Fig. 2.

Effect of TSA on serum-induced phosphorylation and acetylation of signal transducer and activator of transcription 3 (STAT3). Serum-starved NRK-49F cells were exposed to 5% FBS for 0–60 min (A) or pretreated with TSA for 1 h at the indicated concentrations and then exposed to 5% FBS for an additional 1 h (C). Cell lysates were subjected to immunoblot analysis with antibodies to phospho-STAT3 (Tyr705), acetyl-STAT3 (K685), STAT3, or actin. Representative immunoblots from 3 experiments are shown. Expression levels of phospho-STAT3 or acetyl-STAT3 were quantified by densitometry and are expressed as fold-induction over controls (B and D). Values are means ± SD of 3 independent experiments. Bars with different letters (a–d) are significantly different from one another (P < 0.05).