Fig. 7. Normalized tissue architecture of HaCaT organotypic epithelia by TGF-. Morphologic features (H and E staining) of HaCaT organotypic co-cultures with postmitotic fibroblasts (3x10⁵/ml) in collagen type-I gel grown for 10 days in DMEM with 10% FCS (HaCaT) and with TGF- (+ TGF). For comparison, NEK organotypic epithelia were grown and stained under the same conditions. By indirect immunofluorescence microscopy the EGF receptor (EGF-R, red), the early epidermal differentiation marker transglutaminase (TG, red), and the late marker loricrin (Lor, red) have been labeled. Nuclei were counterstained with bisbenzimide (blue). Bar, 100 µm.