Chloride intracellular channel 1 functions in endothelial cell growth and migration

Background: Little is known about the role of CLIC1 in endothelium. These studies investigate CLIC1 as a regulator of angiogenesis by in vitro techniques that mimic individual steps in the angiogenic process. Methods: Using shRNA against clic1, we determined the role of CLIC1 in primary human endothelial cell behavior. Results: Here, we report that reduced CLIC1 expression caused a reduction in endothelial migration, cell growth, branching morphogenesis, capillary-like network formation, and capillary-like sprouting. FACS analysis showed that CLIC1 plays a role in regulating the cell surface expression of various integrins that function in angiogenesis including beta 1 and alpha 3 subunits, as well as alpha V beta 3 and alpha V beta 5. Conclusions: Together, these results indicate that CLIC1 is required for multiple steps of in vitro angiogenesis and plays a role in regulating integrin cell surface expression.