JAM-2 increases paracellular permeability.

Diffusion of FITC-dextran (42 kd) across monolayers of MDCK, MDCK/JAM-1, or MDCK/JAM-2–transfected cells was measured after 3 hours. Quantification of FITC dextran in the lower compartment was measured using Cytofluor II, and the 100% diffusion was calculated according to the fluorescence observed in the lower compartment using a monolayer of nontransfected MDCK cells.