The expression and function of double-stranded RNA-dependent protein kinase (PKR) in rat intestinal epithelial cells

肠上皮细胞（IECs）暴露于微生物和病毒产物中，并作为它们的基本屏障。由于双链rna依赖蛋白激酶（PKR）参与细胞抗病毒反应、细胞分化和凋亡，我们试图研究PKR在大鼠IECs中的表达及其作用。在本研究中，我们发现PKR在成年大鼠IECs中的表达。我们还证实PKR在培养的大鼠IECs中表达。PKR蛋白表达水平和碱性磷酸酶（ALP）活性在培养的IECs中呈时间依赖性升高。PKR抑制剂治疗可降低IECs的ALP活性。添加合成双链RNA以剂量依赖的方式诱导这些细胞凋亡。氢化可的松也能抑制这些细胞中PKR的表达。因此，我们得出结论，PKR在IECs中作为抗原的有效屏障表达，并且可能是大鼠IECs分化和凋亡的调节剂。

Intestinal epithelial cells (IECs) are exposed to microbial and viral products, and serve as essential barriers to them. Since double-stranded RNA-dependent protein kinase (PKR) is involved in cellular antiviral response, cell differentiation and apoptosis, we tried to investigate the expression and roles of PKR in rat IECs. In this study, we showed that the expression of PKR in IECs of adult rats. We also demonstrated that PKR was expressed in cultured rat IECs. The level of PKR protein expression and the activity of alkaline phosphatase (ALP) increased in the cultured IECs in a time-dependent manner. Treatment with PKR inhibitor decreased ALP activity in the IECs. The addition of synthetic double-stranded RNA induced apoptosis in a dose-dependent manner in these cells. Treatment with hydrocortisone also provoked suppression of PKR expression in such cells. Thus, we concluded that PKR is expressed in IECs as potent barriers to antigens and is a possible modulator of the differentiation and apoptosis in rat IECs.