Fig. 3: TLR5 plays an essential role in the FPNI-dependent extension of healthspan.

Amino acid sequences of the TLR5 binding site (top) and its mutant derivative (bottom) (a). The locations of site-directed mutations in the predicted TLR5 binding region are boxed. Activation of NF-κB through TLR5 stimulation with FlaB, FP or FP MUT proteins (b, n = 3 biologically independent samples per group). After the eight times of FP, FP MUT or vehicle administration their phenotypes were determined; hair status (c, O-Ctrl: n = 19 biologically independent animals; O-FP: n = 23 biologically independent animals; O-FP MUT: n = 20 biologically independent animals) and cataracts (d, O-Ctrl: n = 19 biologically independent animals; O-FP: n = 23 biologically independent animals; O-FP MUT: n = 20 biologically independent animals), bone mineral density of the spine and femur (e, O-Ctrl: n = 5 biologically independent animals; O-FP: n = 7 biologically independent animals; O-FP MUT: n = 5 biologically independent animals), analysis of glucose uptake in the brain (f, O-Ctrl: n = 3 biologically independent animals; O-FP: n = 5 biologically independent animals; O-FP MUT: n = 3 biologically independent animals) are displayed in quantitative bar graphs. Survival rates of female mice that received FP or FP MUT intranasally were compared with those of vehicle mice (g, n = 16 biologically independent animals per group). The survival rates were compared using Kaplan-Meier analysis. Error bars represent mean ± SEM. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 using the one-way ANOVA (b–f), and the Log-rank (Mantel-Cox) test (g). ns, not significant. FlaB, Vibrio vulnificus major flagellin; FP MUT, site-directed mutant FP. Source data are provided as a Source Data file.