RNA-seq of intestinal epithelial cells isolated from DSS colitis model mice

In the present study, we demonstrated that mice deficient in chemerin or IEC-specific CMKLR1 expression were highly susceptible to DSS-induced colitis and subsequent tumorigenesis, which was reversed by suppressing colonic neutrophilic inflammation using CXCR2 inhibitor. Surprisingly, we found that lack of the Chemerin-CMKLR1 signaling specifically reduced colonic epithelial expression of lactoperoxidase (LPO), an epithelial peroxidase which could utilize H2O2 to oxidase thiocyanates to antibiotic compound (Bafort et al., 2014). Importantly, we demonstrated that impaired epithelial LPO expression accounted for outgrowth of potentially pathogenic Gram-negative bacteria following epithelial injury, which led to overproduction of CXCL1/2 and pathological neutrophilic inflammation in mice with epithelial Chemerin-CMKLR1 signaling deficiency. Finally, lack of epithelial Chemerin-CMKLR1 signaling impaired early host defense against enteric bacteria, which was reversed by LPO supplementation. Taken together, our study uncovers a critical role of epithelial Chemerin-CMKLR1 signaling in restricting pathological colonic neutrophilia via potentiating LPO-mediated epithelial innate defense, thereby rendering protection against microbiota-driven colitis and tumorigenesis. 18 samples in total was analyzed, including IEC RNA-seq data from DSS treated WT and Rarres2-/- mice at 0,2, and 7 days post DSS, there are 3 replicated samples in each group.