| Objective:The purpose of the study was to investigate whether propofol preconditioning can attenuate intestinal ischemia-reperfusion injury via inhibiting the activation of NLRP3/caspase-1 signaling pathway.Methods: Forty eight adult male rats were randomly divided into one of three groups(n=16 each,weighing 210-250 g): Sham,ischemia/reperfusion(I/R),propofol(P).Rats were subjected to 90 min of ischemia by occluding the superior mesenteric artery(SMA)with a non-invasive artery clamp followed by 2h of reperfusion to establish the model of I/R.Propofol 100 mg/kg was administrated intraperitoneally 30 min before inducing intestinal ischemia in P group.Animals in the Sham and I/R groups were received equal volumes of intralipid(the vehicle solution of propofol)intraperitoneally.The small intestinal tissues were stained with hematoxylin-eosin for observing the histopathology of intestinal mucosa,and Chiu’s pathological score was performed.The expressions of NLRP3,caspase-1 p20,occludin,cleaved caspase-3,bax and bcl-2 were measured by western blotting.Furthermore,the expressions of NLRP3 and caspase-1 p20 were also observed by immunofluorescencestaining.TUNEL staining was used to detect the apoptosis of small intestine.Meanwhile,levels of interleukin-1β(IL-1β)and interleukin-18(IL-18)in the rat blood serum were detected by enzyme-linked immunosorbent assay(ELISA)method.Statistics were analyzed with SPSS version 21.0 statistical software.One-way ANOVA(analysis of variance)was used for the multiple comparisons of multiple means and Least Significance Difference(LSD)test was used for the comparison between the means of two samples.The correlations between NLRP3,caspase-1 p20 expression and small intestinal injury Chiu’s score were assessed by Pearson correlation coefficients.P<0.05 the results were indicated statistical significance.Results: 1.HE staining results demonstrated that the rats in I/R group showed severe intestinal injury and Chiu’s scores in I/R group were significant higher than scores in Sham group,and the difference was statistically significant(P<0.01).However,compared with I/R group,the rats in P group presented obvious mild damage and Chiu’s scores in P group were significantly decreased(P < 0.01).The difference between Sham group and P group was statistically significant(P<0.01)2.The results of Western Blot showed that,compared with Sham group,the expressions of NLRP3,caspase-1 p20,cleaved caspase-3 and bax in I/R group were higher(P<0.01)and the expressions of occludin and bcl-2were lower(P<0.01).Compared with I/R group,the expressions of NLRP3,caspase-1 p20,cleaved caspase-3 and bax in P group weresignificantly decreased(P<0.01);the expressions of occludin and bcl-2in P group were significantly increased(P<0.01).Compared with Sham group,the level of NLRP3(P<0.01)was greater and the levels of occludin and bcl-2 were lower(P<0.01)in P group;while,the levels of caspase-1 p20,cleaved caspase-3 and bax were similar to the Sham group(P>0.05).3.Immunofluorescence results showed that the expressions of NLRP3 and caspase-1 p20 in I/R group were significantly higher than that in Sham group,and the average intensity of fluorescence of NLRP3 and caspase-1 p20 in I/R group was significantly increased(P<0.01).In contrast,the levels of NLRP3 and caspase-1 p20 in P group were significantly lower than I/R group,and the average intensity of fluorescence of NLRP3 and caspase-1 p20 in P group was significantly decreased(P<0.01).Compared with Sham group,the levels of NLRP3 and caspase-1 p20 in P group were higher,and the average intensity of fluorescence of NLRP3 and caspase-1 p20 in P group partly increased(P<0.01).4.According to the results of TUNEL staining,the percentage of apoptosis of small intestinal mucosa in each group: [Sham group:(3.15±1.41)%,I/R group:(59.96±9.76)%,P group:(13.12±1.9)%];the apoptosis of small intestinal mucosa of I/R group and P group was significantly more obvious than Sham group(P<0.01).Whereas,the apoptosis small intestinal mucosa of P group was markedly lower compared to the I/R group(P<0.01).5.Compared with Sham group,the serum IL-1β level and IL-18 level in I/R group and P group weremarkedly increased(P<0.01).However,the serum IL-1β level and IL-18 level in P group were markedly reduced(P<0.01)compared with I/R group.6.Pearson Correlation analysis:The expressions of NLRP3 and caspase-1 p20 were positively correlated with the Chiu’s score of small intestinal injury(P<0.01).Conclusion: 1.Intestinal ischemia-reperfusion can lead to the activation of NLRP3/caspase-1 signaling pathway.2.The protective effects of propofol preconditioning against intestinal injury caused by intestinal ischemia-reperfusion were be partly related to inhibiting the activation of NLRP3/caspase-1 signaling pathway,exerting anti-inflammatory and anti-apoptotic effects. |
PDF Full Text Request