Figure 4

MDCK Tet-off cells secreted exogenous hLIF-D predominantly in the apical direction across a range of expression levels. MDCK cells grown on permeable filters were incubated without doxycycline (No Dox) or with 1 μg/ml of doxycycline (Dox) to regulate the expression of hLIF-D. After 24 hours, conditioned media was collected from the apical and basal chambers and assayed for hLIF by ELISA. a) Total amount of hLIF secreted. b) Percentage of hLIF secreted into the apical chamber. Values are expressed as mean +/- SEM (n = 3). *P < 0.05 vs.1 μg/ml Dox.