Oxidant-injured airway epithelial cells upregulate thioredoxin but do not produce interleukin-8.
We tested the hypothesis that oxidant-injured cells upregulate thioredoxin, whereas oxidant-stressed, but not injured, cells upregulate interleukin (IL)-8 after injury. We exposed primary human tracheobronchial epithelial cells and transformed human bronchial epithelial cells (BEAS-2B S.6) to 0, 200, 400, or 600 microM H(2)O(2) for 1 h followed by an additional 7 h of incubation. Subsequently, the cells were double-labeled with markers of injury (either Ethidium Homodimer-1 for cellular injury or MitoTracker dye for functional mitochondria) or oxidant stress (5-[and 6]-chloromethyl-2',7'-dicholorodihydrofluorescein diacetate) and antibodies specific for the chemoattractants IL-8 or thioredoxin. We found significant inverse relationships between numbers and stained chemoattractant volumes of IL-8 and thioredoxin-positive cells with increasing H(2)O(2) dose. Cells with mitochondrial injury produced thioredoxin but not IL-8, and oxidant-stressed cells were more likely to produce thioredoxin than IL-8. Isolated human neutrophils were more likely to colocalize with thioredoxin-positive BEAS-2B S.6 cells than thioredoxin-negative cells. The H(2)O(2) injury did not induce significant apoptosis in the BEAS-2B S.6 cells as measured by caspase 3 activation. We conclude that oxidant-injured and stressed airway epithelial cells upregulate thioredoxin, but produce little IL-8, which may be important in airway epithelial cell-mediated multistep navigation of neutrophils to sites of oxidant injury.
Oslund
Karen L
KL
The Center for Comparative Respiratory Biology and Medicine, School of Veterinary Medicine, One Shields Ave., Davis, CA 95616, USA.
Miller
Lisa A
LA
Usachenko
Jodie L
JL
Tyler
Nancy K
NK
Wu
Reen
R
Hyde
Dallas M
DM
D017209:Apoptosis / Q000502:physiology; D002478:Cells, Cultured; D002630:Chemotactic Factors / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007150:Immunohistochemistry; D016209:Interleukin-8 / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D020545:Respiratory Mucosa / Q000166:cytology* / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism*; D015854:Up-Regulation
D002630:Chemotactic Factors; D016209:Interleukin-8; D016877:Oxidants; D013879:Thioredoxins; D006861:Hydrogen Peroxide