Pro- and anti-angiogenic factors and receptors in the success and failure of porcine pregnancy

Commercial swine breeds in North.America undergo two waves of spontaneous fetal loss; one during peri-attachment and another during mid-gestation. Attachment sites of arresting conceptuses are associated with decreased vasculature. Previous studies have found decreased VEGF family members at sites of fetal arrest. It was hypothesized that a balance between pro-angiogenic and anti-angiogenic factors is needed at the maternal-fetal interface for successful conceptus development. Selected members of the proangiogenic FGF and PDGF familier and anti-angiogenic factor TSP-1 and receptor CD36 were quantified and localized at the porcine maternal-fetal interface. Transcript levels of FGF and PDGF family members were elevated at sites of arrest, indicating a potential survival mechanism to compensate for decreased VEGF expression. Thrombospondin-1 and CD36 were transcribed at the maternal-fetal interface and their expression was localized to peri-vascular areas. These studies localize the genes of interest to the maternal-fetal interface and reveal dynamic expression patterns related to potential for fetal survival.