Polymorphonuclear leukocytes (PMN) are central to the pathogenesis of a number of intestinal diseases. PMN-induced damage to the protective epithelium occurs in hemorrhagic shock, necrotizing enterocolitis and conditions resulting in intestinal reperfusion injury. In such diseases, tissue hypoxia has been implicated as a pathophysiologic mediator. Thus, we hypothesized that exposure of intestinal epithelia to hypoxia may modulate PMN-epithelial interactions. In this study, T84 cell monolayers, a human intestinal crypt cell line, and isolated human PMN were used to examine the influence of hypoxia/reoxygenation (H/R) on PMN transepithelial migration. Confluent T84 cell monolayers were exposed to hypoxia (range 2-21% O2 for 0-72 h) and reoxygenated with buffer containing PMN. Transmigration of PMN (basolateral to apical orientation) was driven by a transepithelial gradient of the chemotactic peptide tMLP. In response to hypoxia/reoxygenation (H/R), transmigration into, and across epithelial monolayer was increased in a dose- (EC50 approximately 7% O2) and time-dependent fashion (3.5 +/- 0.3-fold increase at 2% O2 for 48 h, P < 0.001). Such conditions of H/R were not toxic to epithelia and did not influence epithelial barrier function. The influence of H/R on PMN transmigration was protein synthesis-dependent (> 80% decreased in the presence of cycloheximide) and could be inhibited by addition of functionally inhibitory antibodies to the PMN beta 2 integrin CD11b/18 (> 80% attenuated) and to CD47 (> 90% decreased compared to control). Hypoxia induced epithelial production and basolateral release of the PMN activating chemokine interleukin-8 (IL-8, nearly sixfold increase over normoxic control) which remained avidly associated with the epithelial matrix. Treatment of epithelial cells with IL-8 antisense oligonucleotides resulted in decreased monolayer-associated PMN but did not influence PMN transmigration, suggesting that epithelial IL-8 production may serve as a recruitment signal for PMN to the basal surface of polarized epithelia. The present observations indicate that H/R provides a relevant stimulus for novel biochemical crosstalk between epithelia and PMN.
Article|
September 01 1996
Epithelial exposure to hypoxia modulates neutrophil transepithelial migration.
S P Colgan,
S P Colgan
Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Boston, Massachusetts, USA.
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A L Dzus,
A L Dzus
Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Boston, Massachusetts, USA.
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C A Parkos
C A Parkos
Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Boston, Massachusetts, USA.
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S P Colgan
Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Boston, Massachusetts, USA.
A L Dzus
Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Boston, Massachusetts, USA.
C A Parkos
Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Online ISSN: 1540-9538
Print ISSN: 0022-1007
J Exp Med (1996) 184 (3): 1003–1015.
Citation
S P Colgan, A L Dzus, C A Parkos; Epithelial exposure to hypoxia modulates neutrophil transepithelial migration.. J Exp Med 1 September 1996; 184 (3): 1003–1015. doi: https://doi.org/10.1084/jem.184.3.1003
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