Thai Acanthamoeba isolate (T4) induced apoptotic death in neuroblastoma cells via the Bax-mediated pathway

A Thai Acanthamoeba isolate named AS recovered from a corneal scraping of a keratitis patient was genotypically determined as T4 AS trophozoites were used for studying Acanthamoeba-induced apoptosis in mouse neuroblastoma NA cells during in vitro co-cultivation The Acanthamoeba-ex posed NA cells showed signs of apoptosis including cell shrinkage nuclear condensation and DNA fragmentation The effect was confirmed by DNA laddering electrophoresis Involvement of caspase enzymes and mitochondrial pro- and anti apoptotic proteins (Bax and Bcl 2) in AS-induced apoptosis was determined The use of Z-VAD-FMK a pan-caspase inhibitor significantly reduced the apoptotic effect while Bax/Bcl-2 ratio analysis showed a significant increase in the expression of apoptotic proteins in AS-exposed NA cells These results strongly indicated that apoptosis induced by AS trophozoites is caspase-dependent and is mediated by over expression of pro-apoptotic proteins in the mitochondrial pathway This is the first report on the role of Bax in mediating apoptosis induced by Acanthamoeba (C) 2010 Elsevier Ireland Ltd All rights reserved