Desenvolvimento e validação de testes sorológicos para o diagnóstico da infecção pelo vírus da imunodeficiência felina (FIV) utilizando antígenos recombinantes

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

Desenvolvimento, caracterização e ação anti-biofilme oralde sistemas nanoestruturados bioadesivos contendo o peptídeo KSL-W

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interação do peptídeo antimicrobiano L1A com membrana modelo: efeito do pH e carga da vesícula

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Conformational changes of the HsDHODH N-terminal microdomain via DEER spectroscopy

The human enzyme dihydroorotate dehydrogenase (HsDHODH) has been studied for being a target for development of new antineoplasic and antiproliferative drugs. The synthetic peptide N-t(DH) represents the N-terminal microdomain of this enzyme, responsible for anchoring it to the inner mitochondrial membrane. Also, it is known to harbor quinones that are essential for enzyme catalysis. Here we report structural features of the peptide/membrane interactions obtained by using CD and DEER spectroscopic techniques, both in micelles and in lipid vesicles. The data revealed different peptide conformational states in micelles and liposomes, which could suggest that this microdomain acts in specific regions or areas of the mitochondria, which can be related with the control of the quinone access to the HsDHODH active site. This is the first study to report on conformational changes of the HsDHODH N-terminal microdomain through a combination of CD and DEER spectroscopic techniques.

Ac2-26 mimetic peptide of annexin A1 inhibits local and systemic inflammatory processes induced by bothrops moojeni venom and the lys-49 phospholipase A2 in a rat model

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

Effect of annexin-A1 peptide treatment during lung inflammation induced by lipopolysaccharide

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

Decoralin, a novel linear cationic alpha-helical peptide from the venom of the solitary eumenine wasp Oreumenes decoratus

A novel peptide, decoralin, was isolated from the venom of the solitary eumenine wasp Oreumenes decoratus. its sequence, Ser-Leu-Leu-Ser-Leu-Ile-Arg-Lys-Leu-Ile-Thr, was determined by Edman degradation and corroborated by solid-phase synthesis. This sequence has the characteristic features of linear cationic a-helical peptides; rich in hydrophobic and basic amino acids with no disulfide bond, and accordingly, it can be predicted to adopt an amphipathic a-helix secondary structure. In fact, the CD spectra of decoralin in the presence of TFE or SDS showed a high a-helical conformation content. In a biological evaluation, decoralin exhibited a significant broad-spectrum antimicrobial activity, and moderate mast cell degranulation and leishmanicidal activities, but showed virtually no hemolytic activity. A synthetic analog with C-terminal amidation showed a much more potent activity in all the biological assays. (c) 2007 Elsevier B.V. All rights reserved.

Annexin-A1 peptide down-regulates the leukocyte recruitment and up-regulates interleukin-10 release into lung after intestinal ischemia-reperfusion in mice

Background: Intestinal ischemia/reperfusion (IR) injury is a serious and triggering event in the development of remote organ dysfunction, from which the lung is the main target. This condition is characterized by intense neutrophil recruitment, increased microvascular permeability. Intestinal IR is also responsible for induction of adult respiratory distress syndrome, the most serious and life-threatening form of acute lung injury. The purpose of this study was to investigate the effect of annexin-A1 protein as an endogenous regulator of the organ remote injury induced by intestinal ischemia/reperfusion. Male C57bl/6 mice were subjected to intestinal ischemia, induced by 45 min occlusion of the superior mesenteric artery, followed by reperfusion. Results: The intestinal ischemia/reperfusion evoked a high intensity lung inflammation as indicated by the number of neutrophils as compared to control group. Treatment with annexin-A1 peptidomimetic Ac2-26, reduced the number of neutrophils in the lung tissue and increased its number in the blood vessels, which suggests a regulatory effect of the peptide Ac2-26 in the neutrophil migration. Moreover, the peptide Ac2-26 treatment was associated with higher levels of plasma IL-10. Conclusion: Our data suggest that the annexin-A1 peptidomimetic Ac2-26 treatment has a regulatory and protective effect in the intestinal ischemia/reperfusion by attenuation of the leukocyte migration to the lung and induction of the anti-inflammatory cytokine IL-10 release into the plasma. The anti-inflammatory action of annexin-A1 and its peptidomimetic described here may serve as a basis for future therapeutic approach in mitigating inflammatory processes due to intestinal ischemia/reperfusion. © 2013 Guido et al.; licensee BioMed Central Ltd.

Anti-inflammatory mechanisms of the annexin A1 protein and its mimetic peptide Ac2-26 in models of ocular inflammation in vivo and in vitro

Annexin A1 (AnxA1) is a protein that displays potent anti-inflammatory properties, but its expression in eye tissue and its role in ocular inflammatory diseases have not been well studied. We investigated the mechanism of action and potential uses of AnxA1 and its mimetic peptide (Ac2-26) in the endotoxin-induced uveitis (EIU) rodent model and in human ARPE-19 cells activated by LPS. In rats, analysis of untreated EIU after 24 and 48 h or EIU treated with topical applications or with a single s.c. injection of Ac2-26 revealed the anti-inflammatory actions of Ac2-26 on leukocyte infiltration and on the release of inflammatory mediators; the systemic administration of Boc2, a formylated peptide receptor (fpr) antagonist, abrogated the peptide's protective effects. Moreover, AnxA1-/- mice exhibited exacerbated EIU compared with wild-type animals. Immunohistochemical studies of ocular tissue showed a specific AnxA1 posttranslational modification in EIU and indicated that the fpr2 receptor mediated the anti-inflammatory actions of AnxA1. In vitro studies confirmed the roles of AnxA1 and fpr2 and the protective effects of Ac2-26 on the release of chemical mediators in ARPE-19 cells. Molecular analysis of NF-κB translocation and IL-6, IL-8, and cyclooxygenase-2 gene expression indicated that the protective effects of AnxA1 occur independently of the NF-κB signaling pathway and possibly in a posttranscriptional manner. Together, our data highlight the role of AnxA1 in ocular inflammation, especially uveitis, and suggest the use of AnxA1 or its mimetic peptide Ac2-26 as a therapeutic approach. Copyright © 2013 by The American Association of Immunologists, Inc.

Interaction of a synthetic antimicrobial peptide with model membrane by fluorescence spectroscopy

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

The essential role of annexin A1 mimetic peptide in the skin allograft survival

Immunosuppressive drugs have a critical role in inhibiting tissue damage and allograft rejection.Studies have demonstrated the anti-infl ammatory effects of the annexin A1 (AnxA1) in the regulationof transmigration and apoptosis of leucocytes. In the present study, an experimental skin allograftmodel was used to evaluate a potential protective effect of AnxA1 in transplantation survival. Micewere used for the skin allograft model and pharmacological treatments were carried out using eitherthe AnxA1 mimetic peptide Ac2-26, with or without cyclosporine A (CsA), starting 3 days beforesurgery until rejection. Graft survival, skin histopathology, leucocyte transmigration and expressionof AnxA1 and AnxA5 post-transplantation were analysed. Pharmacological treatment with Ac2-26increased skin allograft survival related with inhibition of neutrophil transmigration and inductionof apoptos is, thereby reducing the tissue damage compared with control animals. Moreover, AnxA1and AnxA5 expression increased after Ac2-26 treatment in neutrophils. Interestingly, thecombination of Ac2-26 and cyclosporine A showed similar survival of transplants when compared withthe cyclosporine A group, which could be attributed to a synergistic effect of both drugs. Investigationsin vitro revealed that cyclosporine A inhibited extracellular-signal-regulated kinase (ERK) phosphory-lation induced by Ac2-26 in neutrophils. Overall, the results suggest that AnxA1 has an essential role inaugmenting the survival of skin allograft, mainly owing to inhibition of neutrophil transmigration andenhancement of apoptosis. This effect may lead to the development of new therapeutic approachesrelevant to transplant rejection.

Interaction of the Anti-Inflammatory Annexin A1 Protein and Tacrolimus Immunosuppressant in the Renal Function of Rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Annexin 1 mimetic peptide protects against renal ischemia/reperfusion injury in rats

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