Abstract
Wound healing is a multifactorial and complex process which involves the participation of many cell types, tissues and is dependent on synchronized mechanisms of cell signaling and inflammation, which are essential to the beginning of the repair process. During the inflammatory reaction there is the activation of a plenty of nuclear transcription factors like the peroxissome proliferator-activated receptor alpha (PPAR alpha), which may be involved in the modulation of the healing process. However, the exact role of this receptor on tissue repair is not completely elucidated yet. Therefore, the objective of this study is to understand the role of PPAR alpha and the potential therapeutic use of its agonists or antagonists in the treatment of cutaneous wounds. Then, 129/SvEv, female, wild type mice will be submitted to the induction of experimental skin wounds. After the evaluation of PPAR alpha kinetic expression in the lesions, animals and their wounds will be treated by systemic (oral) or topical application of the receptor agonist or antagonist to determine the role of PPAR alpha in the wound closure. Mice will be euthanized at predetermined times (0, 24, 48, 120 and 240h) post-surgery and samples collected will be used for further analysis. The inflammatory infiltrate will be evaluated by histopathology (hematoxylin-eosin for mononuclear cells and toluidine blue for mast cells), myeloperoxidase activity (MPO) for the quantification of neutrophil, eosinophil peroxidase (EPO) for eosinophils and flow cytometry for macrophage infiltration and phenotyping of other cell subsets such as CD4 and CD8 T lymphocytes. Moreover, the tissue fibrosis will be quantified after Picrosirius staining. The gene expression of cytokines TGF-beta, IL-6, IL-17, TNF-alpha, IFN-gama e IL-10, chemokines CCL2, CCL3, CCL6, CCL7 e CXCL9, their receptors CXCR2 e CCR1, metalloproteinases MMP2, MMP9, TIMP-1 inhibitor and growth factor VEGF will be evaluated by real time PCR. Finally, understanding the role of PPAR alpha in wound healing could serve as an important tool for developing new therapeutic strategies for treating non-healing lesions, such as those in diabetic patients, pressure ulcers, burns, post-surgical tissue repair and clarification of deregulated healing processes like hypertrophic scars. (AU)
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