IL-4 induces apoptosis of endothelial cells through the caspase-3-dependent pathway

The present study was designed to investigate the hypothesis that interleuk in-4 (IL-4) can induce apoptosis of human endothelial cells and to study re gulatory pathways of this process, Indeed, DNA ladder assay and flow cytome try study showed that IL-4 can induce apoptosis of endothelial cells in a t ime- and dose-dependent manner. In addition, IL-4 markedly increased activi ty of caspase-3, and inhibition of this enzyme suppressed IL-4-induced apop tosis in a dose-dependent manner. These results provide the first evidence that IL-4 can induce apoptosis of human endothelial cells. In addition, the data indicate that the caspase-3-dependent pathway is critically involved in this process. (C) 2000 Federation of European Biochemical Societies. Pub lished by Elsevier Science B.V. All rights reserved.