Protective mechanism of rhubarb decoction against inflammatory damage of brain tissue in rats with mild hepatic encephalopathy： A study based on the PI3K/AKT/mTOR signaling pathway / 临床肝胆病杂志

ObjectiveTo investigate the role and possible mechanism of action of rhubarb decoction （RD） retention enema in improving inflammatory damage of brain tissue in a rat model of mild hepatic encephalopathy （MHE）. MethodsA total of 60 male Sprague-Dawley rats were divided into blank group （CON group with 6 rats） and chronic liver cirrhosis modeling group with 54 rats using the complete randomization method. After 12 weeks， 40 rats with successful modeling which were confirmed to meet the requirements for MHE model by the Morris water maze test were randomly divided into model group （MOD group）， lactulose group （LT group）， low-dose RD group （RD1 group）， middle-dose RD group （RD2 group）， and high-dose RD group （RD3 group）， with 8 rats in each group. The rats in the CON group and the MOD group were given retention enema with 2 mL of normal saline once a day； the rats in the LT group were given retention enema with 2 mL of lactulose at a dose of 22.5% once a day； the rats in the RD1， RD2， and RD3 groups were given retention enema with 2 mL RD at a dose of 2.5， 5.0， and 7.5 g/kg， respectively， once a day. After 10 days of treatment， the Morris water maze test was performed to analyze the spatial learning and memory abilities of rats. The rats were analyzed from the following aspects： behavioral status； the serum levels of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） and the level of blood ammonia； pathological changes of liver tissue and brain tissue； the mRNA and protein expression levels of phosphatidylinositol 3-kinase （PI3K）， protein kinase B （AKT）， and mammalian target of rapamycin （mTOR） in brain tissue. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the MOD group， the RD1， RD2， and RD3 groups had a significantly shorter escape latency （all P<0.01）， significant reductions in the levels of ALT， AST， IL-1β， IL-6， TNF-α， and blood ammonia （all P<0.05）， significant alleviation of the degeneration， necrosis， and inflammation of hepatocytes and brain cells， and significant reductions in the mRNA and protein expression levels of PI3K， AKT， and mTOR in brain tissue （all P<0.05）， and the RD3 group had a better treatment outcome than the RD1 and RD2 groups. ConclusionRetention enema with RD can improve cognitive function and inflammatory damage of brain tissue in MHE rats， possibly by regulating the PI3K/AKT/mTOR signaling pathway.

Exendin-4 alleviates oxidative stress and liver fibrosis by activating Nrf2/HO-1 in streptozotocin-induced diabetic mice / 南方医科大学学报

OBJECTIVE@#To investigate the effects of exendin-4 on hepatic lipid metabolism, fibrosis and oxidative stress in mice with streptozotocin (STZ)-induced diabetes and explore the underlying mechanisms.@*METHODS@#C57BL/6J mice were fed with high-fat diet (HFD) for 4 weeks and received intraperitoneal injections of 120 mg/kg STZ to induce diabetes. After successful modeling, the mice were randomized into diabetic control group and exendin-4 treatment group (DM+E4), and in the latter group, the mice were given a daily dose of 1 nmol/kg of exendin-4 for 8 weeks. The changes in the body weight (BW) and random blood glucose (RBG) in the mice were recorded. The mRNA expressions of the genes related with liver lipid metabolism, fibrosis and oxidative stress were analyzed using RT-PCR, and the structural changes of the liver tissues were observed with HE, Sirius red and oil red O staining; the expressions of TGF-β1, Nrf2 and HO-1 proteins in the liver tissues were detected using Western blotting.@*RESULTS@#The diabetic mice showed significantly higher RBG levels and BW with obvious lipid deposition, fibrosis and oxidative stress in the liver as compared with the normal control mice ( < 0.001). Exendin-4 treatment of the diabetic mice did not significantly lessened liver lipid deposition but obviously reduced the levels of RBG and TG ( < 0.05), lowered the expression levels of liver fibrosis-related genes TGF-β, -SMA and Col-Ⅰ ( < 0.05), increased the expression levels of the antioxidant genes Nrf2, HO-1 and GPX4 ( < 0.01), and enhanced the protein expressions of Nrf2 and HO-1 in the liver tissues ( < 0.01).@*CONCLUSIONS@#Exendin-4 improves liver fibrosis and oxidative stress in diabetic mice by activating Nrf2/HO-1 pathway without significantly reducing liver lipid deposition.

Study on the effect of Klotho gene interferred by plasmid-mediated short hairpin RNA (shRNA) on sinoatrial node pacing channel gene / 生物医学工程学杂志

The study was aimed to assess the effect of Klotho gene and sinoatrial node pacing channel gene (HCN4 and HCN2) for studying sick sinus syndrome, with Klotho gene under the interference of Plasmid-mediated short hairpin RNA. Twenty-five C57BL/6J mice were divided into four groups, i. e, plasmid shRNA 24h group, plasmid shRNA 12h group, sodium chloride 24h group and sodium chloride 12h group. Plasmid shRNA 50microL (1microg/microL) and sodium chloride 50microl were respectively injected according to mice vena caudalis into those in plasmid shRNA group and sodium chloride group. After 12h or 24h respectively, all mice were executed and their sinoatrial node tissues were cut. The mRNA of Klotho, HCN4 and HCN2 gene were detected by RT-PCR. The results of RT-PCR showed that Klotho, HCN4 and HCN2 mRNA levels were lower compared with those in sodium chloride 12h group after 12h interference interval. The results indicated that there might be the a certain relationship between Klotho gene and sinoatrial node pacing channel gene.