Figure 4. Effects of Trichostatin A (TSA) on in vitro neovascularization were evaluated by a co-culture model of human umbilical vein endothelial cells (HUVECs) and fibroblasts. A: HUVECs form CD31-positive tube-like structure on a fibroblast feeder layer in the presence of vascular endothelial growth factor. TSA seems to inhibit formation of CD31-labeled tube-like tissues. Bar, 50 mm. B: When evaluated by the measurement of total length and the number of the branching points of vessel-like tubes formed by HUVECs, TSA at the concentrations inhibited elongation of CD31-labeled tube like formation by HUVECs in a dose-dependent manner. *, **, and *** represent p<0.05, 0.01, and 0.005, respectively.