Annexin A12-26 Treatment Improves Skin Heterologous Transplantation by Modulating Inflammation and Angiogenesis Processes.

Skin graft successful depends on reduction of local inflammation evoked by the surgical lesion and efficient neovascularization to nutrition the graft. It has been shown that N-terminal portion of the Annexin A1 protein (AnxA1) with its anti-inflammatory properties induces epithelial mucosa repair and presents potential therapeutic approaches. The role of AnxA1 on wound healing has not been explored and we investigated in this study the effect of the peptide Ac2-26 (N-terminal AnxA1 peptide Ac2-26; AnxA12-26) on heterologous skin scaffolds transplantation in BALB/c mice, focusing on inflammation and angiogenesis. Treatment with AnxA12-26, once a day, from day 3-60 after scaffold implantation improved the take of the implant, induced vessels formation, enhanced gene and protein levels of the vascular growth factor-A (VEGF-A) and fibroblast influx into allograft tissue. It also decreased pro- while increasing anti-inflammatory cytokines. The pro-angiogenic activity of AnxA12-26 was corroborated by topical application of AnxA12-26 on the subcutaneous tissue of mice. Moreover, treatment of human umbilical endothelial cells (HUVECs) with AnxA12-26 improved proliferation, shortened cycle, increased migration and actin polymerization similarly to those evoked by VEGF-A. The peptide treatment instead only potentiated the tube formation induced by VEGF-A. Collectively, our data showed that AnxA12-26 treatment favors the tissue regeneration after skin grafting by avoiding exacerbated inflammation and improving the angiogenesis process.

ANXA1Ac2-26 peptide, a possible therapeutic approach in inflammatory ocular diseases.

The eye is immunologically privileged when inflammatory responses are suppressed. One component responsible for the suppression of inflammatory responses is the blood retinal barrier, which comprises the retinal pigment epithelium. The destruction of this barrier initiates inflammation, which can affect any part of the eye. Therefore, inflammatory response is controlled by the action of anti-inflammatory mediators, among these mediators, annexin A1 (ANXA1) protein acts as a modulator of inflammation. In this study we aimed to improve the knowledge of this area by investigating how a peptide of the ANXA1 protein (ANXA1Ac2-26) modulates the morphology, proliferation, migration and expression of genes and proteins in human retinal pigment epithelium cells (ARPE-19). Determining how signaling pathways (NF-κB and UBC) are modulated by the ANXA1Ac2-26 peptide could be important for understanding the inflammatory process. ARPE-19 cells were activated by bacterial lipopolysaccharide endotoxin (LPS) and treated with ANXA1Ac2-26 peptide, in a concentration of 1.7µM and 33.8µM. We observed that the LPS activation diminished the levels of endogenous ANXA1 after 2h and 24h and ANXA1Ac2-26 peptide decreased the proliferation and re-establishes the migration of ARPE-19 cells. After using a hybridization approach, 80 differentially expressed genes were found. Five of these genes were selected (LRAT, CTGF, MAP1B, ALDH1A3 and SETD7) and all were down-regulated after treatment with the peptide. The genes CTGF and LRAT would be considered as potential molecular markers of ophthalmologic inflammation. The expression of pro-inflammatory cytokines was also decreased after the treatment, indicating the efficiency of the anti-inflammatory peptide at high concentrations, since the reduction in the levels of these mediators were observed after the treatment with ANXA1Ac2-26 peptide at 33.8µM. Our results suggest that the retinal pigment epithelial cells are a potential target of the ANXA1 protein and point to possible applications of the ANXA1Ac2-26 peptide as an innovative therapy for the treatment of ocular inflammation.

Plasma concentrations of CCL3 and CCL4 in the cardiac and digestive clinical forms of chronic Chagas disease.

The aim of this study was to investigate the plasma levels of the CCL3 and CCL4 chemokines in patients with the cardiac and digestive clinical forms of chronic Chagas disease and in cardiac patients with and without left ventricular systolic dysfunction (LVSD). Plasma samples from 75 patients were evaluated by enzyme-linked immunosorbent assay (ELISA) to confirm infection by T. cruzi. Plasma levels of the CCL3 and CCL4 chemokines were measured using Milliplex® MAP assay (Millipore). There were no significant differences in the levels of CCL3 and CCL4 between patients with the digestive and cardiac clinical forms of Chagas disease. Moreover, no significant differences were found between patients without LVSD and those with LVSD. Higher CCL3 and CCL4 plasma levels were found in patients with LVSD compared to those with the digestive form of the disease. The CCL3 and CCL4 chemokines might not be involved in differential susceptibility to the digestive and cardiac clinical forms of chronic Chagas disease, and it seems they do not influence the development of LVSD.

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-inflammatory effects of the annexin A1 (AnxA1) in the regulation of transmigration and apoptosis of leucocytes. In the present study, an experimental skin allograft model was used to evaluate a potential protective effect of AnxA1 in transplantation survival. Mice were used for the skin allograft model and pharmacological treatments were carried out using either the AnxA1 mimetic peptide Ac2-26, with or without cyclosporine A (CsA), starting 3 days before surgery until rejection. Graft survival, skin histopathology, leucocyte transmigration and expression of AnxA1 and AnxA5 post-transplantation were analysed. Pharmacological treatment with Ac2-26 increased skin allograft survival related with inhibition of neutrophil transmigration and induction of apoptosis, thereby reducing the tissue damage compared with control animals. Moreover, AnxA1 and AnxA5 expression increased after Ac2-26 treatment in neutrophils. Interestingly, the combination of Ac2-26 and cyclosporine A showed similar survival of transplants when compared with the cyclosporine A group, which could be attributed to a synergistic effect of both drugs. Investigations in vitro revealed that cyclosporine A inhibited extracellular-signal-regulated kinase (ERK) phosphorylation induced by Ac2-26 in neutrophils. Overall, the results suggest that AnxA1 has an essential role in augmenting the survival of skin allograft, mainly owing to inhibition of neutrophil transmigration and enhancement of apoptosis. This effect may lead to the development of new therapeutic approaches relevant to transplant rejection.