Fig. 4: Dectin-1 signaling activates the expression of genes involving PGE₂ synthesis.

a, b WT and Clec7a^−/− mice under SPF conditions were treated with AOM-3DSS for 16 weeks. The expression of Cox2-encoding Ptgs2 was determined by RT-qPCR (a, WT n = 3, Clec7a^−/− n = 5; **P = 0.0030), and the concentration of PGE₂ in tissue homogenates was determined by ELISA (b, WT n = 10, Clec7a^−/− n = 9; pooled data from 2 experiments and normalized by the protein concentration in each lysate; **P = 0.0057, *P = 0.0449). c, d The expression of Ptgs2 in intestinal polyp or non-polyp tissues (c, ***P = 0.0007), or in EpCAM⁺ epithelial cells and in tissue-infiltrating CD45⁺ leukocytes (d, ***P = 0.0008, ****P < 0.0001) from Apc^Min/+ and Apc^Min/+Clec7a^−/− mice at 20 weeks old was determined by RT-qPCR (n = 3/group). e–g According to the scRNA-seq data shown in Fig. 3e–h, Ptgs2 expressing cells in all polyp-infiltrating myeloid cells (e) and Ptgs2 expression levels in Ptgs2⁺ myeloid cells (f, WT n = 1284, Clec7a^−/− n = 635; ****P < 0.0001) in WT and Clec7a^−/− mice are shown. The expression of indicated genes including myeloid subtype-specific genes and PGE₂ synthase genes in WT mice are shown in g. h C57BL/6J mice were treated with AOM-3DSS for 12 weeks. CD11c⁺ and CD11c^–CD11b⁺ cells were purified from colonic polyps and non-polyp tissues with autoMACS, and the mRNA expression of indicated genes was determined by RT-qPCR (n = 4 biologically independent samples/group; ***P = 0.0003, ****P < 0.0001). i Purified CD11b⁺ polyp-infiltrating cells from Apc^Min/+ mice were harvested and were stimulated with curdlan for 20 h. Then, the expression of genes involved in PGE₂ synthesis was determined by RT-qPCR. Laminarin treatment was carried out for 4 h before the treatment with curdlan (n = 4 biologically independent samples/group, ****P < 0.0001). j CD11b⁺ and CD11c⁺ myeloid cells from colonic polyps of AOM-3DSS-treated WT mice were stimulated with curdlan (1 mg/ml) in the presence of each one of inhibitors against IκBα (BAY11-7082, 2 μM)) or SYK (R406, 2 μM). After 20 h, PGE₂ synthase expression was determined by qPCR (n = 3 biologically independent samples/group; *P = 0.0380, **P = 0.0037, ****P < 0.0001). Data in a, c, d, h–j are representatives of two independent experiments and are expressed as means ± SD. Data in a–d, h are analyzed using two-way ANOVA followed by Tukey’s multiple-comparisons test, in f using unpaired two-tailed Student’s t-test, and in i, j using one-way ANOVA followed by Tukey’s multiple-comparisons test. Source data are provided in the Source Data file.