A Fundamental Study on Increasing of Endothelial Permeability by Photochemical Reaction

Abstract

As photochemical reaction (PR) is used in photodynamic therapy (PDT), high reactive oxygen speacies (ROS) concentration often induces cell and tissue injury. In this study, we focused on the mechanism of endothelial cell injury caused by PR. Human umbilical vein endothelial cells (HUVEC) were incubated with delta-aminolevulinic acid and were irradiated by LED light in 630 nm wavelength for 10 min. In vitro cell viability by MTT ssay did not change after PR, while in 3D-cultures of HUVEC in collagen that induces tube formation, PDT reduced the capillary-like structures and increase in endothelial permeability. ROS by PR leaded to shrinkage of endothelial cells, suppressed increase in subendothelial area after PR. Furthermore, F-actin was formed into stress fibers. These results suggest that oxidative stress by PDT strongly affects on endothelial permeability and morphological change of endothelial cells in which generation of stress fibers.