Fig. 9.

Proximal tubule epithelial cells from INK4a knockout mice express increased mesenchymal markers under control conditions and in response to TGF-β. Cells were grown to confluence on collagen-coated Transwell inserts and treated with 400 μm H₂O₂ for 3 h to induce senescence or 5 ng/ml TGF-β for 48 h. A–D: SA-β-galactosidase staining in WT and INK4a knockout proximal tubule cells as indicated demonstrating decreased staining in knockout cells following treatment with 400 μm H₂O₂. E–H: p16^INK4a immunofluorescence demonstrating increased p16^INK4a expression following H₂O₂ treatment. Immunofluorescence demonstrates increased α-SMA (I–L), fibronectin (M–P), and vimentin (Q–T) expression in INK4a knockout cells compared with WT cells. Original magnification ×100.