Toll-like receptor 2 deficiency exacerbates dextran sulfate sodium (DSS)-induced intestinal injury by Marinifilaceae dependent attenuating cell cycle signaling

Ulcerative colitis (UC) is an intestinal pathology characterized by chronic recurrent inflammation, which requires in-depth exploration of its mechanisms. To investigate the biological effects of TLR2 on DSS-induced intestinal inflammation in mice, we constructed the WT and TLR2-KO colitis mice model. We found TLR2-KO mice were severely susceptible to DSS-induced colitis. To determine how TLR2 exerted a protective effect in DSS-induced colitis, we compared the global gene expression profiles in the gut between WT and TLR2-KO mice by RNA-Seq. Results suggested that cell cycle pathway-related genes were significantly downregulated in gut of TLR2-KO colitis mice. 16S rRNA gene sequencing demonstrated remarkable variation in the composition of gut microbiota between WT and TLR2-KO colitis mice. Compared with WT colitis mice, the relative abundance of Marinifilaceae, Rikenellaceae, Desulfovibrionaceae, Tannerellaceae, Ruminococcaceae, Clostridia, Mycoplasmataceae were significantly higher in the gut of TLR2-KO colitis mice at family level. Moreover, we found that the relative abundance of Marinifilaceae was negatively correlated with the expression of cell cycle signaling related genes by microbiome diversity-transcriptome collaboration analysis. We came to this conclusion: TLR 2-KO exacerbated DSS-induced intestinal injury by Marinifilaceae dependent attenuating cell cycle signaling. To examine the function of TLR2 signaling in intestinal injury repair, researchers developed Dextran Sulfate Sodium Salt (DSS)-induced colitis and injury models in both wild-type (WT) mice and TLR2 knockout (TLR2-KO) mice. To assess changes in the gut microbiota, 16S rRNA sequencing was conducted on fecal samples from both the TLR2-KO and WT enteritis mouse models.