Fig. 5.

Differential secretion of matriptase in polarized Caco-2 human intestinal epithelial cells. Caco-2 cells were grown and allowed to differentiate in transwell chambers for 12 days. The cells were incubated with serum-free culture medium in the top and bottom chambers for 1 day, and the conditioned media from both sides were collected, concentrated, separated by SDS-PAGE, and analyzed by immunoblotting with the matriptase mAb M32, the activated matriptase mAb M69, or the HAI-1 mAb M19, respectively. A, apical surface; B, basolateral surface.