Hyperbaric oxygen enhances apoptosis in hematopoietic cells

• Published in: Apoptosis (London) Vol. 7; no. 6; p. 499
• Main Authors: Ganguly, B J, Tonomura, N, Benson, R M, Osborne, B A, Granowitz, E V
• Format: Journal Article
• Language: English
• Published: Netherlands Springer Nature B.V 01-12-2002
• Subjects: Animals; Apoptosis; Apoptosis - drug effects; Apoptosis - physiology; Atmospheric pressure; Caspase 3; Caspases - biosynthesis; Catalase - metabolism; Cells; Dehydroascorbic Acid - pharmacology; Female; Hematopoietic System - cytology; Hematopoietic System - drug effects; HL-60 Cells; Humans; Hydrogen Peroxide - metabolism; Hydrostatic Pressure; Hyperbaric Oxygenation; Hyperoxia; In Vitro Techniques; Jurkat Cells; Mice; Mice, Inbred BALB C; Nucleic Acid Synthesis Inhibitors - pharmacology; Oxygen; Oxygen - physiology; Protein synthesis; Protein Synthesis Inhibitors - pharmacology; Reactive Oxygen Species - metabolism; T-Lymphocytes - cytology; T-Lymphocytes - drug effects
• ISSN: 1360-8185; 1573-675X
• DOI: 10.1023/A:1020686908831

Hyperbaric oxygen (HBO) is 100% oxygen administered at elevated atmospheric pressure. In this study, we examined the effect of HBO on hematopoietic cell apoptosis. Cells exposed to HBO were incubated in a chamber containing 97.9% O(2) and 2.1% CO(2) at 2.4 atmospheres absolute (ATA). HBO enhanced spontaneous HL-60 cell apoptosis in a time-dependent manner; a 12 h exposure increased apoptosis by 42%. Exposing these cells to hyperoxia at standard atmospheric pressure (95% O(2), 5% CO(2) at 1 ATA) or increased pressure alone (8.75% O(2), 2.1% CO(2) at 2.4 ATA) had minimal effect on apoptosis. HBO also enhanced stimulus-induced apoptosis. HL-60 cells stimulated to die using gamma radiation underwent 33% more apoptosis than cells exposed to radiation alone. HBO enhanced melphalan, camptothecin, and chlorambucil-induced apoptosis by 22%, 13%, and 8%, respectively. Jurkat cells stimulated to die with anti-Fas antibody underwent 44% more apoptosis when exposed to HBO. Spontaneous apoptosis was increased by 15% in HBO-exposed murine thymocytes. HBO's effect on apoptosis did not require new protein synthesis. As expected, HBO exposure increased the intracellular concentration of H(2)O(2). Incubating HL-60 cells in the presence of dehydroascorbic acid partially abrogated HBO-induced increases in intracellular H(2)O(2) and apoptosis. In summary, HBO enhances spontaneous and stimulus-induced apoptosis in hematopoietic cells, at least in part, by enhancing the intracellular accumulation of H(2)O(2).