Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Nat Commun ; 12(1): 2626, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976179

RESUMO

By conferring systemic protection and durable benefits, cancer immunotherapies are emerging as long-term solutions for cancer treatment. One such approach that is currently undergoing clinical testing is a therapeutic anti-cancer vaccine that uses two different viruses expressing the same tumor antigen to prime and boost anti-tumor immunity. By providing the additional advantage of directly killing cancer cells, oncolytic viruses (OVs) constitute ideal platforms for such treatment strategy. However, given that the targeted tumor antigen is encoded into the viral genomes, its production requires robust infection and therefore, the vaccination efficiency partially depends on the unpredictable and highly variable intrinsic sensitivity of each tumor to OV infection. In this study, we demonstrate that anti-cancer vaccination using OVs (Adenovirus (Ad), Maraba virus (MRB), Vesicular stomatitis virus (VSV) and Vaccinia virus (VV)) co-administered with antigenic peptides is as efficient as antigen-engineered OVs and does not depend on viral replication. Our strategy is particularly attractive for personalized anti-cancer vaccines targeting patient-specific mutations. We suggest that the use of OVs as adjuvant platforms for therapeutic anti-cancer vaccination warrants testing for cancer treatment.


Assuntos
Antígenos de Neoplasias/administração & dosagem , Vacinas Anticâncer/administração & dosagem , Neoplasias/terapia , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Neoplasias/imunologia , Vírus Oncolíticos/genética , Poli I-C/administração & dosagem , Poli I-C/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Vaccinia virus , Vírus da Estomatite Vesicular Indiana , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Diabetologia ; 61(1): 253, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29119243

RESUMO

In light of forensic evidence indicating duplication and/or manipulation of western blot images the Editor-in-Chief is retracting the article cited above.

3.
Physiol Res ; 66(2): 317-323, 2017 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-27982685

RESUMO

This study aimed to compare the effects of three different resistance exercise models on the quadriceps muscle cross-sectional area, as well as on mTOR phosphorylation and other pivotal molecules involved in the upstream regulation of mTOR. Twenty-four male Wistar rats were divided into untrained (control), endurance resistance training, strength resistance training, and hypertrophy resistance training (HRT) groups (n=6). After 12 weeks of training, the red portion of the quadriceps was removed for histological and Western blot analyses. The results showed that the quadriceps weight and cross-sectional areas in the exercised groups were higher than those of the untrained rats. However, the HRT group presented better results than the other two experimental groups. This same pattern was observed for mTOR phosphorylation and for the most pivotal molecules involved in the upstream control of mTOR (increase of PKB, 14-3-3, ERK, p38 MAPK, and 4E-BP1 phosphorylation, and reduction of tuberin, sestrin 2, REDD1, and phospho AMPK). In summary, our study showed that HRT leads to high levels of mTOR phosphorylation as well as of other proteins involved in the upstream regulation of mTOR.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Condicionamento Físico Animal/métodos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Treinamento Resistido/métodos , Serina-Treonina Quinases TOR/metabolismo , Animais , Masculino , Tamanho do Órgão/fisiologia , Ratos , Ratos Wistar , Resultado do Tratamento
4.
Neuroscience ; 311: 231-42, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26480811

RESUMO

Low body weight gain and food intake are related to exhaustive training and overtraining; however, the molecular mechanisms responsible for these alterations remain unknown. The main aim of this study was to evaluate the effects of running overtraining (OT) protocols performed downhill, uphill and without inclination on the inflammatory pathway in the mouse hypothalamus. The rodents were randomized into the control (C), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR) groups. The body weights and food intake were recorded daily. The incremental load, exhaustive, rotarod and grip force tests were used to measure performance. At 36 h after the grip force test was performed at the end of OT protocols (i.e., week eight) and/or after a 2-week total recovery period (i.e., week 10), the hypothalamus and gastrocnemius were extracted for immunoblotting analysis. In addition, the serum was used to determine cytokine and leptin concentrations. From week 0 to week 8, the OTR/down group exhibited decreased body weight and food intake, and the OTR/up group increased their food intake. At week 10, the OTR/down group exhibited increased body weight, while the OTR group decreased their food intake. The OTR/down group exhibited increased IL-1beta, IL-6, TNF-alpha, pSAPK/JNK and SOCS3 levels at week eight. The OTR/down, OTR/up and OTR groups exhibited increased IL-10 levels at week 10. The OTR/up group displayed increased pJAK2 levels at week eight. While the OTR/down group exhibited increased IL-1beta levels, the OTR/down and OTR/up groups exhibited increased IL-6 and TNF-alpha levels, but decreased IL-10 levels in the gastrocnemius at week eight. The three OT protocols increased the IL-1beta and IL-6 levels, but only the OTR/down and OTR/up groups had increased TNF-alpha levels in serum at week eight. The serum leptin levels were lower for the OTR group compared with the CT group at week eight. In conclusion, the OTR/down protocol induced transitory hypothalamic inflammation with concomitant reductions in the body weight and food intake. After the 2-week total recovery period, the OTR/down group had reversed the hypothalamic inflammation, with the concomitant normalization of the body weight and food intake.


Assuntos
Peso Corporal/fisiologia , Ingestão de Alimentos/fisiologia , Hipotálamo/imunologia , Inflamação/metabolismo , Atividade Motora/fisiologia , Corrida/fisiologia , Animais , Citocinas/metabolismo , Força da Mão/fisiologia , Leptina/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Músculo Esquelético/imunologia , Distribuição Aleatória , Teste de Desempenho do Rota-Rod , Comportamento Sedentário
5.
Endocrinology ; 156(11): 4033-46, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26280128

RESUMO

Subclinical systemic inflammation is a hallmark of obesity and insulin resistance. The results obtained from a number of experimental studies suggest that targeting different components of the inflammatory machinery may result in the improvement of the metabolic phenotype. Unsaturated fatty acids exert antiinflammatory activity through several distinct mechanisms. Here, we tested the capacity of ω3 and ω9 fatty acids, directly from their food matrix, to exert antiinflammatory activity through the G protein-coupled receptor (GPR)120 and GPR40 pathways. GPR120 was activated in liver, skeletal muscle, and adipose tissues, reverting inflammation and insulin resistance in obese mice. Part of this action was also mediated by GPR40 on muscle, as a novel mechanism described. Pair-feeding and immunoneutralization experiments reinforced the pivotal role of GPR120 as a mediator in the response to the nutrients. The improvement in insulin sensitivity in the high-fat substituted diets was associated with a marked reduction in tissue inflammation, decreased macrophage infiltration, and increased IL-10 levels. Furthermore, improved glucose homeostasis was accompanied by the reduced expression of hepatic gluconeogenic enzymes and reduced body mass. Thus, our data indicate that GPR120 and GPR40 play a critical role as mediators of the beneficial effects of dietary unsaturated fatty acids in the context of obesity-induced insulin resistance.


Assuntos
Gorduras na Dieta/farmacologia , Resistência à Insulina , Obesidade/prevenção & controle , Ácido Oleico/farmacologia , Ácido alfa-Linolênico/farmacologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Gorduras na Dieta/administração & dosagem , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/farmacologia , Immunoblotting , Inflamação/metabolismo , Inflamação/fisiopatologia , Inflamação/prevenção & controle , Insulina/administração & dosagem , Insulina/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos Obesos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Obesidade/fisiopatologia , Ácido Oleico/administração & dosagem , Interferência de RNA , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Aumento de Peso/efeitos dos fármacos , Ácido alfa-Linolênico/administração & dosagem
6.
Int J Sports Med ; 36(5): 378-85, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25665003

RESUMO

The aim of this investigation was to evaluate the effects of 3 overtraining (OT) protocols on the glial activation and apoptosis in the spinal cords of mice. Rodents were divided into control (C; sedentary mice), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR). The incremental load test, ambulation test, exhaustive test and functional behavioural assessment were used as performance evaluation parameters. 36 h after the exhaustive test, the dorsal and ventral parts of the lumbar spinal cord (L4-L6) were dissected for subsequent protein analysis by immunoblotting. The OT protocols led to similar responses of some performance parameters. The ventral glial fibrillary acidic protein (GFAP) protein levels were diminished in the OTR/up and OTR compared to CT and OTR/down groups. The ventral ionized calcium binding adaptor molecule 1 (Iba-1), and the dorsal GFAP and Iba-1 protein levels were increased in the OTR/down compared to the other groups. The ratio between the cleaved capase-3/caspase-3 and cleaved caspase-9/caspase-9 measured in the spinal cord were not sensitive to the OT protocols. In summary, the OTR/down activated the glial cells in the motor (i. e. Iba-1) and sensory (i. e. GFAP and Iba-1) neurons without leading to apoptosis.


Assuntos
Apoptose/fisiologia , Músculo Esquelético/fisiopatologia , Miosite/fisiopatologia , Neuroglia/fisiologia , Condicionamento Físico Animal/métodos , Medula Espinal/citologia , Animais , Astrócitos/fisiologia , Proteínas de Ligação ao Cálcio/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/metabolismo , Fadiga Muscular/fisiologia , Corrida/fisiologia
7.
Horm Metab Res ; 46(9): 621-7, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24691733

RESUMO

Obesity is associated with myocardial insulin resistance and impairment of the mammalian target of rapamycin (mTOR) signaling pathway. The activation of the mTOR cascade by exercise has been largely shown in skeletal muscle, but insufficiently analyzed in myocardial tissue. In addition, little is known regarding the mTOR upstream molecules in the hearts of obese animals and even less about the role of exercise in this process. Thus, the present study was aimed to evaluate the effects of physical exercise on P38 Mitogen-Activated Protein Kinase (P38MAPK) phosphorylation and the REDD1 (regulated in development and DNA damage responses 1) and 14-3-3 protein levels in the myocardium of diet-induced obesity (DIO) rats. After achievement of DIO and insulin resistance, Wistar rats were divided in 2 groups: sedentary obese rats and obese rats performed treadmill running (50-min/day, 5 days per week velocity of 1.0 km/h for 2 months). Forty-eight hours after the final physical exercise, the rats were killed, and the myocardial tissue was removed for Western blot analysis. DIO increased the REDD1 protein levels and reduced the 14-3-3 protein levels and P38MAPK, mTOR, P70S6k (p70 ribosomal S6 protein kinase), and 4EBP1 (4E-binding protein-1) phosphorylation. Interestingly, physical exercise reduced the REDD1 protein levels and increased the 14-3-3 protein levels and P38MAPK, mTOR, P70S6k, and 4EBP1 phosphorylation. Moreover, exercise increased the REDD1/14-3-3 association in the heart. Our results indicate that the phospho-P38MAPK, REDD1, and 14-3-3 protein levels were reduced in the myocardium of obese rats and that physical exercise increased the protein levels of these molecules.


Assuntos
Proteínas 14-3-3/metabolismo , Terapia por Exercício , Miocárdio/metabolismo , Obesidade/metabolismo , Obesidade/terapia , Ratos Wistar/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Proteínas 14-3-3/genética , Animais , Dieta Hiperlipídica/efeitos adversos , Humanos , Insulina/metabolismo , Masculino , Músculo Esquelético/metabolismo , Obesidade/etiologia , Obesidade/genética , Ratos , Ratos Wistar/genética , Proteínas Repressoras/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição , Proteínas Quinases p38 Ativadas por Mitógeno/genética
8.
Int J Sports Med ; 35(2): 139-46, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23868687

RESUMO

The aims of the this study were a) to verify whether the performance decrease induced by nonfunctional overreaching (NFOR) is linked to high concentrations of cytokines in serum, skeletal muscles and liver; b) to verify muscle myostatin adaptation to NFOR; c) to verify the effects of chronic glucose supplementation on the parameters mentioned above. Mice were divided into control (C), trained (TR), overtrained (OTR) and supplemented overtrained (OTR + S). The incremental load test (ILT) and exhaustive test (ET) were used to measure performances before and after exercise protocols. 24 h after ET, muscles and liver were removed and stored at -80°C for subsequent measurements. Total blood was collected from decapitation for subsequent determination of cytokine concentrations. Generally, OTR and OTR + S presented higher contents of IL-6, TNF-alpha, GLUT-4 and myostatin in muscle samples compared to C and TR. Glucose supplementation attenuated the high contents of IL-6, TNF-alpha and IL-15 in liver, and of IL-6 in serum. In summary, NFOR led to low-grade chronic inflammation and myostatin upregulation.


Assuntos
Glucose/administração & dosagem , Inflamação/metabolismo , Movimento/fisiologia , Miostatina/metabolismo , Condicionamento Físico Animal/fisiologia , Animais , Biomarcadores/metabolismo , Doença Crônica , Transportador de Glucose Tipo 4/metabolismo , Inflamação/etiologia , Interleucina-6/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/efeitos adversos , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima
10.
Horm Metab Res ; 45(3): 190-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22972182

RESUMO

It is well known that high-fat diets (HFDs) induce obesity and result in an increase in oxidative stress in adipose tissue, which leads to an impairment of fat mobilization by a downregulation of the lipases, such as hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL). On the other hand, exercise training leads to a reduction in adipose tissue and an improvement of antioxidant status and the lipolytic pathway. Our aim was to examine the influence of exercise and moderate intensity training on oxidative stress parameters and the relationship between the proteins involved in the lipolysis of animals subjected to a high-fat fed diet. Twenty-four mice were used and divided into 4 groups (n=6): standard diet (SD); standard diet plus exercise (SD+Ex); high-fat diet (HFD); and high-fat diet plus exercise (HFD+Ex). The animals received HFD for 90 days and submitted to a daily training protocol in swinging. The animals were euthanized 48 h after the last session of exercise. White adipose tissue epididymal fat was excised for the measurement of oxidative stress parameters and protein levels of lipolytic enzymes by Western blotting. The results show an increase in body weight after 90 days of HFD, and exercise training prevented great gain. In adipose tissue, lipid peroxidation and protein carbonylation increased after HFD and decreased significantly after exercise training. The protein level of CGI-58 was reduced, and FAS was increased in the HFD than in SD, whereas ATGL exhibited an increase (p<0.05) in HFD than in SD. The exercise plays a significant role in reducing oxidative damage, along with the regulation of proteins that are involved in the lipolysis of animals exposed to HFD.


Assuntos
Tecido Adiposo/patologia , Dieta Hiperlipídica , Lipólise , Obesidade/patologia , Condicionamento Físico Animal , Espécies Reativas de Oxigênio/metabolismo , Tecido Adiposo/enzimologia , Animais , Antioxidantes/metabolismo , Peso Corporal , Epididimo/enzimologia , Epididimo/patologia , Lipogênese , Masculino , Camundongos , Camundongos Obesos , Obesidade/enzimologia , Oxirredução , Carbonilação Proteica , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
11.
Lipids Health Dis ; 11: 134, 2012 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-23046739

RESUMO

BACKGROUND: The aim of the present study was to evaluate the protective effect of concurrent exercise in the degree of the insulin resistance in mice fed with a high-fat diet, and assess adiponectin receptors (ADIPOR1 and ADIPOR2) and endosomal adaptor protein APPL1 in different tissues. METHODS: Twenty-four mice were randomized into four groups (n = 6): chow standard diet and sedentary (C); chow standard diet and simultaneous exercise training (C-T); fed on a high-fat diet and sedentary (DIO); and fed on a high-fat diet and simultaneous exercise training (DIO-T). Simultaneously to starting high-fat diet feeding, the mice were submitted to a swimming exercise training protocol (2 x 30 minutes, with 5 minutes of interval/day), five days per week, for twelve weeks (90 days). Animals were then euthanized 48 hours after the last exercise training session, and adipose, liver, and skeletal muscle tissue were extracted for an immunoblotting analysis. RESULTS: IR, IRs, and Akt phosphorylation decreased in the DIO group in the three analyzed tissues. In addition, the DIO group exhibited ADIPOR1 (skeletal muscle and adipose tissue), ADIPOR2 (liver), and APPL1 reduced when compared with the C group. However, it was reverted when exercise training was simultaneously performed. In parallel, ADIPOR1 and 2 and APPL1 protein levels significantly increase in exercised mice. CONCLUSIONS: Our findings demonstrate that exercise training performed concomitantly to a high-fat diet reduces the degree of insulin resistance and improves adipoR1-2/APPL1 protein levels in the hepatic, adipose, and skeletal muscle tissue.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Terapia por Exercício , Resistência à Insulina , Receptores de Adiponectina/metabolismo , Tecido Adiposo/metabolismo , Animais , Glicemia/análise , Dieta Hiperlipídica , Humanos , Insulina/metabolismo , Resistência à Insulina/genética , Resistência à Insulina/fisiologia , Fígado/metabolismo , Camundongos , Músculo Esquelético/metabolismo , Obesidade/metabolismo
12.
Horm Metab Res ; 44(12): 885-90, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22932913

RESUMO

The literature has associated hepatic insulin action with NAFLD. In this sense, treatments to revert steatosis and improve hepatic insulin action become important. Our group has demonstrated that inhibition of Sterol Regulatory Element Binding Proteins-1c (SREBP-1c) reverses hepatic steatosis. However, insulin signals after NAFLD reversion require better investigation. Thus, in this study, we investigated if the reversal of NAFLD by SREBP-1c inhibitor results in improvement in the hepatic insulin signal in obesity mice. After installation/achievement of diet-induced obesity and insulin resistance, Swiss mice were divided into 3 groups: i) Lean, ii) D-IHS, diet-induced hepatic steatosis [no treatment with antisense oligonucleotide (ASO)], and iii) RD-IHS, reversion of diet-induced hepatic steatosis (treated with ASO). The mice were treated with ASO SREBP-1c as previously described by our group. After ASO treatment, one set of animals was anesthetized and used for in vivo test, and another mice set was anesthetized and used for histology and Western blot analysis. Reversion of diet-induced hepatic steatosis did not change blood glucose, glucose decay constant (k(ITT)), body weight, or serum insulin levels. In addition, results showed that the protocol did not improve insulin pathway signaling, as confirmed by the absence of changes in IR, IRS1, Akt and Foxo1 phosphorylation in hepatic tissue. In parallel, no alterations were observed in proinflammatory molecules. Thus, our results suggest that the inhibition of SREBP-1c reverts steatosis, but without improving insulin hepatic resistance.


Assuntos
Fígado Gorduroso/prevenção & controle , Resistência à Insulina , Lipotrópicos/uso terapêutico , Fígado/efeitos dos fármacos , Obesidade/fisiopatologia , Oligonucleotídeos Antissenso/uso terapêutico , Proteína de Ligação a Elemento Regulador de Esterol 1/antagonistas & inibidores , Animais , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/etiologia , Fígado Gorduroso/imunologia , Injeções Intraperitoneais , Insulina/sangue , Insulina/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipotrópicos/administração & dosagem , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Hepatopatia Gordurosa não Alcoólica , Obesidade/etiologia , Obesidade/metabolismo , Obesidade/patologia , Oligonucleotídeos Antissenso/administração & dosagem , Fosforilação/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Distribuição Aleatória , Receptor de Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
13.
J Cell Physiol ; 227(7): 2917-26, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21938726

RESUMO

Hepatic insulin resistance is the major contributor to fasting hyperglycemia in type 2 diabetes. The protein kinase Akt plays a central role in the suppression of gluconeogenesis involving forkhead box O1 (Foxo1) and peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α), and in the control of glycogen synthesis involving the glycogen synthase kinase beta (GSK3ß) in the liver. It has been demonstrated that endosomal adaptor protein APPL1 interacts with Akt and blocks the association of Akt with its endogenous inhibitor, tribbles-related protein 3 (TRB3), improving the action of insulin in the liver. Here, we demonstrated that chronic exercise increased the basal levels and insulin-induced Akt serine phosphorylation in the liver of diet-induced obese mice. Endurance training was able to increase APPL1 expression and the interaction between APPL1 and Akt. Conversely, training reduced both TRB3 expression and TRB3 and Akt association. The positive effects of exercise on insulin action are reinforced by our findings that showed that trained mice presented an increase in Foxo1 phosphorylation and Foxo1/PGC-1α association, which was accompanied by a reduction in gluconeogenic gene expressions (PEPCK and G6Pase). Finally, exercised animals demonstrated increased at basal and insulin-induced GSK3ß phosphorylation levels and glycogen content at 24 h after the last session of exercise. Our findings demonstrate that exercise increases insulin action, at least in part, through the enhancement of APPL1 and the reduction of TRB3 expression in the liver of obese mice, independently of weight loss.


Assuntos
Insulina/metabolismo , Fígado/metabolismo , Obesidade/metabolismo , Condicionamento Físico Animal/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/biossíntese , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Dieta , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Gluconeogênese/genética , Gluconeogênese/fisiologia , Glucose-6-Fosfatase/genética , Glucose-6-Fosfatase/metabolismo , Glicogênio/genética , Glicogênio/metabolismo , Quinase 3 da Glicogênio Sintase/genética , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Insulina/genética , Masculino , Camundongos , Camundongos Obesos , Obesidade/etiologia , Obesidade/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Fosforilação , Resistência Física/fisiologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição , Redução de Peso/fisiologia
14.
Acta Physiol (Oxf) ; 198(1): 61-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19681769

RESUMO

AIM: TRB3 became of major interest in diabetes research when it was shown to interact with and inhibit the activity of Akt. Conversely, physical exercise has been linked to improved glucose homeostasis. Thus, the current study was designed to investigate the effects of acute exercise on TRB3 expression and whole body insulin sensitivity in obese diabetic mice. METHODS: Male leptin-deficient (ob/ob) mice swam for two 3-h-long bouts, separated by a 45-min rest period. After the second bout of exercise, food was withdrawn 6 h before antibody analysis. Eight hours after the exercise protocol, the mice were submitted to an insulin tolerance test (ITT). Gastrocnemius muscle samples were evaluated for insulin receptor (IR) and IRS-1 tyrosine phosphorylation, Akt serine phosphorylation, TRB3/Akt association and membrane GLUT4 expression. RESULTS: Western blot analysis showed that TRB3 expression was reduced in the gastrocnemius of leptin-deficient (ob/ob) mice submitted to exercise when compared with respective ob/ob mice at rest. In parallel, there was an increase in the insulin-signalling pathway in skeletal muscle from leptin-deficient mice after exercise. Furthermore, the GLUT4 membrane expression was increased in the muscle after the exercise protocol. Finally, a single session of exercise improved the glucose disappearance (K(ITT)) rate in ob/ob mice. CONCLUSION: Our results demonstrate that acute exercise reverses TRB3 expression and insulin signalling restoration in muscle. Thus, these results provide new insights into the mechanism by which physical activity ameliorates whole body insulin sensitivity in type 2 diabetes.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina/fisiologia , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/fisiologia , Animais , Western Blotting , Transportador de Glucose Tipo 4/metabolismo , Insulina/metabolismo , Masculino , Camundongos , Camundongos Obesos , Transdução de Sinais/fisiologia
15.
Diabetologia ; 48(9): 1860-71, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16025253

RESUMO

AIMS/HYPOTHESIS: The coactivator of nuclear receptors, peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) has been implicated in a series of events that contribute to the control of glucose metabolism. We have recently reported the use of a PGC-1alpha antisense oligonucleotide (PGC-1alphaAS) that inhibits up to 60% of PGC-1alpha expression in pancreatic islets, leading to increased insulin secretion. This oligonucleotide was used in this study to try to ameliorate diet-induced type 2 diabetes in a genetically predisposed mouse strain (Swiss mice). MATERIALS AND METHODS: Glucose and insulin tolerance tests, euglycaemic-hyperinsulinaemic clamp, immunoprecipitation assays, immunoblotting assays and immunohistochemistry were used in this investigation. RESULTS: Swiss mice became obese and overtly diabetic after 8 weeks of feeding with chow containing 24% saturated fat. One daily dose (1.0 nmol) of PGC-1alphaAS significantly reduced glucose and increased insulin blood levels without affecting food intake and body weight. These effects were accompanied by a reduced area under the glucose curve during an intraperitoneal glucose tolerance test, an increased constant of glucose decay (K(itt)) during an insulin tolerance test, and an increased glucose consumption rate during a euglycaemic-hyperinsulinaemic clamp. Moreover, mice treated with PGC-1alphaAS presented an outstanding reduction of macroscopic and microscopic features of hepatic steatosis. These effects were accompanied by reduced expression or function of a series of proteins involved in lipogenesis. CONCLUSIONS/INTERPRETATION: PGC-1alpha is an attractive target for pharmacological therapeutics in type 2 diabetes mellitus and diet-induced hepatic steatosis.


Assuntos
Diabetes Mellitus/prevenção & controle , Fígado Gorduroso/prevenção & controle , Transativadores/antagonistas & inibidores , Transativadores/genética , Tecido Adiposo/fisiologia , Animais , Glicemia/metabolismo , Dieta , Regulação Enzimológica da Expressão Gênica , Insulina/sangue , Camundongos , Camundongos Endogâmicos CBA , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Transdução de Sinais , Fatores de Transcrição
16.
J Endocrinol ; 181(1): 25-38, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15072564

RESUMO

Autocrine and paracrine insulin signaling may participate in the fine control of insulin secretion. In the present study, tissue distribution and protein amounts of the insulin receptor and its major substrates, insulin receptor substrate (IRS)-1 and IRS-2, were evaluated in a model of impaired glucose-induced insulin secretion, the protein-deficient rat. Immunoblot and RT-PCR studies showed that the insulin receptor and IRS-2 expression are increased, whilst IRS-1 protein and mRNA contents are decreased in pancreatic islets of protein-deficient rats. Immunohistochemical studies revealed that the insulin receptor and IRS-1 and -2 are present in the great majority of islet cells; however, the greatest staining was localized at the periphery, suggesting a co-localization with non-insulin-secreting cells. Exogenous insulin stimulation of isolated islets promoted higher insulin receptor and IRS-1 and -2 tyrosine phosphorylation in islets from protein-deficient rats, as compared with controls. Moreover, insulin-induced IRS-1- and IRS-2-associated phosphatidylinositol 3-kinase activity are increased in islets of protein-deficient rats. The reduction of IRS-1 and IRS-2 protein expression in islets isolated from protein-deficient rats by the use of antisense IRS-1 or IRS-2 phosphorthioate-modified oligonucleotides partially restored glucose-induced insulin secretion. Thus, the impairment of insulin cell signaling through members of the IRS family of proteins in isolated rat pancreatic islets improves glucose-induced insulin secretion. The present data reinforced the role of insulin paracrine and autocrine signaling in the control of its own secretion.


Assuntos
Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Fosfoproteínas/metabolismo , Deficiência de Proteína/metabolismo , Animais , Glucagon/metabolismo , Glucose/administração & dosagem , Imuno-Histoquímica/métodos , Proteínas Substratos do Receptor de Insulina , Secreção de Insulina , Peptídeos e Proteínas de Sinalização Intracelular , Ilhotas Pancreáticas/química , Masculino , Comunicação Parácrina/fisiologia , Fosfoproteínas/análise , Deficiência de Proteína/fisiopatologia , Ratos , Ratos Wistar , Somatostatina/análise
17.
Diabetologia ; 46(11): 1522-31, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14576981

RESUMO

AIMS/HYPOTHESIS: Sympathetic inputs inhibit insulin secretion through alpha2-adrenergic receptors coupled with Gi protein. High adrenergic tonus generated by exposure of homeothermic animals to cold reduces insulin secretion. In this study we evaluate the participation of UCP-2 in cold-induced regulation of insulin secretion. METHODS: Static insulin secretion studies, western blotting and immunohistochemistry were used in this investigation. RESULTS: Exposure of rats to cold during 8 days promoted 60% ( n=15, p<0.05) reduction of basal serum insulin levels concentration accompanied by reduction of the area under insulin curve during i.p. GTT (50%, n=15, p<0.05). Isolated islets from cold-exposed rats secreted 57% ( n=6, p<0.05) less insulin following a glucose challenge. Previous sympathectomy, partially prevented the effect of cold exposure upon insulin secretion. Islets isolated from cold-exposed rats expressed 51% ( n=6, p<0.5) more UCP-2 than islets from control rats, while the inhibition of UCP-2 expression by antisense oligonucleotide treatment partially restored insulin secretion of islets obtained from cold-exposed rats. Cold exposure also induced an increase of 69% ( n=6, p<0.05) in PGC-1 protein content in pancreatic islets. Inhibition of islet PGC-1 expression by antisense oligonucleotide abrogated cold-induced UCP-2 expression and partially restored insulin secretion in islets exposed to cold. CONCLUSION/INTERPRETATION: Our data indicate that sympathetic tonus generated by exposure of rats to cold induces the expression of PGC-1, which participates in the control of UCP-2 expression in pancreatic islets. Increased UCP-2 expression under these conditions could reduce the beta-cell ATP/ADP ratio and negatively regulate insulin secretion.


Assuntos
Aclimatação/fisiologia , Insulina/metabolismo , Ilhotas Pancreáticas/fisiologia , Proteínas de Membrana Transportadoras/genética , Proteínas Mitocondriais/genética , Fatores de Transcrição/genética , Animais , Sequência de Bases , Glicemia/metabolismo , Temperatura Baixa , Primers do DNA , Metabolismo Energético , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas In Vitro , Injeções Intravenosas , Insulina/sangue , Insulina/farmacologia , Secreção de Insulina , Canais Iônicos , Ilhotas Pancreáticas/inervação , Ilhotas Pancreáticas/metabolismo , Leptina/sangue , Oligonucleotídeos Antissenso/farmacologia , Ratos , Fatores de Transcrição/antagonistas & inibidores , Proteína Desacopladora 2
18.
AIDS Care ; 15(4): 539-48, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14509868

RESUMO

The study objective was to assess willingness of men who have sex with men (MSM) enrolled in a vaccine preparedness study ('Projeto Rio') to participate in phase III anti-HIV/AIDS vaccine trials. Overall, 57% of Projeto Rio participants stated they would participate in a putative vaccine trial. MSM who reported commercial sex work were significantly (p < 0.05) more likely to engage in risky behaviours than others. In bivariate analysis, commercial sex workers (CSWs) were significantly (p < 0.05) more likely than non-commercial sex workers (NCSWs) to be willing to participate in vaccine trials (62.6% versus 51.4%). Among those willing, CSWs reported significantly more often (p < 0.05) (50.5%) than NCSWs (38.0%) that they would enroll to protect themselves from HIV. In multivariate analyses, variables associated with willingness to participate (WTP) were lower educational level, positive serology for syphilis, and 'engagement, under the influence of alcohol, in risky sexual practices that would normally be avoided', but not commercial sex work. The potential enrollment in vaccine trials of MSM CWSs, as well as participants of low socio-economic status and high risk, seems thus to be possible.


Assuntos
Vacinas contra a AIDS , Infecções por HIV/psicologia , Participação do Paciente/psicologia , Trabalho Sexual/psicologia , Comportamento Sexual/psicologia , Adolescente , Adulto , Brasil , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Assunção de Riscos , Sífilis/microbiologia
19.
Physiol Chem Phys Med NMR ; 33(1): 63-71, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11758736

RESUMO

The present study was designed to evaluate the effects of chronic aerobic exercise (swimming, 1h/day, 5 days/week, with an overload of 5% body weight) on glucose metabolism in obese male Wistar rats. Hypothalamic obesity was induced through administration of monosodium glutamate (MSG) at 4 mg/g of body weight every other day from birth to 14 days old. Fourteen weeks after drug administration, the rats were separated into two groups: MSG-S (sedentary) and MSG-T (swimming for 10 weeks). Rats of the same age and strain, receiving saline in place of MSG, were used as control (C), and subdivided into two groups: C-S and C-T. At the end of the experimental period, an oral glucose tolerance test was performed and serum glucose (AG) and insulin (AI) were evaluated. A constant for serum glucose decrease (Kitt) in response to exogenous insulin was calculated. Soleus muscle strips and adipose tissue samples were incubated and insulin stimulated glucose uptake determined. No differences were observed in AG among the 4 groups. MSG-S rats showed higher Al (418%) and lower Kitt (92.3%) than C-S rats. T-rats showed higher glucose uptake by muscle (224.0%) and adipose tissues (94.1%) than S-rats. Among trained rats, glucose uptake by muscle was higher in MSG-T (5.4%) than in C-T, while the opposite was observed in adipose tissue (39% higher in C-T). Chronic aerobic exercise was able to improve glucose tolerance and reduce insulin resistance in MSG-obese rats. These effects were associated to an increase in glucose uptake by muscle and adipose tissue in response to insulin.


Assuntos
Aditivos Alimentares , Glucose/metabolismo , Insulina/fisiologia , Obesidade/induzido quimicamente , Obesidade/metabolismo , Condicionamento Físico Animal/fisiologia , Glutamato de Sódio , Tecido Adiposo/metabolismo , Tecido Adiposo/fisiologia , Animais , Glicemia/metabolismo , Composição Corporal/fisiologia , Feminino , Teste de Tolerância a Glucose , Ácido Láctico/sangue , Masculino , Músculo Esquelético/metabolismo , Ratos , Ratos Wistar , Aumento de Peso/fisiologia
20.
Arq Neuropsiquiatr ; 57(2A): 301-5, 1999 Jun.
Artigo em Português | MEDLINE | ID: mdl-10412535

RESUMO

Cysticercosis is the most ordinary parasitary disease involving the nervous system. The involvement of the spine is rare, ranging from 0.7% to 5.8%, and the intramedullary incidence is rather uncommon. We report the case of a 52-year-old female patient with intramedullary cysticercosis at the C4-C5 level, treated at the Neurology and Neurosurgery Service of Santa Casa de Belo Horizonte. The patient was operated with the complete exeresis of the lesion and had a good outcome. Forty-five cases of intramedullary cysticercosis were found in the literature review. We conclude that although it is a rare pathology, intramedullary cysticercosis should be included in the differential diagnosis of intramedullary lesions, mainly in cases of patients with previous diagnosis for neurocysticercosis and also of those who live in endemic areas.


Assuntos
Cisticercose/patologia , Medula Espinal/patologia , Cisticercose/cirurgia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Radiografia , Crânio/diagnóstico por imagem , Medula Espinal/cirurgia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA