Figure 2: Induction of CK-18, an epithelial expression marker, in MMCs in vitro. Representative photomicrographs of immunofluorescent staining of MMCs induced for 3, 6 or 9 days in medium supplemented with ADR/rat serum (a), renal cortex homogenate (e), normal rat serum (b), or renal cortex homogenate (f). Standard culture medium consisting of DMEM with 10% FBS was used as a control (c and g) (400×). Western blotting was performed to detect CK-18 expression and its relative abundance was determined as the densitometric ratio of CK-18/GAPDH (d and h). Values are means ± SE (n = 3). #P < 0.05 versus medium containing normal rat serum or homogenate at the same time. ##P < 0.01 versus medium containing normal rat serum or homogenate at the same time.