Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.370
Filtrar
1.
Environ Pollut ; 255(Pt 1): 113193, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31521998

RESUMO

Phthalate esters (PAEs), as widely used plasticizers, have been concerned for their possible disruption of estrogen functions via binding to and activating the transcription of estrogen receptors (ERs). Nevertheless, the computational interpretation of the mechanism of ERs activities modulated by PAEs at the molecular level is still insufficient, which hinders the reliable screening of the ERs-active PAEs with high speed and high throughput. To bridge the gap, the in silico simulations considering the effects of coactivators were accomplished to explore the molecular mechanism of action for the purpose of predicting the estrogenic potencies of PAEs. The transcriptional activation functions of human ERα (hERα) modulated by PAEs is predicted via the simulations including binding interaction of PAEs and hERα, conformational changes of PAEs-hERα complexes and recruitment of coactivators. Molecular insight into the diverse estrogen mechanism of action among PAEs with regard to hERα agonists and selective estrogen receptor modulators (SERMs) is provided. Agonist-modulated conformational change of hERα leads to the optimal exposure of its Activation Function 2 (AF-2) surface which, in turn, facilitates the recruitment of coactivators, therefore promoting the transcriptional activation functions of hERα. Conversely, binding interaction of hERα with SERMs among PAEs leads to the conformational change with blocked AF-2 surface, thus preventing the recruitment of coactivators and consequently inhibiting the AF-2 activity. The two-hybrid recombinant yeast is experimentally used for verification. The established in silico evaluation methodology exhibits great promise to speed up the prediction of chemicals which work as hERα agonist or SERMs.


Assuntos
Poluentes Ambientais/toxicidade , Antagonistas de Estrogênios/química , Receptor alfa de Estrogênio/química , Estrogênios/química , Ácidos Ftálicos/toxicidade , Plastificantes/toxicidade , Estrona , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular , Ativação Transcricional/efeitos dos fármacos
2.
Environ Pollut ; 254(Pt B): 113098, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31479813

RESUMO

While humans are exposed to mixtures of persistent organic pollutants (POPs), their risk assessment is usually based on a chemical-by-chemical approach. To assess the health effects associated with mixed exposures, knowledge on mixture toxicity is required. Several POPs are potential ligands of the Aryl hydrocarbon receptor (AhR), which involves in xenobiotic metabolism and controls many biological pathways. This study assesses AhR agonistic and antagonistic activities of 29 POPs individually and in mixtures by using Chemical-Activated LUciferase gene eXpression bioassays with 3 transgenic cell lines (rat hepatoma DR-H4IIE, human hepatoma DR-Hep G2 and human mammary gland carcinoma DR-T47-D). Among the 29 POPs, which were selected based on their abundance in Scandinavian human blood, only 4 exerted AhR agonistic activities, while 16 were AhR antagonists in DR-H4IIE, 5 in DR-Hep G2 and 7 in DR-T47-D when tested individually. The total POP mixture revealed to be AhR antagonistic. It antagonized EC50 TCDD inducing AhR transactivation at a concentration of 125 and 250 and 500 fold blood levels in DR-H4IIE, DR-T47-D and DR-Hep G2, respectively, although each compound was present at these concentrations lower than their LOEC values. Such values could occur in real-life in food contamination incidents or in exposed populations. In DR-H4IIE, the antagonism of the total POP mixture was due to chlorinated compounds and, in particular, to PCB-118 and PCB-138 which caused 90% of the antagonistic activity in the POP mixture. The 16 active AhR antagonists acted additively. Their mixed effect was predicted successfully by concentration addition or generalized concentration addition models, rather than independent action, with only two-fold IC50 underestimation. We also attained good predictions for the full dose-response curve of the antagonistic activity of the total POP mixture.


Assuntos
Poluentes Ambientais/farmacologia , Bifenilos Policlorados/farmacologia , Receptores de Hidrocarboneto Arílico/química , Ativação Transcricional/efeitos dos fármacos , Animais , Linhagem Celular , Humanos , Bifenilos Policlorados/química , Ratos , Receptores de Hidrocarboneto Arílico/agonistas , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores
3.
Food Chem Toxicol ; 133: 110792, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31472229

RESUMO

Parabens are widely used as preservatives in personal care products, medicines and foods, resulting in substantial human exposures, even though some harmful effects, such as endocrine-disrupting activity, have been reported. Pregnane X receptor (PXR), constitutive androstane receptor (CAR) and peroxisome proliferator-activated receptor α (PPARα), which are members of the nuclear receptor superfamily, regulate the metabolism of endogenous substrates including hormones. Therefore, we hypothesized that parabens may alter hormone-metabolizing activities by acting on these receptors, and such changes could contribute to the endocrine-disrupting activity. To test this idea, we systematically examined the effects of 17 parabens on these receptors using reporter gene assays. Nine parabens significantly activated human and rat PXR. Parabens with C2-C5 (linear and branched) side chains were most active. Butylparaben and isobutylparaben also significantly activated rat CAR. We found that long-side-chain (C7-C12) parabens showed up to 2-fold activation of PPARα at 10 µM. Furthermore, pentylparaben and hexylparaben showed rat PXR antagonistic activity and rat CAR inverse agonistic activity. The activity of butylparaben towards PXR and CAR was lost after carboxylesterase-mediated metabolism. These findings confirm that parabens influence the activities of PXR, CAR and PPARα, and thus have the potential to contribute to endocrine disruption by altering hormone metabolism.


Assuntos
PPAR alfa/metabolismo , Parabenos/farmacologia , Receptor de Pregnano X/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Ativação Transcricional/efeitos dos fármacos , Animais , Agonismo Inverso de Drogas , Humanos , Masculino , Microssomos Hepáticos/metabolismo , PPAR alfa/agonistas , PPAR alfa/genética , Parabenos/metabolismo , Receptor de Pregnano X/antagonistas & inibidores , Receptor de Pregnano X/genética , Ratos Sprague-Dawley , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/genética
4.
Molecules ; 24(15)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370197

RESUMO

The interaction between androgen receptor (AR) and coactivator proteins plays a critical role in AR-mediated prostate cancer (PCa) cell growth, thus its inhibition is emerging as a promising strategy for PCa treatment. To develop potent inhibitors of the AR-coactivator interaction, we have designed and synthesized a series of bis-benzamides by modifying functional groups at the N/C-terminus and side chains. A structure-activity relationship study showed that the nitro group at the N-terminus of the bis-benzamide is essential for its biological activity while the C-terminus can have either a methyl ester or a primary carboxamide. Surveying the side chains with various alkyl groups led to the identification of a potent compound 14d that exhibited antiproliferative activity (IC50 value of 16 nM) on PCa cells. In addition, biochemical studies showed that 14d exerts its anticancer activity by inhibiting the AR-PELP1 interaction and AR transactivation.


Assuntos
Benzamidas/farmacologia , Proteínas Correpressoras/química , Neoplasias da Próstata/tratamento farmacológico , Receptores Androgênicos/química , Fatores de Transcrição/química , Antagonistas de Androgênios/química , Antagonistas de Androgênios/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas Correpressoras/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Antígeno Prostático Específico/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Conformação Proteica em alfa-Hélice/efeitos dos fármacos , Mapas de Interação de Proteínas/efeitos dos fármacos , Receptores Androgênicos/efeitos dos fármacos , Relação Estrutura-Atividade , Fatores de Transcrição/genética , Ativação Transcricional/efeitos dos fármacos
5.
Endocrinology ; 160(9): 2101-2114, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31373631

RESUMO

Angiotensin II (AngII) and the mineralocorticoid receptor (MR) ligand aldosterone both contribute to cardiovascular disorders, including hypertension and adverse vascular remodeling. We previously demonstrated that AngII activates MR-mediated gene transcription in human vascular smooth muscle cells (SMCs), yet the mechanism and the impact on SMC function are unknown. Using an MR-responsive element-driven transcriptional reporter assay, we confirm that AngII induces MR transcriptional activity in vascular SMCs and endothelial cells, but not in Cos1 or human embryonic kidney-293 cells. AngII activation of MR was blocked by the MR antagonist spironolactone or eplerenone and the protein kinase C-δ (PKCδ) inhibitor rottlerin, implicating both in the mechanism. Similarly, small interfering RNA knockdown of PKCδ in SMCs prevented AngII-mediated MR activation, whereas knocking down of MR blocked both aldosterone- and AngII-induced MR function. Coimmunoprecipitation studies reveal that endogenous MR and PKCδ form a complex in SMCs that is enhanced by AngII treatment in association with increased serine phosphorylation of the MR N terminus. AngII increased mRNA expression of the SMC-MR target gene, FKBP51, via an MR-responsive element in intron 5 of the FKBP51 gene. The impact of AngII on FKBP51 reporter activity and gene expression in SMCs was inhibited by spironolactone and rottlerin. Finally, the AngII-induced increase in SMC number was also blocked by the MR antagonist spironolactone and the PKCδ inhibitor rottlerin. These data demonstrate that AngII activates MR transcriptional regulatory activity, target gene regulation, and SMC proliferation in a PKCδ-dependent manner. This new mechanism may contribute to synergy between MR and AngII in driving SMC dysfunction and to the cardiovascular benefits of MR and AngII receptor blockade in humans.


Assuntos
Angiotensina II/farmacologia , Miócitos de Músculo Liso/fisiologia , Proteína Quinase C-delta/fisiologia , Receptores de Mineralocorticoides/efeitos dos fármacos , Proliferação de Células , Células HEK293 , Humanos , Fosforilação , Receptores de Mineralocorticoides/fisiologia , Proteínas de Ligação a Tacrolimo/genética , Ativação Transcricional/efeitos dos fármacos
6.
J Agric Food Chem ; 67(33): 9286-9294, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31339733

RESUMO

Natural aryl hydrocarbon (AHR) ligands have been identified in food and herbal medicines, and they may exhibit beneficial activity in humans. In this study, white button (WB) feeding significantly decreased AHR target gene expression in the small intestine of both conventional and germ-free mice. High-performance liquid chromatography (HPLC) fractionation and ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) combined with an AHR-responsive cell-based luciferase gene reporter assay were used to isolate and characterize benzothiazole (BT) derivatives and 6-methylisoquinoline (6-MIQ) as AHR modulators from WB mushrooms. The study showed dose-dependent changes of AHR transformation determined by the cell-based luciferase gene reporter assay and transcription of CYP1A1 in human Caco-2 cells by BT derivatives and 6-MIQ. These findings suggested that WB mushroom contains new classes of natural AHR modulators and demonstrated HPLC fractionation and UHPLC-MS/MS combined with a cell-based luciferase gene reporter assay as a useful approach for isolation and characterization of the previously unidentifed AHR modulators from natural products.


Assuntos
Agaricus/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Receptores de Hidrocarboneto Arílico/genética , Animais , Benzotiazóis/química , Benzotiazóis/isolamento & purificação , Benzotiazóis/farmacologia , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Genes Reporter , Humanos , Isoquinolinas/química , Isoquinolinas/isolamento & purificação , Isoquinolinas/farmacologia , Ligantes , Camundongos , Extratos Vegetais/farmacologia , Receptores de Hidrocarboneto Arílico/metabolismo , Espectrometria de Massas em Tandem , Ativação Transcricional/efeitos dos fármacos , Verduras/química
7.
EMBO J ; 38(16): e102003, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31313851

RESUMO

Many eukaryotic proteins are regulated by modification with the ubiquitin-like protein small ubiquitin-like modifier (SUMO). This linkage is reversed by SUMO proteases, of which there are two in Saccharomyces cerevisiae, Ulp1 and Ulp2. SUMO-protein conjugation regulates transcription, but the roles of SUMO proteases in transcription remain unclear. We report that Ulp2 is recruited to transcriptionally active genes to control local polysumoylation. Mutant ulp2 cells show impaired association of RNA polymerase II (RNAPII) with, and diminished expression of, constitutively active genes and the inducible CUP1 gene. Ulp2 loss sensitizes cells to 6-azauracil, a hallmark of transcriptional elongation defects. We also describe a novel chromatin regulatory mechanism whereby histone-H2B ubiquitylation stimulates histone sumoylation, which in turn appears to inhibit nucleosome association of the Ctk1 kinase. Ctk1 phosphorylates serine-2 (S2) in the RNAPII C-terminal domain (CTD) and promotes transcript elongation. Removal of both ubiquitin and SUMO from histones is needed to overcome the impediment to S2 phosphorylation. These results suggest sequential ubiquitin-histone and SUMO-histone modifications recruit Ulp2, which removes polySUMO chains and promotes RNAPII transcription elongation.


Assuntos
Endopeptidases/metabolismo , Histonas/metabolismo , Mutação , Proteínas de Saccharomyces cerevisiae/metabolismo , Elongação da Transcrição Genética , Endopeptidases/genética , Regulação Fúngica da Expressão Gênica , Metalotioneína/genética , RNA Polimerase II/metabolismo , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética , Sumoilação , Elongação da Transcrição Genética/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Uracila/análogos & derivados , Uracila/farmacologia
8.
Int J Mol Sci ; 20(13)2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31269628

RESUMO

Low fruit and vegetable consumption and high saturated fat consumption causes elevated circulating cholesterol and are breast cancer risk factors. During cholesterol metabolism, oxysterols form that bind and activate the liver X receptors (LXRs). Oxysterols halt breast cancer cell proliferation but enhance metastatic colonization, indicating tumour suppressing and promoting roles. Phytosterols and phytostanols in plants, like cholesterol in mammals, are essential components of the plasma membrane and biochemical precursors, and in human cells can alter LXR transcriptional activity. Here, a panel of breast cancer cell lines were treated with four dietary plant sterols and a stanol, alone or in combination with oxysterols. LXR activation and repression were measured by gene expression and LXR-luciferase reporter assays. Oxysterols activated LXR in all cell lines, but surprisingly phytosterols failed to modulate LXR activity. However, phytosterols significantly inhibited the ability of oxysterols to drive LXR transcription. These data support a role for phytosterols in modulating cancer cell behaviour via LXR, and therefore suggest merit in accurate dietary recordings of these molecules in cancer patients during treatment and perhaps supplementation to benefit recovery.


Assuntos
Neoplasias da Mama/genética , Receptores X do Fígado/genética , Oxisteróis/metabolismo , Fitosteróis/farmacologia , Ativação Transcricional/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Receptores X do Fígado/metabolismo
9.
Future Microbiol ; 14: 749-755, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31271060

RESUMO

Aim: Antibiotic resistance in Mycobacterium abscessus renders treatment poorly effective. Despite erm(41)-gene-mediated macrolide resistance, treatment with azithromycin or clarithromycin is recommended. It is contested whether macrolides differ in erm(41) induction. We determine whether this is the case. Methods: M. abscessus CIP104536 was used. Minimum inhibitory concentrations of clarithromycin and azithromycin were determined. Time-kill kinetics of M. abscessus exposed to azithromycin or clarithromycin were performed and RNA was isolated at predetermined intervals for erm(41) quantification. Results: Minimum inhibitory concentrations increased >30-fold. Time-kill kinetics showed a temporary bacteriostatic effect, abrogated by induced resistance. Erm(41) expression was increased following exposure to either macrolide for 7 days. Conclusion: Both macrolides induce resistance similarly, and this should not be an argument in choosing either macrolide for therapy.


Assuntos
Antibacterianos/farmacologia , Azitromicina/farmacologia , Claritromicina/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Mycobacterium abscessus/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Perfilação da Expressão Gênica , Macrolídeos/farmacologia , Testes de Sensibilidade Microbiana , RNA Bacteriano/análise , RNA Mensageiro/análise
10.
Eur J Pharmacol ; 859: 172546, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31319068

RESUMO

Ginsenoside Rb1 (Rb1), a major component of ginseng, has a steroidal chemical structure, implying that it exerts sex hormone-like actions. Recent studies have been suggested cardioprotective actions of Rb1. However, the actions of Rb1 in vascular calcification, one of the significant pathological features associated with aging and atherosclerosis, have not been examined. In the present study, we examined the effects of Rb1 on vascular calcification, focusing on its androgen-like actions. Using inorganic phosphate (Pi)-induced calcification of vascular smooth muscle cells (VSMC), we found that Rb1, like testosterone, significantly inhibited calcium deposition in a concentration-dependent manner. Further, this inhibition of Rb1 was abolished by bicalutamide, an androgen receptor antagonist, but not by MPP or PHTPP, estrogen receptor α or ß antagonists. Rb1 significantly inhibited apoptosis, one of the regulatory mechanisms of calcification, and restored growth arrest-specific gene 6 (Gas6) expression that was suppressed by Pi. Moreover, Rb1 transactivated Gas6, and proximal androgen-responsive element (ARE) of the promoter region was found to be crucial for Gas6 transactivation. In contrast, in a human prostate cancer cell line, testosterone-induced ARE activity was abrogated by Rb1. This antagonistic effect was also confirmed by the transrepression and downregulation of prostate-specific antigen in the presence of testosterone and Rb1 together. Thus, these findings provide a novel mechanistic insight into the vasculoprotective actions of Rb1 as a selective androgen receptor modulator, i.e., inhibitory effects on VSMC calcification through androgen receptor-mediated Gas6 transactivation and antagonistic effects in prostate cancer cells.


Assuntos
Ginsenosídeos/farmacologia , Receptores Androgênicos/metabolismo , Calcificação Vascular/tratamento farmacológico , Calcificação Vascular/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Ginsenosídeos/uso terapêutico , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Antígeno Prostático Específico/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ativação Transcricional/efeitos dos fármacos , Calcificação Vascular/genética , Adulto Jovem
11.
Eur J Pharmacol ; 859: 172517, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31265843

RESUMO

Tissue factor (TF) is the primary cause of atherothrombosis, the rupture of atherosclerotic plaques with subsequent thrombosis, leading to acute cardiovascular events, such as myocardial infarction and stroke. Wogonin (Wog) is an active component of Scutellaria baicalensis, used for inflammatory diseases, atherosclerosis, and hyperlipidemia. The anticoagulant effect of Wog on TF expression remains unexplored. In this study, we have investigated the effects of Wog on TF gene expression and its underlying molecular mechanism in human vascular endothelial cells (ECs). We found that Wog dose-dependently inhibited PMA-enhanced TF mRNA, protein, and activity in ECs. This inhibition was attributed to its decreasing nuclear accumulations of transcription factors, phospho-c-Jun and early growth response-1(Egr-1), not nuclear factor-κB (NF-κB), through blocking extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways. Reduction by Wog of Egr-1 nuclear level and Egr-1/DNA binding activity was associated with its inhibition of Egr-1 de novo synthesis. Wog as well as inhibitors to ERK and JNK suppressed TF promoter activity and protein expression in reporter gene and Western blot analyses. Furthermore, it also exhibited anticoagulant function by inhibiting TF expression and activity in tumor necrosis factor-alpha (TNF-α)- and lipopolysaccharide (LPS)-treated ECs and THP-1 cells. These results suggest that Wog inhibits ERK/Egr-1- and JNK/AP-1-mediated transactivation of TF promoter activity, leading to downregulation of TF expression and activity induced by inflammatory mediators. Wog targeting pathological TF expression without affecting its basal level may be a safer templet in the development of anticoagulant agent for cardiovascular thrombotic diseases related to atherothrombosis.


Assuntos
Anticoagulantes/farmacologia , Flavanonas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Tromboplastina/genética , Proteína 1 de Resposta de Crescimento Precoce/biossíntese , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Tromboplastina/metabolismo , Ativação Transcricional/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
12.
Biotechnol Lett ; 41(8-9): 921-928, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31286325

RESUMO

OBJECTIVES: To enhance the productivity of foreign protein in culture cells using baculovirus expression system. RESULTS: A low concentration of MßCD, with the optimal application concentration of 0.25 mM and the appropriate preincubation time range from 10 to 120 min, can efficiently enhance expression levels in both the AcMNPV and BmNPV expression systems. CONCLUSIONS: Preincubation with a low concentration MßCD enhance baculovirus infection and foreign protein expression productivity.


Assuntos
Expressão Gênica/efeitos dos fármacos , Proteínas Recombinantes/biossíntese , Ativação Transcricional/efeitos dos fármacos , beta-Ciclodextrinas/metabolismo , Vetores Genéticos
13.
Food Chem Toxicol ; 131: 110532, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31154085

RESUMO

Pyrrolizidine alkaloids (PAs) are secondary metabolites from plants that have been found in substantial amounts in herbal supplements, infusions and teas. Several PAs cause cancer in animal bioassays, mediated via a genotoxic mode of action, but for the majority of the PAs, carcinogenicity data are lacking. It is assumed in the risk assessment that all PAs have the same potency as riddelliine, which is considered to be one of the most potent carcinogenic PAs in rats. This may overestimate the risks, since many PAs are expected to have lower potencies. In this study we determined the concentration-dependent genotoxicity of 37 PAs representing different chemical classes using the γH2AX in cell western assay in HepaRG human liver cells. Based on these in vitro data, PAs were grouped into different potency classes. The group with the highest potency consists particularly of open diester PAs and cyclic diester PAs (including riddelliine). The group of the least potent or non-active PAs includes the monoester PAs, non-esterified necine bases, PA N-oxides, and the unsaturated PA trachelanthamine. This study reveals differences in in vitro genotoxic potencies of PAs, supporting that the assumption that all PAs have a similar potency as riddelliine is rather conservative.


Assuntos
Histonas/metabolismo , Mutagênicos/toxicidade , Alcaloides de Pirrolizidina/toxicidade , Bioensaio , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Histonas/genética , Humanos , Internet , Modelos Biológicos , Alcaloides de Pirrolizidina/classificação , Ativação Transcricional/efeitos dos fármacos
14.
Life Sci ; 231: 116551, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31185236

RESUMO

Octreotide (OCT) shows clinical efficacies in the treatment of liver cirrhosis complicated with gastrointestinal hemorrhage. Experiments were designed to investigate its function mechanism associated with endoplasmic reticulum stress (ERS)-induced autophagy and microRNA (miR). Protein associated with ERS and autophagy was detected by western blot. miR-101 was examined by qRT-PCR. Besides, miR-101 or G protein-coupled receptor 78 (GPR78)-silenced Caco-2 cells were established by transfection. Furthermore, western blot was used to determine TGF-beta activated kinase 1 (TAK1), AMPK, mTOR, p70S6K as well as their phosphorylated forms. Lipopolysaccharide (LPS) enforced the expression of GPR78. Besides, LPS triggered the production of Beclin-1 and LC3-II while mitigated the accumulation of p62. Then all these above results were reversed by OCT pretreatment. Moreover, miR-101 expression was downregulated by LPS while upregulated by OCT. Further, miR-101 knockdown strengthened ERS and promoted autophagy. GPR78 silence retarded autophagy process. In the end, OCT mitigated phosphorylation of TAK1, AMPK while enhanced the phosphorylated expression of mTOR and p70S6K in LPS-treated Caco-2 cells. The anti-autophagy property of OCT was mediated by miR-101-induced suppression of GPR78 in LPS-treated Caco-2 cells.


Assuntos
Estresse do Retículo Endoplasmático/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , MicroRNAs/metabolismo , Octreotida/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Proteína Beclina-1/genética , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Estresse do Retículo Endoplasmático/fisiologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Lipopolissacarídeos/farmacologia , MicroRNAs/genética , Octreotida/metabolismo , Fosforilação , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
15.
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
16.
Life Sci ; 231: 116559, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31200001

RESUMO

AIM: Previously, we reported that mice deficient in most of the Zfp521 coding region (Zfp521Δ/Δ mice) displayed abnormal behaviors, including hyperlocomotion and lower anxiety. In this study, we aimed to elucidate the involvement and mechanisms of monoamine variation. MAIN METHODS: First, we compared the levels of dopamine (DA), noradrenaline (NA), and serotonin in the brains of Zfp521Δ/Δ and Zfp521+/+ mice using enzyme-linked immunosorbent assay. Next, we elucidated the mechanisms using quantitative PCR and Western Blotting. Additionally, we administered inhibitory drug to the mice and performed behavioral tests. KEY FINDINGS: Our results showed that the DA level decreased and the NA level increased in Zfp521Δ/Δ mice. We found that ZFP521 suppresses the expression of dopamine ß-hydroxylase (DBH), which converts DA into NA. We also demonstrated that paired homeodomain transcription factor 2 and early growth response protein-1, which are the transcription factors for Dbh, were involved in the upregulation of Dbh by ZFP521. The administration of nepicastat, a specific inhibitor of DBH, attenuated the abnormal behaviors of Zfp521Δ/Δ mice. SIGNIFICANCE: These results suggest that the lack of ZFP521 upregulates the expression of DBH, which leads to a decrease in the DA level and an increase in the NA level in the brain, resulting in abnormal behaviors.


Assuntos
Comportamento Animal/fisiologia , Encéfalo/metabolismo , Dopamina beta-Hidroxilase/metabolismo , Fatores de Transcrição/deficiência , Animais , Encéfalo/enzimologia , Linhagem Celular Tumoral , Dopamina/metabolismo , Imidazóis/farmacologia , Locomoção/efeitos dos fármacos , Locus Cerúleo/efeitos dos fármacos , Masculino , Camundongos , Camundongos Knockout , Norepinefrina/metabolismo , Serotonina/metabolismo , Tionas/farmacologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Dedos de Zinco
17.
Ecotoxicol Environ Saf ; 181: 463-471, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31228822

RESUMO

To assess the effect of exposure to persistent organic pollutants (POPs) on the estrogen receptor (ER) signaling pathway in Baikal seals (Pusa sibirica), we investigated the molecular characterizations and functions of two Baikal seal ER (bsER) isoforms, bsERα and bsERß. The bsERα and bsERß cDNA clones isolated have an open reading frame of 595 and 530 amino acid residues, respectively. The tissue distribution analyses of bsER mRNAs showed that bsERα transcripts were primarily found in the ovary and uterus, and bsERß in the muscle in wild Baikal seals. The immunofluorescence staining assay showed that 17ß-estradiol (E2) treatment promoted the nuclear translocation of in vitro-expressed bsERα. Transient transfection of bsERα in U2OS cells enhanced the transcription of pS2, an ER target gene of E2. We then measured bsER-mediated transactivation potencies of POPs in an in vitro reporter gene assay system, in which a bsERα or bsERß expression vector was transfected into COS-1 cells. For comparison, transactivation potencies of POPs on mouse ERs (mERα and mERß) were also evaluated in the same manner. Results showed significant dose-dependent responses of bsERs and mERs when treated with p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE). bsERs and mERs showed no response when exposed to polychlorinated biphenyls (PCBs) or 2,3,7,8-tetrachlorodibenzo-p-dioxin. Comparison of the dose-response curves of DDTs across species (bsERs vs. mERs) showed that bsERα had a response similar to mERα, but bsERß was less sensitive than mERß. Comparing the lowest observable effective concentrations of p,p'-DDT (2.8 µM) and p,p'-DDE (10 µM) for in vitro bsERα-mediated transactivation with their hepatic concentrations in wild Baikal seals indicated that some individuals accumulated these compounds at levels comparable to the effective concentrations, suggesting the potential disruption of the bsERα signaling pathway in the wild population by these compounds. Co-transfection experiments with bsER and the aryl hydrocarbon receptor (AHR) suggested that high accumulation of estrogenic compounds exerts a synergistic effect with dioxin-like congeners on ER signaling through AHR activation in the wild seal population.


Assuntos
Dioxinas e Compostos Semelhantes a Dioxinas/toxicidade , Poluentes Ambientais/toxicidade , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Ativação Transcricional/efeitos dos fármacos , Animais , Dioxinas e Compostos Semelhantes a Dioxinas/metabolismo , Poluentes Ambientais/metabolismo , Feminino , Camundongos , RNA Mensageiro/metabolismo , Focas Verdadeiras
18.
Life Sci ; 231: 116589, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31226416

RESUMO

AIMS: Despite the protective effect of galacto-oligosaccharides (GOS) on human colon has been widely-reported, the mechanism of its beneficial effect is still unclear. This paper aims to reveal the internal mechanism underlined the anti-colitis effect of GOS by studying its regulatory effect on miRNAs. MAIN METHODS: An in vitro model of colitis was constructed by using human colon epithelial FHC cells and lipopolysaccharide (LPS). An in vivo colitis model was established as well, by injecting Rag2-/- Sprague-Dawley (SD) rats with helicobacter hepaticus. The effects of GOS pre-treatment on these two models were tested, and the miRNAs involved in these effects were studied. KEY FINDINGS: The expression of miR-19b, miR-590-5p and miR-495 was up-regulated, and the expression of miR-29a, miR-31 and miR-142-5p was down-regulated by GOS treatment in both normal and LPS-stimulated FHC cells. Among which, miR-19b was the most varied miRNA. GOS pre-treatment significantly attenuated LPS-induced cell injury, as evidenced by the increase of cell viability, the decrease of apoptosis, as well as the suppressed release of TNF-α, IFN-γ and IL-1ß. GOS pre-treatment could also prevent Rag2-/- rats against helicobacter hepaticus injection induced diarrhea and inflammation, as the body weight and colon organ weight were recovered, diarrhea score was declined, and the release of pro-inflammatory cytokines was inhibited. The in vitro and in vivo effects of GOS abovementioned were all impeded when miR-19b was silenced. SIGNIFICANCE: In vitro and in vivo experiments showed that GOS have certain anti-colitis effect, and this effect may be achieved by up-regulating miR-19b.


Assuntos
MicroRNAs/genética , Oligossacarídeos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Colite/genética , Colite/fisiopatologia , Colo/efeitos dos fármacos , Colo/metabolismo , Citocinas/metabolismo , Células Epiteliais/efeitos dos fármacos , Feminino , Humanos , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , MicroRNAs/metabolismo , Oligossacarídeos/metabolismo , Ratos , Ratos Sprague-Dawley , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima
19.
Int J Mol Sci ; 20(12)2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31226734

RESUMO

Vitamin K is classified into three homologs depending on the side-chain structure, with 2-methyl-1,4-naphthoqumone as the basic skeleton. These homologs are vitamin K1 (phylloquinone: PK), derived from plants with a phythyl side chain; vitamin K2 (menaquinone-n: MK-n), derived from intestinal bacteria with an isoprene side chain; and vitamin K3 (menadione: MD), a synthetic product without a side chain. Vitamin K homologs have physiological effects, including in blood coagulation and in osteogenic activity via γ-glutamyl carboxylase and are used clinically. Recent studies have revealed that vitamin K homologs are converted to MK-4 by the UbiA prenyltransferase domain-containing protein 1 (UBIAD1) in vivo and accumulate in all tissues. Although vitamin K is considered to have important physiological effects, its precise activities and mechanisms largely remain unclear. Recent research on vitamin K has suggested various new roles, such as transcriptional activity as an agonist of steroid and xenobiotic nuclear receptor and differentiation-inducing activity in neural stem cells. In this review, we describe synthetic ligands based on vitamin K and exhibit that the strength of biological activity can be controlled by modification of the side chain part.


Assuntos
Neurogênese/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Vitamina K/análogos & derivados , Vitamina K/farmacologia , Vitaminas/química , Vitaminas/farmacologia , Animais , Humanos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Receptor de Pregnano X/metabolismo
20.
Environ Toxicol ; 34(10): 1094-1104, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31199065

RESUMO

Fine particulate matter (PM2.5 ) is an important environmental risk factor for cardiovascular diseases. However, little is known about the effects of PM2.5 on arteries. The present study investigated whether PM2.5 alters 5-hydroxytryptamine (5-HT) receptor expression and inflammatory mediators on rat mesenteric arteries, and examined the underlying mechanisms. Isolated rat mesenteric arteries segments were cultured with PM2.5 in the presence or absence of ERK1/2, JNK, and p38 pathway inhibitors. Contractile reactivity was monitored by a sensitive myograph. The expression of 5-HT2A/1B receptors and inflammatory mediators were studied by a real-time polymerase chain reaction and/or by immunohistochemistry. The phosphorylation of mitogen-activated protein kinases (MAPK) pathway was detected by Western blot. Compared with the fresh or culture alone groups, 1.0 µg/mL PM2.5 cultured for 16 hours significantly enhanced contractile response induced by 5-HT and increased 5-HT2A receptor mRNA and protein expressions, indicating PM2.5 upregulates 5-HT2A receptor. SB203580 (p38 inhibitor) and U0126 (ERK1/2 inhibitor) significantly decreased PM2.5 -induced elevated contraction and mRNA and protein expression of 5-HT2A receptor. Cultured with PM2.5 significantly increased the mRNA expression of inflammatory mediators (NOS2, IL-1ß, and TNF-α), while SB203580 decreased mRNA expression level of NOS2, IL-1ß, and TNF-α. SP600125 (JNK inhibitor) decreased mRNA expression level of TNF-α and IL-1ß. After PM2.5 exposure, the phosphorylation of p38 and ERK1/2 protein were increased. SB203580 and U0126 inhibited the PM2.5 caused increased phosphorylation protein of p38 and ERK1/2. In conclusion, PM2.5 induces inflammatory-mediated MAPK pathway in artery which subsequently results in enhanced vascular contraction responding to 5-HT via the upregulated 5-HT2A receptors.


Assuntos
Artérias Mesentéricas/imunologia , Proteínas Quinases Ativadas por Mitógeno/imunologia , Material Particulado/toxicidade , Receptor 5-HT2A de Serotonina/imunologia , Animais , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Artérias Mesentéricas/efeitos dos fármacos , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/imunologia , Proteínas Quinases Ativadas por Mitógeno/genética , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina/genética , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Regulação para Cima , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA