RESUMO
Hepatitis Delta virus (HDV) is responsible for the most aggressive form of chronic hepatitis, which may evolve towards cirrhosis, hepatocellular carcinoma and death within few years. During the last 30 years the only available therapy was interferon or peg-IFN, which was characterized by poor tolerability and modest results. The detailed knowledge of the HDV replication cycle and its interaction with HBV allowed the introduction of new drugs which are currently in phase II or III of experimentation. Basically, bulevirtide, to date the only one approved by EMA, inhibits the entry of the virus into the hepatocytes and hence its intrahepatic spread; lonafarnib inhibits the pharnesylation process of the L-HDAg, which is critical for the assembly of the HDV virion; the nucleic acid polymers (NAPs) mainly block the production/release of HBsAg. The available clinical trials with these compounds showed an excellent anti-viral activity against HDV.
Assuntos
Hemorragia Gastrointestinal/etiologia , Neoplasias do Jejuno/complicações , Linfangioma/complicações , Endoscopia por Cápsula , Enteroscopia de Duplo Balão , Hemorragia Gastrointestinal/diagnóstico por imagem , Humanos , Neoplasias do Jejuno/diagnóstico por imagem , Linfangioma/diagnóstico por imagem , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: Chronic liver diseases (CLDs) impose a significant socioeconomic burden on patients and the healthcare system, but to what extent remains underexplored. We estimated costs and health-related-quality-of-life (HRQoL) among patients with CLDs at different stages and with different aetiologies. DESIGN: A cost-of-illness study was conducted. Direct costs, productivity loss and HRQoL were estimated in patients with chronic hepatitis, cirrhosis hepatocellular carcinoma (HCC) or where orthotopic liver transplantation (OLT) had been performed, for hepatitis C virus (HCV) infection, hepatitis B virus (HBV) infection, or in those with liver disease from other causes. Patients were retrospectively observed for 6â months. The societal perspective was adopted to calculate costs. RESULTS: In total, 1088 valid patients (median age=59.5â years, 60% men) were enrolled. 61% had chronic hepatitis, 20% cirrhosis, 8% HCC and 12% underwent OLT. HCV infection was identified in 52% and HBV infection in 29% of the patients. Adjusted mean direct costs increased from <200/patient-month in HCV-infected patients with hepatitis to >3000/patient-month in HBV infected patients with OLT. Antiviral treatment was the cost driver in patients with hepatitis, while hospital costs were the driver in the other subgroups. Absenteeism increased from HBV-infected patients with hepatitis (0.7â day/patient-month) to patients with OLT with other aetiologies (3.7â days/patient-month). HRQoL was on average more compromised in cirrhosis and patients with HCC, than in hepatitis and patients with OLT. HBV-infected patients generated higher direct costs, patients with other aetiologies generated the highest productivity loss and HCV-infected patients reported the worst HRQoL levels. CONCLUSIONS: The present study can be considered a benchmark for future research and to guide policies aimed at maximising the cost-effective of the interventions.
RESUMO
AIM: To evaluate the long-term eradication of hepatitis C virus (HCV) infection and liver-related complications in chronically infected patients that have achieved sustained virological response. METHODS: One hundred and fifty subjects with chronic hepatitis C (CHC) or cirrhosis and sustained virological response (SVR) between the years of 1989 and 2008 were enrolled in a long-term clinical follow-up study at the Gastrointestinal and Liver Unit of the University Hospital of Naples "Federicoâ II". At the beginning of the study, the diagnosis of HCV infection was made on the basis of serum positivity for antibodies to HCV and detection of HCV RNA transcripts, while a diagnosis of chronic hepatitis was formulated using imaging techniques and/or a liver biopsy. SVR was achieved by interferon-based therapy, both conventional and pegylated, with and without ribavirin treatment. The patients were evaluated for follow-up at a median length of 8.6 years, but ranged from 2-19.9 years. Among them, 137 patients had pre-treatment CHC and 13 had cirrhosis. The patients were followed with clinical, biochemical, virological, and ultrasound assessments on a given schedule. Finally, a group of 27 patients underwent a liver biopsy at the beginning of the study and transient elastography at their final visit to evaluate changes in liver fibrosis. RESULTS: The median follow-up was 8.6 years (range 2-19.9 years). HCV RNA remained undetectable in all patients, even in patients who eventually developed liver-related complications, indicating no risk of HCV recurrence. Three liver-related complications were observed: two cases of hepatocellular carcinoma and one case of bleeding from esophageal varices resulting in an incidence rate of 0.23%/person per year. Further, all three complications took place in patients diagnosed with cirrhosis before treatment began. Only one death due to liver-related causes occurred, resulting in a mortality rate of 0.077% person per year. This amounts to a 99.33% survival rate in our cohort of patients after therapy for HCV infection. Finally, of the 27 patients who underwent a liver biopsy at the beginning of the study, a reduction in liver fibrosis was observed in 70.3% of the cases; only three cases registering values of liver stiffness indicative of significant fibrosis. CONCLUSION: Patients with CHC and SVR show an excellent prognosis with no risk of recurrence and a very low rate of mortality. Our data indicate that virus-eradication following interferon treatment can last up to 20 years.
Assuntos
Antivirais/uso terapêutico , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Adulto , Idoso , Biomarcadores/sangue , Biópsia , Quimioterapia Combinada , Feminino , Seguimentos , Hepacivirus/genética , Hepacivirus/crescimento & desenvolvimento , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/sangue , Hepatite C Crônica/sangue , Hepatite C Crônica/complicações , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/mortalidade , Hospitais Universitários , Humanos , Interferon alfa-2 , Itália , Cirrose Hepática/diagnóstico , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/virologia , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Proteínas Recombinantes/uso terapêutico , Recidiva , Indução de Remissão , Fatores de Tempo , Resultado do Tratamento , Carga Viral , Adulto JovemRESUMO
PURPOSE: To assess the performance of the EQ-5D-5L version compared with the standard EQ-5D-3L in a clinical setting targeted at patients with chronic hepatic diseases (CHDs). METHODS: We introduced the 5L descriptive system into a cost-of-illness study involving patients with different CHDs. The patients completed a questionnaire including the two versions of the EQ-5D, together with other questions related to their condition. We tested the feasibility, the level of inconsistency, the redistribution properties among consistent responses, the ceiling effect, the discriminative power, and the convergent validity of the 5L compared with the 3L system. RESULTS: A total of 1,088 valid patients were recruited: 62% male, 19-89 (median = 59) years old. Patients had chronic hepatitis from HCV (31.8%) or HBV infections (29.3%) or other causes (7.8%), 20.4% had cirrhosis, 11.9% underwent liver transplantation, and 7.8% had hepatic carcinoma. Less than 1% of EQ-5D-5L were returned blank, and 1.6% or less of missing values were calculated on the dimensions of the partially completed questionnaires. The proportion and weight of inconsistent responses (i.e., 3L responses that were at least two levels away from the 5L responses) was 2.9% and 1.2 on average, respectively. Regarding redistribution, 57-65% of the patients answering level 2 with the 3L version redistributed their responses to levels 2 or 4 with the 5L version. A relative 7% reduction of the ceiling effect was found. Furthermore, the absolute informativity increased but the relative informativity slightly decreased in every domain, and the convergent validity with the VAS improved. CONCLUSIONS: In a clinical setting involving CHD patients, the EQ-5D-5L was shown to be feasible and with promising levels of performance. Our findings suggest that the 5L performs better in at least some of the properties analyzed, and encourage further research to also test other psychometric properties of this new version of the EQ-5D.
Assuntos
Hepatopatias/psicologia , Medição da Dor/métodos , Psicometria/métodos , Qualidade de Vida , Inquéritos e Questionários , Atividades Cotidianas , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos TestesRESUMO
Breast cancer cells with the CD44+/CD24- phenotype have been reported to be tumourigenic due to their enhanced capacity for cancer development and their self-renewal potential. The identification of human tumourigenic breast cancer cells in surgical samples has recently received increased attention due to the implications for prognosis and treatment, although limitations exist in the interpretation of these studies. To better identify the CD44+/CD24- cells in routine surgical specimens, 56 primary breast carcinoma cases were analysed by immunofluorescence and confocal microscopy, and the results were compared using flow cytometry analysis to correlate the amount and distribution of the CD44+/CD24- population with clinicopathological features. Using these methods, we showed that the breast carcinoma cells displayed four distinct sub-populations based on the expression pattern of CD44 and CD24. The CD44+/CD24- cells were found in 91% of breast tumours and constituted an average of 6.12% (range, 0.11%-21.23%) of the tumour. A strong correlation was found between the percentage of CD44+/CD24- cells in primary tumours and distant metastasis development (p = 0.0001); in addition, there was an inverse significant association with ER and PGR status (p = 0.002 and p = 0.001, respectively). No relationship was evident with tumour size (T) and regional lymph node (N) status, differentiation grade, proliferative index or HER2 status. In a multivariate analysis, the percentage of CD44+/CD24- cancer cells was an independent factor related to metastasis development (p = 0.004). Our results indicate that confocal analysis of fluorescence-labelled breast cancer samples obtained at surgery is a reliable method to identify the CD44+/CD24- tumourigenic cell population, allowing for the stratification of breast cancer patients into two groups with substantially different relapse rates on the basis of CD44+/CD24- cell percentage.
Assuntos
Neoplasias da Mama/metabolismo , Antígeno CD24/metabolismo , Carcinoma/metabolismo , Receptores de Hialuronatos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Carcinoma/mortalidade , Carcinoma/patologia , Feminino , Humanos , Imunofenotipagem , Glândulas Mamárias Humanas/metabolismo , Pessoa de Meia-Idade , Gradação de Tumores , Metástase Neoplásica , Estadiamento de NeoplasiasRESUMO
BACKGROUND: Receptor activator of NFkB (RANK), its ligand (RANKL) and the decoy receptor of RANKL (osteoprotegerin, OPG) play a pivotal role in bone remodeling by regulating osteoclasts formation and activity. RANKL stimulates migration of RANK-expressing tumor cells in vitro, conversely inhibited by OPG. MATERIALS AND METHODS: We examined mRNA expression levels of RANKL/RANK/OPG in a publicly available microarray dataset of 295 primary breast cancer patients. We next analyzed RANK expression by immunohistochemistry in an independent series of 93 primary breast cancer specimens and investigated a possible association with clinicopathological parameters, bone recurrence and survival. RESULTS: Microarray analysis showed that lower RANK and high OPG mRNA levels correlate with longer overall survival (Pâ=â0.0078 and 0.0335, respectively) and disease-free survival (Pâ=â0.059 and 0.0402, respectively). Immunohistochemical analysis of RANK showed a positive correlation with the development of bone metastases (Pâ=â0.023) and a shorter skeletal disease-free survival (SDFS, Pâ=â0.037). Specifically, univariate analysis of survival showed that "RANK-negative" and "RANK-positive" patients had a SDFS of 105.7 months (95% CI: 73.9-124.4) and 58.9 months (95% CI: 34.7-68.5), respectively. RANK protein expression was also associated with accelerated bone metastasis formation in a multivariate analysis (Pâ=â0.029). CONCLUSIONS: This is the first demonstration of the role of RANK expression in primary tumors as a predictive marker of bone metastasis occurrence and SDFS in a large population of breast cancer patients.
Assuntos
Neoplasias Ósseas/secundário , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Receptor Ativador de Fator Nuclear kappa-B/biossíntese , Idoso , Neoplasias da Mama/patologia , Feminino , Humanos , Imuno-Histoquímica/métodos , Ligantes , Pessoa de Meia-Idade , Metástase Neoplásica , Análise de Sequência com Séries de Oligonucleotídeos , Osteoprotegerina/biossíntese , Ligante RANK/biossíntese , RNA Mensageiro/metabolismoAssuntos
Antineoplásicos/uso terapêutico , Neoplasias Colorretais/genética , Análise Mutacional de DNA , Testes Genéticos/métodos , Mutação , Medicina de Precisão , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/genética , Proteínas ras/genética , Atitude do Pessoal de Saúde , Conscientização , Códon , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/secundário , Receptores ErbB/antagonistas & inibidores , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Terapia de Alvo Molecular , Seleção de Pacientes , Reação em Cadeia da Polimerase , Valor Preditivo dos Testes , Proteínas Proto-Oncogênicas p21(ras) , Estudos RetrospectivosRESUMO
Friedreich's ataxia (FRDA) is an autosomal recessive disorder caused by mutations in the gene encoding frataxin, a mitochondrial protein implicated in iron metabolism. Current evidence suggests that loss of frataxin causes iron overload in tissues, and increase in free-radical production leading to oxidation and inactivation of mitochondrial respiratory chain enzymes, particularly Complexes I, II, III and aconitase. Glutathione plays an important role in the detoxification of ROS in the Central Nervous System (CNS), where it also provides regulation of protein function by glutathionylation. The cytoskeletal proteins are particularly susceptible to oxidation and appear constitutively glutathionylated in the human CNS. Previously, we showed loss of cytoskeletal organization in fibroblasts of patients with FRDA found to be associated with increased levels of glutathione bound to cytoskeletal proteins. In this study, we analysed the glutathionylation of proteins in the spinal cord of patients with FRDA and the distribution of tubulin and neurofilaments in the same area. We found, for the first time, a significant rise of the dynamic pool of tubulin as well as abnormal distribution of the phosphorylated forms of human neurofilaments in FRDA motor neurons. In the same cells, the cytoskeletal abnormalities co-localized with an increase in protein glutathionylation and the mitochondrial proteins were normally expressed by immunocytochemistry. Our results suggest that in FRDA oxidative stress causes abnormally increased protein glutathionylation leading to prominent abnormalities of the neuronal cytoskeleton.
Assuntos
Citoesqueleto/metabolismo , Ataxia de Friedreich/metabolismo , Glutationa/metabolismo , Neurônios/metabolismo , Estresse Oxidativo/fisiologia , Medula Espinal/metabolismo , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/patologia , Adulto , Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/patologia , Feminino , Ataxia de Friedreich/patologia , Ataxia de Friedreich/fisiopatologia , Humanos , Distúrbios do Metabolismo do Ferro/complicações , Distúrbios do Metabolismo do Ferro/metabolismo , Distúrbios do Metabolismo do Ferro/fisiopatologia , Proteínas de Ligação ao Ferro/genética , Proteínas de Ligação ao Ferro/metabolismo , Masculino , Microtúbulos/metabolismo , Microtúbulos/patologia , Pessoa de Meia-Idade , Doenças Mitocondriais/etiologia , Doenças Mitocondriais/fisiopatologia , Proteínas de Neurofilamentos/metabolismo , Neurônios/patologia , Espécies Reativas de Oxigênio/metabolismo , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Tubulina (Proteína)/metabolismo , Adulto Jovem , FrataxinaRESUMO
A balanced redox status is necessary to optimize force production in contractile apparatus, where free radicals generated by skeletal muscle are involved in some basic physiological processes like excitation-contraction coupling. Protein glutathionylation has a key role in redox regulation of proteins and signal transduction. Here we show that myosin is sensitive to in vitro glutathionylation and MALDI-TOF analysis identified three potential sites of glutathione binding, two of them locating on the myosin head. Glutathionylation of myosin has an important impact on the protein structure, as documented by the lower fluorescence quantum yield of glutathionylated myosin and its increased susceptibility to the proteolytic cleavage. Myosin function is also sensitive to glutathionylation, which modulates its ATPase activity depending on GSSG redox balance. Thus, like the phosphorylation/dephosphorylation cycle, glutathionylation may represent a mechanism by which glutathione modulates sarcomere functions depending on the tissue redox state, and myosin may constitute a muscle redox-sensor.
Assuntos
Dissulfeto de Glutationa/química , Glutationa/química , Miosinas/química , Adenosina Trifosfatases/metabolismo , Animais , Western Blotting , Catálise/efeitos dos fármacos , Ditiotreitol/química , Ditiotreitol/metabolismo , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Dissulfeto de Glutationa/farmacologia , Miosinas/isolamento & purificação , Miosinas/metabolismo , Oxirredução , Fragmentos de Peptídeos/metabolismo , Conformação Proteica , Ratos , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Compostos de Sulfidrila/química , Compostos de Sulfidrila/metabolismo , Tripsina/química , Tripsina/metabolismoRESUMO
BACKGROUND AND AIM: Oxidative stress is an important pathophysiological mechanism in non-alcoholic steatohepatitis, where hepatocyte apoptosis is significantly increased correlating with disease severity. Protein glutathionylation occurs as a response to oxidative stress, where an increased concentration of oxidized glutathione modifies post-translational proteins by thiol disulfide exchange. In this study, we analyzed the protein glutathionylation in non-alcoholic fatty liver disease (NAFLD) and evaluated a potential association between glutathionylation, fibrosis, and vitamin E treatment. METHODS: Protein glutathionylation was studied in the livers of 36 children (mean age 12.5 years, range 4-16 years) subdivided into three groups according to their NAFLD activity score (NAS) by Western blot analysis and immunohistochemistry, using a specific monoclonal antibody. In addition, we identified the hepatocyte ultrastructures involved in glutathionylation by immunogold electron microscopy. RESULTS: Our findings showed that protein glutathionylation increases in the livers of patients with NAFLD and it is correlated with steatohepatitis and liver fibrosis. Its increase appears mainly in nuclei and cytosol of hepatocytes, and it is reversed by antioxidant therapy with reduced fibrosis. CONCLUSION: Protein glutathionylation significantly increases in livers with NAFLD, strongly suggesting that oxidative injury plays a crucial role in this disease. Furthermore, the marked increase of protein glutathionylation, in correlation with collagen VI immunoreactivity, suggests a link between the redox status of hepatic protein thiols and fibrosis.
Assuntos
Fígado Gorduroso/metabolismo , Glutationa/metabolismo , Fígado/metabolismo , Estresse Oxidativo , Proteínas/metabolismo , Adolescente , Antioxidantes/uso terapêutico , Criança , Pré-Escolar , Colágeno Tipo VI/metabolismo , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/fisiopatologia , Feminino , Hepatócitos/metabolismo , Humanos , Cirrose Hepática/metabolismo , Cirrose Hepática/fisiopatologia , Cirrose Hepática/terapia , Masculino , Vitamina E/uso terapêuticoRESUMO
Neuronal defense against free radicals is mediated primarily by the glutathione system. A cerebral defect of this system gives rise to the oxidative stress occurring in some neurological diseases. Glutathione provides a means of regulating protein function by glutathionylation, consisting of the formation of mixed disulfides between cysteines and glutathione. The glutathionylation of proteins, during both constitutive metabolism and oxidative stress, represents for the cell a mechanism to link physiological processes, and/or adaptive stress responses, to changes in intracellular redox states. In this study, we analyzed the topographic distribution of the protein glutathionylation normally occurring in human central nervous system. Constitutively glutathionylated proteins appeared uniformly distributed throughout all cortical layers of the cerebral and cerebellar cortex as well as throughout the gray matter of the spinal cord. The degree of immunocytochemical staining was clear in neurons, mild in oligodendrocytes, and weaker in astrocytes. The proteins preferentially glutathionylated were cytoskeletal proteins. Our results suggest a potential role of glutathionylation in the redox regulation of neuronal survival and in the control of axon/dendrite stability.
Assuntos
Sistema Nervoso Central/metabolismo , Radicais Livres/toxicidade , Glutationa/metabolismo , Neurônios/fisiologia , Oxirredução , Proteínas/metabolismo , 2',3'-Nucleotídeo Cíclico Fosfodiesterases/metabolismo , Actinas/metabolismo , Adolescente , Adulto , Western Blotting/métodos , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/patologia , Criança , Pré-Escolar , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Imuno-Histoquímica/métodos , Imunoprecipitação/métodos , Proteínas Associadas aos Microtúbulos/metabolismo , Pessoa de Meia-Idade , Proteínas de Neurofilamentos/metabolismo , Mudanças Depois da Morte , Tubulina (Proteína)/metabolismoRESUMO
BACKGROUND: Oxidative stress and accumulation of excessive fat in the liver may underlie the pathophysiology of nonalcoholic steatohepatitis (NASH). Given that glutathione blood metabolism may represent an indicator of tissue oxidative status, we analysed the blood profile of various forms of glutathione in children with NASH, and we evaluated the presence of systemic oxidative stress by calculating the oxidised/reduced glutathione ratio (GSSG/GSH). Furthermore, we analysed the catalytic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione transferase (GST), and glutathione reductase (GR) in blood of patients. METHODS: Blood samples were obtained from 21 children with NASH and 28 controls. Total, reduced, oxidised, and protein-bound glutathione concentrations were determined by reversed-phase liquid chromatography with fluorescence detection. Antioxidant enzymes were spectrophotometrically assayed by using specific substrates. RESULTS: Our findings showed a 1.5-fold increase of GSSG in patients, resulting in a significant rise of the GSSG/GSH ratio. SOD, GPx, and GR activities were not significantly different in NASH respect to controls, whereas GST, which provides the second defence line against oxidative stress, was 17.8% increased. CONCLUSIONS: Our data demonstrate an impairment of glutathione metabolism and antioxidant enzyme activities in blood of patients with NASH, supporting a consistent role of free radical cytotoxicity in the pathophysiology of the disease.
Assuntos
Antioxidantes/metabolismo , Fígado Gorduroso/metabolismo , Glutationa/metabolismo , Fígado/enzimologia , Adolescente , Criança , Pré-Escolar , Fígado Gorduroso/enzimologia , Feminino , Humanos , MasculinoRESUMO
In several neurodegenerative diseases, axonal degeneration occurs before neuronal death and contributes significantly to patients' disability. Hereditary spastic paraplegia (HSP) is a genetically heterogeneous condition characterized by selective degeneration of axons of the corticospinal tracts and fasciculus gracilis. HSP may therefore be considered an exemplary disease to study the local programs mediating axonal degeneration. We have developed a mouse model for autosomal recessive HSP due to mutations in the SPG7 gene encoding the mitochondrial ATPase paraplegin. Paraplegin-deficient mice are affected by a distal axonopathy of spinal and peripheral axons, characterized by axonal swelling and degeneration. We found that mitochondrial morphological abnormalities occurred in synaptic terminals and in distal regions of axons long before the first signs of swelling and degeneration and correlated with onset of motor impairment during a rotarod test. Axonal swellings occur through massive accumulation of organelles and neurofilaments, suggesting impairment of anterograde axonal transport. Retrograde axonal transport is delayed in symptomatic mice. We speculate that local failure of mitochondrial function may affect axonal transport and cause axonal degeneration. Our data suggest that a timely therapeutic intervention may prevent the loss of axons.
Assuntos
Axônios/patologia , Metaloendopeptidases/genética , Mitocôndrias/metabolismo , ATPases Associadas a Diversas Atividades Celulares , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Animais , Axônios/metabolismo , Transporte Biológico , Southern Blotting , Western Blotting , DNA Complementar/metabolismo , Transporte de Elétrons , Feminino , Genótipo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/patologia , Modelos Genéticos , Músculos/patologia , Mutação , Doenças Neurodegenerativas/genética , Fenótipo , Recombinação Genética , Paraplegia Espástica Hereditária/genética , Medula Espinal/patologia , Medula Espinal/ultraestrutura , Fatores de TempoRESUMO
Increasing evidence suggests that iron-mediated oxidative stress might underlie the development of neurodegeneration in Friedreich's ataxia (FRDA), an autosomal recessive ataxia caused by decreased expression of frataxin, a protein implicated in iron metabolism. In this study, we demonstrate that, in fibroblasts of patients with FRDA, the cellular redox equilibrium is shifted toward more protein-bound glutathione. Furthermore, we found that actin is glutathionylated, probably as a result of the accumulation of reactive oxygen species, generated by iron overload in the disease. Indeed, high-pressure liquid chromatography analysis of control fibroblasts in vivo treated with FeSO4 showed a significant increase in the protein-bound/free GSH ratio, and Western blot analysis indicated a relevant rise in glutathionylation. Actin glutathionylation contributes to impaired microfilament organization in FRDA fibroblasts. Rhodamine phalloidin staining revealed a disarray of actin filaments and a reduced signal of F-actin fluorescence. The same hematoxylin/eosin-stained cells showed abnormalities in size and shape. When we treated FRDA fibroblasts with reduced glutathione, we obtained a complete rescue of cytoskeletal abnormalities and cell viability. Thus, we conclude that oxidative stress may induce actin glutathionylation and impairment of cytoskeletal functions in FRDA fibroblasts.
Assuntos
Actinas/metabolismo , Fibroblastos/metabolismo , Ataxia de Friedreich/patologia , Glutationa/metabolismo , Antioxidantes/farmacologia , Western Blotting , Estudos de Casos e Controles , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Feminino , Compostos Ferrosos/farmacologia , Ataxia de Friedreich/metabolismo , Glutationa/análise , Humanos , Masculino , Oxirredução , Pele/química , Pele/patologiaRESUMO
Oxidative stress has been proposed as a pathogenic mechanism of atherosclerosis, cell aging, and neurologic disorders in Down syndrome. This study demonstrates a systemic decrease of all glutathione forms, including glutathionyl-hemoglobin, in the blood of children with Down syndrome. Furthermore, we obtained a disequilibrium, in vivo, between the antioxidant enzyme activities.
Assuntos
Síndrome de Down/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Superóxido Dismutase/metabolismo , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Síndrome de Down/enzimologia , Feminino , Humanos , Masculino , Espécies Reativas de Oxigênio/metabolismoRESUMO
Since glutathionyl-hemoglobin has been suggested to be a clinical marker of oxidative stress in human blood and given the growing biological relevance of oxidative stress as a pathogenic factor in several diseases, we describe a method to measure glutathionyl-hemoglobin concentration in erythrocytes, by using cation-exchange high-pressure liquid chromatography with UV detection. The glutathionyl-hemoglobin peak has been identified on the basis of the following findings: (a) the peak increased when the sample was incubated with oxidized glutathione; (b) the peak disappeared when the sample was reduced with dithiothreitol, with the simultaneous increase of that corresponding to hemoglobin A(0); (c) the peak could be detected by incubating hemoglobin A(0) with reduced glutathione; (e) deconvoluted mass spectrum of the glutathionyl-hemoglobin peak showed a 16172.0-Da molecular mass, corresponding to hemoglobin beta bound to glutathione. Glutathionyl-hemoglobin concentration has been determined in erythrocytes of 40 healthy subjects, with a mean value of 2.58+/-0.7%, calculated as the percentage of its peak area ratio to that of total hemoglobin (HbA(0)+HbA(2)+HbA(1C)+glutathionyl-hemoglobin). The availability of a simple and reproducible method to detect glutathionyl-hemoglobin concentration in blood could be useful in monitoring oxidative stress, and for investigating the efficacy of antioxidant therapies in clinical trials.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Eritrócitos/química , Glutationa/análise , Hemoglobinas/análise , Cátions/química , Feminino , Hemoglobina A/análise , Humanos , Masculino , OxirreduçãoRESUMO
El presente trabajo muestra un instrumento nuevo para la colocación de sonda o microtalla suprapúbica con las características adecuadas para tal propósito, a nuestra consideración. Se colocaron 36 sondas suprapúbicas con más facilidad, en menor tiempo y sin complicaciones. Por lo que recomendamos su uso