Effect Of TLR-9 Gene Silencing On Intestinal Mucosal Barrier In Septic Mice And Its Molecular Mechanism

Background:Sepsis is the systemic inflammatory response to infection of body,and the gut is the earliest organ involved in sepsis.This can cause inflammatory damage and damage the intestinal mucosal immune barrier.The aggravated sepsis.Toll like receptor is a receptor for identifying the pathogen pattern(PAMPs),TLRs specifically recognizes PAMP,and activates different downstream signals.TLRs may be an important factor of intestinal mucosal immune barrier damage in sepsis.Objective:Gene silencing siRNAs were used to inhibit the expression of Toll like receptor 9(TLR-9).At the same time,the effect of CpG-DNA on the regulation of intestinal immune barrier in model mice was observed by the stimulation of artificial CpG ODN drugs.To provide a new idea for the treatment of clinical sepsis.Methods:1.Isolation and purity identification of mouse intestinal epithelial cells;2.Real-time fluorescence quantitative PCR and Western blot were used to detect the expression of TLR-9 protein in intestinal epithelial cells.Elisa was used to detect the concentration of IL-10 and MCP-1 in ileum tissue;3.To analyze the effect of siRNA silencing TLR-9 on intestinal mucosal immune barrier in septic mice.Results:1.The expression of TLR-9 in intestinal epithelial cells and the concentrations of TNF-α IL-6 and MCP-1 in ileum in septic mice were significantly higher than those in normal control group and model group,and the permeability of intestinal mucosa was increased;2.The expression of TLR-9 was inhibited in TLR-9 gene silencing group,and the concentrations of TNF-α IL-6 and MCP-1 in ileum were also decreased.Conclusion:1.the increased expression of TLR-9 in intestinal epithelial cells during sepsis can lead to impaired intestinal mucosal barrier function and increased permeability,thereby promoting the development of sepsis;2.Gene silencing the expression of TLR-9 may protect the intestinal mucosal immune barrier in septic mice,and its mechanism may be related to the reduction of the expression of multiple inflammatory factors in ileum.