Fig 5. TSA reduces HIF-1α and VEGF expression and up-regulates the expression of PEDF.

Real-time PCR (A) and Western blot assays (B) were performed on RPE cells treated with 0–0.5 μM TSA and 150 μM CoCl₂. (A) Cells were treated with 0–0.5 μM TSA for 14 h and then co-treated with 150 μM CoCl₂ for 6 h for the analysis of gene expression by real-time PCR. Changes in HIF-1α mRNA levels were not statistically significant. CoCl₂ causes a fourfold enhancement of VEGF mRNA expression; but at 0.5 μM TSA, the mRNA level of VEGF reduces to less than half of that in cells treated with CoCl₂ only. TSA induces a statistically significant increase in the mRNA level of PEDF. (B) Cells were treated with 0–0.5 μM TSA for 18 h and then co-treated with 150 μM CoCl₂ for 6 h for Western blot analysis. TSA reduces the CoCl₂-induced HIF-1α and VEGF protein levels by 4.3-fold and 5.7-fold, respectively, and up-regulates PEDF protein level by threefold. (C) Densitometry data for Western blot of HIF-1α, VEGF and PEDF. (*: t test p<0.05; **: t test p<0.01).