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1.
Clin Child Psychol Psychiatry ; 28(3): 877-894, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36125333

RESUMO

INTRODUCTION: Child-centered play therapy (CCPT) is a practical and recommended non-medication intervention for children with Attention-deficit/hyperactivity disorder (ADHD) but the mechanism in between is unclear. AIM: This study proposed to examine the effectiveness of CCPT on neuropsychological deficits and behavioral symptoms in ADHD. METHODS: Participants with ADHD diagnosis were referred from senior child and adolescent psychiatrists, and typical developmental children (TD) were recruited from community as a control group. All participants' executive functions were evaluated using Cambridge Neuropsychological Test Automated Battery. First of all, the participants were evaluated using Child Behavior Checklist (CBCL) by their parents. The ADHD participants were assigned into CCPT (ADHDc) and waitlist (ADHDw) group; and the ADHDc group then received CCPT weekly for 12 sessions, while the ADHDw continuously received their regular treatment (i.e., medication treatment or other alternative treatments) as usual. RESULTS: Total 52 participants were recruited (17 with ADHD and 35 typically developed children, TD). The results showed that overall the ADHD groups had worse neuropsychological performance and more behavioural disturbance than did the TD (ps < .05). After receiving the CCPT, the results showed that the ADHDc group had significant improvement in the cognitive flexibility (p < .05); while the ADHDw group had no changes.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Adolescente , Humanos , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Função Executiva , Ludoterapia , Transtornos de Deficit da Atenção e do Comportamento Disruptivo , Pais
2.
J Pharm Pharmacol ; 70(9): 1253-1261, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29943490

RESUMO

OBJECTIVES: Hypercholesterolaemia is a major risk factor for developing atherosclerosis. Increased consumption of fruits and vegetables is recommended to hypercholesterolaemic patients. In this study, the hypocholesterolaemic effect of apigenin and luteolin was evaluated in a hamster model. METHODS: Hamsters were put on a high-cholesterol diet for 9 weeks, and apigenin or luteolin was administered in the diet at 60 and 300 ppm. KEY FINDINGS: Both apigenin and luteolin supplementations could attenuate the aorta plaque formation by 30% and 20%, respectively. Apigenin-fed hamsters at both dosages displayed a 1.5-fold increase in hepatic Ldlr expression and a 40% reduction in non-HDL cholesterol level as compared with those in the control fed a high-cholesterol (HC) diet. Besides, faecal elimination of cholesterol was facilitated by 20% in the hamsters with high apigenin consumption. Suppressing the expression of the cholesterol transporter ncp1l1 in the intestinal mucosa could block the cholesterol absorption and promote its elimination. The differential regulations of ncp1l1 and Ldlr appeared to be the underlying hypocholesterolaemic mechanism of apigenin in this model system. Luteolin supplementation, on the other hand, had no effect on the blood cholesterol. CONCLUSIONS: This study illustrated that dietary administration of apigenin attenuated HC feeding-induced hypercholesterolemia in hamsters.


Assuntos
Apigenina/administração & dosagem , Colesterol na Dieta/efeitos adversos , Hipercolesterolemia/etiologia , Hipercolesterolemia/prevenção & controle , Animais , Cricetinae , Hipercolesterolemia/sangue , Masculino , Mesocricetus
3.
Age Ageing ; 47(5): 714-720, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29796607

RESUMO

Objective: to examine the associations of cardiovascular disease (CVD) and cardiovascular risk factors with frailty. Design: a cross-sectional study. Setting: the Irish Longitudinal Study on Ageing (TILDA). Participants: frailty measures were obtained on 5,618 participants and a subset of 4,330 participants with no prior history of CVD. Exposures for observational study: cardiovascular risk factors were combined in three composite CVD risk scores (Systematic Coronary Risk Evaluation [SCORE], Ideal Cardiovascular Health [ICH] and Cardiovascular Health Metrics [CHM]). Main outcome measures: a frailty index (40-items) was used to screen for frailty. Methods: the associations of CVD risk factors with frailty were examined using logistic regression. Results: overall, 16.4% of participants had frailty (7.6% at 50-59 years to 42.5% at 80+ years), and the prevalence was higher in those with versus those without prior CVD (43.0% vs. 10.7%). Among those without prior CVD, mean levels of CVD risk factors were closely correlated with higher frailty index scores. Combined CVD risk factors, assessed using SCORE, were linearly and positively associated with frailty. Compared to low-to-moderate SCOREs, the odds ratio (OR) (95% confidence interval, CI) of frailty for those with very high risk was 3.18 (2.38-4.25). Conversely, ICH was linearly and inversely associated with frailty, with an OR for optimal health of 0.29 (0.21-0.40) compared with inadequate health. Conclusions: the concordant positive associations of SCORE and inverse associations of ICH and CHM with frailty highlight the potential importance of optimum levels of CVD risk factors for prevention of disability in frail older people.


Assuntos
Doenças Cardiovasculares/economia , Doenças Cardiovasculares/terapia , Prestação Integrada de Cuidados de Saúde , Idoso Fragilizado , Fragilidade/terapia , Medicina Geral , Atenção Primária à Saúde , Atividades Cotidianas , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Ensaios Clínicos Controlados como Assunto , Análise Custo-Benefício , Estudos Transversais , Prestação Integrada de Cuidados de Saúde/economia , Feminino , Fragilidade/diagnóstico , Fragilidade/economia , Fragilidade/epidemiologia , Medicina Geral/economia , Custos de Cuidados de Saúde , Humanos , Masculino , Países Baixos/epidemiologia , Atenção Primária à Saúde/economia , Prognóstico , Qualidade de Vida , Medição de Risco , Fatores de Risco , Comportamento Social
4.
Biomed Pharmacother ; 96: 1000-1007, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29198743

RESUMO

Hypercholesterolemia is a major risk factor in the development of atherosclerosis. High blood cholesterol can be the result of increased biosynthesis or reduced elimination of cholesterol in the system. Increased consumption of fruits and vegetables is recommended for patients suffering from hypercholesterolemia. The plant food flavones apigenin and luteolin have previously been shown to suppress the synthesis of cholesterol in human hepatocytes. The effectiveness of these two flavones in controlling blood cholesterol was examined in a mouse model in the present study. Mice were fed a high-fat diet and apigenin or luteolin at 50 and 250 ppm was mixed in the diet. After 8 weeks of treatment, the administration of 250 ppm apigenin or 250 ppm luteolin could modulate the total and serum non-HDL cholesterol. The expressions of srebf-2 mRNA, Srebp-2 protein and Hmgcr protein were decreased in the livers of apigenin-treated mice; meanwhile, AMPK was activated in this group of mice. In contrast, suppressed ncp1l1 and induced abcg-5/8 mRNA expressions were seen in the intestinal mucosa of luteolin-fed animals. Increased fecal cholesterol content was also observed in the luteolin-treated mice. These results revealed that apigenin suppressed the biosynthesis of cholesterol, whereas luteolin promoted the elimination of cholesterol. In summary, this study illustrated that the two flavones could attenuate high-fat feeding-induced hypercholesterolemia in two different mechanisms.


Assuntos
Anticolesterolemiantes/farmacologia , Apigenina/farmacologia , Dieta Hiperlipídica/efeitos adversos , Luteolina/farmacologia , Animais , Colesterol/sangue , Flavonas/farmacologia , Hepatócitos/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo
5.
Mol Cell Biochem ; 424(1-2): 163-172, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27778136

RESUMO

Consumption of fruits and vegetables is generally regarded as beneficial to plasma lipid profile. The mechanism by which the plant foods induce desirable lipid changes remains unclear. SREBP-2 is crucial in cholesterol metabolism, and it is a major regulator of the cholesterol biosynthesis enzyme HMGCR. Our lab has previously illustrated that apigenin and luteolin could attenuate the nuclear translocation of SREBP-2 through an AMPK-dependent pathway. In the present study, these two flavones were studied for their ability to deter the same in an AMPK-independent signaling route. The processing of SREBP-2 protein was promoted by phorbol 12-myristate 13-acetate (PMA) in the hepatic cells WRL and HepG2, and the increased processing was reversed by apigenin or luteolin co-administration. EMSA results demonstrated that the PMA-induced DNA-binding activity was weakened by the flavones. The increased amount of nuclear SREBP-2 in cells was attenuated by the flavonoid as shown by immunocytochemical imaging. Quantitative reverse transcriptase-polymerase chain reaction assay demonstrated that the transcription of HMGCR under both flavone treatments was reduced. However, apigenin appeared to be stronger than luteolin in restraining PMA-induced HMGCR mRNA expression. Since PMA is a diacylglycerol analog, these findings might have some physiological implications.


Assuntos
Apigenina/farmacologia , Suplementos Nutricionais , Fígado/metabolismo , Luteolina/farmacologia , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Acetato de Tetradecanoilforbol/toxicidade , Proteínas Quinases Ativadas por AMP/metabolismo , Células Hep G2 , Humanos , Hidroximetilglutaril-CoA Redutases/metabolismo
6.
Int J Biochem Cell Biol ; 75: 1-10, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27032751

RESUMO

Sterol regulatory element-binding protein (SREBP)-2 is a pivotal transcriptional factor in cholesterol metabolism. Factors interfering with the proper functioning of SREBP-2 potentially alter plasma lipid profiles. Phorbol 12-myristate 13-acetate (PMA), which is a common protein kinase C (PKC) activator, was shown to promote the post-translational processing and nuclear translocation of SREBP-2 in hepatic cells in the current study. Following SREBP-2 translocation, the transcripts of its target genes HMGCR and LDLR were upregulated as demonstrated by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Electrophoretic mobility shift assays (EMSA) also demonstrated an induced DNA-binding activity on the sterol response element (SRE) domain under PMA treatment. The increase of activated Srebp-2 without the concurrent induced mRNA expression was also observed in an animal model. As the expression of SREBP-2 was not increased by PMA, the activation of PKC was the focus of investigation. Specific PKC isozyme inhibition and overexpression supported that PKCß was responsible for the promoting effect. Further studies showed that the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinases (JNK), but not 5' adenosine monophosphate-activated protein kinase (AMPK), were the possible downstream signaling proteins of PKCß. In conclusion, this study illustrated that PKCß increased SREBP-2 nuclear translocation in a pathway mediated by MEK/ERK and JNK, rather than the one dictated by AMPK. These results revealed a novel signaling target of PKCß in the liver cells.


Assuntos
Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hidroximetilglutaril-CoA Redutases/genética , Proteínas Quinases/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de LDL/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/química
7.
PLoS One ; 10(8): e0135637, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26302339

RESUMO

High blood cholesterol has been associated with cardiovascular diseases. The enzyme HMG CoA reductase (HMGCR) is responsible for cholesterol synthesis, and inhibitors of this enzyme (statins) have been used clinically to control blood cholesterol. Sterol regulatory element binding protein (SREBP) -2 is a key transcription factor in cholesterol metabolism, and HMGCR is a target gene of SREBP-2. Attenuating SREBP-2 activity could potentially minimize the expression of HMGCR. Luteolin is a flavone that is commonly detected in plant foods. In the present study, Luteolin suppressed the expression of SREBP-2 at concentrations as low as 1 µM in the hepatic cell lines WRL and HepG2. This flavone also prevented the nuclear translocation of SREBP-2. Post-translational processing of SREBP-2 protein was required for nuclear translocation. Luteolin partially blocked this activation route through increased AMP kinase (AMPK) activation. At the transcriptional level, the mRNA and protein expression of SREBP-2 were reduced through luteolin. A reporter gene assay also verified that the transcription of SREBF2 was weakened in response to this flavone. The reduced expression and protein processing of SREBP-2 resulted in decreased nuclear translocation. Thus, the transcription of HMGCR was also decreased after luteolin treatment. In summary, the results of the present study showed that luteolin modulates HMGCR transcription by decreasing the expression and nuclear translocation of SREBP-2.


Assuntos
Doenças Cardiovasculares/tratamento farmacológico , Hidroximetilglutaril-CoA Redutases/biossíntese , Luteolina/administração & dosagem , Proteína de Ligação a Elemento Regulador de Esterol 2/biossíntese , Adenilato Quinase/genética , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Hidroximetilglutaril-CoA Redutases/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , RNA Mensageiro/biossíntese , Proteína de Ligação a Elemento Regulador de Esterol 2/genética
8.
Br J Nutr ; 113(12): 1844-52, 2015 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-25978649

RESUMO

Sterol regulatory element-binding protein-2 (SREBP-2) is a pivotal transcriptional factor in cholesterol metabolism. Factors interfering with the proper functioning of SREBP-2 potentially alter plasma lipid concentrations. Consuming fruits and vegetables is associated with beneficial plasma lipid profile. The mechanism by which plant foods induce desirable lipid changes remains unclear. Apigenin, a common plant food flavonoid, was shown to modulate the nuclear translocation of SREBP-2 in the hepatic cells WRL-68 in the present study. The processing of SREBP-2 protein occurred after translation, and apigenin blocked this activation route. Further examination indicated that AMP-activated protein kinase (AMPK) was activated by the flavone, and co-administrating the AMPK-specific inhibitor compound C could release the blockage. Reporter gene assay revealed that the transactivation of sterol responsive element (SRE)-containing 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) promoter was suppressed by the flavone. Similarly, electromobility shift assay result also demonstrated a reduced DNA-binding activity on the SRE domain under the same treatment. The reduced transactivity and DNA-binding activity could be attributed to a decreased amount of SREBP-2 translocating from cytosol to nucleus as depicted by confocal microscopy. Quantitative RT-PCR assay demonstrated that the transcription of HMGCR followed the same pattern of SREBP-2 translocation. In summary, the present study showed that apigenin prevented SREBP-2 translocation and reduced the downstream gene HMGCR transcription. The minimum effective dosage should be achievable in the form of functional food consumption or dietary supplementation.


Assuntos
Apigenina/farmacologia , Núcleo Celular/efeitos dos fármacos , Fígado/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Transporte Biológico/efeitos dos fármacos , Linhagem Celular , Núcleo Celular/química , Citosol/química , Ativação Enzimática/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Genes Reporter , Humanos , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Sintase/genética , Imuno-Histoquímica , Fígado/metabolismo , Fígado/ultraestrutura , Luciferases/genética , Luciferases/metabolismo , Fragmentos de Peptídeos/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Proteínas Quinases/metabolismo , Esqualeno Mono-Oxigenase/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/análise
9.
J Pharmacol Exp Ther ; 351(2): 270-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25138022

RESUMO

Aromatase inhibitors (AIs) have been used as adjuvant therapeutic agents for breast cancer. Their adverse side effect on blood lipid is well documented. Some natural compounds have been shown to be potential AIs. In the present study, we compared the efficacy of the flavonoid luteolin to the clinically approved AI letrozole (Femara; Novartis Pharmaceuticals, East Hanover, NJ) in a cell and a mouse model. In the in vitro experimental results for aromatase inhibition, the Ki values of luteolin and letrozole were estimated to be 2.44 µM and 0.41 nM, respectively. Both letrozole and luteolin appeared to be competitive inhibitors. Subsequently, an animal model was used for the comparison. Aromatase-expressing MCF-7 cells were transplanted into ovariectomized athymic mice. Luteolin was given by mouth at 5, 20, and 50 mg/kg, whereas letrozole was administered by intravenous injection. Similar to letrozole, luteolin administration reduced plasma estrogen concentrations and suppressed the xenograft proliferation. The regulation of cell cycle and apoptotic proteins-such as a decrease in the expression of Bcl-xL, cyclin-A/D1/E, CDK2/4, and increase in that of Bax-was about the same in both treatments. The most significant disparity was on blood lipids. In contrast to letrozole, luteolin increased fasting plasma high-density lipoprotein concentrations and produced a desirable blood lipid profile. These results suggested that the flavonoid could be a coadjuvant therapeutic agent without impairing the action of AIs.


Assuntos
Inibidores da Aromatase/farmacologia , Luteolina/farmacologia , Nitrilas/farmacologia , Triazóis/farmacologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Estradiol/sangue , Feminino , Letrozol , Lipoproteínas HDL/sangue , Células MCF-7 , Camundongos , Camundongos Nus
10.
Chem Biol Interact ; 221: 70-6, 2014 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-25110319

RESUMO

Licorice is derived from the rhizomes of Glycyrrhiza glabra. It has been used for confectioneries or culinary purposes. The rhizomes contain many flavonoidal compounds that have been shown to be biologically active. In the present study, effect of the licorice flavonoid isoliquiritigenin (ILN) on polycyclic aromatic hydrocarbon (PAH)-induced XRE transactivation and the downstream expression were investigated in MCF-7 cells. The environmental toxicant PAHs are pro-carcinogens and are biotransformed into their ultimate genotoxic structures by cytochrome P450 (CYP) 1 enzymes. Reporter gene assay revealed that ILN reduced XRE transactivation triggered by 7,12-dimethylbenz[α]anthracene (DMBA) or 2,3,7,8-Tetrachlorodibenzodioxin (TCDD). Our EMSA results also demonstrated that the flavonoid diminished DMBA-induced XRE binding. The reduced transactivation could be the result of a decreased amount of AhR translocating from cytosol to nucleus as shown in Western analysis. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay demonstrated that expressions of genes with XRE-containing promoters, including CYP1A1, 1A2, and 1B1, followed the same pattern of XRE transactivation. The present study illustrated that ILN might downregulate PAH-induced expressions through antagonizing AhR translocation.


Assuntos
Chalconas/farmacologia , DNA/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , DNA/química , Regulação para Baixo/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Ativação Enzimática/efeitos dos fármacos , Flavonoides/farmacologia , Glycyrrhiza/química , Humanos , Células MCF-7 , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Hidrocarboneto Arílico/química
11.
BMC Cancer ; 14: 426, 2014 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-24923427

RESUMO

BACKGROUND: Breast cancer is one of the most deadly diseases in women. Inhibiting the synthesis of estrogen is effective in treating patients with estrogen-responsive breast cancer. Previous studies have demonstrated that use of cyclooxygenase (COX) inhibitors is associated with reduced breast cancer risk. METHODS: In the present study, we employed an established mouse model for postmenopausal breast cancer to evaluate the potential mechanisms of the COX-2 inhibitor celecoxib. Aromatase-expressing MCF-7 cells were transplanted into ovariectomized athymic mice. The animals were given celecoxib at 1500 ppm or aspirin at 200 ppm by oral administration with androstenedione injection. RESULTS: Our results showed that both COX inhibitors could suppress the cancer xenograft growth without changing the plasma estrogen level. Protein expression of ERα, COX-2, Cyclin A, and Bcl-xL were reduced in celecoxib-treated tumor samples, whereas only Bcl-xL expression was suppressed in those treated with aspirin. Among the breast cancer-related miRNAs, miR-222 expression was elevated in samples treated with celecoxib. Further studies in culture cells verified that the increase in miR-222 expression might contribute to ERα downregulation but not the growth deterrence of cells. CONCLUSION: Overall, this study suggested that both celecoxib and aspirin could prevent breast cancer growth by regulating proteins in the cell cycle and apoptosis without blocking estrogen synthesis. Besides, celecoxib might affect miR expression in an undesirable fashion.


Assuntos
Aromatase/genética , Neoplasias da Mama/genética , Inibidores de Ciclo-Oxigenase 2/farmacologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Pirazóis/farmacologia , Sulfonamidas/farmacologia , Animais , Apoptose/genética , Aromatase/metabolismo , Aspirina/farmacologia , Peso Corporal/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Celecoxib , Ciclo Celular/genética , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Modelos Animais de Doenças , Fator de Transcrição E2F2/genética , Estradiol/sangue , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Genes myc , Humanos , Fígado/anatomia & histologia , Fígado/efeitos dos fármacos , Células MCF-7 , Camundongos , RNA Mensageiro/genética , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Toxicol In Vitro ; 28(4): 640-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24512813

RESUMO

Zeranol, aflatoxin B1, zearalenone are mycotoxins that are commonly found as food contaminants. The chemical structures of zeranol and zearalenone resemble estrogen, and may disrupt hormone metabolism. The biosynthesis of estrogen is catalyzed by aromatase or CYP19. In the present study, effect of these mycotoxins on aromatase was evaluated by using 4 cell lines, i.e. the CYP19-overexpressing cells MCF-7aro, the placental cells JEG-3, the breast cells MCF-7, and the brain cells T98G. Our data indicated that zearalenone was a competitive inhibitor of aromatase with a K(i) value of 1 µM. As aromatase expression is promoter-specific and regulated by alternate splicing, we employed three cell lines for investigation. Our results showed that zearalenone and zeranol could suppress aromatase expression through promoters II and I.3. For aromatase transcription dictated by promoters I.f and I.1, the expression was not affected. Taken together, zearalenone was a potential aromatase inhibitor among the three mycotoxins tested. Furthermore, this 4-cell line approach could be employed in principle to screen for compounds inhibiting or inducing estrogen synthesis.


Assuntos
Zearalenona/toxicidade , Zeranol/toxicidade , Aromatase/genética , Aromatase/metabolismo , Linhagem Celular , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo
13.
Mol Cell Endocrinol ; 375(1-2): 106-12, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23727336

RESUMO

Dioxins are the most concerned environmental pollutants. Recent studies have shown that these compounds could disrupt the proper functioning of our endocrine system. Estrogen is synthesized in glial cells of the brain. The hormone has been linked to the maintenance of normal brain operation, ranging from neurotransmission to synapse formation. Aromatase or CYP19 is the enzyme responsible for estrogen synthesis. In the present study, we demonstrated that 2,3,7,8-tetrachloro-dibenzo-para-dioxin (TCDD) stimulated the enzyme activity in human brain cells as low as 1pM. Increased brain-specific CYP19 mRNA species was also observed in these cells. Since the brain-specific promoter I.f of CYP19 contains two binding motifs for CCAAT/enhancer binding protein, electrophoretic mobility shift assay was performed to validate the activation. We further traced the triggering signal and found that the mitogen-activated protein kinases ERK-1/2 were activated. In summary, TCDD could induce CYP19 transcription in brain cells. Exposure to the pollutant might perturb the hormonal balance in the brain.


Assuntos
Aromatase/genética , Poluentes Ambientais/farmacologia , Dibenzodioxinas Policloradas/farmacologia , Aromatase/metabolismo , Butadienos/farmacologia , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Indução Enzimática/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glioma , Humanos , Sistema de Sinalização das MAP Quinases , Neuroglia/efeitos dos fármacos , Neuroglia/enzimologia , Nitrilas/farmacologia , Especificidade de Órgãos , Regiões Promotoras Genéticas , Ligação Proteica
14.
Toxicol Appl Pharmacol ; 269(2): 163-8, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23545179

RESUMO

Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasma estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase.


Assuntos
Compostos Benzidrílicos/toxicidade , Estrogênios não Esteroides/toxicidade , Fenóis/toxicidade , Placenta/efeitos dos fármacos , Proteína Quinase C/metabolismo , Animais , Aromatase/genética , Aromatase/metabolismo , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Ativação Enzimática/efeitos dos fármacos , Estradiol/metabolismo , Feminino , Isoenzimas , Camundongos , Camundongos Endogâmicos ICR , Placenta/enzimologia , Gravidez , Progesterona/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , DNA Polimerase Dirigida por RNA , Reação em Cadeia da Polimerase em Tempo Real , Testosterona/sangue
15.
Br J Nutr ; 109(9): 1598-605, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22935222

RESUMO

Exposure to environmental toxicants or exogenous oestrogen increases the risk of cancer. Some toxicants such as polycyclic aromatic hydrocarbons (PAH) undergo biotransformation to become genotoxic agents. Cytochrome p450 (CYP) 1B1 is an enzyme catalysing this transformation. Consumption of fruit and vegetables is considered to be protective against carcinogenesis, and naringenin can be found abundantly in citrus fruits. In the present study, the effect of naringenin on the regulation of CYP1B1 was investigated in MCF-7 cells. Enzyme inhibition assays revealed that naringenin inhibited CYP1B1 at or above 5 µm but not CYP1A1 activity. Quantitative PCR analysis also demonstrated that 1 µm-naringenin reduced CYP1B1 mRNA expression induced by 7,12-dimethylbenz(α)anthracene (DMBA). Further study illustrated that the suppression was at the transcriptional level. Since previous studies have shown that oestrogen response element (ERE) and xenobiotic-responsive element (XRE) are functional binding sequences in the promoter region of CYP1B1, interference of DNA binding on these two elements was pursued. Employing reporter gene assays as well as the electromobility shift assay, we verified that naringenin counteracted DMBA-induced XRE binding at − 1675. These results supported the notion that fruit consumption could be a protective measure against PAH biotransformation.


Assuntos
Hidrocarboneto de Aril Hidroxilases/genética , Flavanonas/farmacologia , Ativação Transcricional/efeitos dos fármacos , Xenobióticos/metabolismo , 9,10-Dimetil-1,2-benzantraceno/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Citocromo P-450 CYP1B1 , Ensaio de Desvio de Mobilidade Eletroforética , Genes Reporter , Humanos , Luciferases/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
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