Objective To study the effect of IL-22 on the colonic barrier and its relationship with Nrf2 pathway in liver fibrosis mice.Methods The mice were divided into four groups:the control group(CON group),the model group(MOD group),the interleukin-22 group(IL-22 group),and the IL-22+ML385 group(ML385,an inhibitor of Nrf2),with 10 mice in each group,and the modeling cycle was 8 weeks.Liquid feed containing alcohol and carbon tetrachloride olive oil were given intraperitoneally in all groups except the CON group;IL-22 was given on top of this in the IL-22 group;and ML385 was injected intraperitoneally in the IL-22+ML385 group one hour before IL-22 treatment.At the end of modeling,the livers were stained with HE and Masson staining to clarify whether fibrosis occurred in the mice;the feces were collected to detect the cocci to bacillus ratio and observe the growth of intestinal flora;the colons were stained with HE staining,immunofluorescence and immunohistochemistry,and analyzed for the expression of tight junction proteins ZO-1,Occludin,and the Nrf2 pathway proteins(Nrf2,HO-1,and NQO1).The expression of these proteins was analyzed by immunohistochemistry.Results Compared with the CON group,mice in the MOD group showed significant fibrosis in the liver tissue,inflammatory cell infiltration in the colon tissue,and decreased expression of tight junction proteins(P<0.05).No overgrowth of various pathogenic bacteria was seen in fecal media.And there was no significant difference in the bulb-to-bar ratio.Compared with the MOD group,both liver and colon histopathologic damage were reduced in the IL-22 group,and tight junction protein expression was elevated,in addition,the expression levels of Nrf2,NQO1,and HO-1 were also elevated(P<0.05),whereas there was no significant change in the IL-22+ML385 group.Conclusion IL-22 improved the colonic barrier function in liver fibrosis mice,and the mechanism was related to the activation of Nrf2 anti-oxidative stress pathway.

Aim To investigate the role of matrix metalloproteinase-9 down-regulation in the learning and memory dysfunction induced by propofol treatment in rats.Methods 7-day-old SD rats were randomly divided into three groups(n=18):control group(NS group) and repeated doses of propofol group(RP group) was intraperitoneally injected with normal saline and propofol respectively for consecutive seven days, single dose of propofol group(SP group) were intraperitoneally injected with normal saline first for consecutive six days, and then injected with propofol on 7th day.The blood gas and glucose levels were monitored of six rats randomly selected from each group.Morris water maze was conducted to test the learning and memory functions of the remaining rats.The expression of MMP-9, BDNF and caspase-3 was detected by Western blot, and the hippocampal neuron apoptosis was determinated by TUNEL staining.Results Compared with NS group and SP group, the escape latency in RP group was prolonged significantly, exploration time and the number of crossing the platform in RP group were markedly decreased(P<0.05).The expressions of MMP-9 and mBDNF in RP group declined, but the expression of proBDNF and the ratio of proBDNF/mBDNF in RP group were higher than those in NS group and SP group(P<0.05).Compared with NS group and SP group, the number of apoptotic neurons and the expression of cleaved-caspase-3 in RP group were increased significantly, but the expression of pro-Caspase3 in RP group was reduced(P<0.05).There was no difference between SP group and NS group regarding all the results(P>0.05).Conclusions Repeated exposure to propofol can lead to a decline in long-term learning and memory functions in neonatal rats, which may be related to the down-regulation of MMP-9 expression, proBDNF and mBDNF conversion disorder in hippocampus and the apoptosis of hippocampal neurons.However, single exposure to propofol has no significant effect.

AIM: To investigate the effects of propofol on the expression of tissue-type plasminogen activator (tPA) and matrix metalloproteinase 9 (MMP9) in the hippocampus and the cognitive function in neonatal rats.METHODS: The 7-day-old rats were randomly divided into 3 groups: the rats in control (CON) group were intraperitoneally injected with normal saline for 7 d;the rats in single dose of propofol anesthesia (SP) group were intraperitoneally injected with normal saline for 6 d and with propofol on the 7th day;the rats in repeated dose of propofol anesthesia (RP) group were intraperitoneally injected with propofol for 7 d.Blood glucose and blood gas analysis were tested in 6 rats of each group.The rats were randomly selected from each group to isolate the hippocampal tissues at 2 h, 24 h, 48 h, 72 h and 30 d after the last injection.The spatial learning and memory functions of the other rats aged 25 d were determined by Morris water maze.The morphological changes of the hippocampus were observed by HE staining and Nissl's staining.The expression of tPA and MMP9 at mRNA and protein levels was determined by RT-PCR and Western blot.RESULTS: Compared with group CON, the protein expression of tPA and MMP9 in RP group was significantly decreased at each time point, while no significant decrease was observed in SP group except at the time point of 24 h.Compared with CON group, the mRNA expression of tPA and MMP9 was down-regulated obviously in RP group, which was not significantly down-regulated in SP group.From the 3rd training day of Morris water maze beginning, the escape latency was prolonged, and the space exploration time and the number of crossing the original platform location were reduced in RP group compared with CON group and SP group, while no significant difference was observed between CON group and SP group.Compared with CON group, the number of nerve cells reduced and nerve cells arranged in disorder in the hippocampus in RP group.Moreover, the number of Nissl body decreased significantly and finally developed into neuronal degeneration and necrosis in RP group, and no significant difference between SP group and CON group was observed.CONCLUSION: Repeated dose of propofol anesthesia leads to long-term cognitive dysfunction in neonatal rats, which may be related to the down-regulation of tPA and MMP9 expression and destruction of normal morphology and function of neurons in hippocampus, whereas single dose of propofol anesthesia has no such effects.