultured human hepatic cells in a ROS-mediated manner. Deletion of NOX1 (CgNOX1) in C. glabrata blocks the ability of C. glabrata to induce TG2 activity. Here, we investigated whether Nox proteins from C. albicans and Saccharomyces cerevisiae are related with induction of TG2 activity in hepatic cells. C. albicans CFL11 (CaCFL11) was identified as a key factor in this fungus for hepatic TG2 induction in the co-cultures. The cfl11 mutant of C. albicans did not induce TG2 activity in hepatocytes. In addition, overexpression of YNO1, a homolog of CgNOX1, in S. cerevisiae led to induction of ROS generation and TG2 activity in hepatic cells in co-incubation experiments. These findings indicated that a fungal Nox plays a role in enhancing TG2 activity in human hepatocytes and leads to apoptosis.


Assuntos
Candida albicans/enzimologia , Proteínas de Ligação ao GTP/metabolismo , NADPH Oxidases/metabolismo , Saccharomyces cerevisiae/enzimologia , Transglutaminases/metabolismo , Candida albicans/genética , Candida glabrata/enzimologia , Candida glabrata/genética , Células Cultivadas , Hepatócitos/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Mutação , NADPH Oxidases/genética , Proteína 2 Glutamina gama-Glutamiltransferase , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/genética
13.
Plant J ; 93(6): 992-1006, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29356222

RESUMO

Ammonium influx into plant roots via the high-affinity transport system (HATS) is down-modulated under elevated external ammonium, preventing ammonium toxicity. In ammonium-fed Arabidopsis, ammonium transporter 1 (AMT1) trimers responsible for HATS activity are allosterically inactivated in a dose-dependent manner via phosphorylation of the conserved threonine at the carboxyl-tail by the calcineurin B-like protein 1-calcineurin B-like protein-interacting protein kinase 23 complex and other yet unidentified protein kinases. Using transcriptome and reverse genetics in ammonium-preferring rice, we revealed the role of the serine/threonine/tyrosine protein kinase gene OsACTPK1 in down-modulation of HATS under sufficient ammonium. In wild-type roots, ACTPK1 mRNA and protein accumulated dose-dependently under sufficient ammonium. To determine the function of ACTPK1, two independent mutants lacking ACTPK1 were produced by retrotransposon Tos17 insertion. Compared with segregants lacking insertions, the two mutants showed decreased root growth and increased shoot growth under 1 mm ammonium due to enhanced ammonium acquisition, via aberrantly high HATS activity, and use. Furthermore, introduction of OsACTPK1 cDNA fused to the synthetic green fluorescence protein under its own promoter complemented growth and the HATS influx, and suggested plasma membrane localization. Root cellular expression of OsACTPK1 also overlapped with that of ammonium-induced OsAMT1;1 and OsAMT1;2. Meanwhile, threonine-phosphorylated AMT1 levels were substantially decreased in roots of ACTPK1-deficient mutants grown under sufficient ammonium. Bimolecular fluorescence complementation assay further confirmed interaction between ACTPK1 and AMT1;2 at the cell plasma membrane. Overall, these findings suggest that ACTPK1 directly phosphorylates and inactivates AMT1;2 in rice seedling roots under sufficient ammonium.


Assuntos
Compostos de Amônio/metabolismo , Perfilação da Expressão Gênica , Oryza/genética , Proteínas de Plantas/genética , Proteínas Serina-Treonina Quinases/genética , Plântula/genética , Transporte Biológico/genética , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Mutação , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fosforilação , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
14.
Physiol Plant ; 167(1): 75-89, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30426495

RESUMO

Nitrogen is one of the most important elements for plant growth, and urea is one of the most frequently used nitrogen fertilizers worldwide. Besides the exogenously-supplied urea to the soil, urea is endogenously synthesized during secondary nitrogen metabolism. Here, we investigated the contribution of a urea transporter, DUR3, to rice production using a reverse genetic approach combined with localization studies. Tos17 insertion lines for DUR3 showed a 50% yield reduction in hydroponic culture, and a 26.2% yield reduction in a paddy field, because of decreased grain filling. Because shoot biomass production and shoot total N was not reduced, insertion lines were disordered not only in nitrogen acquisition but also in nitrogen allocation. During seed development, DUR3 insertion lines accumulated nitrogen in leaves and could not sufficiently develop their panicles, although shoot and root dry weights were not significantly different from the wild-type. The urea concentration in old leaf harvested from DUR3 insertion lines was lower than that in wild-type. DUR3 promoter-dependent ß-glucuronidase (GUS) activity was localized in vascular tissue and the midribs of old leaves. These results indicate that DUR3 contributes to nitrogen translocation and rice yield under nitrogen-deficient and field conditions.


Assuntos
Proteínas de Membrana Transportadoras/metabolismo , Nitrogênio/metabolismo , Oryza/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Brotos de Planta/metabolismo , Transportadores de Ureia
15.
Bioorg Med Chem ; 27(3): 470-478, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30552008

RESUMO

Hepatitis B, a viral infectious disease caused by hepatitis B virus (HBV), is a life-threatening disease that leads liver cirrhosis and liver cancer. Because the current treatments for HBV, such as an interferon (IFN) formulation or nucleoside/nucleotide analogues, are not sufficient, the development of a more effective agent for HBV is urgent required. CDM-3008 (1, 2-(2,4-bis(trifluoromethyl)imidazo[1,2-a][1,8]naphthyridin-8-yl)-1,3,4-oxadiazole) (RO8191)) is a small molecule with an imidazo[1,2-a][1,8]naphthyridine scaffold that shows anti-HCV activity with an IFN-like effect. Here, we report that 1 was also effective for HBV, although the solubility and metabolic stability were insufficient for clinical use. Through the structure-activity relationship (SAR), we discovered that CDM-3032 (11, N-(piperidine-4-yl)-2,4-bis(trifluoromethyl)imidazo[1,2-a][1,8]naphthyridine-8-carboxamide hydrochloride) was more soluble than 1 (>30 mg/mL for 11 versus 0.92 mg/mL for 1). In addition, the half-life period of 11 was dramatically improved in both mouse and human hepatic microsomes (T1/2, >120 min versus 58.2 min in mouse, and >120 min versus 34.1 min in human, for 11 and 1, respectively).


Assuntos
Antivirais/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Naftiridinas/farmacologia , Oxidiazóis/farmacologia , Animais , Antivirais/síntese química , Antivirais/química , Células Cultivadas , Relação Dose-Resposta a Droga , Desenvolvimento de Medicamentos , Humanos , Camundongos , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Naftiridinas/síntese química , Naftiridinas/química , Oxidiazóis/síntese química , Oxidiazóis/química , Relação Estrutura-Atividade
16.
Plant Cell Physiol ; 59(3): 601-613, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29373725

RESUMO

Ammonium is a major nitrogen source for plants; it is assimilated into glutamine via a reaction catalyzed by glutamine synthetase (GLN). Arabidopsis expresses four cytosolic GLN genes, GLN1; 1, GLN1; 2, GLN1; 3 and GLN1; 4, in roots. However, the function and organization of these GLN1 isozymes in ammonium assimilation in roots remain unclear. In this study, we aimed to characterize the four GLN1 isozymes. The levels of growth of the wild type and gln1 single and multiple knockout lines were compared in a hydroponic culture at ammonium concentrations of 0.1 and 3 mM. Under the low-ammonium concentration, in single mutants for each GLN1 gene, there was little effect on growth, whereas the triple mutant for GLN1; 1, GLN1; 2 and GLN1; 3 grew slowly and accumulated ammonium. Under the high-ammonium concentration, the single mutant for GLN1; 2 showed 50% decreases in fresh weight and glutamine, whereas the other gln1 single mutants did not show notable changes in the phenotype. The double mutant for GLN1; 1 and GLN1; 2 showed less growth and a lower glutamine concentration than the single mutant for GLN1; 2. Promoter analysis indicated an overlapping expression of GLN1; 1 with GLN1; 2 in the surface layers of the roots. We thus concluded that: (i) at a low concentration, ammonium was assimilated by GLN1; 1, GLN1; 2 and GLN1; 3, and they were redundant; (ii) low-affinity GLN1; 2 could contribute to ammonium assimilation at concentrations ranging from 0.1 to 3 mM; and (iii) GLN1; 1 supported GLN1; 2 within the outer cell layers of the root.


Assuntos
Compostos de Amônio/metabolismo , Arabidopsis/enzimologia , Citosol/enzimologia , Glutamato-Amônia Ligase/metabolismo , Raízes de Plantas/enzimologia , Compostos de Amônio/farmacologia , Arabidopsis/citologia , Arabidopsis/efeitos dos fármacos , Biomassa , Carbono/farmacologia , Técnicas de Inativação de Genes , Isoenzimas/metabolismo , Mutação/genética , Nitrogênio/farmacologia , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Regiões Promotoras Genéticas
17.
Biochem Biophys Res Commun ; 504(4): 857-864, 2018 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-30219233

RESUMO

Acute liver injury (ALI) is highly lethal acute liver failure caused by different etiologies. Transforming growth factor ß (TGF-ß) is a multifunctional cytokine and a well-recognized inducer of apoptotic and necrotic cell death in hepatocytes. Latent TGF-ß is activated partly through proteolytic cleavage by a serine protease plasma kallikrein (PLK) between the R58 and L59 residues of its propeptide region. Recently, we developed a specific monoclonal antibody to detect the N-terminal side LAP degradation products ending at residue R58 (R58 LAP-DPs) that reflect PLK-dependent TGF-ß activation. This study aimed to explore the potential roles of PLK-dependent TGF-ß activation in the pathogenesis of ALI. We established a mouse ALI model via the injection of anti-Fas antibodies (Jo2) and observed increases in the TGF-ß1 mRNA level, Smad3 phosphorylation, TUNEL-positive apoptotic hepatocytes and R58-positive cells in the liver tissues of Jo2-treated mice. The R58 LAP-DPs were observed in/around F4/80-positive macrophages, while macrophage depletion with clodronate liposomes partly alleviated the Jo2-induced liver injury. Blocking PLK-dependent TGF-ß activation using either the serine proteinase inhibitor FOY305 or the selective PLK inhibitor PKSI-527 or blocking the TGF-ß receptor-mediated signaling pathway using SB431542 significantly prevented Jo2-induced hepatic apoptosis and mortality. Furthermore, similar phenomena were observed in the mouse model of ALI with the administration of acetaminophen (APAP). In summary, R58 LAP-DPs reflecting PLK-dependent TGF-ß activation may serve as a biomarker for ALI, and targeting PLK-dependent TGF-ß activation has potential as a therapeutic strategy for ALI.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/prevenção & controle , Calicreína Plasmática/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Acetaminofen/efeitos adversos , Lesão Pulmonar Aguda/tratamento farmacológico , Animais , Anticorpos Monoclonais/efeitos adversos , Benzamidas/farmacologia , Biomarcadores/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Dioxóis/farmacologia , Modelos Animais de Doenças , Proteínas de Ligação a TGF-beta Latente/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Calicreína Plasmática/genética , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Fator de Crescimento Transformador beta/genética , Receptor fas/imunologia
18.
Genome Res ; 25(12): 1812-24, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26510915

RESUMO

An increasing number of noncoding RNAs (ncRNAs) have been implicated in various human diseases including cancer; however, the ncRNA transcriptome of hepatocellular carcinoma (HCC) is largely unexplored. We used CAGE to map transcription start sites across various types of human and mouse HCCs with emphasis on ncRNAs distant from protein-coding genes. Here, we report that retroviral LTR promoters, expressed in healthy tissues such as testis and placenta but not liver, are widely activated in liver tumors. Despite HCC heterogeneity, a subset of LTR-derived ncRNAs were more than 10-fold up-regulated in the vast majority of samples. HCCs with a high LTR activity mostly had a viral etiology, were less differentiated, and showed higher risk of recurrence. ChIP-seq data show that MYC and MAX are associated with ncRNA deregulation. Globally, CAGE enabled us to build a mammalian promoter map for HCC, which uncovers a new layer of complexity in HCC genomics.


Assuntos
Carcinoma Hepatocelular/etiologia , Perfilação da Expressão Gênica , Neoplasias Hepáticas/etiologia , Regiões Promotoras Genéticas , RNA não Traduzido/genética , Sequências Repetidas Terminais , Sítio de Iniciação de Transcrição , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Animais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Viral , Biologia Computacional/métodos , Modelos Animais de Doenças , Progressão da Doença , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Knockout , Ligação Proteica , Fatores de Transcrição/metabolismo , Transcriptoma , Membro 4 da Subfamília B de Transportadores de Cassetes de Ligação de ATP
19.
Hepatology ; 65(4): 1104-1116, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27863453

RESUMO

Introduction of direct-acting antivirals against hepatitis C virus (HCV) has provided a revolutionary improvement in the treatment outcome. In contrast to HCV, however, the strategy for developing new antiviral agents against hepatitis B virus (HBV), especially viral-targeting compounds, is limited because HBV requires only four viral genes for its efficient replication/infection. Here, we identify an oligomeric flavonoid, proanthocyanidin (PAC) and its analogs, which inhibit HBV entry into host cells by targeting the HBV large surface protein (LHBs). Through cell-based chemical screening, PAC was identified to inhibit HBV infection with little cytotoxic effect. PAC prevented the attachment of the preS1 region in the LHBs to its cellular receptor, sodium taurocholate cotransporting polypeptide (NTCP). PAC was shown to target HBV particles and impair their infectivity, whereas it did not affect the NTCP-mediated bile acid transport activity. Chemical biological techniques demonstrated that PAC directly interacted with the region essential for receptor binding in the preS1 region in the LHBs protein. Importantly, PAC had a pan-genotypic anti-HBV activity and was also effective against a clinically relevant nucleoside analog-resistant HBV isolate. We further showed that PAC augmented the ability of a nucleoside analog, tenofovir, to interrupt HBV spread over time in primary human hepatocytes by cotreatment. Moreover, derivative analysis could identify small molecules that demonstrated more-potent anti-HBV activity over PAC. CONCLUSION: PAC and its analogs represent a new class of anti-HBV agents that directly target the preS1 region of the HBV large surface protein. These agents could contribute to the development of a potent, well-tolerated, and broadly active inhibitor of HBV infection. (Hepatology 2017;65:1104-1116).


Assuntos
Hepatite B/tratamento farmacológico , Hepatite B/genética , Hepatite D/tratamento farmacológico , Hepatite D/genética , Proantocianidinas/administração & dosagem , Proteínas Estruturais Virais/efeitos dos fármacos , Antivirais/administração & dosagem , Antivirais/farmacologia , Previsões , Genótipo , Hepatite B/diagnóstico , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/genética , Hepatite D/diagnóstico , Vírus Delta da Hepatite/efeitos dos fármacos , Vírus Delta da Hepatite/genética , Humanos , Terapia de Alvo Molecular/tendências , Proteínas Estruturais Virais/genética
20.
Plant Cell Physiol ; 58(4): 679-690, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28186255

RESUMO

A mutation abolishing cytosolic glutamine synthetase1;2 (GS1;2) activity impairs assimilation of ammonium into glutamine in both roots and basal portions of shoots, and severely decreases axillary bud outgrowth (tillering) in mutant rice seedlings. Although the gs1;2 mutant phenotype is independent of strigolactone, which inhibits tillering, it also demonstrates glutamine- or related metabolite-responsive biosynthesis of cytokinin (CK), which promotes tillering. Here, we examined the connection between GS1;2 and CK biosynthesis during tillering, focusing on basal portions of the shoots as well as apical and axillary bud meristems in the gs1;2 mutant. Despite a sufficient ammonium supply, decreases in precursor CK contents and a decrease in ammonium assimilation into glutamine were observed in basal portions of mutant shoots. Reintroducing expression of OsGS1;2 cDNA driven by its own promoter restored precursor CK contents and ammonium assimilation to wild-type levels. In basal portions of the shoots, glutamine-responsive adenosine phosphate-isopentenyltransferase4 (OsIPT4), which is also predominant in rice roots, was the predominant isogene for IPT, which synthesizes CK. Cell-specific expression of OsIPT4 in phloem companion cells in nodal vascular anastomoses connected to the axillary bud vasculature also decreased in the gs1;2 mutant. Expression of CK-responsive type-A response regulator genes as local indicators of active CKs was also abolished in the axillary bud meristem of the mutant. These results suggest that the lack of GS1;2 activity decreased levels of glutamine or a related metabolite required for CK biosynthesis, causing a deficiency in active CK in the axillary bud meristem necessary for tillering.


Assuntos
Citocininas/metabolismo , Glutamato-Amônia Ligase/metabolismo , Nitrogênio/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Compostos de Amônio/metabolismo , Citosol/enzimologia , Glutamato-Amônia Ligase/genética , Glutamina/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Mutação , Floema/genética , Floema/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA