Fig. 1: The absence of microbial pattern recognition receptor TLR5 in colonic PYY-labelled cells increases food intake.
a, Mouse colon with GFP-labelled PYY-labelled cells was rolled longitudinally (proximal colon in the centre); representative of n = 3 mice. Inset: magnified view of the outlined area showing a single PYY–GFP cell with apical process reaching into the lumen and neuropod reaching towards the base of the crypt. DAPI, 4′,6-diamidino-2-phenylindole. Scale bars, 10 μm. b, Volcano plot of microbial pattern recognition receptor gene expression in epithelial PYY–GFP and non-GFP cells by RNA sequencing. Compared to non-GFP cells, PYY–GFP cells are enriched for the pattern recognition receptor gene Tlr5 (n = 6 mice; adjusted P < 0.01 by DESeq2 with two-tailed t-test). c, Fluorescence in situ hybridization of Tlr5 in PYY–GFP cells. Error bars represent s.e.m. Left: regional expression of Tlr5 in PYY–GFP cells (n = 3 mice, each dot represents 50 cells). n.d., not detected (no cells expressing Tlr5). Dist. distal; Duo., duodenum; Jej., jejunum; Ile., ileum; Prox., proximal. Right, PYY-labelled cell (green) expressing Tlr5 (red) in the distal colon; representative of n = 3 mice. Scale bar, 10 μm. White dashed line represents PYY-labelled cell outline. d, Left, genetic deletion of Tlr5 exclusively in PYY-labelled cells causes increased weight gain in male and female mice (males (M) Pyycre;Tlr5fl/fl: n = 7 mice, starting weight = 5.78 g ± 0.61; Tlr5fl/fl littermate controls: n = 15 mice, starting weight = 14.28 g ± 0.71; females (F) Pyycre;Tlr5fl/fl: n = 6 mice, starting weight = 15.04 g ± 0.53; Tlr5fl/fl littermate controls: n = 11 mice, starting weight = 14.16 g ± 0.39; *P < 0.05 genotype–time interaction by repeated-measures analysis of variance (ANOVA) with post hoc Tukey honestly significant difference (HSD). Error bars represent s.e.m. Right, meal duration in females and meal size in males and females significantly increased in Pyycre;Tlr5fl/fl mice (Tlr5fl/fl males: n = 413 meals, n = 6 mice; 5Pyycre;Tlr5fl/fl males: n = 612 meals, n = 9 mice; Tlr5fl/fl females: n = 399 meals, n = 8 mice; Pyycre;Tlr5fl/fl females: n = 468 meals, n = 9 mice; n = 2 independent experiments; *P < 0.05 by two-way ANOVA with post hoc Tukey HSD; P < 0.05 main effect of genotype and sex for meal size and duration with P > 0.05 genotype–sex interaction). No changes observed in meal frequency (see Extended Data Fig. 5 for further analyses). Box plots represent interquartile range; white lines indicate median; whiskers extend to the furthest point above the third quartile or below the first quartile within 1.5× the interquartile range.
