Bouncing back: Immune regulated healing in the rat uterus after labor and delivery
The uterus is extensively remodeled by pregnancy. These profound changes must be reversed after labor and delivery. The immune system is dynamic in this progression because of immune cell’s abilities to influence healing of the uterus through cytokines. The role of specific immune cells in postpartum healing has not been studied heavily. In contrast, wound healing is well understood. In a wound phagocytotic cells called macrophages clean up dead and dying cells and secrete cytokines that suppress inflammation and accelerate healing of the wound. Based on what is known about wound healing, it is hypothesized that a transition from a proinflammatory to an anti-inflammatory phenotype in macrophages should be detectable in the first week following labor and delivery. Using the rat as a model system, real-time quantitative polymerase chain reaction was utilized at four time points (days 1, 3, 5, or 7 postpartum) to identify changes in expression of cytokines that are associated with inflammatory or anti-inflammatory phenotypes. In particular, we looked at TNFα associated with inflammation, MerTK associated with efferocytosis, and MRC1, TGFβ, and IL-10 associated with the resolution of inflammation. It was found that gene expression of each cytokine was highest earlier in the week on postpartum days 1 and 3. The data indicates that molecules associated with both environments are present in the uterus in the first week postpartum, but there is no pattern of a transition between the two. It appears that the cell-cell interactions in the first week postpartum are complex and may resist a simple classification as pro- or anti-inflammatory.