Lack of association between IL27 gene variants and type 1 diabetes susceptibility.

BACKGROUND: Recently, a new subpopulation of T cells, the Th17 subset, has been implicated in autoimmune diseases. Its development is influenced by IL-27, expressed in macrophages or dendritic cells. IL-27 blockage delays the onset of diabetes in non obese diabetes mouse, but its role in type 1 diabetes (T1D) in human has not been reported yet. The aim of this study was identify variants in the entire coding regions of IL-27 gene, including the 5' proximal region, and their possible association with the disease. METHODS: Those regions were amplified by polymerase chain reaction followed by automatic sequencing and restriction fragments length polymorphisms. The cohort involved 614 individuals - 318 patients with T1D (19.6 ± 11.2 y, 129M/189F) and 296 healthy control subjects (30.3 ± 13.2 y, 131M/165F). RESULTS: We identified eight allelic variants in the 5' proximal and coding regions of IL-27 gene, including two new variants: the c.-324 C>T in the 5' proximal region and the c.521 G>C in exon 5. None of these variants compromised transcription factor binding sites or the protein structure. The frequency of the alleles and genotypes of IL-27 variants did not differ between T1D patients and controls. There was no association between IL27 variants with gender, ethnicity, age at diagnosis of diabetes or presence of pancreatic and extrapancreatic autoantibodies. CONCLUSION: Our findings suggest that allelic variants in IL27 are not associated with susceptibility to T1D in a Brazilian population.

Increased Expression of Circulating microRNA 101-3p in Type 1 Diabetes Patients: New Insights Into miRNA-Regulated Pathophysiological Pathways for Type 1 Diabetes.

MicroRNAs (miRs) are master regulators of post-transcriptional gene expression, and they are often dysregulated in individuals suffering from diabetes. We investigated the roles of miR-101-3p and miR-204-5p, both of which negatively regulate insulin secretion and cell survival and are highly expressed in pancreatic ß cells, in the context of type 1 diabetes (T1D) pathogenesis. Using quantitative real time PCR, we evaluated serum levels of miR-101-3p and miR-204-5p in four groups, including recent-onset T1D patients (T1D group; n = 50), individuals with normal glucose levels expressing one islet autoantibody (Ab) (single Ab group; n = 26) or multiple autoantibodies (multiple Ab group; n = 12), and healthy controls (control group; n = 43). An in silico analysis was performed to identify potential target genes of these miRNAs and to delineate enriched pathways. The relative expression of serum miR-101-3p was approximately three times higher in the multiple Ab and T1D groups than that in the single Ab and control groups (p < 0.0001). When considering all groups together, miR-101-3p expression was positively correlated with the level of islet autoantibodies GADA (r = 0.267; p = 0.0027) and IA-2A (r = 0.291; p = 0.001), and the expression of the miRNA was not correlated with levels of ZnT8A (r = 0.125; p = 0.183). miR-101-3p expression did not correlate with HbA1c (r = 0.178; p = 0.052) or glucose levels (r = 0.177; p = 0.051). No significant differences were observed in miR-204-5p expression among the analyzed groups. Computational analysis of the miR-101-3p target gene pathways indicated a potential activation of the HGF/c-Met, Ephrin receptor, and STAT3 signaling pathways. Our study demonstrated that the circulating levels of miR-101-3p are higher in T1D patients and in individuals with normal glucose levels, testing positive for multiple autoantibodies, indicating that miR-101-3p precedes loss of glucose homeostasis. The pathogenic role of miR-101-3p in T1D may involve multiple molecular pathways.

Diabetes mellitus-related autoantibodies in childhood autoimmune hepatitis.

OBJECTIVE: To determine the frequency and significance of diabetes mellitus (DM)-related autoantibodies in children with autoimmune hepatitis (AIH). RESEARCH DESIGN AND METHODS: Anti-islet cell antibodies (ICA), insulin autoantibodies (IAA), and anti-glutamic acid decarboxylase (GAD65) antibodies were assessed in 28 children (25 female) with AIH before and after 3-9 years of therapy with azathioprine and prednisone. RESULTS: There was biochemical and clinical remission of AIH activity in 76% of the children after 1 year of immunosuppressive therapy. Positive ICA and IAA were found in 60.7% and 18.5% of the patients, decreasing to 38.5% and 12% after 3-9 years of therapy. Anti-GAD autoantibodies were present in only one patient who had Graves' disease, high ICA titer, and developed type 1 DM after 3 years. After 3-9 years of follow up, all had normal fasting glycemia, glycosylated hemoglobin (HbA1c), and, with a single exception, normal responses to oral glucose tolerance testing. No increase in the frequencies of HLA antigens was observed in ICA- and IAA-positive patients compared to antibody-negative patients or a control population. The majority of the patients with HLA-DRB1*03 or DRB1*04, however, were positive for ICA (7/10), and three of them had IAA. The frequency of high risk HLA DQB1*0302 or DQB1*02 alleles was low and similar to control frequencies, indicating low-risk for DM despite the presence of DM-related autoimmunity markers. CONCLUSIONS: AIH in childhood is associated with high frequency of ICA and IAA, with less than expected rates of progression to DM. Immunosuppression reduced ICA and IAA frequency and titers.

Differential regulation of PGC-1alpha expression in rat liver and skeletal muscle in response to voluntary running.

BACKGROUND: The beneficial actions of exercise training on lipid, glucose and energy metabolism and insulin sensitivity appear to be in part mediated by PGC-1alpha. Previous studies have shown that spontaneously exercised rats show at rest enhanced responsiveness to exogenous insulin, lower plasma insulin levels and increased skeletal muscle insulin sensitivity. This study was initiated to examine the functional interaction between exercise-induced modulation of skeletal muscle and liver PGC-1alpha protein expression, whole body insulin sensitivity, and circulating FFA levels as a measure of whole body fatty acid (lipid) metabolism. METHODS: Two groups of male Wistar rats (2 Mo of age, 188.82 +/- 2.77 g BW) were used in this study. One group consisted of control rats placed in standard laboratory cages. Exercising rats were housed individually in cages equipped with running wheels and allowed to run at their own pace for 5 weeks. At the end of exercise training, insulin sensitivity was evaluated by comparing steady-state plasma glucose (SSPG) concentrations at constant plasma insulin levels attained during the continuous infusion of glucose and insulin to each experimental group. Subsequently, soleus and plantaris muscle and liver samples were collected and quantified for PGC-1alpha protein expression by Western blotting. Collected blood samples were analyzed for glucose, insulin and FFA concentrations. RESULTS: Rats housed in the exercise wheel cages demonstrated almost linear increases in running activity with advancing time reaching to maximum value around 4 weeks. On an average, the rats ran a mean (Mean +/- SE) of 4.102 +/- 0.747 km/day and consumed significantly more food as compared to sedentary controls (P < 0.001) in order to meet their increased caloric requirement. Mean plasma insulin (P < 0.001) and FFA (P < 0.006) concentrations were lower in the exercise-trained rats as compared to sedentary controls. Mean steady state plasma insulin (SSPI) and glucose (SSPG) concentrations were not significantly different in sedentary control rats as compared to exercise-trained animals. Plantaris PGC-1alpha protein expression increased significantly from a 1.11 +/- 0.12 in the sedentary rats to 1.74 +/- 0.09 in exercising rats (P < 0.001). However, exercise had no effect on PGC-1alpha protein content in either soleus muscle or liver tissue. These results indicate that exercise training selectively up regulates the PGC-1alpha protein expression in high-oxidative fast skeletal muscle type such as plantaris muscle. CONCLUSION: These data suggest that PGC-1alpha most likely plays a restricted role in exercise-mediated improvements in insulin resistance (sensitivity) and lowering of circulating FFA levels.

High- or low-salt diet from weaning to adulthood: effect on body weight, food intake and energy balance in rats.

OBJECTIVE: To get some additional insight on the mechanisms of the effect of salt intake on body weight. DESIGN AND METHODS: Rats were fed a low (LSD), normal (NSD), or high (HSD) salt diet. In a first set, body weight, tail-cuff blood pressure, fasting plasma thyroid-stimulating hormone, triiodothyronine, L-thyroxine, glucose, insulin, and angiotensin II were measured. Angiotensin II content was determined in white and brown adipose tissues. Uncoupling protein 1 expression was measured in brown adipose tissue. In a second set, body weight, food intake, energy balance, and plasma leptin were determined. In a third set of rats, motor activity and body weight were evaluated. RESULTS: Blood pressure increased on HSD. Body weight was similar among groups at weaning, but during adulthood it was lower on HSD and higher on LSD. Food intake, L-thyroxine concentration, uncoupling protein 1 expression and energy expenditure were higher in HSD rats, while non-fasting leptin concentration was lower in these groups compared to NSD and LSD animals. Plasma thyroid-stimulating hormone decreased on both HSD and LSD while plasma glucose and insulin were elevated only on LSD. A decrease in plasma angiotensin II was observed in HSD rats. On LSD, an increase in brown adipose tissue angiotensin II content was associated to decreased uncoupling protein 1 expression and energy expenditure. In this group, a low angiotensin II content in white adipose tissue was also found. Motor activity was not influenced by the dietary salt content. CONCLUSIONS: Chronic alteration in salt intake is associated with changes in body weight, food intake, hormonal profile, and energy expenditure and tissue angiotensin II content.

Acanthosis nigricans em mulheres obesas de uma população miscigenada: um marcador de distúrbios metabólicos / Acanthosis nigricans in obese women in a mixed-race population: a marker of metabolic disturbances

Acanthosis nigricans (AN) tem sido associada a diversos distúrbios metabólicos e endócrinos. O objetivo deste estudo é avaliar a freqüência das co-morbidades da síndrome metabólica em mulheres obesas de uma população miscigenada com AN, comparada a um grupo sem AN. Casuística e métodos - Foram estudadas 481 mulheres, consecutivamente admitidas em um ambulatório de obesidade (388 com AN e 93 sem AN) e submetidas ao teste de tolerância à glicose oral, excetuando-se 20, que já se sabiam diabéticas. A distribuição segundo a raça indicou 34,5 por cento de brancas, 38,9 por cento de pardas e 26,6 por cento de negras. A freqüência global de AN foi de 80,7 por cento, sendo fortemente maior nas negras versus brancas (90,6 por cento e 66,9 por cento, p=0,000000) e negras versus pardas (86 por cento e 90,6 por cento, p= 0,000006). Foi também maior nas pardas versus brancas (86 por cento e 66,9 por cento, p<0,02). As pacientes com AN eram mais jovens (35 ± 10 versus 38 ± 10 anos, p < 0,01), mais obesas (41 ± 6 versus 39 ± 6 kg/m2, p<0.01), tinham maior circunferência de cintura, maior freqüência de obesidade andróide, de diabetes tipo 2 (11,1 por cento versus 4,3 por cento, p=0,05), maiores níveis de insulina de jejum e de resistência insulina (Homa IR) do que aquelas sem AN. As freqüências de hipertensão diastólica e alterações do colesterol total e frações e de triglicérides entre os grupos foram similares. Em mulheres obesas de uma população miscigenada, AN foi mais freqüente nas de raça negra e parda e foi observada maior freqüência de co-morbidades da síndrome metabólica em comparação à população sem AN. As mulheres obesas com AN devem ser investigadas para distúrbios metabólicos, mesmo sendo jovens

Diabetes autoimune em adultos: características clínicas e autoanticorpos / Autoimmune diabetes in adults: clinical characteristics and antoantibody

Avaliamos a prevalência dos anticorpos anti-insulina (IAA), anti-decarboxilase do ácido glutãmico (anti-GAD), anti-ilhota de Langerhans (ICA) e as características clínicas e metabólicas de 66 pacientes com diabetes mellitus (DM) de início na idade adulta (47,2ñ11,6 anos) e duração do DM de 14,3ñ8,4 anos. Resultados: ICA foi positivo em 10 casos (10 a 640U JDF), três deles também positivos para anti-GAD (15,6 a 113,5U/ml) e um deles para IAA (naqueles sem terapia insulínica). 15,2 por cento dos pacientes tinham um ou mais autoanticorpos, com maior prevalência para ICA. Os pacientes com e sem autoanticorpos não diferiram quanto à apresentação clínica do DM ou à prevalência de complicações. Apenas os níveis de colesterol foram menores no grupo anticorpo positivo (205,2ñ49,6 vs. 247,1ñ61,3mg/dl; p<0,05). Conclusão: 15,2 por cento dos pacientes com DM de início na idade adulta tinham um ou mais autoanticorpos, com maior prevalência para ICA. A determinação de autoanticorpos é necessária para o diagnóstico do DM autoimune.