The Effect And Mechanism Of Phosphorylated Heat Shock Protein 27 In The Inflammatory Response Of Intestinal Epithelial Cells

Background and Objective:Diarrhea-predominant irritable bowel syndrome(IBS-D)is a functional intestinal disease with diarrhea as the main clinical symptom.The incidence is high,the symptoms are repeated and it has a great impact on patients.At present,the pathogenesis of IBS-D is not clear.The treatment is mainly symptomatic,but its efficacy is not good.The study of the pathogenesis of IBS-D will be crucial to its treatment.Intestinal infections and low-grade intestinal inflammation play an important role in the pathogenesis of IBS-D.Activation of factor-kappa B(NF-?B)signaling pathway is an important factor in inducing chronic intestinal inflammation.The NF-?B signaling pathway is involved in regulating various biological processes such as cellular inflammatory response and cell proliferation and apoptosis.In the previous study,it was found that the expression of HSP27 in the intestinal mucosa of IBS-D patients was increased,and the expression of NF-?B in the intestinal mucosa of IBS-D model rats was increased.Blocking the NF-?B pathway can alleviate the damage of intestinal mucosa barrier.However,the mechanism of NF-?B activity regulation in IBS-D intestinal inflammation is still unclear.Heat shock protein 27(HSP27)is a highly conserved protein that widely exists in a variety of cells and can enhance the body's ability to resist external stress.Studies have shown that HSP27 mainly plays a role through its phosphorylated form(p-HSP27),and HSP27 can inhibit the activation of the NF-?B pathway,thereby inhibiting the inflammatory response.And in the previous study,it was found that the expression of HSP27 in the intestinal mucosa of patients with IB S-D is increased,but the role and mechanism of HSP27 in IBS-D are not yet clear.This study intends to investigate the role of HSP27 expression and its phosphorylation in inflammatory response of IBS-D intestinal epithelial cells simulated in vitro and its relationship with NF-?B signaling pathway,and provide theoretical basis for the pathogenesis of IBS-D caused by infection and provide new ideas for the diagnosis and treatment of the disease.Method:LPS was used to treat Caco-2 and NCM460 intestinal epithelial cells to simulate the IBS-D intestinal epithelial inflammatory response model in vitro.The HSP27 phosphorylation inhibitor KRIBB3 was used to inhibit the phosphorylation of HSP27.siRNA-HSP27 down-regulates the expression of HSP27 in cells.Western Blot test was used to detect the expression levels of HSP27,p-HSP27,p-I?B? and I?B-? in cells.ELISA test was used to detect the changes of IL-1? and IL-6 in cells.Annexin V-FITC/PI double staining method was used to detect the level of apoptosis,and CCK8 experiment was used to detect the cell proliferation ability.SPSS 22.0 was used for statistical analysis of the results.Result:1.LPS can promote the expression of HSP27 and its phosphorylation in intestinal epithelial cells.KRIBB3 significantly inhibits the phosphorylation of HSP27 in cells.2.LPS induces the expression of IL-1? and IL-6 in intestinal epithelial cells.Inhibition of HSP27 phosphorylation significantly enhance the expression of IL-1?and IL-6 mediated by LPS.3.LPS can induce apoptosis of intestinal epithelial cells and inhibit cell proliferation.Inhibition of HSP27 phosphorylation can promote LPS-mediated intestinal epithelial cell apoptosis and proliferation inhibition.4.LPS can promote the phosphorylation and degradation of I?B-?.Inhibition of HSP27 phosphorylation can enhance the phosphorylation of I?B-? caused by LPS and reduce the degradation of I?B-?.5.Down-regulation of HSP27 expression in cells had no significant effect on the expression of I?B-? and p-I?B? in intestinal epithelial cells.Conclusion:LPS can promote the expression of HSP27 and its phosphorylation in intestinal epithelial cells.HSP27 can inhibit the activation of p-I?B?/NF-?B signaling pathway and the expression of IL-1?,IL-6 and other inflammatory factors through its phosphorylation,and promote the proliferation of intestinal epithelial cells,inhibit their apoptosis.These can alleviate the inflammatory response of IBS-D intestinal mucosa.The p-HSP27/p-I?B?/NF-?B pathway may provide a new target for the treatment of IBS-D.