Gremlin Activates the Smad Pathway Linked to Epithelial Mesenchymal Transdifferentiation in Cultured Tubular Epithelial Cells
Figure 1
(a) Stimulation with Gremlin rapidly increased Smad 3 phosphorylation in cultured human tubuloepithelial cells. HK2 cells were stimulated with Gremlin (50 ng/mL) for different times. (b) Early Smad 3 phosphorylation induced by stimulation with Gremlin was not mediated by TGF-β. TGF-β was blocked or not (control) by pretreatment of cells for 1 hour with an anti-TGF-β neutralizing antibody and then treated with Gremlin for 10 minutes. (c) In some points, HK2 cells were preincubated with BMP-2 or BMP-4 and then treated with Gremlin for 10 minutes. Total proteins were isolated and protein levels were evaluated by western blot. GAPDH or Smad 3 were used as loading controls. Figures show a representative western blot of phosphorylated levels of Smad 3 and data are expressed as n-fold over control (considered as 1), as the mean ± SEM of 3-4 independent experiments. * versus control.
