ABSTRACT
Objective:To evaluate the role of peroxidase proliferator-activated receptor γ (PPARγ)/nuclear factor kappa B (NF-κB) signaling pathway in sodium butyrate-induced reduction of intestinal ischemia-reperfusion (I/R) injury in mice.Methods:Thirty-two SPF-grade healthy adult male C57BL/6J mice, aged 7-9 weeks, weighing 20-25 g, were divided into 4 groups ( n=8 each) using a random number table method: sham operation group (Sham group), intestinal I/R group (IIR group), sodium butyrate group (NaB group) and PPARγ inhibitor GW9662 group (GW9662 group). The model of intestinal I/R was established by occlusion of superior mesenteric artery for 45 min followed by 2-h reperfusion in anesthetized animals.GW9662 2 mg/kg was intraperitoneally injected at 1 h before ischemia in GW9662 group, and sodium butyrate 500 mg/kg was intraperitoneally injected at 30 min before ischemia in NaB and GW9662 groups.Blood samples were obtained via cardiac puncture at 2 h of reperfusion, and the animals were then sacrificed.The intestinal tissues were removed for determination of diamine oxidase (DAO), tumor necrosis factorα (TNF-α) and interleukins 6 (IL-6) concentrations in serum (by enzyme-linked immunosorbent assay) and the expression of PPAR and NF-κB p65 (by Western blot). The damage to intestinal mucous membrane was assessed and scored according to Chiu. Results:Compared with group Sham, the Chiu′s score was significantly increased, levels of DAO, TNF-α and IL-6 in serum and intestinal tissues were increased, expression of PPARγ was down-regulated, and expression of NF-κB p65 was up-regulated in group IIR ( P<0.05). Compared with group IIR, the Chiu′s score, levels of DAO, TNF-α and IL-6 in serum and intestinal tissues were decreased, and expression of PPARγ was up-regulated in group NaB, and expression of NF-κB p65 was up-regulated in NaB and GW9662 groups ( P<0.05). Compared with group NaB, the Chiu′s score, levels of DAO, TNF-α and IL-6 in serum and intestinal tissues were increased, and expression of PPARγ was down-regulated, and expression of NF-κB p65 was up-regulated in group GW9662 ( P<0.05). Conclusion:The mechanism by which sodium butyrate reduces intestinal I/R injury may be related to activating PPARγ/NF-κB signaling pathway and inhibiting inflammatory responses in mice.
ABSTRACT
Objective:To evaluate the role of nuclear factor NF-E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in atorvastatin-induced reduction of intestinal ischemia-reperfusion (I/R) injury in mice.Methods:Twenty-four healthy male C57BL/6 mice, aged 6-8 weeks, weighing 18-22 g, were divide into 4 groups ( n=6 each) using a random number table method: sham operation group (S group), intestinal I/R group (I/R group), atorvastatin group (ATV group) and atorvastatin+ Nrf2 inhibitor ML385 group (AM group). Intestinal I/R was produced by occlusion of superior mesenteric artery for 45 min followed by reperfusion.In ATV and AM groups, atorvastatin 10 mg/kg was given by gavage for 3 consecutive days daily at 3 day before establishment of the model, while the equal volume of normal saline was given by gavage in S and I/R groups.Nrf2 inhibitor ML385 30 mg/kg was intraperitoneally injected at 1 h before establishment of the model in group AM.The mice were sacrificed at 2 h of reperfusion, and intestine tissues were obtained for examination of the pathological changes of intestinal tissues (with a light microscope) which were scored according to Chiu, for determination of wet/dry weight ratio (W/D ratio), for detection of the activity of superoxide dismutase (SOD) and content of malondialdehyde (MDA) (by xanthine oxidase method and thiobarbituric acid condensation method) and for determination of the expression of Nrf2 and HO-1 (by Western blot). Results:Compared with S group, the Chiu score, W/D ratio and MDA content were significantly increased, the activity of SOD was decreased, and the expression of Nrf2 and HO-1 was up-regulated in the other 3 groups ( P<0.05). Compared with the group I/R, the Chiu score, W/D ratio and MDA content were significantly decreased, the SOD activity was increased, and the expression of Nrf2 and HO-1 was up-regulated ( P<0.05), and the pathological changes were significantly attenuated in group ATV, and no significant change was found in the parameters mentioned above in AM group ( P>0.05). Compared with the group ATV, the Chiu score, W/D ratio and MDA content were significantly increased, the SOD activity was decreased, the expression of Nrf2 and HO-1 was decreased ( P<0.05), and the pathological changes were significantly aggravated in group AM. Conclusion:The mechanism by which atorvastatin reduces intestinal I/R injury is related to activating Nrf2/HO-1 signaling pathway in mice.
ABSTRACT
Objective:To investigate the effect of atorvastatin preconditioning on intestinal ischemia-reperfusion (I/R) injury in mice and the relationship with phosphatidylinositol 3-kinase (PI3K)/serine-threonine kinase (Akt) signaling pathway.Methods:Twenty-four healthy male C57BL/6 mice, aged 6-8 weeks, weighing 18-22 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (S group), I/R group, atorvastatin preconditioning group (A group), atorvastatin plus PI3K inhibitor LY294002 group (AL group). Atorvastatin 10 mg/kg was given by intragastric gavage for 3 consecutive days in A and AL groups, and in addition LY294002 0.3 mg/kg was intraperitoneally injected at 30 min before the last administration of atorvastatin in AL group.Intestinal I/R was produced by occlusion of superior mesenteric artery (SMA) for 45 min followed by 2 h reperfusion in anesthetized mice.The superior mesenteric artery was only isolated but not clamped in S group.The mice were sacrificed at the end of reperfusion, and small intestinal tissues were taken for determination of the pathological changes with a light microscope after HE staining and for determination of wet to dry weight ratio(W/D ratio) and expression of PI3K, phosphorylated Akt (p-Akt), autophagy-related proteins Beclin-1, microtubule-associated protein 1 light chain 3Ⅰ (LC3Ⅰ) and LC3Ⅱ.The intestinal damage was assessed and scored according to Chiu.The ratio of LC3Ⅱ expression to LC3Ⅰ expression (LC3Ⅱ/LC3Ⅰ) was calculated. Results:Compared with S group, Chiu′s scores and W/D ratio were significantly increased, the expression of PI3K and p-Akt was down-regulated, the expression of Beclin-1 was up-regulated, and LC3Ⅱ/LC3Ⅰ ratio was increased in I/R, A and AL groups ( P<0.05). Compared with I/R group, Chiu′s scores and W/D ratio were significantly decreased, the expression of PI3K and p-Akt was up-regulated, the expression of Beclin-1 was down-regulated, and LC3Ⅱ/LC3Ⅰ ratio was decreased in A group ( P<0.05). Compared with A group, Chiu′s scores and W/D ratio were significantly increased, the expression of PI3K and p-Akt was down-regulated, the expression of Beclin-1 was up-regulated, and LC3Ⅱ/LC3Ⅰ ratio was increased in AL group ( P<0.05). Conclusion:Atorvastatin preconditioning can mitigate intestinal I/R injury in mice, and the mechanism is related to activating PI3K/Akt signaling pathway and inhibiting the level of autophagy.
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Objective:To identify and screen out immune-related long non-coding RNAs (lncRNAs) in pancreatic cancer, and construct a prognostic risk assessment model to predict the prognostic factors of patients with pancreatic cancer.Methods:RNA-Seq data and corresponding clinicopathological and follow-up information of 177 pancreatic cancer patients were downloaded from The Cancer Genome Atlas (TCGA) database. The 177 pancreatic cancer samples were randomly divided into discovery cohort ( n=89) and validation cohort ( n=88) using random number table method. Immune-related lncRNAs were identified by Pearson correlation coefficient analysis. Univariate and multivariate Cox analysis were used to select prognosis-related lncRNAs and construct the risk score formula based on the data of discovery cohort. The conclusion generated from discovery cohort would be verified in the validation cohort. Results:A total of 788 immune-related lncRNAs were screened out using Pearson correlation coefficient calculation formula, and 5 lncRNAs (AC006237.1, AC025154.2, RASSF8-AS1, AL122010.1 and AC073896.3) were selected by univariate and multivariate Cox analysis to build the risk score formula based on the discovery cohort. Based on the above risk score formula, pancreatic cancer patients from the discovery cohort were divided into high-risk group ( n=44) and low-risk group ( n=45). Survival analysis indicated that the median survival time of high-risk group (1.09 years) was significantly shorter than that of low-risk group (4.11 years; χ2=26.016, P<0.001). The validation cohort was also divided into high-risk group ( n=44) and low-risk group ( n=44) based on the above risk score formula. Survival analysis showed that the median survival time of high-risk group (1.28 years) was also significantly shorter than that of low-risk group (1.90 years; χ2=4.422, P=0.035). Besides, univariate and multivariate analyses suggested that the prognostic risk assessment model could effectively predict the prognosis of patients with pancreatic cancer, and could be used as an independent prognostic prediction model ( HR=2.618, 95% CI: 1.285-5.332, P=0.008). The predictive efficiency of this model was better than that of common clinicopathological information such as age, gender and tumor histopathological grade [1-year area under curve (AUC)=0.687, 3-year AUC=0.725 and 5-year AUC=0.782]. The expression levels of AC025154.2, AC073896.3, AL122010.1 and RASSF8-AS1 were significantly different in various clinical characteristics of pancreatic cancer (all P<0.05), and might serve as potential new targets for diagnosis and treatment in pancreatic cancer. Interferon α, mammalian target of rapamycin complex 1 (mTORC1), MYC regulatory genes and transforming growth factor-β (TGF-β) signaling pathways were significantly activated, and myogenesis and pancreas β cells signaling pathways were significantly suppressed in the high-risk group, which may explain the underlying molecular mechanisms of the prognostic risk assessment model. Conclusion:The prognostic risk assessment model based on 5 immune-related lncRNAs can effectively predict the prognosis of pancreatic cancer patients. Besides, the above immune-related lncRNAs may serve as new biomarkers in the diagnosis and therapy in pancreatic cancer.