Gluten-free diet reduces adiposity, inflammation and insulin resistance associated with the induction of PPAR-alpha and PPAR-gamma expression.

Gluten exclusion (protein complex present in many cereals) has been proposed as an option for the prevention of diseases other than coeliac disease. However, the effects of gluten-free diets on obesity and its mechanisms of action have not been studied. Thus, our objective was to assess whether gluten exclusion can prevent adipose tissue expansion and its consequences. C57BL/6 mice were fed a high-fat diet containing 4.5% gluten (Control) or no gluten (GF). Body weight and adiposity gains, leukocyte rolling and adhesion, macrophage infiltration and cytokine production in adipose tissue were assessed. Blood lipid profiles, glycaemia, insulin resistance and adipokines were measured. Expression of the PPAR-α and γ, lipoprotein lipase (LPL), hormone sensitive lipase (HSL), carnitine palmitoyl acyltransferase-1 (CPT-1), insulin receptor, GLUT-4 and adipokines were assessed in epidydimal fat. Gluten-free animals showed a reduction in body weight gain and adiposity, without changes in food intake or lipid excretion. These results were associated with up-regulation of PPAR-α, LPL, HSL and CPT-1, which are related to lipolysis and fatty acid oxidation. There was an improvement in glucose homeostasis and pro-inflammatory profile-related overexpression of PPAR-γ. Moreover, intravital microscopy showed a lower number of adhered cells in the adipose tissue microvasculature. The overexpression of PPAR-γ is related to the increase of adiponectin and GLUT-4. Our data support the beneficial effects of gluten-free diets in reducing adiposity gain, inflammation and insulin resistance. The data suggests that diet gluten exclusion should be tested as a new dietary approach to prevent the development of obesity and metabolic disorders.

Evaluation of the allergenicity potential of TcPR-10 protein from Theobroma cacao.

BACKGROUND: The pathogenesis related protein PR10 (TcPR-10), obtained from the Theobroma cacao-Moniliophthora perniciosa interaction library, presents antifungal activity against M. perniciosa and acts in vitro as a ribonuclease. However, despite its biotechnological potential, the TcPR-10 has the P-loop motif similar to those of some allergenic proteins such as Bet v 1 (Betula verrucosa) and Pru av 1 (Prunus avium). The insertion of mutations in this motif can produce proteins with reduced allergenic power. The objective of the present work was to evaluate the allergenic potential of the wild type and mutant recombinant TcPR-10 using bioinformatics tools and immunological assays. METHODOLOGY/PRINCIPAL FINDINGS: Mutant substitutions (T10P, I30V, H45S) were inserted in the TcPR-10 gene by site-directed mutagenesis, cloned into pET28a and expressed in Escherichia coli BL21(DE3) cells. Changes in molecular surface caused by the mutant substitutions was evaluated by comparative protein modeling using the three-dimensional structure of the major cherry allergen, Pru av 1 as a template. The immunological assays were carried out in 8-12 week old female BALB/c mice. The mice were sensitized with the proteins (wild type and mutants) via subcutaneous and challenged intranasal for induction of allergic airway inflammation. CONCLUSIONS/SIGNIFICANCE: We showed that the wild TcPR-10 protein has allergenic potential, whereas the insertion of mutations produced proteins with reduced capacity of IgE production and cellular infiltration in the lungs. On the other hand, in vitro assays show that the TcPR-10 mutants still present antifungal and ribonuclease activity against M. perniciosa RNA. In conclusion, the mutant proteins present less allergenic potential than the wild TcPR-10, without the loss of interesting biotechnological properties.

Biodistribution of free 99mTc-ovalbumin and 99mTc-ovalbumin encapsulated in liposomes

The oral administration of proteic antigens, like ovalbumin, may result in the induction of oral tolerance or immunization. The aim of this work was to label a protein antigen with 99mTechnetium, encapsulate it in liposomes and investigate its absorption and tissue distribution after oral administration in mice. Ovalbumin was labeled with 99mTechnetium and encapsulated in small unilamellar vesicles. 99mTc-OVA encapsulated or not in liposomes was administrated to mice that were sacrificed after different times. The radioactivity was measured in various organs of the animals. Differences concerning the biodistribution of 99mTc-OVA were noticed. The technique may represent alternatives for the induction of immunization or oral tolerance.

A administração oral de antígenos protéicos pode levar a indução ou supressão da resposta imune. A indução da resposta imune é de grande importância para o desenvolvimento de vacinas orais. Já a supressão, denominada de tolerância oral, pode vir a representar uma solução terapêutica a numerosas enfermidades. O objetivo deste trabalho foi de compreender o comportamento in vivo de um antígeno modelo, a ovalbumina (OVA), marcado com um radioisótopo, o 99m tecnécio (99mTc), e administrado por via oral na sua forma livre e encapsulado em lipossomas de pequeno tamanho (SUV). As amostras foram administradas por gavagem à camundongos, sacrificados após 30, 60, 90, 120, 180 e 360 minutos. A radioatividade foi medida no estômago, intestinos, placas de Peyer, linfonodos mesentéricos, baço, fígado e sangue dos animais. Os resultados mostraram que a OVA livre ou encapsulada em lipossomas SUV apresenta biodistribuições distintas. As diferenças encontradas na biodistribuição da OVA livre ou encapsulada podem representar mecanismos diferentes para a indução ou não de tolerância oral.