大鼠胰腺次全切除后导管细胞同源盒基因-1表达规律研究

The PDX-1 expression in duct epithelial cells after partial pancreatectomy in rats

目的 研究大鼠胰腺大部分切除术后,残余胰腺导管上皮细胞转录因子胰-十二指肠同源盒基因(PDX)-1表达规律,探讨PDX-1表达的意义。方法手术切除大鼠胰腺约90％组织,不同时间点处死动物后取材,解剖显微镜下游离胰腺导管,逆转录-聚合酶链反应(RT-PCR)与Western blot检测导管上皮中PDX-1 mRNA和蛋白表达。结果实验组手术后第2天与第3天导管上皮细胞PDX-1蛋白表达显著升高,高于对照组两倍以上,与对照组比较差异有显著性(P<0.05),第5天到第7天逐渐恢复到对照组水平;实验组在各时间点PDX-1 mRNA表达水平与对照组无明显差异(P>0.05)。结论残余胰腺再生过程中导管上皮细胞中出现PDX-1高表达,表明胰腺干细胞参与残余胰腺再生,且PDX-1表达受转录后调控。

Objective To sudy the PDX-1 expression in pancreatic duct epithelial cells of remnant pancreas, and evaluate the significence of PDX-1 expression. Methods Partial (90%) pancreatectomy was performed on Sprague-Dawley rats. Pancreatic tissues were obtained at various time points while rats were sarcnficed, and pancreatic ducts were hand-picked and cleaned under a dissecting microscope. Western blots and RT-PCR were used to detect the expression of PDX-1 protein and mRNA respectively. Results The PDX-1 protein expression in pancreatic duct epithelial cells was significantly increased in experimental group after partial pancreatectomy on the 2th and 3th day. Densitomeric measuerements showed that the PDX-1 expression in operated rats were 3 times of that in sham operated rats with the difference being significant (P<0.05);The PDX-1 protein expression on the 5th and 7th day in the experimental group gradually returned to the levels of control group. The PDX-1 mRNA expression remained unchange at various time points after partial pancreatectomy (P > 0.05). Conclusion The PDX-1 expression is overexpressed in pancreatic duct epitherlial cells during the regeneration of remnant pancreas after partial pancreatectomy, suggesting pancreatic stem cells involve this process and the PDX-1 expression is regulated by a posttrascriptional mechanism.