Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Nutrients ; 15(8)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37111106

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver condition with significant risk of progression to steatohepatitis and cirrhosis. Therapeutic strategies in NAFLD include lifestyle changes mainly related to dietary interventions and use of drugs or nutritional components that could improve plasma lipid profiles and insulin sensitivity and decrease the local inflammatory response. In this study, we tested the effects of monacolin K, an inhibitor of HMCoA reductase. In a prospective, uncontrolled, open study, we treated 24 patients with NAFLD and mild hypercholesterolemia with 10 mg/day of monacolin K. At baseline and after 26 weeks, we measured in plasma liver tests, lipids, malondialdehyde, and oxidized glutathione, and assessed biochemical steatosis scores, liver elastography, and body composition with bioimpedance analysis. Monacolin K significantly reduced plasma alanine aminotransferase, cholesterol, triglycerides and the homeostatic model assessment (HOMA) index that indicated improved insulin sensitivity. No significant changes were found in body fat mass and visceral fat, nor in liver elastography, while the fatty liver index (FLI) was significantly decreased. Plasma levels of both malondialdehyde and oxidized glutathione were markedly reduced by monacolin K treatment, suggesting a reduction in oxidative stress and lipid peroxidation. In summary, this pilot study suggests possible benefits of monacolin K use in NAFLD patients that could be linked to a reduction in oxidative stress. This hypothesis should be further investigated in future studies.


Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Projetos Piloto , Lovastatina , Dissulfeto de Glutationa , Estudos Prospectivos , Fígado , Malondialdeído
2.
Front Cardiovasc Med ; 9: 1030968, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36312275

RESUMO

Background and aims: Cardiac structural and functional changes have been demonstrated in patients with non-alcoholic fatty liver disease (NAFLD). Because of the frequent association of NAFLD with hypertension, we aimed to examine the relationship of liver steatosis with left ventricular (LV) changes in patients with hypertension. Materials and methods: In a cross-sectional study, we included 360 untreated, essential hypertensive patients who were free of major cardiovascular and renal complications. Liver steatosis was assessed by three different biochemical scores (NAFLD Liver Fat Score, LFS; Fatty Liver Index, FLI; Hepatic Steatosis Index, HSI). Echocardiography was performed with standard B-mode and tissue-Doppler imaging. Results: LV hypertrophy was present in 19.4% and LV diastolic dysfunction in 49.2% of patients who had significantly higher body mass index (BMI), blood pressure (BP), and homeostatic model assessment (HOMA) index and higher frequency of the metabolic syndrome and liver steatosis that was defined by presence of 2 or more positive scores. LV mass index increased progressively across patients who had none, 1, or 2 or more liver steatosis scores, with associated progressive worsening of LV diastolic function. LV mass index was significantly and positively correlated with age, BMI, BP, HOMA-index, LFS, and HSI. Logistic regression analysis showed that age, BP, and liver steatosis scores independently predicted LV hypertrophy and diastolic dysfunction. Liver steatosis independently predicted LV dysfunction but not LV hypertrophy even after inclusion in analysis of the HOMA-index. Conclusion: NAFLD is associated with LV hypertrophy and diastolic dysfunction in untreated patients with hypertension. In hypertension, NAFLD could contribute to LV diastolic dysfunction with mechanisms unrelated to insulin resistance.

4.
Clin J Gastroenterol ; 13(2): 260-266, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31410743

RESUMO

Chronic HCV liver infection is considered one of the main causes of liver cirrhosis and hepatocellular carcinoma (HCC). For a selected group of patients, orthotopic liver transplantation (OLTx) is the most effective option to cure both liver diseases. After liver transplantation, patients may be at risk of viral infection reactivation and HCC recurrence. HCV recurrence on the transplanted organ can lead to graft cirrhosis and therefore the clearance of virus with antiviral therapies has a pivotal role on the prevention of graft damage. Nowadays, direct antiviral agents (DAAs) represent the choice treatment for HCV recurrence in liver transplanted patients, ensuring high eradication rates. We present the case of a liver transplant recipient who developed, 7 years after OLTx and immediately after a DAAs treatment, a subcutaneous abdominal mass with histological characteristics of HCC.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Hepatite C Crônica/tratamento farmacológico , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado , Recidiva Local de Neoplasia/patologia , Complicações Pós-Operatórias/tratamento farmacológico , Complicações Pós-Operatórias/virologia , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/secundário , Hepatite C Crônica/complicações , Humanos , Neoplasias Hepáticas/complicações , Masculino , Pessoa de Meia-Idade , Recidiva
5.
World J Gastroenterol ; 25(40): 6094-6106, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31686765

RESUMO

BACKGROUND: Direct-acting antiviral agents (DAAs) are extremely effective in eradicating hepatitis C virus (HCV) in chronically infected patients. However, the protective role of the sustained virologic response (SVR) achieved by second- and third-generation DAAs against the onset of hepatocellular carcinoma (HCC) and mortality is less well established. AIM: To examine the occurrence of HCC or death from any cause in a retrospective-prospective study of patients treated with DAAs. METHODS: Patients were enrolled from a tertiary academic hospital center for liver disease management that collects subject data mainly from northeastern Italy. The study was conducted in 380 patients (age: 60 ± 13 years, 224 males, 32% with cirrhosis) treated with DAAs with or without SVR (95/5%), with a median follow up of 58 wk (interquartile range: 38-117). The baseline anthropometric features, HCV viral load, severity of liver disease, presence of extra-hepatic complications, coinfection with HIV and/or HBV, alcohol consumption, previous interferon use, alpha-fetoprotein levels, and renal function were considered to be confounders. RESULTS: The incidence rate of HCC in patients with and without SVR was 1.3 and 59 per 100 person-years, respectively (incidence rate ratio: 44, 95%CI: 15-136, P < 0.001). Considering the combined endpoint of HCC or death from any cause, the hazard ratio (HR) for the SVR patients was 0.070 (95%CI: 0.025-0.194, P < 0.001). Other independent predictors of HCC or death were low HCV viremia (HR: 0.808, P = 0.030), low platelet count (HR: 0.910, P = 0.041), and presence of mixed cryoglobulinemia (HR: 3.460, P = 0.044). Considering SVR in a multi-state model, the independent predictors of SVR achievement were absence of cirrhosis (HR: 0.521, P < 0.001) and high platelet count (HR: 1.019, P = 0.026). Mixed cryoglobulinemia predicted the combined endpoint in patients with and without SVR (HR: 5.982, P = 0.028 and HR: 5.633, P = 0.047, respectively). CONCLUSION: DAA treatment is effective in inducing SVR and protecting against HCC or death. A residual risk of HCC persists in patients with advanced liver disease or with complications, such as mixed cryoglobulinemia or renal failure.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/epidemiologia , Hepatite C Crônica/tratamento farmacológico , Neoplasias Hepáticas/epidemiologia , Resposta Viral Sustentada , Idoso , Carcinoma Hepatocelular/prevenção & controle , Carcinoma Hepatocelular/virologia , Quimioterapia Combinada/métodos , Feminino , Hepacivirus/isolamento & purificação , Hepatite C Crônica/patologia , Hepatite C Crônica/virologia , Humanos , Incidência , Itália/epidemiologia , Neoplasias Hepáticas/prevenção & controle , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Carga Viral/efeitos dos fármacos
6.
Metab Syndr Relat Disord ; 9(5): 397-401, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21561340

RESUMO

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is strongly associated to oxidative stress, metabolic syndrome, and cardiovascular risk. Hepatocytes overloaded with fatty acids (FA) could generate substances that interfere with endothelial function, providing a potential explanation for this association. We have investigated the response of cultured human hepatoblastoma cells (Hep-G2) that were exposed to FA by measuring markers of oxidative stress and thrombosis and expression of the insulin receptor. METHODS: Hep-G2 cells were conditioned with a mixture of FA with or without N-acetyl-L-cysteine (NAC), glutathione (GSH), or adiponectin (ADN). After 7 days, we measured intracellular GSH (iGSH), nitric oxide (NO), malondialdehyde (MDA), and tissue plasminogen inhibitor-1 (PAI-1). Real-time polymerase chain reaction (PCR) was used to determine gene expression of inducible nitric oxide synthase (iNOS) and insulin receptor (INS-R). RESULTS: Exposure to FA decreased iGSH and NO levels in Hep-G2 cells and increased MDA and PAI-1 production. Gene expression of iNOS and INS-R in Hep-G2 cells was decreased by exposure to FA. Co-incubation with NAC and GSH prevented the change of iNOS mRNA levels, but not of INS-R; co-incubation with ADN restored the gene expression of INS-R, but not of i-NOS. ADN prevented also the FA-induced increase in MDA in cultured human endothelial cells. CONCLUSION: Exposure to FA activates oxidative stress and production of prothrombotic markers and decreases expression of insulin receptors in cultured human hepatocytes. These effects of FA are partially prevented by ADN and might contribute to the increased cardiovascular risk in patients with NAFLD and metabolic syndrome.


Assuntos
Ácidos Graxos não Esterificados/metabolismo , Hepatócitos/metabolismo , Adiponectina/metabolismo , Antioxidantes/metabolismo , Células Cultivadas , Ácidos Graxos/metabolismo , Fígado Gorduroso/metabolismo , Glutationa/metabolismo , Hepatoblastoma/metabolismo , Humanos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Hepatopatia Gordurosa não Alcoólica , Estresse Oxidativo , Receptor de Insulina/metabolismo , Risco , Trombose/metabolismo
7.
Clin Pharmacokinet ; 49(11): 767-72, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20923249

RESUMO

BACKGROUND AND OBJECTIVES: Combination therapy with interferon-α and ribavirin is considered the treatment of choice for chronic hepatitis C. However, interferon-α may induce severe depression. It has been suggested that interferon-α is able to modify cytochrome P450 (CYP) 1A2 and 2D6 activity. We therefore decided to study the effects of the interferon-α-2b pegylated derivative on fluoxetine disposition in patients receiving combination chemotherapy for chronic hepatitis C. METHODS: After approval by the institutional ethics committee, 20 adult patients with chronic hepatitis C, but with no history of other liver diseases, were prospectively admitted to the study, which included phenotyping by means of a dextromethorphan test and evaluation of fluoxetine and norfluoxetine pharmacokinetic parameters (the area under the serum concentration-time curve, maximum serum concentration, time to reach the maximum serum concentration and terminal elimination half-life) before and after 2 months of continuous peginterferon-α-2b therapy. RESULTS: The only statistically significant difference we observed was a significant reduction in the terminal elimination half-life of fluoxetine (from 47.30 to 33.23 hours; p = 0.014) after peginterferon-α-2b treatment. CONCLUSION: These data suggest that interferon-α may induce, rather than inhibit, the biotransformation of fluoxetine.


Assuntos
Antidepressivos de Segunda Geração/farmacocinética , Antivirais/uso terapêutico , Fluoxetina/farmacocinética , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/metabolismo , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Adulto , Antidepressivos de Segunda Geração/sangue , Antidepressivos de Segunda Geração/uso terapêutico , Área Sob a Curva , Interações Medicamentosas , Quimioterapia Combinada , Feminino , Fluoxetina/sangue , Fluoxetina/uso terapêutico , Meia-Vida , Hepacivirus/genética , Hepatite C Crônica/genética , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Fenótipo , Proteínas Recombinantes , Ribavirina/uso terapêutico , Adulto Jovem
8.
Hypertens Res ; 31(2): 345-51, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18360055

RESUMO

Alcohol-induced endothelial changes might contribute to an increase in blood pressure in regular alcohol consumers. Some antihypertensive drugs affect oxidative stress and endothelial function and might counteract the effects of alcohol at the cellular level. The aim of this study was to investigate in vitro the effects of three different types of antihypertensive agents on alcohol-induced endothelial responses and oxidative stress. Cultured human endothelial cells were exposed to increasing concentrations (1, 10, 60 micromol/L) of zofenoprilat, carvedilol, and lacidipine in the absence and in the presence of ethanol (140 mmol/L). Concentrations of endothelin (ET) and nitric oxide (NO) were measured in the culture media as markers of endothelial function, and malondialdehyde (MDA) and intracellular glutathione (GSHi) were measured as markers of oxidative stress. Exposure to alcohol increased the levels of ET, NO, and MDA, and decreased GSHi. Carvedilol and zofenoprilat were more effective than lacidipine in counteracting the effects of alcohol on ET production. Alcohol-induced NO production was enhanced by carvedilol, whereas zofenoprilat and lacidipine did not have a significant effect. The alcohol-induced increase in MDA concentrations was blunted by all three drugs, but only carvedilol restored a normal response. All three drugs increased GSHi levels, with the effect being greater for carvedilol and lacidipine than zofenoprilat. Carvedilol is more effective than zofenoprilat and lacidipine in counteracting alcohol-induced endothelial responses in vitro and in decreasing oxidative stress. These effects might be particularly beneficial in patients with alcohol-related hypertension.


Assuntos
Anti-Hipertensivos/farmacologia , Células Endoteliais/efeitos dos fármacos , Etanol/toxicidade , Captopril/análogos & derivados , Captopril/farmacologia , Carbazóis/farmacologia , Carvedilol , Células Cultivadas , Di-Hidropiridinas/farmacologia , Relação Dose-Resposta a Droga , Células Endoteliais/fisiologia , Humanos , Malondialdeído/sangue , Óxido Nítrico/biossíntese , Estresse Oxidativo , Propanolaminas/farmacologia
9.
J Hypertens ; 24(8): 1493-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16877950

RESUMO

BACKGROUND: Epidemiological investigations have demonstrated a close association between heavy alcohol consumption and hypertension. The mechanisms of this association, however, remain elusive. We studied the effects of alcohol withdrawal on blood pressure, hormonal parameters, and circulating markers of endothelial activity. METHODS: In 14 hypertensive heavy alcohol consumers (> 200 g/day) who agreed to participate in a hospital withdrawal programme we monitored, for 30 days, blood pressure, plasma levels of renin, aldosterone, cortisol, endothelin, and plasminogen activator inhibitor 1 (PAI-1), and urinary levels of catecholamines. Patients in the withdrawal group were compared with eight hypertensive heavy drinkers who refused to participate in the programme and maintained regular alcohol consumption and 11 normotensive teetotalers. RESULTS: By the third day after withdrawal, blood pressure was significantly decreased and the normalization of levels was obtained in 13 of 14 patients by the end of the study. Alcohol withdrawal significantly decreased plasma aldosterone and cortisol levels, but did not affect levels of active renin and fractionated urinary catecholamines. At baseline, plasma endothelin and PAI-1 levels were significantly higher in alcoholic individuals than in teetotalers, and after the cessation of alcohol intake decreased progressively, reaching levels different from baseline within 1 week. A significant correlation was found between changes in endothelin and PAI-1, and blood pressure variations during alcohol abstinence that remained significant only for endothelin with the multivariate approach. CONCLUSION: Hypertension is rapidly reversible in the majority of heavy drinkers after the withdrawal of alcohol consumption. In these patients, hypertension is associated with an increased release of endothelial factors that might contribute to the increase in blood pressure.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Depressores do Sistema Nervoso Central/efeitos adversos , Etanol/efeitos adversos , Hipertensão/fisiopatologia , Síndrome de Abstinência a Substâncias/fisiopatologia , Adulto , Aldosterona/sangue , Análise de Variância , Biomarcadores/sangue , Biomarcadores/urina , Catecolaminas/urina , Endotelinas/sangue , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Hidrocortisona/sangue , Hipertensão/etiologia , Hipertensão/metabolismo , Masculino , Pessoa de Meia-Idade , Natriurese/efeitos dos fármacos , Inibidor 1 de Ativador de Plasminogênio/sangue , Renina/sangue , Projetos de Pesquisa , Síndrome de Abstinência a Substâncias/complicações , Síndrome de Abstinência a Substâncias/metabolismo , Fatores de Tempo
10.
J Clin Endocrinol Metab ; 91(3): 1081-6, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16394091

RESUMO

CONTEXT: The recently discovered hormone resistin is linked to the development of insulin resistance, but direct evidence of resistin levels in humans with nonalcoholic fatty liver disease (NAFLD) is lacking. METHODS: We conducted this study to assess the relationship between serum resistin and NAFLD. We measured serum resistin and biochemical, hormonal, and histological correlates in 28 NAFLD patients, 33 controls, and 30 obese patients [body mass index (BMI), >30 kg/m2] without NAFLD. RESULTS: Resistin and adiponectin expression were measured in sc adipose tissue by quantitative RT-PCR. Resistin was higher in NAFLD patients compared with controls (5.87 +/- 0.49 vs. 4.30 +/- 0.20 ng/ml; P = 0.002) and obese patients (4.37 +/- 0.27 ng/ml; P = 0.002). Increased resistin mRNA was also found in the adipose tissue of NAFLD patients compared with controls and obese subjects. CONCLUSIONS: Both NAFLD and obese patients had lower adiponectin levels, whereas leptin was increased only in the obese group. No correlation was found between resistin and high-sensitivity C-reactive protein, BMI, homeostasis model assessment, insulin, glucose, transaminases, and lipid values. A positive correlation was found between resistin and histological inflammatory score. These data report increased resistin in NAFLD patients that is related to the histological severity of the disease, but do not support a link between resistin and insulin resistance or BMI in these patients.


Assuntos
Fígado Gorduroso/sangue , Resistência à Insulina/fisiologia , Resistina/sangue , Adiponectina/sangue , Adiponectina/genética , Tecido Adiposo/fisiologia , Tecido Adiposo/fisiopatologia , Adulto , Índice de Massa Corporal , Fígado Gorduroso/fisiopatologia , Feminino , Humanos , Leptina/sangue , Lipídeos/sangue , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Valores de Referência , Resistina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Índice de Gravidade de Doença
11.
Alcohol Clin Exp Res ; 29(10): 1889-98, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16269920

RESUMO

BACKGROUND: Although heavy alcohol drinkers are at an increased risk of developing cardiovascular events, moderate alcohol intake is associated with reduced incidence of cardiovascular death. This paradox might reflect a dose-related effect of different alcohol intakes on endothelial function and this, in turn, might depend on changes in oxidative stress. METHODS: We tested the effects of alcohol withdrawal in heavy alcohol consumers and compared the plasma levels of endothelin-1, nitric oxide, plasminogen activator inhibitor-1, von Willebrand factor, malondialdehyde, and intracellular glutathione with those of alcoholics that did not modify their alcohol intake and teetotalers. In human endothelial cells that had been cultured for 2 weeks in the presence of different concentrations of ethanol, we assessed the same parameters after withdrawal of ethanol exposure. RESULTS: Alcohol increased the levels of endothelin-1, nitric oxide, and plasminogen activator inhibitor-1 and decreased the levels of von Willebrand factor both in vivo and in vitro. These changes were dose dependent, rapidly reversed after withdrawal of exposure, and associated with the presence of increased oxidative stress as indicated by increased levels of both malondialdehyde and intracellular glutathione. Blockade of oxidative stress by incubation of endothelial cells in the presence of oxidants' scavengers prevented the alcohol-induced functional modifications of the endothelium. CONCLUSIONS: Alcohol affects endothelial function with an effect that is mediated by an activated oxidative stress and is rapidly reversed after withdrawal. Dose-related endothelial responses to different alcohol intakes might translate in either vascular protection or vascular damage.


Assuntos
Consumo de Bebidas Alcoólicas/patologia , Endotélio Vascular/patologia , Estresse Oxidativo/efeitos dos fármacos , Adulto , Células Cultivadas , Relação Dose-Resposta a Droga , Endotelina-1/sangue , Feminino , Sequestradores de Radicais Livres/farmacologia , Glutationa/sangue , Humanos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Óxido Nítrico/sangue , Inibidor 1 de Ativador de Plasminogênio/sangue , Fator de von Willebrand/metabolismo
12.
Eur J Endocrinol ; 152(1): 113-8, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15762194

RESUMO

OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver-related morbidity and is frequently associated with obesity and metabolic syndrome. The recently discovered hormone adiponectin is produced by adipose tissue, and low plasma adiponectin is considered a key factor in the development of the insulin resistance underlying metabolic syndrome. Animal studies suggest that adiponectin may protect against non-alcoholic steatohepatitis, but direct evidence in humans is lacking. We therefore conducted this study to assess the relationship between plasma adiponectin and nonalcoholic fatty liver disease to explore its role in the pathogenesis of this disease. DESIGN AND METHODS: We measured plasma adiponectin and anthropometric, biochemical, hormonal and metabolic correlates in a group of 17 NAFLD patients with diagnosis confirmed by biopsy, and 20 controls with comparable age, body-mass index and sex. Furthermore we compared plasma adiponectin in patients with simple steatosis and steatohepatitis. RESULTS: Plasma adiponectin was significantly lower in NAFLD patients than controls (5.93+/-0.45 vs 15.67+/-1.60ng/ml). Moreover, NAFLD patients were significantly more insulin resistant while having similar serum leptin. Adiponectin was similar in simple steatosis and in steatohepatitis (6.16+/-0.78 vs 5.69+/-0.49ng/ml). An inverse correlation was observed between adiponectin and homeostatic model assessment (HOMA) of insulin resistance (P = 0.008), while adiponectin did not correlate with serum transaminases and lipid values. CONCLUSIONS: These data support a role for low circulating adiponectin in the pathogenesis of NAFLD and confirm the strict association between reduced adiponectin production by adipose tissue, NAFLD and insulin resistance.


Assuntos
Glicemia/metabolismo , Fígado Gorduroso/sangue , Peptídeos e Proteínas de Sinalização Intercelular/sangue , Adiponectina , Adulto , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Aspartato Aminotransferases/sangue , HDL-Colesterol/sangue , Feminino , Humanos , Insulina/metabolismo , Resistência à Insulina/fisiologia , Leptina/sangue , Masculino , Análise Multivariada , Análise de Regressão , Triglicerídeos/sangue , gama-Glutamiltransferase/sangue
13.
Thyroid ; 13(8): 747-53, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14558917

RESUMO

Apoptosis plays an important role within the endocrine system, particularly in the thyroid gland, although little is known about its regulation in normal thyroids. Because thyrotropin (TSH) regulates many thyroid-specific functions and cell proliferation, we investigated whether TSH can influence such mechanisms. To induce apoptosis we used UV-C radiation. The FRTL-5 rat thyroid cell strain, a cloned strain of differentiated and untransformed cells that reproduces many of the characteristics of the normal thyroid was chosen for this study. The FRTL-5 cells are a particularly suitable model because they actively proliferate when cultured in the presence of TSH (6H medium), while in TSH-free medium (5H medium) cells remain in a physiologic quiescent state for a long period of time. FRTL-5 cells in both culture conditions were irradiated with UV-C radiation (254 nm wavelength). At 48 hours after radiation, 6H cultured cells showed the characteristic signs of apoptosis. However, 5H cultured cells did not present macroscopic signs of damage, DNA fragmentation, or detectable apoptosis. Furthermore, the expression of 23 apoptosis-related genes was compared. Results indicate that Bcl2 and caspase-2 expression is enhanced, while bax, GADD45 and mdm-2 expression is reduced in irradiated cells. These data confirm that TSH plays a major role in regulating UV-induced apoptosis in FRTL-5 cells.


Assuntos
Apoptose/efeitos da radiação , Glândula Tireoide/citologia , Glândula Tireoide/efeitos da radiação , Tireotropina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , DNA Complementar/genética , Relação Dose-Resposta à Radiação , Citometria de Fluxo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Glândula Tireoide/fisiologia , Raios Ultravioleta
14.
Biochimie ; 85(7): 701-5, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-14505826

RESUMO

Several thrombogenic abnormalities are associated with diabetes. Since endothelial dysfunction occurs at early stages of disease, it may reflect pathophysiological changes that are responsible for alterations in vascular structure, growth and modifications of adhesivity to platelets and leukocytes, leading to atherosclerosis and thrombosis. Predisposing factors of vascular diseases, such as diabetes, are also associated with endothelial dysfunction. Restoration or replacement of endothelium-related factors like nitric oxide impede the progression of vascular thrombogenic diseases, and prevent the action of vasoconstrictor factors such as endothelin or other prothrombotic factors such as plasminogen-activator inhibitor-1. Since high glucose concentration in blood is the hallmark of diabetes and because the vascular lesions of atherosclerosis are localized in large artheries, we have cultured endothelial cells from the human aorta. Two endothelial cell strains from the same aortic tract that show different characteristics and behavior in high glucose were isolated. Such findings reflect the importance to have well characterized and standardized cell culture systems to carry out experiments to study the glucose-dependent atherosclerotic process in vitro. Our cell strains may represent a useful in vitro model to study the complex pathophysiology of diabetes-related atherosclerosis.


Assuntos
Células Cultivadas , Endotélio Vascular/citologia , Endotélio Vascular/fisiologia , Glucose/farmacologia , Modelos Cardiovasculares , Fatores Biológicos/fisiologia , Diferenciação Celular , Diabetes Mellitus/metabolismo , Angiopatias Diabéticas/etiologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Glucose/metabolismo , Humanos , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Molécula-1 de Adesão Celular Endotelial a Plaquetas/fisiologia , Doenças Vasculares/etiologia , Fator de von Willebrand/análise , Fator de von Willebrand/fisiologia
15.
Thyroid ; 13(6): 517-21, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12930594

RESUMO

vasodilative Thyroid diseases have been associated with pathophysiological changes in the vasculature that may result from altered thyroid hormone production or to direct effect of elevated thyrotropin (TSH) levels on smooth muscle cells. A direct effect of TSH on vascular endothelium has not been considered. In the present study a strain of human aortic endothelial cells has been stimulated with TSH, and vascular parameters correlated with the atherosclerotic process have been analyzed. Addition of TSH induced an increase of cyclic AMP (cAMP) concentration in human aortic endothelial cells. Furthermore it induced a decrease of endothelin (from 30 +/- 2.5 to 13 +/- 1 fmol/mL) and of tissue plasminogen activator secretion (from 2,800 +/- 200 to 1,600 +/- 150 ng/mL). On the other hand, it increased nitric oxide (from 148 +/- 8 to 211 +/- 12 microM). TSH did not affect plasminogen activator inhibitor 1. Similar results were obtained when immunoglobulin Gs (IgGs) from Graves' disease patients were used. In conclusion, our findings suggest that TSH and IgGs from Graves' disease patients could stimulate endothelial cells, increasing the secretion of procoagulant and vasodilative factors, and that cAMP is involved in the transduction pathway. These findings are consistent with modifications of the fibrinolytic system reported in hypothyroidism and in Graves' disease. On the other hand, the increase of vascular resistance found in patients with hypothyroidism may be due to the altered thyroid hormone production and not to TSH directly, or to a different effect of TSH on peripheral vessels.


Assuntos
Endotelinas/biossíntese , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Óxido Nítrico/biossíntese , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Tireotropina/farmacologia , Aorta/citologia , Linhagem Celular , Células Cultivadas , AMP Cíclico/biossíntese , Endotélio Vascular/citologia , Citometria de Fluxo , Doença de Graves/imunologia , Humanos , Imunoglobulina G/farmacologia , Receptores da Tireotropina/metabolismo , Glândula Tireoide/citologia , Glândula Tireoide/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA