Efeitos do tratamento intradérmico com a jararagina-C, uma proteína tipo-disintegrina isolada da peçonha de Bothrops jararaca, sobre a cicatrização de feridas cutâneas em camundongos

Abstract

In this work, the effect of intradermal administration of jararhagin-C, a disintegrin-type protein, isolated from B. jararaca venom and with affinity for α2β1 integrin, was evaluated during the healing of excisional wounds. Four lesions were performed on the dorsal region of Swiss strain mice, with the aid of a 5 mm surgical biopsy punch. The animals were divided into two experimental groups, whose subjects were daily treated with injections of 10 µl of PBS (control group) or of the toxin (200 ng), applied to the edges of the wound. Ten animals from each of the experimental groups, were euthanized at the following time intervals 1, 3, 7, 10 and 14 days after lesion induction (totaling 20 animals for each interval). After euthanasia, the wounds and skin around them were removed with the aid of an 8 mm biopsy punch, weighed and processed for biochemical, histological and molecular biology analysis. Wounds treated with jararhagin-C showed a faster rate of closure, accompanied by a rapid resolution of the inflammatory response, with a reduction in neutrophil infiltrate, levels of pro-inflammatory cytokines (TNF-α, CXCL-1 and CCL2 / JE / MCP-1) and an accumulation of macrophages in the analyzed tissues. It was also observed, in the lesions treated with this protein, a greater expression of genes associated with the phenotype of alternatively activated macrophages (M2), responsible for the resolution of the inflammatory response and for the secretion of several mediators associated with the subsequent stages of repair. Concomitantly, the administration of the toxin was able to incite angiogenesis in the wounds, increasing the hemoglobin content, the density of new blood vessels and the synthesis of pro-angiogenic cytokines (VEGF and FGF). Finally, in the wounds of the treated groups, we also observed an increase in the collagen deposition in the wounds, accompanied by higher levels of the pro-fibrogenic cytokine TGF-β1. In addition, when evaluating the organization and maturation of the matrix, by differentiating between type I collagen fibers and type III collagen fibers, we observed that treatment with jararhagin-C resulted in an early and higher deposition of type I collagen fibers. Considering everything, the data suggest that the administration of jararhagin-C accelerated the closure of excisional wounds by modulating important responses to the wound healing process (e.g., inflammation, angiogenesis and fibrogenesis). Thus, this work not only contributes to the elucidation of the effects caused by the administration of jararhagin-C, but also to the deepening of knowledge about the signaling mediated by the integrin α2β1 in the evaluated processes, allowing the development of new therapies for the treatment of skin wounds.