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Cytotoxicity of TNFα is regulated by integrin‐mediated matrix signaling
Author(s) -
Chen ChihChiun,
Young Jennifer L,
Monzon Ricardo I,
Chen Ningyu,
Todorović Viktor,
Lau Lester F
Publication year - 2007
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601596
Subject(s) - biology , integrin , cytotoxicity , microbiology and biotechnology , tumor necrosis factor alpha , signal transduction , matrix (chemical analysis) , immunology , cancer research , biochemistry , receptor , in vitro , materials science , composite material
Cytokines of the tumor necrosis factor (TNF) family regulate inflammation and immunity, and a subset of this family can also induce cell death in a context‐dependent manner. Although TNFα is cytotoxic to certain tumor cell lines, it induces apoptosis in normal cells only when NFκB signaling is blocked. Here we show that the matricellular protein CCN1/CYR61 can unmask the cytotoxic potential of TNFα without perturbation of NFκB signaling or de novo protein synthesis, leading to rapid apoptosis in the otherwise resistant primary human fibroblasts. CCN1 acts through binding to integrins α v β 5 , α 6 β 1 , and syndecan‐4, triggering the generation of reactive oxygen species (ROS) through a Rac1‐dependent mechanism via 5‐lipoxygenase and the mitochondria, leading to the biphasic activation of JNK necessary for apoptosis. Mice with the genomic Ccn1 locus replaced with an apoptosis‐defective Ccn1 allele are substantially resistant to TNFα‐induced apoptosis in vivo . These results indicate that CCN1 may act as a physiologic regulator of TNFα cytotoxicity, providing the contextual cues from the extracellular matrix for TNFα‐mediated cell death.