Antioxidant enzyme levels as a function of growth state in cell culture

• Published in: Free radical biology & medicine Vol. 19; no. 1; pp. 53 - 65
• Main Authors: Oberley, Terry D., Schultz, Janice L., Li, Ning, Oberley, Larry W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.1995
• Subjects: 3T3 Cells; Animals; Antioxidants; Blotting, Western; Catalase - metabolism; Cell Count; Cell culture; Cell cycle; Cell Cycle - physiology; Cell Division - physiology; Cell Line; Cricetinae; Density inhibition of growth; Dogs; Free radicals; Glutathione Peroxidase - metabolism; Kidney; Male; Manganese; Manganese superoxide dismutase; Mesocricetus; Mice; Superoxide Dismutase - metabolism; Tumor Cells, Cultured; Cell culture; Density inhibition of growth; Free radicals; Cell cycle; Manganese superoxide dismutase
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/0891-5849(95)00012-M

Manganese superoxide dismutase (MnSOD) levels were monitored as a function of time in culture to determine whether these levels were altered at logarithmic growth versus when the cells exhibited density limitation of growth. For comparison, activities of the antioxidant enzymes copper, zinc superoxide dismutase (CuZnSOD), catalase, and glutathione peroxidase were also evaluated. Four cell lines were studied, two of which exhibited density limitation of growth and two of which did not. Each cell line showed a unique antioxidant enzyme profile. The two cell lines that showed density limitation of growth also demonstrated induction of MnSOD at the time when the cells stopped proliferating in culture, whereas the other two cell lines did not show induction of MnSOD. There was no strict correlation between density limitation of growth and activities of the other antioxidant enzymes. To determine whether SOD varied with various phases of the cell cycle, NIH/3T3 cells were synchronized using serum starvation, and then SOD activities were measured during quiescence (G 0) and the phase of DNA synthesis (S-phase). MnSOD was decreased during S-phase compared with G 0, whereas CuZnSOD was increased during S-phase compared with G 0, demonstrating alteration of SOD activities with varying phases of the cell cycle. This study suggests the possibility that increased MnSOD may correlate with decreased cell proliferation and suggests significant alterations in SOD activities during the cell cycle.