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

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Food Microbiol ; 83: 193-199, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31202413

RESUMO

The fastidious requirement of the zoonotic pathogen Campylobacter jejuni contrasts with its ability to overcome harsh conditions. Different strategies might be involved in the survival and persistence of C. jejuni through the poultry food chain. Therefore, the aims of this study were to get insights in the survival strategies in the poultry slaughterhouse environment by (i) characterizing factors such as biofilm formation, virulence and antimicrobial resistance in environmental isolates and (ii) understanding the possible link between the phenotypic and genetic characterization using whole genome sequencing (WGS). Results have shown that three STs: ST 443 (PFGE A), ST 904 (PFGE C) and ST 3769 (PFGE G), out of the six studied, formed biofilms with variable intensity according to different conditions (temperatures -37 °C, 30 °C, 25°C- and materials -stainless steel and plastic-). High levels of antimicrobial resistance were found in isolates to ciprofloxacin, nalidixic acid and tetracycline as well as to two common detergents used in the slaughterhouse. A combination of several changes in the genome of ST 904 (PFGE C) including mutations, insertions in antimicrobial resistance genes, the presence of T6SS and a set of genes related to virulence factors might explain its ability to form biofilm and persist longer in the environment. However, the complexity of the survival strategies adopted by the different strains of C. jejuni suggests that multiple mechanisms may exist that allow these organisms to persist and ultimately cause disease in humans.


Assuntos
Matadouros , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Infecções por Campylobacter/veterinária , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/patogenicidade , Aves Domésticas/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Campylobacter jejuni/genética , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana/genética , Microbiologia de Alimentos , Genoma Bacteriano , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Fatores de Virulência/genética , Sequenciamento Completo do Genoma
2.
Food Microbiol ; 76: 457-465, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166174

RESUMO

Contaminated chicken products have been recognized as the primary vehicles of Campylobacter transmission to human. Pulsed-field gel electrophoresis (PFGE) and antimicrobial resistance of Campylobacter isolates from fresh chicken products at retail were studied. A total of 512 samples including: thigh, breast, marinated and minced chicken were purchased from different retail stores. Half of the samples were packed and the other half were unpacked. The 39.4% of the samples were Campylobacter positive; being unpacked chicken products (45.3%) more contaminated than packed chicken (33.6%). PFGE typing showed a high diversity among isolates; clustering 204 isolates into 76 PFGE types: 55 clusters of C. jejuni, 19 of C. coli and 2 of C. lari. C. coli genotypes showed higher resistance than other Campylobacter species. Although modified atmosphere packaging can reduce the prevalence of Campylobacter spp., it does not avoid their presence in at least 33.6% of packed chicken products analyzed. Some pulsotypes might persist in the processing plant or butcher shops environment for longer than previously thought. More stringent control measures are needed in previous steps of the chicken food chain, in order to avoid the presence of Campylobacter spp. strains at retail that can compromise consumer's safety.


Assuntos
Antibacterianos/farmacologia , Campylobacter/efeitos dos fármacos , Campylobacter/isolamento & purificação , Farmacorresistência Bacteriana , Produtos da Carne/microbiologia , Animais , Antibacterianos/efeitos adversos , Campylobacter/classificação , Campylobacter/genética , Galinhas , Contaminação de Alimentos , Genótipo , Testes de Sensibilidade Microbiana
3.
Food Microbiol ; 65: 185-192, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28400001

RESUMO

Campylobacteriosis is the most common cause of bacterial gastroenteritis worldwide. Consumption of poultry, especially chicken's meat is considered the most common route for human infection. The aim of this study was to determine if Campylobacter spp. might persist in the poultry plant environment before and after cleaning and disinfection procedures and the distribution and their genetic relatedness. During one month from a poultry plant were analyzed a total of 494 samples -defeathering machine, evisceration machine, floor, sink, conveyor belt, shackles and broiler meat- in order to isolate C. jejuni and C. coli. Results showed that C. jejuni and C. coli prevalence was 94.5% and 5.5% respectively. Different typing techniques as PFGE, MLST established seven C. jejuni genotypes. Whole genome MLST strongly suggest that highly clonal populations of C. jejuni can survive in adverse environmental conditions, even after cleaning and disinfection, and persist for longer periods than previous thought (at least 21 days) in the poultry plant environment. Even so, it might act as a source of contamination independently of the contamination level of the flock entering the slaughter line.


Assuntos
Campylobacter jejuni/fisiologia , Manipulação de Alimentos/instrumentação , Aves Domésticas/microbiologia , Animais , Campylobacter jejuni/genética , Desinfecção , Eletroforese em Gel de Campo Pulsado , Manipulação de Alimentos/normas , Microbiologia de Alimentos , Genótipo , Humanos , Viabilidade Microbiana , Tipagem de Sequências Multilocus , Filogenia
4.
Cell Biol Toxicol ; 31(2): 95-110, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25764371

RESUMO

Melatonin, the product of the pineal gland, possesses antioxidant, anti-inflammatory, and antitumor properties in different tissues, in addition to its role as regulator of biological rhythms. In this study, the effects of pharmacological concentrations of melatonin (1 µM-1 mM) on pancreatic stellate cells (PSCs) have been examined. Cell viability was studied using AlamarBlue® test. Cell-type specific markers and total amylase content were analyzed by immunocytochemistry and colorimetric methods, respectively. Changes in intracellular free Ca(2+) concentration were followed by fluorimetric analysis of fura-2-loaded cells. The cellular red-ox state was monitored following CM-H2DCFDA-derived fluorescence. Determination of the activation of p44/42 mitogen-activated protein kinase (MAPK), SAPK/JNK and p38 was measured by Western blot analysis. Our results show that PSCs viability decreased in the presence of 100 µM or 1 mM melatonin. However, in the presence of 1 or 10 µM melatonin, no changes in cell viability were observed. Melatonin MT1 and MT2 receptors could not be detected. Melatonin induced Ca(2+) mobilization from intracellular pools. In the presence of melatonin, activation of crucial components of MAPKs pathway was noticed. Finally, the indole did not change the oxidative state of PSCs, but exerted a protective effect against H2O2-induced oxidation. We conclude that melatonin, at pharmacological concentrations, might regulate cellular proliferation of PSCs independently of specific plasma membrane receptors.


Assuntos
Antioxidantes/farmacologia , Cálcio/metabolismo , Proliferação de Células/efeitos dos fármacos , Melatonina/farmacologia , Células Estreladas do Pâncreas/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Sobrevivência Celular/efeitos dos fármacos , Corantes Fluorescentes , Fura-2 , Regulação da Expressão Gênica , Peróxido de Hidrogênio/antagonistas & inibidores , Peróxido de Hidrogênio/farmacologia , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Oxirredução , Células Estreladas do Pâncreas/citologia , Células Estreladas do Pâncreas/metabolismo , Cultura Primária de Células , Ratos , Receptor MT1 de Melatonina/genética , Receptor MT1 de Melatonina/metabolismo , Receptor MT2 de Melatonina/genética , Receptor MT2 de Melatonina/metabolismo , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
Clin Transl Oncol ; 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734800

RESUMO

PURPOSE: Breast cancer is an important health problem, like obesity and dyslipidemia, with a strong association between body mass index (BMI) and breast cancer incidence and mortality. The risk of breast cancer is also high in women with high mammographic breast density (MBD). The purpose of this study was to analyze the association between BMI and MBD according to breast cancer molecular subtypes. METHODS: This transversal, descriptive, multicenter study was conducted at three Spanish breast cancer units from November 2019 to October 2020 in women with a recent diagnosis of early breast cancer. Data were collected at the time of diagnosis. RESULTS: The study included 162 women with a recent diagnosis of early breast cancer. The median age was 52 years and 49.1% were postmenopausal; 52% had normal weight, 32% overweight, and 16% obesity. There was no association between BMI and molecular subtype but, according to menopausal status, BMI was significantly higher in postmenopausal patients with luminal A (p = 0.011) and HER2-positive (p = 0.027) subtypes. There was no association between MBD and molecular subtype, but there were significant differences between BMI and MBD (p < 0.001), with lower BMI in patients with higher MBD. Patients with higher BMI had lower HDL-cholesterol (p < 0.001) and higher insulin (p < 0.001) levels, but there were no significant differences in total cholesterol or vitamin D. CONCLUSIONS: This study showed higher BMI in luminal A and HER2-positive postmenopausal patients, and higher BMI in patients with low MBD regardless of menopausal status.

6.
Clin Genitourin Cancer ; 21(3): e166-e174, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36610891

RESUMO

INTRODUCTION: The long-term clinical outcomes of patients with metastatic renal cell carcinoma (mRCC) and a complete response (CR) to the tyrosine kinase inhibitor (TKI) sunitinib are poorly known. The characteristics of these patients could reveal previously undetected associations with clinical variables. PATIENTS AND METHODS: This observational, retrospective study (ATILA) used data from a registry of patients with mRCC who had received first-line sunitinib and had achieved CR from 2007 to 2018 in Spain. RESULTS: Sixty-two patients with CR were included; 48 patients (77.4%) received sunitinib in monotherapy and 14 (22.6%) combined with or followed by local treatment. Median age was 58.5 years (range, 32-81). Most patients (79.0%) had clear cell histology and had undergone previous nephrectomy (90.3%). The majority (70.2%) had an intermediate IMDC prognosis, 23% favorable and 7.0% poor. The median time on treatment with sunitinib was 28.2 months (IQR, 16.7-41.0) and the median time to CR was 10.9 months (IQR, 7.2-19.3). After a median follow-up of 8 years (range, 3-13 years), the median PFS was not reached. The overall median duration of complete response was 64.1 months (IQR, 32.2-99.4). The tolerance and safety profile of sunitinib was consistent with previous reports. CONCLUSION: Durable CR to sunitinib was observed in patients regardless the prognosis group, metastasis site or histology type, with 75% of patients remaining in CR after 10 years. CLINICALTRIALS: gov: NCT03916458.


Assuntos
Antineoplásicos , Carcinoma de Células Renais , Neoplasias Renais , Humanos , Pessoa de Meia-Idade , Sunitinibe/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/secundário , Antineoplásicos/uso terapêutico , Estudos Retrospectivos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia , Indóis/uso terapêutico , Pirróis/uso terapêutico
7.
Mol Cell Biochem ; 362(1-2): 15-23, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22012614

RESUMO

Resveratrol (3,4',5-trihydroxy-trans-stilbene), a phytoalexin naturally found in grapes and red wine, is a redox-active compound endowed with significant positive activities. In this study, the effects of resveratrol on intracellular free Ca(2+) concentration ([Ca(2+)](c)) and on cell viability in tumoral AR42J pancreatic cells are examined. The results show that resveratrol (100 µM and 1 mM) induced changes in [Ca(2+)](c), that consisted of single or short lasting spikes followed by a slow reduction toward a value close to the resting level. Lower concentrations of resveratrol (1 and 10 µM) did not show detectable effects on [Ca(2+)](c). Depletion of intracellular Ca(2+) stores by stimulation of cells with 1 nM CCK-8, 20 pM CCK-8 or 1 µM thapsigargin, blocked Ca(2+) responses evoked by resveratrol. Conversely, prior stimulation of cells with resveratrol inhibited Ca(2+) mobilization in response to a secondary application of CCK-8 or thapsigargin. In addition, resveratrol inhibited oscillations in [Ca(2+)](c) evoked by a physiological concentration of CCK-8 (20 pM). On the other hand, incubation of cells in the presence of resveratrol induced a reduction of cell viability. Finally, incubation of AR42J cells in the presence of resveratrol led to activation of c-Jun N-terminal kinase (JNK), a mitogen-activated protein kinase responsive to stress stimuli. Activation of JNK was reduced in the absence of extracellular Ca(2+). In summary, the results show that resveratrol releases Ca(2+) from intracellular stores, most probably from the endoplasmic reticulum, and reduces AR42J cells viability. Reorganization of cell's survival/death processes in the presence of resveratrol may involve Ca(2+)-mediated JNK activation.


Assuntos
Cálcio/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neoplasias Pancreáticas/metabolismo , Estilbenos/farmacologia , Animais , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/biossíntese , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Ratos , Resveratrol , Sincalida/farmacologia , Tapsigargina/farmacologia
8.
Rev Esp Patol ; 54(1): 59-64, 2021.
Artigo em Espanhol | MEDLINE | ID: mdl-33455695

RESUMO

Spindle cell carcinoma of the nasal cavity is a rare variant of squamous cell carcinoma. We report a case of a 50 year-old male presenting with a polypoid mass in the left nasal cavity. Histologically, the tumor was biphasic, composed of non-keratinizing squamous nests and a sarcomatoid stroma with positivity for CKAE1-AE3. Metastatic ipsilateral lymph nodes were present and the patient underwent radical neck dissection, followed by adjuvant radiotherapy and cisplatin. Two years after diagnosis the patient is free of disease.


Assuntos
Carcinoma de Células Escamosas/patologia , Cavidade Nasal/patologia , Neoplasias Nasais/patologia , Sarcoma/patologia , Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/química , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasais/química , Sarcoma/química
9.
Prev Vet Med ; 176: 104935, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32109783

RESUMO

Campylobacter spp. are the leading causes of bacterial human gastroenteritis worldwide; being poultry farms the main source of infections. In order to obtain information on prevalence and diversity of Campylobacter-infected flocks in the North of Spain, fourteen farms were studied between autumn and spring in 2014 and 2015, respectively. Moreover, virulence genes involved in pathogenicity and antimicrobial resistance were investigated. A survey about preventive hygiene practices at farms was performed to determine the risky practices that could contribute to the presence of Campylobacter in this step of the poultry food chain. Testing the presence of Campylobacter spp. showed 43 % of the farms were positive during autumn, whereas only 31 % were positive in spring. A very high prevalence within-flock was observed (43.1 % to 88.6 %) and C. jejuni was the most prevalent species in both periods. Genotyping by pulsed field gel electrophoresis (PFGE) showed a high heterogeneity among farms (309 isolates clustered into 21 pulsotypes). Virulence genes were present in all C. jejuni isolates while cdtA and cdtC were absent in C. coli. On the contrary, the latter showed higher antimicrobial resistance than C. jejuni. This study suggests that environment might be one of the main sources for Campylobacter transmission, as water supply seemed to be a clear cause of the contamination in a specific farm. However, in other farms other environmental factors contributed to the contamination, confirming the multifactorial origin of Campylobacter colonization in broilers. Therefore, biosecurity measures in farms are crucial to reduce Campylobacter contamination, which may have important implications for human and animal health.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter coli/efeitos dos fármacos , Campylobacter jejuni/efeitos dos fármacos , Galinhas , Farmacorresistência Bacteriana/genética , Genótipo , Doenças das Aves Domésticas/epidemiologia , Animais , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Campylobacter coli/genética , Campylobacter coli/patogenicidade , Campylobacter jejuni/genética , Campylobacter jejuni/patogenicidade , Doenças das Aves Domésticas/microbiologia , Prevalência , Estações do Ano , Espanha/epidemiologia , Virulência/genética
10.
Clin Colorectal Cancer ; 7(6): 398-401, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19036693

RESUMO

Isolated metastases to the pancreas from colorectal cancer (CRC) are very rare. We report a case of a 37-year-old man with a hereditary nonpolyposis CRC with a solitary metastasis to the pancreas who was treated with right hemicolectomy, neoadjuvant chemotherapy, complete surgical resection of the pancreatic metastasis, and adjuvant chemotherapy. After 12 months of follow-up, the patient remains free of disease. Differential diagnosis of isolated metastasis to the pancreas should be performed with pancreatic primary adenocarcinomas and neuroendocrine tumors. Symptoms and signs might be similar in these diseases: pain, weight loss, obstructive jaundice, and duodenal obstruction. Nevertheless, both primary and secondary tumors might be totally asymptomatic. Imaging techniques such as computed tomography, ultrasonography, magnetic resonance imaging, positron emission tomography, or endoscopic retrograde colangiopancreatography can provide relevant information about pancreatic lesions. However, it remains difficult to distinguish primary from metastatic pancreatic tumors. Although there is currently very limited experience with the surgical resection of isolated pancreatic metastases from CRC, it should be considered in selected patients with low surgical risk in order to prolong progression-free survival and overall survival. Additional chemotherapy is recommended.


Assuntos
Neoplasias Colorretais/patologia , Neoplasias Pancreáticas/secundário , Neoplasias Pancreáticas/cirurgia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/genética , Terapia Combinada , Mutação em Linhagem Germinativa , Humanos , Masculino , Proteína 2 Homóloga a MutS/genética , Neoplasias Pancreáticas/tratamento farmacológico , Linhagem
11.
Adv Food Nutr Res ; 86: 215-252, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30077223

RESUMO

Currently Campylobacter is the most commonly reported zoonosis in developed and developing countries. In the European Union, the number of reported confirmed cases of human campylobacteriosis was 246,307 in 2016, which represents 66.3 cases per 100,000 population. The genus Campylobacter includes 31 species with 10 subspecies. Within the genus Campylobacter, C. jejuni subsp. jejuni and C. coli are most frequently associated with human illness. Mainly, the infection is sporadic and self-limiting, although some cases of outbreaks have been also reported and some complications such as Guillain-Barré syndrome might appear sporadically. Although campylobacters are fastidious microaerophilic, unable to multiply outside the host and generally very sensitive, they can adapt and survive in the environment, exhibiting aerotolerance and resistance to starvation. Many mechanisms are involved in this, including pathogenicity, biofilm formation, and antibiotic resistant pathways. This chapter reviews the sources, transmission routes, the mechanisms, and strategies used by Campylobacter to persist in the whole food chain, from farm to fork. Additionally, different strategies are recommended for application along the poultry food chain to avoid the public health risk associated with this pathogen.


Assuntos
Infecções por Campylobacter/microbiologia , Campylobacter/fisiologia , Cadeia Alimentar , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Animais , Humanos , Zoonoses
12.
Rev Esp Salud Publica ; 912017 Mar 30.
Artigo em Espanhol | MEDLINE | ID: mdl-28356551

RESUMO

OBJECTIVE: Campylobacter is considered the most frequent agent of gastroenteritis in humans all around the world. The aim of this study was to know the incidence, trend and seasonality of notified campylobacteriosis cases in Castile and Leon, Spain, from 2008 to 2015. In addition, to describe the type of case and source of notification, and study the influence of age, sex and Campylobacter species on the hospitalization of cases. METHODS: Retrospective cross-sectional study with a time series analysis. Data on notified campylobacteriosis cases were collected from the Epidemiological Surveillance System of Castile and Leon (2008-2015). Incidence rates and incidence rate ratios by age, sex and year of notification were calculated. In order to estimate trend and seasonality, a time series analysis was performed using a multiplicative method and adjusted to a linear and exponential model. RESULTS: From 4,330 cases analyzed, 49.4% of children aged under 5 were affected. The ratio of men to women was 1.43 and 61.8% of cases were notified from secondary care. C. jejuni was isolated from 72.3% of samples (n=2,593). Incidence rate ranged from 11.42 cases per 100,000 inhabitants in 2008 to 33.53 in 2015. The seasonality range was from 71.97% (13th four-week period) to 125.54% (9th four-week period). Hospitalization reached 62.5% for people aged 60 or over. CONCLUSIONS: A growing trend of notified campylobacteriosis cases is observed in Castile and Leon (2008-2015), mainly in children aged under 5, with a peak in summer months. Males are more affected than females and hospitalization increases with age.


OBJETIVO: El Campylobacter es considerado el agente causal más común en el mundo de gastroenteritis humana. El objetivo de este estudio fue conocer la incidencia, tendencia y estacionalidad de los casos de campilobacteriosis declarados en Castilla y León (periodo 2008-2015) así como describir el tipo de presentación y nivel asistencial de declaración y estudiar la influencia de la edad, sexo y especie de Campylobacter en la hospitalización de las personas afectadas. METODOS: Estudio retrospectivo con análisis de la serie temporal. Los datos se obtuvieron de los casos notificados al Sistema de Vigilancia Epidemiológica de Castilla y León (2008-2015). Para cada año, se hallaron tasas de incidencia y razón de tasas de incidencia globales y por edad y sexo. Se analizó la tendencia y estacionalidad de la serie temporal mediante método multiplicativo, ajustándose a un modelo lineal y exponencial. RESULTADOS: Se analizaron 4.330 casos, con un 49,4% de afectación en menores de 5 años. La ratio hombre/mujer fue 1,43 y un 61,8% de casos se notificó desde atención especializada. C. jejuni se aisló en un 72,3% de muestras (n=2.593). La tasa de incidencia pasó de 11,42 casos por 100.000 habitantes en 2008 a 33,53 en 2015. El índice de estacionalidad varió entre 71,97% (cuatrisemana 13) y 125,54% (cuatrisemana 9). La hospitalización en ≥60 años alcanzó el 62,5%.


Assuntos
Infecções por Campylobacter/epidemiologia , Gastroenterite/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estações do Ano , Distribuição por Sexo , Espanha/epidemiologia , Adulto Jovem
13.
Free Radic Biol Med ; 87: 226-36, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26163001

RESUMO

The goal of this study was to evaluate the potential activation of the nuclear factor erythroid 2-related factor and the antioxidant-responsive element (Nrf2-ARE) signaling pathway in response to melatonin in isolated mouse pancreatic acinar cells. Changes in intracellular free Ca(2+) concentration were followed by fluorimetric analysis of fura-2-loaded cells. The activations of PKC and JNK were measured by Western blot analysis. Quantitative reverse transcription-polymerase chain reaction was employed to detect the expression of Nrf2-regulated antioxidant enzymes. Immunocytochemistry was employed to determine nuclear location of phosphorylated Nrf2, and the cellular redox state was monitored following MitoSOX Red-derived fluorescence. Our results show that stimulation of fura-2-loaded cells with melatonin (1 µM to 1 mM), in the presence of Ca(2+) in the extracellular medium, induced a slow and progressive increase of [Ca(2+)](c) toward a stable level. Melatonin did not inhibit the typical Ca(2+) response induced by CCK-8 (1 nM). When the cells were challenged with indoleamine in the absence of Ca(2+) in the extracellular solution (medium containing 0.5 mM EGTA) or in the presence of 1 mM LaCl(3), to inhibit Ca(2+) entry, we could not detect any change in [Ca(2+)](c). Nevertheless, CCK-8 (1 nM) was able to induce the typical mobilization of Ca(2+). When the cells were incubated with the PKC activator PMA (1 µM) in the presence of Ca(2+) in the extracellular medium, we observed a response similar to that noted when the cells were challenged with melatonin 100 µM. However, in the presence of Ro31-8220 (3 µM), a PKC inhibitor, stimulation of cells with melatonin failed to evoke changes in [Ca(2+)]c. Immunoblots, using an antibody specific for phospho-PKC, revealed that melatonin induces PKCα activation, either in the presence or in the absence of external Ca(2+). Melatonin induced the phosphorylation and nuclear translocation of the transcription factor Nrf2, and evoked a concentration-dependent increase in the expression of the antioxidant enzymes NAD(P)H-quinone oxidoreductase 1, catalytic subunit of glutamate-cysteine ligase, and heme oxygenase-1. Incubation of MitoSOX Red-loaded pancreatic acinar cells in the presence of 1 nM CCK-8 induced a statistically significant increase in dye-derived fluorescence, reflecting an increase in oxidation, that was abolished by pretreatment of cells with melatonin (100 µM) or PMA (1 µM). On the contrary, pretreatment with Ro31-8220 (3 µM) blocked the effect of melatonin on CCK-8-induced increase in oxidation. Finally, phosphorylation of JNK in the presence of CCK-8 or melatonin was also observed. We conclude that melatonin, via modulation of PKC and Ca(2+) signaling, could potentially stimulate the Nrf2-mediated antioxidant response in mouse pancreatic acinar cells.


Assuntos
Antioxidantes/metabolismo , Melatonina/administração & dosagem , Fator 2 Relacionado a NF-E2/biossíntese , Pâncreas/metabolismo , Proteína Quinase C/metabolismo , Células Acinares/metabolismo , Animais , Elementos de Resposta Antioxidante/genética , Cálcio/metabolismo , Sinalização do Cálcio/genética , Glutamato-Cisteína Ligase/genética , Glutamato-Cisteína Ligase/metabolismo , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Masculino , Camundongos , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Fator 2 Relacionado a NF-E2/genética , Pâncreas/citologia , Fosforilação , Proteína Quinase C/genética
14.
Toxicol Lett ; 229(3): 465-73, 2014 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-25068500

RESUMO

Ebselen is a seleno-organic compound that causes cell death in several cancer cell types. The mechanisms underlying its deleterious effects have not been fully elucidated. In this study, the effects of ebselen (1 µM-40 µM) on AR42J tumor cells have been examined. Cell viability was studied using AlamarBlue(®) test. Cell cycle phase determination was carried out by flow cytometry. Changes in intracellular free Ca(2+) concentration were followed by fluorimetry analysis of fura-2-loaded cells. Distribution of mitochondria, mitochondrial Ca(2+) concentration and mitochondrial membrane potential were monitored by confocal microscopy of cells loaded with Mitotracker Green™ FM, rhod-2 or TMRM respectively. Caspase-3 activity was calculated following the luorogenic substrate ACDEVD-AMC signal with a spectrofluorimeter. Results show that cell viability decreased in the presence of ebselen. An increase in the number of cells in the S-phase of the cell cycle was observed. Ebselen induced a concentration-dependent mobilization of Ca(2+) from agonist- and thapsigargin-sensitive Ca(2+) pools. Ebselen induced also a transient increase in mitochondrial Ca(2+) concentration, a progressive decrease of the mitochondrial membrane potential and a disruption of the mitochondrial network. Finally, a concentration-dependent increase in caspase-3 activity was detected. We conclude that ebselen exerts deleterious actions on the cells that involve the impairment of mitochondrial physiology and the activation of caspase-3-mediated apoptotic pathway.


Assuntos
Azóis/toxicidade , Morte Celular/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Compostos Organosselênicos/toxicidade , Animais , Cálcio/análise , Caspase 3/efeitos dos fármacos , Caspase 3/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citometria de Fluxo , Isoindóis , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/química , Neoplasias Pancreáticas/metabolismo , Ratos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA