Fig. 1.

NLRP1 expression is associated with senescence. A Human fibroblasts were exposed to 20 Gy ionizing irradiation (IR). On day 1, 5 and 7, NLRP1 and senescence protein expression were analyzed by immunoblotting. B Representative images of Ki67 and NLRP1 immunofluorescence. Scale bar = 50 μm. C,D IL-1β, IL18, IL-6 and IL-8 were quantified by ELISA. All data are presented as means ± SEM, n = 4 independent experiments; ** P < 0.005, *** P < 0.001 differences between time points after irradiation and day 0. E,F Human fibroblasts were treated with Valboropro (Vbpro) to induce NLRP1 expression. After 24 h, NLRP1 and IL-6 protein expression were analyzed by immunoblotting and cytokines were analyzed by ELISA. Human fibroblasts were irradiated (G) or stimulated with palbociclib (Palbo) (H) to induce two different senescence models. Then, cells were transfected with a non-targeting control siRNA (Control) or with siRNAs against NLRP1 (siNLRP1). Expression of NLRP1 and senescence-associated proteins p16, p21, p53 and IL-6 were assessed by immunoblotting and IL6, IL-8 or IL-18 were quantified by ELISA. All data are presented as means ± SEM, n = 4 independent experiments; ** P < 0.005, *** P < 0.001 irradiated vs. control. ^aaa P < 0.001, IR + siRNA vs. IR cells (color figure online)