Inhibition of TAK1 abolishes the activation of TGF-β cascades.

<p><b>A</b>: Serum-starved RPE cells were pretreated with or without with 5Z-7-oxozeaenol (1μM) for 1 hour and then with TGF-β (2.5ng/ml) for the indicated times. Total protein extracts were analyzed by western blot using the indicated antibodies. The blot shows a representative result of four independent experiments. <b>B:</b> Levels of phospho-Smad2/3 were quantified and normalized to total Smad2/3 <b>C:</b> Statistical analysis of p-p38 and p-Smad3 activation normalized to p38 and Smad3 respectively, with or without TGF-β stimulation. The histograms present results of 5 independent experiments. Statistics were computed using student t-test (Two tailed distribution equal variance). Data is expressed as the Mean±SD.