VIP (vasoactive intestinal peptide) and PACAP (pituitary adenylate cyclase-activating polypeptide) roles in M2 polarization and their impact on the alveolar bone repair process

Abstract

Bone is a mineralized tissue, with support functions, protection, transportation and reserves of minerals; that in the oral cavity, plays an important role in sustaining the teeth. Within the osteoimmunological processes, macrophages (classically pro-inflammatory considered) may present different functional phenotypes, called M1 and M2. The presence or absence of macrophages, as well as changes in phenotype, may affect the alveolar bone repair process suggesting that M2 polarized macrophages are associated with the default success of this process. However, the active involvement of M2 as well its involved in polarization during the repair process remain unknown. Factors such as PACAP and VIP have been described as potential mediators of local polarization M2, and consequently, activation of macrophages modulators influencing the alveolar bone repair process. Preliminary results from our group showed that VIP and PACAP are expressed in repair sites, reinforcing a potential involvement in M2 polarization and in process per se. Thus, the propose of this project is investigate the role of VIP and PACAP in cell migration and the impact on the repair process. For this, C57BL/6WT mice will be used, subjected to extraction of the upper incisor, kept in control conditions or treated with VIP and/or PACAP and their antagonists, in order to analyze the effect of treatments in the repair process. The animals submitted to the extraction will be later euthanized, and the specimens removed for the microtomography, histomorphometric, birefringence, immunohistochemistry analysis and PCRarray for quantification of tissue repair indicators, subpopulations of macrophages and markers involved in repair process, previously described by our group (VIEIRA et al., 2015).