Dr. Arie Horowitz studies fundamental molecular mechanisms and cell biological aspects of the vascular system. The focus of his laboratory is on the regulation vascular permeability, and in particular the homeostasis and the response to extracellular signals of endothelial intercellular junctions. In this context, the response of endothelial cell junctions to VEGF has been the main pathway of interest. To this end, the laboratory uses cell culture and mouse models in combination with advanced imaging modalities. He validated recently a new assay that is compatible with high throughput genome-wide screening of permeability. He has addressed recently also the underlying pathophysiological and molecular mechanisms of congenital hydrocephalus. He made contributions to understanding the involvement of membrane trafficking in the maintenance of intercellular junctions, and to the role of Rho and Rab GTPases in this process. His research has been supported by grants from the National Heart Lung and Blood institute, and from the American Heart Association.