Apoptosis was determined using the Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) apoptosis Kit (Beckman Coulter, Brea, CA, USA), as described.21 (link),22 (link) Mean percentage of AnnexinV+/PI- (early apoptotic) and Annexin V+/PI+ (late apoptotic and/or dead) ± standard error of the mean (SEM) from one representative experiment is shown.