title: Hypoxia/reoxygenation-induced cytotoxicity in cultured human lymphocytes.
abstract: Reactive oxygen species (ROS) generated after exposure to hypoxia and reoxygenation (H/R) play a pivotal role in the stimulation of cell death. In this study, we explored H/R-induced cytotoxicity in human lymphocytes. Compared to cells under normoxic conditions, H/R-treated cells exhibited significantly decreased viability and increased DNA breakage. Western blotting analysis demonstrated that H/R-induced the accumulation of p53 and p63 proteins. H/R also led to the activation of caspase-3 and -9, accompanied by the cleavage of PARP (poly(ADP-ribose)polymerase). Because apoptosis is usually accompanied by ROS generation and collapse of the mitochondrial membrane potential (MMP, Deltapsi(m)), we examined ROS and MMP levels in H/R-treated lymphocytes. Cells subjected to H/R exhibited significantly increased ROS and decreased MMP, compared with normoxic cells. Taken together, these results indicate that H/R treatment of human lymphocytes induces rapid ROS generation and MMP collapse, which triggers apoptosis.
authors.affiliation: School of Public Health and Institute of Health and Environment, Seoul National University, 28 Yunkeun-dong, Chongno-ku, Seoul 110-460, Republic of Korea.
authors.forename: Jun Yeol
authors.initials: JY
authors.lastname: Choi
authors.forename: Byeong Mo
authors.initials: BM
authors.lastname: Kim
authors.forename: Yang Jee
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hae Dong
authors.initials: HD
authors.lastname: Woo
authors.forename: Hai Won
authors.initials: HW
authors.lastname: Chung
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D015687:Cell Hypoxia / Q000502:physiology; D002470:Cell Survival / Q000502:physiology*; D002478:Cells, Cultured; D006801:Humans; D008214:Lymphocytes / Q000166:cytology* / Q000502:physiology*; D053078:Membrane Potential, Mitochondrial / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D010100:Oxygen