The natural behavior of mononuclear phagocytes in XXXX formation.

@entity1 @entity82 @entity19 @entity2805 @entity130
@entity2805 ( @entity2805 ) are caused by @entity130 or burn injuries to the deep dermis and are considered @entity82 in the skin. Monocytes, M1 and M2 macrophages are mononuclear phagocytes. Studies suggest that M2 macrophages are profibrotic and might contribute to @entity2805 formation. Our lab has established a @entity1 @entity2805 -like nude @entity19 model, in which the grafted @entity1 skin develops red, raised, and firm scarring, resembling @entity2805 seen in @entity1 . In this study, we observed the natural behavior of mononuclear phagocyte system in this nude @entity19 model of dermal @entity82 at multiple time points. Thirty athymic @entity19 received @entity1 skin grafts and an equal number of @entity19 received @entity19 skin grafts as controls. The grafted skin and blood were harvested at 1, 2, 3, 4, and 8 weeks. Wound area, thickness, collagen morphology and level, the cell number of myofibroblasts, M1- and M2-like macrophages in the grafted skin, as well as monocyte fraction in the blood were investigated at each time points. Xenografted @entity19 developed contracted and thickened scars grossly. The xenografted skin resembled @entity1 @entity2805 tissue based on enhanced thickness, fibrotic orientation of collagen bundles, increased collagen level, and infiltration of myofibroblasts. In the blood, monocytes dramatically decreased at 1 week postgrafting and gradually returned to normal in the following 8 weeks. In the xenografted skin, M1-like macrophages were found predominantly at 1-2 weeks postgrafting; whereas, M2-like macrophages were abundant at later time points, 3-4 weeks postgrafting coincident with the development of @entity82 in the @entity1 skin tissues. This understanding of the natural behavior of mononuclear phagocytes in vivo in our @entity19 model provides evidence for the role of M2-like macrophages in @entity82 of @entity1 skin and suggests that macrophage depletion in the subacute phases of wound healing might reduce or prevent @entity2805 formation.
