TY - JOUR
T1 - Necrotic cell death in response to oxidant stress involves the activation of the apoptogenic caspase-8/bid pathway
AU - Wang, Xue
AU - Ryter, Stefan W.
AU - Dai, Chunsun
AU - Tang, Zi Lue
AU - Watkins, Simon C.
AU - Yin, Xiao Ming
AU - Song, Ruiping
AU - Choi, Augustine M.K.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2003/8/1
Y1 - 2003/8/1
N2 - Human epithelial (A549) cells exposed to hyperoxia die by cellular necrosis. In the current study, we demonstrated the involvement of apoptogenic factors in epithelial cell necrosis in response to hyperoxia, including the formation of the Fas-related death-inducing signaling complex and initiation of mitochondria-dependent apoptotic pathways. We showed increased activation of both Bid and Bax in A549 cells subjected to hyperoxia. Bax activation involved a Bid-assisted conformational change. We discovered that the response to hyperoxia in vivo predominantly involved the activation of the Bid/caspase-8 pathway without apparent increases in Bax expression. Disruption of the Bid pathway by gene deletion protected against cell death in vivo and in vitro. Likewise, inhibition of caspase-8 by Flip also protected against cell death. Taken together, we have demonstrated the involvement of apoptogenic factors in epithelial cell responses to hyperoxia, despite a final outcome of cellular necrosis. We have, for the first time, identified a predominant role for the caspase-8/Bid pathway in signaling associated with hyperoxic lung injury and cell death in vivo and in vitro.
AB - Human epithelial (A549) cells exposed to hyperoxia die by cellular necrosis. In the current study, we demonstrated the involvement of apoptogenic factors in epithelial cell necrosis in response to hyperoxia, including the formation of the Fas-related death-inducing signaling complex and initiation of mitochondria-dependent apoptotic pathways. We showed increased activation of both Bid and Bax in A549 cells subjected to hyperoxia. Bax activation involved a Bid-assisted conformational change. We discovered that the response to hyperoxia in vivo predominantly involved the activation of the Bid/caspase-8 pathway without apparent increases in Bax expression. Disruption of the Bid pathway by gene deletion protected against cell death in vivo and in vitro. Likewise, inhibition of caspase-8 by Flip also protected against cell death. Taken together, we have demonstrated the involvement of apoptogenic factors in epithelial cell responses to hyperoxia, despite a final outcome of cellular necrosis. We have, for the first time, identified a predominant role for the caspase-8/Bid pathway in signaling associated with hyperoxic lung injury and cell death in vivo and in vitro.
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U2 - 10.1074/jbc.M301624200
DO - 10.1074/jbc.M301624200
M3 - Article
C2 - 12754217
AN - SCOPUS:0042707655
SN - 0021-9258
VL - 278
SP - 29184
EP - 29191
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 31
ER -