地塞米松对小鼠急性胰腺炎中miRNA-155及NF-κB信号通路的影响

The effect of dexamethasone on the miRNA-155 and NF-κB signaling pathway in mice with acute pancreatitis.

目的探讨地塞米松(dexamethasone,DEX)对急性胰腺炎(acute pancreatitis,AP)小鼠模型胰腺组织中miRNA-155及核因子-κB(NF-κB)信号通路的影响.方法利用蛙皮素建立小鼠AP动物模型,实验分组为对照组、模型组、地塞米松组(DEX组),分别连续3次予生理盐水、蛙皮素(10μg/mL浓度按50μg/kg)、蛙皮素(剂量同模型组)+DEX(1 mL/kg)腹腔注射.利用ELISA法检测各组动物胰腺组织及血清中肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-6(interleukin-6,IL-6)、白细胞介素-1β(interleukin-1β,IL-1β)的含量;利用实时荧光定量PCR(RT-qPCR)检测各组动物胰腺组织中miRNA-155 mRNA的表达情况;利用Western blot检测各组胰腺组织中磷酸化p65及IκBα蛋白的表达情况.结果ELISA检测结果显示,与模型组比较,DEX组动物胰腺组织及血清中IL-1β、TNF-α与IL-6的含量显著降低,对照组最低.RT-qPCR结果显示,与模型组相比较,DEX组胰腺组织中miRNA-155 mRNA的表达显著降低,对照组最低.Western blot结果显示,与模型组相比较,DEX组胰腺组织中磷酸化p65及IκBα蛋白的表达均显著降低.结论DEX可能通过抑制miRNA-155的表达,进而抑制p65及IκBα蛋白的磷酸化,从而抑制NF-κB信号通路的活化,减少炎症因子如IL-1β、TNF-α与IL-6等的合成与释放,对胰腺腺泡细胞起到保护作用.

Objective To investigate the effect of dexamethasone on the miRNA-155 and NF-κB signal path-way in pancreas in mice with acute pancreatitis(AP).Methods Establishment of the AP mouse model by using caer-ulein.The mice were randomly divided into control group(the saline group),the model group and dexamethasone group(DEX group).The contents of TNF-αand IL-6,IL-1βin pancreas tissue and serum in each group were tested using ELISA method.RT-qPCR was used to assess expression of miRNA-155 mRNA in pancreas.Western blot was used to assess expression of p-p65and p-IκBa proteins in pancreas.Results The results of ELISA test showed that dexametha-sone could significantly reduce the contents of IL-1β,TNF-αand IL-6 in pancreas tissue and serum,comparing with the model group.The RT-qPCR results showed that dexamethasone could significantly reduce the expression of miRNA-155 mRNA in pancreas tissue,compared with the model group.Western blot results showed that dexamethasone could sig-nificantly reduce the expression of p-p65 and P-IκBo proteins in pancreas tissues,compared with the model group.Conclusion Dexamethasone could inhibit the expression of miRNA-155,further inhibit the phosphorylation of p65 and IκBa,thus inhibit the activation of NF-κB signaling pathway.These reduce the synthesis and release of inflammatory factors such as IL-1β,TNF-αand IL-6.It plays protective effect on pancreatic acinar cells.