Expression And Clinical Significance Of Il-18 And Inflammasome In Patients With Colorectal Adenomatous Polyps

Objective To investigate the expression of Interleukin18(IL-18)and inflammasome in colorectal adenomatous polyps and its clinical significance.Research methods(1)Forty seven patients with colon polyps in our hospital were selected and divided into non-adenomatous polyps group(Polypus,21 cases)and adenomatous polyp group(26 cases)according to the results of pathological diagnosis,another 20 cases of healthy check-up volunteers were recruitmented as the control group.The general information,fresh serum specimens and polyposis intestinalis tissues were gathered of all the research subject.(2)Enzyme linked immunosorbent test(ELISA)to detect the production of IL-18,Interleukin1β(IL-1β),Granulocyte-macrophage colony stimulating factor(GM-CSF),Interferon-γ(IFN-γ)in their serum,at the same time detection of intestinal polyps organizational pyrolysis liquid IL-1β,IFN-γ expression quantity.(3)Using immunohistochemical staining(IHC)observed the expression level of IL-18,Ki-67 in the three groups of patients with intestinal polyps tissue section,and after scanning slides statisticed Ki-67 positive rate.(4)Protein imprinting experiments(western blot,WB)detected the expression of IL-1β,NLR family pyrin domain containing3(NLRP3),Caspase-1,Glyceraldehyde-3-phosphate dehydrogenase(GAPDH),Apoptosis-associated speck-like protein containing CARD(ASC),IL-18 R in intestinal polyp tissues of patients and the WB results gray-scale analysis.(5)The mRNA secretion levels of IL-18,IL-18 R,IL-18 BP,ASC,NLRP3,IL-1 and caspase-1 in the lysis fluid of intestinal polyp tissues in each group were detected by real-time fluorescence quantitative PCR,and the differences of the above indicators were compared and analyzed among patients in each group.(6)GraphPad Prism7 software was used for statistical analysis and plotting,and Image J was used for analysis and plotting of experimental results.The data was expressed as mean ± standard deviation,and T-test was used for comparison among the data of each group.p <0.05 was considered statistically significance.Results(1)In this study,the incidence of colorectal polyps was significantly higher in males than in females,and there was no significant statistical difference in gender,age and clinical symptoms between the adenomatous polyp group and the non-adenomatous polyp group.(2)ELISA’s results indicated that the serum expression level of IL 18 in patients with adenomatous polyp was significantly up-regulated than the control group and the non-adenomatous polyp group(p = 0.000001,0.0000009).The expression level of IL 18 in serum in the non-adenomatous polyp group was also up-regulated compared with the control group(p = 0.040).The secretion level of IFN-γ in the lysis fluid of intestinal polyp tissues of adenomatous polyp patients was significantly up-regulated compared with that of non-adenomatous polyp group(p =0.0008),and there was no significant difference in the expression level of IFN-γ between control group and non-adenomatous polyp group,control group and adenomatous polyp group.Expression of IL-1β in serum and intestinal polyp lysate of the three groups showed no significant difference.(3)The WB figure and gray analysis results suggested that the adenomatous polyp group’s IL-1β,NLRP3,Active-caspase-1 than the expression of non-adenomatous polyp group and the control group obviously raised,and the expression of caspase-1 quantity was gradually reduced in the control group,the non-adenomatous polyp,adenomatous polyp.WB results of intestinal polyps pyrolysis liquid also showed that IL-18R’s expression was obviously up-regulated in the adenomatous polyp patients group than the control group.(4)Immunohistochemical staining(IHC)showed that the expressions of IL-18 and Ki-67 in the polyp tissues of the adenomatous polyp group were significantly enhanced compared with the other two groups,and the statistical results of the positive rate of Ki-67 showed that the positive rate of Ki-67 in the adenomatous polyp group was significantly increased compared with the non-adenomatous polyp group and the control group.(5)The results of Real-time fluorescence quantitative PCR indicated that the secretion levels of IL-18,IL-18 rR and IL=18BP m RNA were not significantly different in adenomatous polyps,non-adenomatous polyps and the control group,and there was no significant statistical difference in the secretion levels of ASC,NLRP3,IL-1β and caspase-1 mRNA in the three groups.Conclusion IL-18,IL-1β,IFN-γ,NLRP3 and Caspase-1 secreted in the serum of patients with adenomatous polyp and(or)expressed in intestinal polyps group obviously enhanced.NLRP3 inflammatory pathways,ASC-Caspase-1-IL-18/IL-1βpathway in the adenomatous polyp is activated during the process of formation,and prompted that IL-18,inflammatory corpuscle may play an important role in the processof transformation from intestinal inflammatory hyperplastic polyp to adenomatous polyp.IL-18 and inflammasomes may be new biomarkers for the diagnosis of adenomatous polyps.