Neutrophil and asbestos fiber-induced cytotoxicity in cultured human mesothelial and bronchial epithelial cells.
This study investigates reactive oxygen species generation and oxidant-related cytotoxicity induced by amosite asbestos fibers and polymorphonuclear leucocytes (PMNs) in human mesothelial cells and human bronchial epithelial cells in vitro. Transformed human pleural mesothelial cells (MET 5A) and bronchial epithelial cells (BEAS 2B) were treated with amosite (2 micrograms/cm2) for 48 h. After 24 h of incubation, the cells were exposed for 1 h to nonactivated or amosite (50 micrograms) activated PMNs, washed, and incubated for another 23 h. Reactive oxygen species generation by the PMNs and the target cells was measured by chemiluminescence. Cell injury was assessed by cellular adenine nucleotide depletion, extracellular release of nucleotides, and lactate dehydrogenase (LDH). Amosite-activated (but also to a lesser degree nonactivated) PMNs released substantial amounts of reactive oxygen metabolites, whereas the chemiluminescence of amosite-exposed mesothelial cells and epithelial cells did not differ from the background. Amosite treatment (48 h) of the target cells did not change intracellular adenine nucleotides (ATP, ADP, AMP) or nucleotide catabolite products (xanthine, hypoxanthine, and uric acid). When the target cells were exposed to nonactivated PMNs, significant adenine nucleotide depletion and nucleotide catabolite accumulation was observed in mesothelial cells only. In separate experiments, when the target cells were exposed to amosite-activated PMNs, the target cell injury was further potentiated compared with the amosite treatment alone or exposure to nonactivated PMNs. In conclusion, this study suggests the importance of inflammatory cell-derived free radicals in the development of amosite-induced mesothelial cell injury.
Kinnula
V L
VL
University of Helsinki, Department of Pulmonary Medicine, Finland.
Raivio
K O
KO
Linnainmaa
K
K
Ekman
A
A
Klockars
M
M
D000227:Adenine Nucleotides / Q000378:metabolism; D000975:Antioxidants / Q000494:pharmacology; D017639:Asbestos, Amosite / Q000633:toxicity*; D001980:Bronchi / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002461:Cell Line, Transformed; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D007249:Inflammation / Q000209:etiology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008163:Luminescent Measurements; D008175:Lung Neoplasms / Q000209:etiology; D008654:Mesothelioma / Q000209:etiology; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010994:Pleura / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
D000227:Adenine Nucleotides; D000975:Antioxidants; D005609:Free Radicals; D017382:Reactive Oxygen Species; D017639:Asbestos, Amosite; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase