Associação do receptor toll-like 2 com o estado pró-inflamatório do diabetes tipo 1

Inflammation has been pointed out as an important factor in development of chronic diseases, as diabetes. Hyperglycemia condition would be responsible by toll-like receptors, TLR2 and TLR4, and, consequently by local and systemic inflammation induction. Thus, the objective of present study was to evaluate type 1 Diabetes mellitus (T1DM) pro-inflammatory state through mRNA expression of TLRs 2 and 4 and proinflammatory cytokines IL-1β, IL-6 and TNF-α correlating to diabetic nephropathy. In order to achieve this objective, 76 T1DM patients and 100 normoglycemic (NG) subjects aged between 6 and 20 years were evaluated. T1DM subjects were evaluated as a total group DM1, and considering glycemic control (good glycemic control DM1G, and poor glycemic control DM1P) and considering time of diagnosis (before achieving 5 years of diagnosis DM1< 5yrs, and after achieving 5 years of diagnosis DM1 <5yrs). Metabolic control was evaluated by glucose and glycated hemoglobin concentrations; to assess renal function serum urea, creatinine, albumin, total protein and urinary albumin-to-creatinine ratio were determined and to evaluate hepatic function, AST and ALT serum activities were measured. Pro-inflammatory status was assessed by mRNA expression of TLRs 2 and 4 and the inflammatory cytokines IL-1β, IL-6 and TNF-α. Except for DM1G group (18.4%), DM1NC patients (81.6%) showed a poor glycemic control, with glycated hemoglobin (11,2%) and serum glucose (225,5 md/dL) concentrations significantly increased in relation to NG group (glucose: 76,5mg/dL and glycated hemoglobin: 6,9%). Significantly enhanced values of urea (20%) and ACR (20,8%) and diminished concentrations of albumin (5,7%) and total protein (13,6%) were found in T1DM patients, mainly associated to a poor glycemic control (DM1P increased values of urea: 20% and ACR:49%, and diminished of albumin: 13,6% and total protein:13,6%) and longer disease duration (DM1 <5yrs - increased values of urea: 20% and ACR:20,8%, and diminished of albumin: 14,3% and total protein:13,6%). As regarding pro-inflammatory status evaluation, significantly increased mRNA expressions were presented for TLR2 (37,5%), IL-1β (43%), IL-6 (44,4%) and TNF-α (15,6%) in T1DM patients in comparison to NG, mainly associated to DM1P (poor glycemic control TLR2: 82%, IL-1β: 36,8% increase) and DM1 <5yrs (longer time of diagnosis TLR2: 85,4%, IL-1β: 46,5% increased) groups. Results support the existence of an inflammatory state mediated by an increased expression of TLR2 and pro-inflammatory cytokines IL-1β, IL-6 and TNF-α in T1DM

Avaliação do status antioxidante, expressão gênica e polimorfismos dos genes SOD1, SOD2 e GPx1 em crianças, adolescentes e adultos jovens com diabetes tipo 1

Studies report that the pathophysiological mechanism of diabetes complications is associated with increased production of Reactive Oxygen Species (ROS)-induced by hyperglycemia and changes in the capacity the antioxidant defense system. In this sense, the aim of this study was to evaluate changes in the capacity of antioxidant defense system, by evaluating antioxidant status, gene expression and polymorphisms in the genes of GPx1, SOD1 and SOD2 in children, adolescents and young adults with type 1 diabetes. We studied 101 individuals with type 1 diabetes (T1D) and 106 normoglycemic individuals (NG) aged between 6 and 20 years. Individuals with type 1 diabetes were evaluated as a whole group and subdivided according to glycemic control in DM1G good glycemic control and DM1P poor glycemic control. Glycemic and metabolic control was evaluate by serum glucose, glycated hemoglobin, triglycerides, total cholesterol and fractions (HDL and LDL). Renal function was assessed by measurement of serum urea and creatinine and albumin-to-creatinine ratio (ACR) in spot urine. Antioxidant status was evaluate by content of reduced glutathione (GSH) in whole blood and the activity of erythrocyte enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD). We also analyzed gene expression and gene polymorphisms of GPx1 (rs1050450), SOD1 (rs17881135) and SOD2 (rs4880) by the technique of real-time PCR (Taqman®). Most individuals with DM1 (70.3%) had poor glycemic control (glycated hemoglobin> 8%). Regarding the lipid profile, individuals with type 1 diabetes had significantly elevated total cholesterol (p <0.001) and LDL (p <0.000) compared to NG; for triglycerides only DM1NC group showed significant increase compared to NG. There was an increase in serum urea and RAC of individuals with DM1 compared to NG. Nine individuals with type 1 diabetes showed microalbuminuria (ACR> 30 mg / mg). There was a decrease in GSH content (p = 0.006) and increased erythrocyte GPx activity (p <0.001) and SOD (p <0.001) in DM1 group compared to NG. There was no significant difference in the expression of GPx1 (p = 0.305), SOD1 (.365) and SOD2 (0.385) between NG and DM1. The allele and genotype frequencies of the polymorphisms studied showed no statistically significant difference between the groups DM1 and NG. However, the GPx1 polymorphism showed the influence of erythrocyte enzyme activity. There was a decrease in GPx activity in individuals with type 1 diabetes who had a polymorphic variant T (p = 0.012). DM1 patients with the polymorphic variant G (AG + GG) for polymorphism of SOD2 (rs4880) showed an increase in the RAC (p <0.05). The combined data suggest that glucose control seems to be the predominant factor for the emergence of changes in lipid profile, renal function and antioxidant system, but the presence of the polymorphisms studied may partly contribute to the onset of complications

Effects of six carbohydrate sources on diet digestibility and postprandial glucose and insulin responses in cats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The intravenous glucose tolerance and postprandial glucose tests may present different responses in the evaluation of obese dogs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exercise intensity, but not electrolyte reposition, alters plasmatic cortisol and glucose levels of horses submitted to 30 and 60km distance endurance rides

O presente estudo teve como objetivo comparar os níveis plasmáticos de glicose e cortisol de um grupo de eqüinos atletas submetidos ao esforço de longa duração (enduro eqüestre) em distâncias de 30 e 60km, com velocidades médias de 10 e 15km h-1, respectivamente. Os animais foram aleatoriamente separados em dois grupos, sendo que a um deles foi administrada, por via oral, uma pasta eletrolítica hipertônica antes, durante e após as referidas provas. O outro grupo foi usado como controle. Os resultados das concentrações de cortisol revelaram um aumento significativo, no primeiro momento, em que a intensidade do esforço era maior (15km/h), ou com a continuação deste (30km de distância), no segundo momento, para todos os grupos. Os resultados referentes à concentração de glicose permaneceram constantes durante a prova de 30km; entretanto, nos primeiros 20km da prova de 60km, tais resultados revelaram um aumento significativo no grupo controle, retornando a valores basais no momento subseqüente. A reposição eletrolítica tem a sua importância na manutenção do equilíbrio hidroeletrolítico e ácido básico e, no presente estudo, pode ter contribuído para a manutenção da concentração média de glicose plasmática.

Blood lactate threshold reflects glucose responses in horses submitted to incremental exercise test

Determinou-se, em eqüinos, o efeito do treinamento sobre as concentrações sangüíneas de lactato e plasmáticas de glicose durante exercício de intensidade progressiva em esteira rolante. Demonstrou-se que o treinamento aeróbico causou diminuição da concentração máxima de lactato e que o limiar de lactato corresponde ao ponto de inflexão da curva de glicose plasmática, confirmando esse parâmetro como indicador da capacidade aeróbica de cavalos.

Growth and enzymatic responses of phytopathogenic fungi to glucose in culture media and soil

The effect of inoculation of Aspergillus flavus, Fusarium verticillioides, and Penicillium sp. in Dystrophic Red Latosol (DRL) and Eutroferric Red Latosol (ERL) soils with or without glucose on the total carbohydrate content and the dehydrogenase and amylase activities was studied. The fungal growth and spore production in culture medium with and without glucose were also evaluated. A completely randomized design with factorial arrangement was used. The addition of glucose in the culture medium increased the growth rate of A. flavus and Penicillium sp. but not of F. verticillioides. The number of spores increased 1.2 for F. verticillioides and 8.2 times for A. flavus in the medium with glucose, but was reduced 3.5 times for Penicillium sp. The total carbohydrates contents reduced significantly according to first and second degree equations. The consumption of total carbohydrates by A. flavus and Penicillium sp. was higher than the control or soil inoculated with F. verticillioides. The addition of glucose to soils benefited the use of carbohydrates, probably due to the stimulation of fungal growth. Dehydrogenase activity increased between 1.5 to 1.8 times (p <0.05) in soils with glucose and inoculated with the fungi (except F. verticillioides), in relation to soil without glucose. Amylase activity increased 1.3 to 1.5 times due to the addition of glucose in the soil. Increased amylase activity was observed in the DRL soil with glucose and inoculated with A. flavus and Penicillium sp. when compared to control.

Whole-genome expression profiling of Xylella fastidiosa in response to growth on glucose

Xylella fastidiosa is the etiologic agent of diseases in a wide range of economically important crops including citrus variegated chlorosis, a major threat to the Brazilian citrus industry. The genomes of several strains of this phytopathogen have been completely sequenced enabling large-scale functional studies. In this work we used whole-genome DNA microarrays to investigate the transcription profile of X. fastidiosa grown in defined media with different glucose concentrations. Our analysis revealed that while transcripts related to fastidian gum production were unaffected, colicin-V-like and fimbria precursors were induced in high glucose medium. Based on these results, we suggest a model for colicin-defense mechanism in X. fastidiosa.

Purification and structural characterisation of (1 -> 3 ; 1 -> 6)-beta-D-glucans (botryosphaerans) from Botryosphaeria rhodina grown on sucrose and fructose as carbon sources: a comparative study

Two botryosphaerans, exopolysaccharides (EPS) secreted by the ascomyceteous fungus Botryosphaeria rhodina, when grown on sucrose and fructose as sole carbon sources, were structurally compared after their isolation from the culture medium. Both EPS were submitted to trypsin digestion, and eluted as a single peak on gel filtration. Total acid hydrolysis yielded only glucose, and data from methylation analysis and Smith degradation indicated that both EPS constituted a main chain of glucopyranosyl beta(1 -> 3) linkages substituted at O-6. The products obtained after partial acid hydrolysis demonstrated side chains consisting of glucosyl- and gentiobiosyl- linked beta(1 -> 6) residues. C-13-NMR spectroscopy studies showed that all glucosidic linkages were of the beta-configuration. The carbon source affected the side chain structures of botryosphaeran but not the main chain makeup. Sucrose produced less branching (21%) than fructose (31%). (c) 2005 Published by Elsevier Ltd.

Structural characterization of Botryosphaeran: a (1 -> 3;1 -> 6)-beta-D-glucan produced by the ascomyceteous fungus, Botryosphaeria sp.

The exopolysaccharide, Botryosphaeran, produced by the ligninolytic, ascomycetcous fungus Botryosphaeria sp., was isolated from the extracellular fluid by precipitation with ethanol, and purified by gel permeation chromatography to yield a carbohydrate-rich fraction (96%) composed mainly of glucose (98%). Infra-red and C-13 NMR spectroscopy showed that all the glucosidic linkages were in the beta-configuration. Data from methylation analysis and Smith degradation indicated that Botryosphaeran was a (1 --> 3)-beta-(D)-glucan with approx 22% side branching at C-6. The products obtained from partial acid hydrolysis demonstrated that the side branches consisted of single (1 --> 6)-beta-linked glucosyl, and (1 --> 6)-beta-linked gentiobiosyl residues.[GRAPHICS](C) 2003 Elsevier Ltd. All rights reserved.

Enzymatic hydrolysis of botryosphaeran and laminarin by beta-1,3-glucanases produced by Botryosphaeria rhodina and Trichoderma harzianum Rifai

Botryosphaeran, a (1 -> 3; 1 -> 6)-beta-D-glucan produced by Botryosphaeria rhodina, and laminarin were hydrolysed by two fungal beta-glucanases predominantly of the 1,3-type produced by B. rhodina and Trichoderma harzianum Rifai grown on botryosphaeran as sole carbon source. Both beta-glucanase preparations presented different modes of attack on botryosphaeran and laminarin. Laminarin was hydrolysed to the extent of similar to 50% in 1 hand 100% within 24 h, and its hydrolysis products were mainly glucose and gentiobiose, and lesser amounts of laminaribiose and oligosaccharides of DP 3-4 during the early stages of hydrolysis, while botryosphaeran 'yielded mainly glucose and gentiobiose with some trisaccharide, but no laminaribiose or tetrasaccharide when hydrolysed by the T. harzianum enzyme. By contrast, B. rhodina beta-1,3-glucanases produced predominantly glucose during all stages of botryosphaeran hydrolysis. Some physicochemical properties of the 1,3- and 1,6-beta-glucanases, and beta-glucosidases contained in the two fungal P-glucanase preparations are also described for the first time. (c) 2006 Elsevier Ltd. All rights reserved.

Insulin and glucose sensitivity, insulin secretion and beta-cell distribution in endocrine pancreas of the fruit bat Artibeus lituratus

The fruit bat Artibeus lituratus absorbs large amounts of glucose in short periods of time and maintains normoglycemia even after a prolonged starvation period. Based on these data, we aimed to investigate various aspects related with glucose homeostasis analyzing: blood glucose and insulin levels, intraperitoneal glucose and insulin tolerance tests (ipGTT and ipITT), glucose-stimulated insulin secretion (2.8, 5.6 or 8.3 mmol/L glucose) in pancreas fragments, cellular distribution of beta cells, and the amount of pAkt/Akt in the pectoral muscle and liver. Blood glucose levels were higher in fed bats (6.88 +/- 0.5 mmol/L) than fasted bats (4.0 +/- 0.8 mmol/L), whereas insulin levels were similar in both conditions. The values of the area-under-the curve obtained from ipGTT were significantly higher when bats received 2 (5.5-fold) or 3 g/kg glucose (7.5-fold) b.w compared to control (saline). These bats also exhibited a significant decrease of blood glucose values after insulin administration during the iplTT. Insulin secretion from fragments of pancreas under physiological concentrations of glucose (5.6 or 8.3 mmol/L) was similar but higher than in 2.8 mmol/L glucose 1.8- and 2.0-fold, respectively. These bats showed a marked beta-cell distribution along the pancreas, and the pancreatic beta cells are not exclusively located at the central part of the islet. The insulin-induced Akt phosphorylation was more pronounced in the pectoral muscle, compared to liver. The high sensitivity to glucose and insulin, the proper insulin response to glucose, and the presence of an apparent large beta-cell population could represent benefits for the management of high influx of glucose from a carbohydrate-rich meal, which permits appropriate glucose utilization. (C) 2010 Elsevier B.V. All rights reserved.

Estudo da imunoexpressão dos transportadores de glicose 1 e 3 em carcinomas epidermóides de lábio inferior e sua relação com parâmetros clínico-patológicos

The Epidermoid Carcinoma (EC) is the most common lesions located in the region of the head and neck and, despite advances in treatment modalities, the prognosis is still poor. The malignant cells show an increase in glucose uptake, process mediated by glucose transporters (GLUTs). Increased expression of GLUT 1 and GLUT 3 is related to the aggressive behavior of this lesion. The aim of this study was to evaluate, through immunohistochemistry, the expression of GLUTs 1 and 3 in EC of the lower lip. The sample consisted of 40 cases of EC of the lower lip, of which 20 had regional lymph node metastasis and the remaining 20 with absence of metastasis. The percentages of immunostained cells in front of tumor invasion and in the center of tumor were evaluated. These results were related to the presence and absence of lymph node metastasis, TNM classification and histological grading. The percentage of cytoplasmic/membranous expression of GLUT 1 ranged from 77.35% to 100%, while for GLUT 3 this value ranged from 0.79% to 100%. As for nuclear staining for GLUT 1, this percentage ranged from 0 to 0.42%, however. GLUT 3 showed only one case with nuclear staining. Despite the significant expression of tumor cells related to the proteins studied, we observed no statistically significant relationship between the variables and the antibodies analyzed, regardless of the region evaluated. However, there was a moderate positive correlation between cytoplasmic/membranous immunoexpressions of GLUT 1 in invasion front and in the tumor center (r = 0.679, p <0.001). Similarly, moderate positive correlation was found between the nuclear immunoexpressions of GLUT 1 in the invasion front and in the tumor center (r = 0.547, p <0.001). For GLUT 3, was also observed a moderate statistically significant positive correlation between cytoplasmic/membranous expression in tumor invasion front and in tumor center (r = 0.589, p <0.001). We also observed that the immunoreactivity for GLUT 1 was higher than GLUT 3 expression in invasion front (p <0.001) and tumor center (p <0.001). From these results, this study suggests that tumor hypoxia is a remarkable characteristic of the EC of the lower lip and GLUT 1 may be primarily responsible for glucose uptake into the interior of the malignant cells

Glucose-6-phosphate dehydrogenase and glutathione reductase activity in methemoglobin reduction by methylene blue and cyst amine: study on glucose-6-phosphate dehydrogenase-deficient individuals, on normal subjects and on riboflavin-treated subjects

Os autores padronizaram métodos para a avaliação da atividade da glicose-6-fosfato desidrogenase e glutationa redutase. O princípio geral do primeiro método baseou-se na formação de metahemoglobina pelo nitrito de sódio, seguido da estimulação da via das pentoses pelo azul de metileno. Foram estudados 46 indivíduos adultos, sendo 23 do sexo masculino e 23 do feminino, não deficientes em glicose-6-fosfato desidrogenase (G6PD), com idades variando entre 20 e 30 anos. Os resultados revelaram que a redução da metahemoglobina pelo azul de metileno para sangue total, foram de 154.50 e 139.90 mg/min (p<0.05) respectivamente para o sexo masculino e feminino. Para hemácias lavadas os valores foram de 221.10 e 207.85 mg/min (n.s.) respectivamente. Estas observações permitiram concluir que ao se empregar hemácias lavadas e 0.7 g% de concentração de nitrito de sódio, por um lado não houve diferença entre os sexos e por outro, abreviou o tempo de leitura da quantidade residual de metahemoglobina para 90 minutos. A avaliação da atividade da glutationa redutase foi feita baseado no fato de que a cistamina (agente tiol) liga-se aos grupos SH da hemoglobina formando complexos. Estes complexos são revertidos pela ação da glutationa redutase, ocorrendo conjuntamente nesta reação a redução da metahemoglobina. Foram estudados 32 indivíduos adultos, sendo 16 do sexo masculino e 16 do feminino, não deficientes em G6PD, com idades variando entre 20 e 30 anos. Os resultados revelaram valores de redução da metahemoglobina pela cistamina de 81.27 e 91.13 mg/min (p<0.01) respectivamente para o sexo masculino e feminino. Estas observações permitiram concluir que o emprego de hemácias lavadas e 0.1 molar de concentração de cistamina torna possível a leitura da quantidade residual de metahemoglobina aos 180 minutos de incubação. A atividade da glutationa redutase avaliada por meio da redução da metahemoglobina pela cistamina, foi estudada em 14 indivíduos do sexo feminino antes e após o tratamento com 10 mg por dia de riboflavina durante 8 dias. Os resultados foram de 73.69 e 94.26 mg/min (p<0.01) antes e após o tratamento. Estas observações permitiram concluir que a oferta de riboflavina, mesmo para indivíduos normais, aumenta a atividade da glutationa redutase. Foram ainda avaliados 3 indivíduos da raça negra e deficientes em G6PD, sendo 2 do sexo masculino e 1 do feminino. Houve ativação parcial da G6PD e glutationa redutase, sendo estas alterações mais intensas nos indivíduos do sexo masculino. Considerando-se a raça e as características laboratoriais observadas, foi possível sugerir que a deficiência em G6PD verificada é do tipo Africano, bem como, permitiu considerar os indivíduos do sexo feminino coin o sendo heterozigoto para esta deficiência. Por fim, a análise dos resultados em seu conjunto permitiu concluir que os métodos propostos se mostraram eficientes para avaliar a atividade da G6PD e glutationa redutase. Esta última é dependente da via das pentoses, geradora de NADPH e da riboflavina, vitamina precursora de FAD.