Resistance of quiescent and proliferating airway epithelial cells to H2O2 challenge.
Alveolar epithelial cell injury and recovery are important in the pathogenesis of oxidant-induced lung damage. The alveolar cell line A549 was used to study responses of proliferating and quiescent cells in culture to time- and dose-dependent hydrogen peroxide (H(2)O(2)) challenges. Recovery was monitored after 24 h of incubation in fresh medium with 10% serum. The adherent cells were counted and the resistance and recovery of the attached cells was assessed by appearance, by measuring the number of viable, apoptotic and necrotic cells using fluorescent-activated cell sorting, and by determining the intracellular free thiol content. A549 cells recovered from a 1-h challenge with up to 1 mM H(2)O(2) but could not sustain a more prolonged challenge (6 or 24 h) with 0.5 mM or 1.0 mM H(2)O(2). These more severe conditions resulted in: loss of cells by detachment from the plate surface; reduced numbers of viable cells primarily due to necrosis; and a strong reduction of the intracellular free thiol content. Quiescent cells proved to be more sensitive to oxidative stress than proliferating cells. Intracellular free thiol levels apparently play a decisive role in cell survival, preferentially protecting proliferating cells.
Smit-de Vries
M P
MP
Department of Analytical Biochemistry, University of Groningen, 9713 AV Groningen, The Netherlands.
van der Toorn
M
M
Bischoff
R
R
Kauffman
H F
HF
D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009336:Necrosis; D016877:Oxidants / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013997:Time Factors; D014132:Trachea / Q000378:metabolism
D016877:Oxidants; D013438:Sulfhydryl Compounds; D012710:Serum Albumin, Bovine; D006861:Hydrogen Peroxide; D010100:Oxygen