Abstract
This study was undertaken to investigate the effect of hydrogen peroxide (HP), a reactive oxygen species, and vitamin C, an antioxidant, on apoptosis and prostaglandin (PGE2) release in human amnion epithelial and mesenchymal cells, and intact amnion. Amnion cells and explants were incubated with and without HP and vitamin C. Cytoproliferation assay for viability, DNA fragmentation and PARP cleavage for apoptosis, EIA for PGE2, and western blots for cyclooxygenases (COX) were performed. In amnion cells and explants, HP (0-5 mM) induced dose dependent apoptosis as per DNA fragmentation and PARP cleavage. HP (0-0.5 mM) also induced PGE2 release concomitant with apoptosis in both cell types. In amnion explants, HP (0-10 mM) induced COX-2 protein and PGE2 release concomitant with apoptosis. Vitamin C (0.01-10 mM), alone, enhanced epithelial but inhibited mesenchymal cell viability. It induced PGE2 release in amnion explants. Vitamin C (1 mM) failed to inhibit HP induced apoptosis, but instead exacerbated it in epithelial and mesenchymal cells, and amnion explants. Vitamin C (0-10 mM) enhanced HP induced PGE2 in mesenchyrnal cells. HP induces concomitant apoptosis and PGE2 release in amnion epithelial and mesenchymal cells, and in intact amnion explants. HP induced apoptosis is not inhibited but enhanced by vitamin C. © 2004 Elsevier Ltd. All rights reserved.