Retinal pigment epithelium and endothelial cell interaction causes retinal pigment epithelial barrier dysfunction via a soluble VEGF-dependent mechanism.

Purpose: To investigate the effect of endothelial cells (EC) on the barrier function of the retinal pigment epithelium (RPE).

Methods: Primary bovine RPE were grown in solo culture or in coculture with bovine EC. Culture media of RPE were varied to develop a monolayer with stable barrier properties determined by transepithelial electrical resistance (TER) and permeability to sodium fluorescein.

Defective pulmonary development in the absence of heparin-binding vascular endothelial growth factor isoforms.

Development of the airways, alveoli, and the pulmonary vasculature in the fetus is a process that is precisely controlled. One of the growth factors involved, vascular endothelial growth factor (VEGF), is so critical for embryonic development that in the mouse, elimination of just a single allele is lethal. In the early stages of lung development, the mouse VEGF gene expresses three isoforms (120, 164, and 188) in a distinct temporo-spatial pattern, suggesting a specific function for each.

Skeletal defects in VEGF(120/120) mice reveal multiple roles for VEGF in skeletogenesis.

Angiogenesis is an essential component of skeletal development and VEGF signaling plays an important if not pivotal role in this process. Previous attempts to examine the roles of VEGF in vivo have been largely unsuccessful because deletion of even one VEGF allele leads to embryonic lethality before skeletal development is initiated. The availability of mice expressing only the VEGF120 isoform (which do survive to term) has offered an opportunity to explore the function of VEGF during embryonic skeletal development.