Hypoxia/reoxygenation-induced cytotoxicity in cultured human lymphocytes.
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.
Choi
Jun Yeol
JY
School of Public Health and Institute of Health and Environment, Seoul National University, 28 Yunkeun-dong, Chongno-ku, Seoul 110-460, Republic of Korea.
Kim
Byeong Mo
BM
Kim
Yang Jee
YJ
Woo
Hae Dong
HD
Chung
Hai Won
HW
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*
D017382:Reactive Oxygen Species; D010100:Oxygen