Kidneys were collected at 7 days after UUO treatments with or without PCI34051(PCI) (A). TKPT were serum starved for 24 hours and then treated with PCI34051 at 6.25 μM for 1 hour (D) or transfected with HDAC8 siRNA or scrambled siRNA for 24 hours (F) followed by exposure of cells to TGFβ1 (5ng/ml) for an additional 24 hours. Kidney and cell lysates were subjected to immunoblot analysis with antibodies against TGFF-β1 (A), phosphorylated Smad3 (p-Smad3), Smad3 and GAPDH (A, D, F). Expression levels of all those proteins were quantified by densitometry and TGF-β1 was normalized with GAPDH (B), and p-Smad3 was normalized with Smad3 (C, E, G). Values are the means ± S.D (n = 6). Bars with different letters (a–c) are significantly different from one another (P < 0.05).