Fig. 4.

ATRA protects HUVEC barrier function. (A) A laser confocal microscope was used to image the changes in the junction protein VE-cadherin (green) and DAPI (blue) staining. The inset bar represents 10 µm. (B) The permeability of NB4-treated HUVECs incubated with or without ATRA (1 µmol/L) or ATO (5 µmol/L) was tested as previously described. (C) The number of leaked RBCs was measured as previously described. (D) The distribution of intercellular gap size was improved by ATRA treatment of the target HUVECs; n = 200 gaps from 10 glass coverslips. (E, F) Effect of ATRA and ATO on ICAM-1 and VCAM-1 concentrations. (G) Schematic illustration of the effect of ATRA and ATO on NB4-treated HUVECs. ATRA protects NB4-treated HUVECs, whereas ATO worsens the damage. *P <0.05 and **P <0.01. The results are displayed as the mean ± SD from at least 6 experiments. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)