Cell growth, phase-contrast microscopy, and MitoTracker mitochondrial labeling of cells. (A) Numbers of cells at seeding (0 days) and during culture. Black line indicates cultures with TGF-β; continuous gray line, cultures without TGF-β; and discontinuous pale gray line, cells cultured with anti–TGF-β. In the last condition, the cells grew significantly less than in the other ones (P < .05). The results came from 15 experiments with and without TGF-β and 2 experiments with anti–TGF-β. (B,E,G,I,K,M,O) Fluorescence microscopy on MitoTracker Green FM staining. (C,F,H,J,L,N,P) Phase-contrast microscopy. (B-C) Start of culture. (E-H) Seven-day culture with (E-F) and without (G-H) TGF-β. (I-L) Fourteen-day culture with (I-J) and without (K-L) TGF-β. (M-P) Eighteen-day culture with (M-N) and without (O-P) TGF-β. Bar represents 20 μm. (D) MitoTracker Green FM staining intensity (in arbitrary units; mean ± SD), in cells cultured with (black columns) and without TGF-β (gray columns). The differences between cultures with and without TGF-β were significant at all time points (P < .05). Slides were mounted with Gel/Mount (Biomeda); images were taken with Axio Vision 4.1 software through an AxioCam HRm camera applied to an Axioskop microscope with a 40×/0.75 NA air objective (Carl Zeiss), and were processed for print with Photoshop 6.0 for Macintosh (Adobe).