|
|
|
|
|
|
|
||
© The Rockefeller University Press,
0021-9525/2001//633 $5.00
The Journal of Cell Biology, Volume 152, Number 3,
, 2001 633-644
Original Article |
Matrix Attachment Regulates FAS-Induced Apoptosis in Endothelial Cells
: A Role for C-Flip and Implications for Anoikis
Cancer Research Center, The Burnham Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037.(858) 646-3199(858) 646-3100
kvuori{at}burnham.org
Survival of endothelial cells is critical for cellular processes such as angiogenesis. Cell attachment to extracellular matrix inhibits apoptosis in endothelial cells both in vitro and in vivo, but the molecular mechanisms underlying matrix-induced survival signals or detachment-induced apoptotic signals are unknown. We demonstrate here that matrix attachment is an efficient regulator of Fas-mediated apoptosis in endothelial cells. Thus, matrix attachment protects cells from Fas-induced apoptosis, whereas matrix detachment results in susceptibility to Fas-mediated cell death. Matrix attachment modulates Fas-mediated apoptosis at two different levels: by regulating the expression level of Fas, and by regulating the expression level of c-Flip, an endogenous antagonist of caspase-8. The extracellular signal–regulated kinase (Erk) cascade functions as a survival pathway in adherent cells by regulating c-Flip expression. We further show that detachment-induced cell death, or anoikis, itself results from activation of the Fas pathway by its ligand, Fas-L. Fas-L/Fas interaction, Fas–FADD complex formation, and caspase-8 activation precede the bulk of anoikis in endothelial cells, and inhibition of any of these events blocks anoikis. These studies identify matrix attachment as a survival factor against death receptor–mediated apoptosis and provide a molecular mechanism for anoikis and previously observed Fas resistance in endothelial cells.
Key Words: apoptosis • endothelium • extracellular matrix • integrin • signaling
© 2001 The Rockefeller University Press
Abbreviations used in this paper: AICD, activation-induced cell death; DISC, death-inducing signaling complex; dn, dominant negative; ECM, extracellular matrix; Erk, extracellular signal–regulated kinase; FADD, Fas-associated death domain; FAK, focal adhesion kinase; GFP, green fluorescent protein; HUVEC, human umbilical vein endothelial cell; JNK, c-Jun NH2-terminal kinase; JNKK, JNK kinase; MAPK, mitogen-activated protein kinase; MEK, MAP kinase kinase; PI 3'-kinase, phosphatidylinositol 3'-kinase; RT, reverse transcriptase.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
|
|
