Fig. 7

Epithelial PRLR inhibited TNFSF13B of macrophages through attenuated CXCL1-NF-κB signaling. THP-1 cells were pretreated with PMA for 48 h to induce the differentiation of macrophage. Then, these cells were stimulated with cultural supernatant of PRLR-overexpressed (OE) Caco-2 or PRLR-wide type (WT) Caco-2 for 24 h. a, b The mRNA and protein levels of TNFSF13B were detected by qRT-PCR and western blot, respectively. c RNA-sequencing was performed for the PRLR-WT (n = 3) and PRLR-OE (n = 3) Caco-2 cells after LPS stimulation for 48 h. KEGG enrichment for the significant down-regulated DEGs (Log2(Fold change) < -0.2, P value < 0.05) of PRLR-OE Caco-2 compared with PRLR-WT Caco-2 cells. d Heatmap of the significantly down-regulated genes in cytokine-cytokine interaction pathway. e scRNA-seq from GSE182270 exhibited the expression levels of CXCL1 in different cell types. f, h THP-1-derived macrophages were stimulated with the supernatant of PRLR-OE Caco-2, and supplemented with different doses of CXCL1 for 24 h. TNFSF13B levels and phosphorylated NF-κB p65 were detected by western blot. g, i CXCR2 inhibitory SB225002 (10 μM) and NF-KB pathway inhibitor Bay 11–7082 (1 μM) were used to block the CXCL1-induced effect. The TNFSF13B levels were detected by qRT-PCR. j The correlation of PRLR or TNFSF13B with CXCL1 expression in the UC tissues (n = 208). k The CXCL1 expression in IIA/WIA and IHL, and the sensitivity of CXCL1 expression in IHL to distinguish from IIA/WIA