Figure 7

BMP-7 reverses TGF-β-induced EMT detected by immunofluorescence. BMP-7 reverses TGF-β-induced EMT as demonstrated by immunofluorescence of ZO-1 (A) and α-sm actin (B) in human proximal tubular cells (HK-2, n = 3). Stimulation with TGF-β alone (10 ng/ml) led to a distinctive morphological transformation into fibroblastoid cells in combination with a lowered expression of ZO-1 (A) and a higher expression of α-sm actin (B). Reversal of EMT was demonstrated by co-stimulation of HK-2 cells with TGF-β (10 ng/ml) and BMP-7 (10, 100 ng/ml) showing epithelial morphology. Co-Stimulation with 10 ng/ml TGF-β and 100 ng/ml BMP-7 were leading to a significantly higher expression of ZO-1 (p < 0.01; A) and lower expression of α-sm-actin (p < 0.001; B) compared to TGF-β stimulation alone. BMP-7 alone did not substantially influence the expression of ZO-1 and α-sm-actin. Values were evaluated by determination of the staining intensity per cell using Student's t-test and are presented as % of unstimulated cells.