ABSTRACT Pamela P. Lockyer: Bone Morphogenetic Protein Binding Endothelial Regulator (BMPER) Regulates Vascular Inflammatory Responses in Endothelial Cells (Under the direction of Xinchun Pi) Dysfunction of the vascular endothelium results in various cardiovascular, circulatory and blood diseases highlighting the importance of endothelial integrity. How BMPER mediates signaling events to regulate endothelial cell functions in response to vascular injury with the expectation that these functions can be regulated to affect these vascular responses in clinically relevant pathophysiological conditions was the goal for these studies. Aim 1-We crossed ApoE−/− and Bmper+/− and measured the development of atherosclerosis in mice fed a high-fat diet. BMPER haploinsufficiency in ApoE−/− mice led to a more severe phenotype. Aim 2-BMPER+/− were used for LPS challenge. LPS-induced pulmonary inflammation and injury was reduced in BMPER+/- mice. We conclude that BMPER is essential in the maintenance of normal vascular homeostasis during chronic inflammation and atherosclerosis. Furthermore, BMPER plays a pivotal role in pulmonary inflammatory response, to provides new therapeutic options against septic shock, and broadens our understanding of BMPER’s role in vascular homeostasis.