Interleukin 1 alpha is a marker of endothelial cellular senescence

BACKGROUND: The functional changes associated with endothelial senescence may be involved in human aging and age-related vascular disorders. Since the inflammatory cytokine interleukin (IL-)1 inhibits endothelial growth, we evaluated the expression of IL-1a, IL-1b and their antagonist, the IL-1 receptor antagonist (IL-1ra), in endothelial in vitro senescence and quiescence. We also examined the expression of IL-1a in human senescent and progeric fibroblasts. RESULTS: We found that the overexpression of IL-1a specifically characterizes endothelial senescence. No modulation of this cytokine was observed in endothelial quiescence and in senescent or progeric human fibroblasts. The expression of IL-1b and IL-1ra was also assessed and found not to be affected by senescence. CONCLUSIONS: Our results indicate that a dysfunction of the cytokine network associates with aging and point to a specific role of IL-1a in endothelial senescence.