Comparison of EMT phenotype in TGF-β-treated mock or PGC-1α HK-2 cells. To confirm the protective effect of PGC-1α on EMT, HK-2 cells stably overexpressing PGC-1α (PGC-1α cells) and mock cells were treated with TGF-β and compared. (A) The protein expression levels of PGC-1α (c-myc tagged) and EMT markers (fibronectin, E-cadherin, vimentin, and α-SMA). (B) Morphological changes in PGC-1α (red) and EMT markers (green, labeled E-cadherin and α-SMA) by immunofluorescence staining (original magnification, 800×; bar = 20 μm). (C) Effects of changes in transcription factors (Snail and Slug) on E-cadherin expression in both cell lines were compared. Bar graphs show mean PGC-1α (c-myc-tagged), fibronectin, E-cadherin, vimentin, and α-SMA/β-actin expression levels, as measured by densitometry. * p < 0.05, mock cells vs. PGC-1α cells at the indicated time (0, 1, 3, and 5 days).