Expression of c-FLIP in a rat model of sepsis and its effects on endothelial apoptosis

Sepsis is characterized by the impaired regulation of inflammatory responses. Apoptosis is important in the pathogenesis of sepsis. Cellular FLICE-inhibitory protein (c-FLIP) is a catalytically inactive caspase-8 homologue, which negatively interferes with apoptotic signaling. The role of c-FLIP in sepsis and in endothelial cell apoptosis, a critical step in the pathogenesis of sepsis, remains controversial. In the present study, to investigate the relationship between c-FLIP and sepsis, a rat model of sepsis was induced by cecal ligation and puncture, and western blot analysis was used to detect the expression of c-FLIP(L), the long isoform of c-FLIP. Lower protein expression levels of c-FLIP(L) were found in the brain, intestine and lung of the rat sepsis model, compared with the rats in the sham surgery group. The association between the expression of c-FLIP(L) and endothelial cell apoptosis was further examined in vitro by c-FLIP(L) overexpression and flow cytometry, which demonstrated that the expression of c-FLIP(L) was inversely correlated with endothelial cell apoptosis. These data suggested that c-FLIP may be important in sepsis and shed light on therapeutic strategies.