149 research outputs found

    Islet neogenesis-associated protein signaling in neonatal pancreatic rat islets: Involvement of the cholinergic pathway

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    Islet neogenesis associated protein (INGAP) increases islet mass and insulin secretion in neonatal and adult rat islets. In the present study, we measured the short- and long-term effects of INGAP-PP (a pentadecapeptide having the 104-118 amino acid sequence of INGAP) upon islet protein expression and phosphorylation of components of the P13K, MAPK and cholinergic pathways, and on insulin secretion. Short-term exposure of neonatal islets to INGAP-PP (90 s, 5, 15, and 30 min) significantly increased Akt1-Ser473 and MAPK3/1-Thr202/ Tyr204 phosphorylation and INGAP-PP also acutely increased insulin secretion from islets perifused with 2 and 20 mM glucose. Islets cultured for 4 days in the presence of INGAP-PP showed an increased expression of Akt1, Frap1, and Mapk1 mRNAs as well as of the muscarinic M3 receptor subtype, and phospholipase C (PLC)-β2 proteins. These islets also showed increased Akt1 and MAPK3/1 protein phosphorylation. Brief exposure of INGAP-PP-treated islets to carbachol (Cch) significantly increased P70S6K-Thr389 and MAPK3/1 phosphorylation and these islets released more insulin when challenged with Cch that was prevented by the M3 receptor antagonist 4-DAMP, in a concentration-dependent manner. In conclusion, these data indicate that short- and long-term exposure to INGAP-PP significantly affects the expression and the phosphorylation of proteins involved in islet P13K and MAPK signaling pathways. The observations of INGAPP-PP-stimulated up-regulation of cholinergic M3 receptors and PLC- proteins, enhanced P70S6K and MAPK3/1 phosphorylation and Cch-induced insulin secretion suggest a participation of the cholinergic pathway in INGAP-PP-mediated effects.Facultad de Ciencias MédicasCentro de Endocrinología Experimental y Aplicad

    Prolactin protects against cytokine-induced beta-cell death by NFκB and JNK inhibition

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    FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESType 1 diabetes is caused by an autoimmune assault that induces progressive beta-cell dysfunction and dead. Pro-inflammatory cytokines, such as interleukin 1 beta (IL1B), tumor necrosis factor (TNF) and interferon gamma (IFNG) contribute for beta-cell dea6112536FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçãosem informaçãosem informaçãoThe authors thank the personnel from the Laboratory of Endocrine Pancreas and Metabolism (UNICAMP) and ULB Center for Diabetes Research: W O Floriano, J P Agulhari, N Pachera, A Musuaya, M Pangerl, S Mertens and I Millard for excellent technical suppor

    O contributo da articulação entre a família e o jardim de infância para o desenvolvimento da literacia emergente

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    O presente trabalho enquadra-se na realização do relatório final de Mestrado em Educação Pré-Escolar (EPE) e Ensino do 1.º Ciclo do Ensino Básico (1.º CEB) e tem como tema “O contributo da articulação entre a família e o jardim de infância no desenvolvimento da literacia emergente”. Este relatório final é o reflexo do percurso efetuado em contexto do referido Mestrado. Este relatório encontra-se estruturado em duas partes, sendo que a primeira se inicia com uma reflexão sobre as práticas em contexto de Prática de Ensino Supervisionada (PES) relativas aos semestres da PES II e PES III. Na segunda parte, é apresentado o trabalho de investigação. Com o intuito de perceber o contributo da família e do jardim de infância no desenvolvimento da literacia emergente foi realizada uma investigação de caráter quantitativo, utilizando o questionário direcionado aos educadores e pais/encarregados de educação de um agrupamento de escolas da cidade de Viseu. A análise dos dados recolhidos revelou que as educadoras de infância e os pais/encarregados de educação dizem promover atividades literácitas conducentes à articulação entre ambos os contextos: família e o jardim de infância. Os resultados obtidos permitiram concluir que existe articulação entre a família e as educadoras de infância de um agrupamento de escolas de Viseu, contribuindo para o desenvolvimento da literacia emergente. Assim, a família e o jardim de infância, contextos privilegiados e enriquecedores de literacia, podem contribuir de forma decisiva para o desenvolvimento da literacia emergente na criança.Abstract This work is part of the completion of the final report of Master in Pre-School Education (EPE) and education of the 1st cycle of basic education (1st CEB) and has as its theme "The contribution of the relationship between the family and kindergarten in the development of emergent literacy" This final report is a reflection of the journey effected in the said Master context. This report is structured in two parts, the first of which begins with a reflection on the practice Practice context Supervised Teaching (PES) for the six months of PES PES II and III. In the second part, the research work is presented. In order to realize the contribution of family and kindergarten in the development of emergent literacy one character quantitative research was carried out using a questionnaire directed to educators and parents / guardians of a group of Viseu of city schools. The analysis of the data collected revealed childhood educators and parents / guardians say promote activities leading to the linkage between the two contexts: family and kindergarten. The results showed that there is coordination between the family and the kindergarten teachers of a school group of Viseu, contributing to the development of emergent literacy. So the family and kindergarten, privileged and enriching contexts of literacy, can contribute decisively to the development of emergent literacy in children

    Effect of nutritional recovery with soybean flour diet on body composition, energy balance and serum leptin concentration in adult rats

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    <p>Abstract</p> <p>Background</p> <p>Malnutrition in early life is associated with obesity in adulthood and soybean products may have a beneficial effect on its prevention and treatment. This study evaluated body composition, serum leptin and energy balance in adult rats subjected to protein restriction during the intrauterine stage and lactation and recovering on a soybean flour diet.</p> <p>Methods</p> <p>Five groups of the Wistar strain of albino rats were used: CC, offspring born to and suckled by mothers fed a control diet and fed the same diet after weaning; CS, offspring born to and suckled by mothers fed a control diet and fed a soybean diet with 17% protein after weaning; LL, offspring of mothers fed a low protein diet and fed the same diet after weaning; LC, offspring of mothers fed a low protein diet, but fed a control diet after weaning; LS, offspring of mothers fed a low protein diet, but fed a soybean diet with 17% protein after weaning. Food intake, body, perirenal and retroperitoneal adipose tissue were measured in grams. Leptin was quantified using the Enzyme Linked Immuno Sorbent Assay (ELISA) and insulin by radioimmunoassay (RIA). Carcass composition was determined by chemical methods and energy expenditure was calculated by the difference between energy intake and carcass energy gain. Data were tested by analysis of variance (ANOVA).</p> <p>Results</p> <p>The LC and LS groups had higher energetic intake concerning body weight, lower energy expenditure, proportion of fat carcass and fat pads than CC and CS groups. The LS group showed reduced body weight gain and lower energy efficiency, which was reflected in less energy gain as protein and the proportion of carcass protein, and lower energy gain as lipid than in the LC groups, although both groups had eaten the same amount of diet and showed equal energy expenditure. Serum leptin did not differ among groups and was unrelated to food or energy intake and energy expenditure. Serum insulin was higher in the LS than in the LC group.</p> <p>Conclusion</p> <p>Protein restriction during intrauterine life and lactation periods did not provoke obesity in adulthood. Nutritional recovery with soybean diet decreased the body weight at the expense of lower energy efficiency with repercussion on lean mass.</p

    Augmented β-cell function and mass in glucocorticoid-treated rodents are associated with increased islet ir-β /AKT/mTOR and decreased AMPK/ACC and AS160 signaling

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOGlucocorticoid (GC) therapies may adversely cause insulin resistance (IR) that lead to a compensatory hyperinsulinemia due to insulin hypersecretion. The increased β-cell function is associated with increased insulin signaling that has the protein kinase B (AKT) substrate with 160 kDa (AS160) as an important downstream AKT effector. In muscle, both insulin and AMP-activated protein kinase (AMPK) signaling phosphorylate and inactivate AS160, which favors the glucose transporter (GLUT)-4 translocation to plasma membrane. Whether AS160 phosphorylation is modulated in islets from GC-treated subjects is unknown. For this, two animal models, Swiss mice and Wistar rats, were treated with dexamethasone (DEX) (1 mg/kg body weight) for 5 consecutive days. DEX treatment induced IR, hyperinsulinemia, and dyslipidemia in both species, but glucose intolerance and hyperglycemia only in rats. DEX treatment caused increased insulin secretion in response to glucose and augmented β-cell mass in both species that were associated with increased islet content and increased phosphorylation of the AS160 protein. Protein AKT phosphorylation, but not AMPK phosphorylation, was found significantly enhanced in islets from DEX-treated animals. We conclude that the augmented β-cell function developed in response to the GC-induced IR involves inhibition of the islet AS160 protein activity.Glucocorticoid (GC) therapies may adversely cause insulin resistance (IR) that lead to a compensatory hyperinsulinemia due to insulin hypersecretion. The increased β-cell function is associated with increased insulin signaling that has the protein kinase2014114FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOsem informaçãosem informaçã

    Islet neogenesis-associated protein signaling in neonatal pancreatic rat islets: Involvement of the cholinergic pathway

    Get PDF
    Islet neogenesis associated protein (INGAP) increases islet mass and insulin secretion in neonatal and adult rat islets. In the present study, we measured the short- and long-term effects of INGAP-PP (a pentadecapeptide having the 104-118 amino acid sequence of INGAP) upon islet protein expression and phosphorylation of components of the P13K, MAPK and cholinergic pathways, and on insulin secretion. Short-term exposure of neonatal islets to INGAP-PP (90 s, 5, 15, and 30 min) significantly increased Akt1-Ser473 and MAPK3/1-Thr202/ Tyr204 phosphorylation and INGAP-PP also acutely increased insulin secretion from islets perifused with 2 and 20 mM glucose. Islets cultured for 4 days in the presence of INGAP-PP showed an increased expression of Akt1, Frap1, and Mapk1 mRNAs as well as of the muscarinic M3 receptor subtype, and phospholipase C (PLC)-β2 proteins. These islets also showed increased Akt1 and MAPK3/1 protein phosphorylation. Brief exposure of INGAP-PP-treated islets to carbachol (Cch) significantly increased P70S6K-Thr389 and MAPK3/1 phosphorylation and these islets released more insulin when challenged with Cch that was prevented by the M3 receptor antagonist 4-DAMP, in a concentration-dependent manner. In conclusion, these data indicate that short- and long-term exposure to INGAP-PP significantly affects the expression and the phosphorylation of proteins involved in islet P13K and MAPK signaling pathways. The observations of INGAPP-PP-stimulated up-regulation of cholinergic M3 receptors and PLC- proteins, enhanced P70S6K and MAPK3/1 phosphorylation and Cch-induced insulin secretion suggest a participation of the cholinergic pathway in INGAP-PP-mediated effects.Facultad de Ciencias MédicasCentro de Endocrinología Experimental y Aplicad

    Interleukin-6 increases the expression and activity of insulin-degrading enzyme

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOImpairment of the insulin-degrading enzyme (IDE) is associated with obesity and type 2 diabetes mellitus (T2DM). Here, we used 4-mo-old male C57BL/6 interleukin-6 (IL-6) knockout mice (KO) to investigate the role of this cytokine on IDE expression and activity. IL-6 KO mice displayed lower insulin clearance in the liver and skeletal muscle, compared with wild type (WT), due to reduced IDE expression and activity. We also observed that after 3-h incubation, IL-6, 50 and 100 ng ml(-1), increased the expression of IDE in HEPG2 and C2C12 cells, respectively. In addition, during acute exercise, the inhibition of IL-6 prevented an increase in insulin clearance and IDE expression and activity, mainly in the skeletal muscle. Finally, IL-6 and IDE concentrations were significantly increased in plasma from humans, after an acute exercise, compared to pre-exercise values. Although the increase in plasma IDE activity was only marginal, a positive correlation between IL-6 and IDE activity, and between IL-6 and IDE protein expression, was observed. Our outcomes indicate a novel function of IL-6 on the insulin metabolism expanding the possibilities for new potential therapeutic strategies, focused on insulin degradation, for the treatment and/or prevention of diseases related to hyperinsulinemia, such as obesity and T2DM.Impairment of the insulin-degrading enzyme (IDE) is associated with obesity and type 2 diabetes mellitus (T2DM). Here, we used 4-mo-old male C57BL/6 interleukin-6 (IL-6) knockout mice (KO) to investigate the role of this cytokine on IDE expression and act7112FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2014/24719-7; 2015/12611-

    Ciliary Neurotrophic Factor Protects Mice Against Streptozotocin-induced Type 1 Diabetes Through Socs3: The Role Of Stat1/stat3 Ratio In β-cell Death.

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    Type 1 diabetes is characterized by a loss of islet β-cells. Ciliary neurotrophic factor (CNTF) protects pancreatic islets against cytokine-induced apoptosis. For this reason, we assessed whether CNTF protects mice against streptozotocin-induced diabetes (a model of type 1 diabetes) and the mechanism for this protection. WT and SOCS3 knockdown C57BL6 mice were treated for 5 days with citrate buffer or 0.1 mg/kg CNTF before receiving 80 mg/kg streptozotocin. Glycemia in non-fasted mice was measured weekly from days 0-28 after streptozotocin administration. Diabetes was defined as a blood glucose > 11.2 mmol/liter. Wild-type (WT) and SOCS3 knockdown MIN6 cells were cultured with CNTF, IL1β, or both. CNTF reduced diabetes incidence and islet apoptosis in WT but not in SOCS3kd mice. Likewise, CNTF inhibited apoptosis in WT but not in SOCS3kd MIN6 cells. CNTF increased STAT3 phosphorylation in WT and SOCS3kd mice and MIN6 cells but reduced STAT1 phosphorylation only in WT mice, in contrast to streptozotocin and IL1β. Moreover, CNTF reduced NFκB activation and required down-regulation of inducible NO synthase expression to exert its protective effects. In conclusion, CNTF protects mice against streptozotocin-induced diabetes by increasing pancreatic islet survival, and this protection depends on SOCS3. In addition, SOCS3 expression and β-cell fate are dependent on STAT1/STAT3 ratio.28741628-3
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