糖原合成酶激酶3在猪气道上皮细胞鳞状分化中作用的初步探讨

为探讨糖原合成酶激酶3（glycogen synthase kinase 3,GSK3）在气道（气管和支气管）上皮细胞鳞状分化中的作用,培养原代猪气道上皮细胞,用GSK3的高度选择性抑制剂氯化锂处理,观察细胞形态变化,用Western blot检测β-连环素、磷酸化GSK3和鳞状分化标记物外皮蛋白的表达、RT-PCR检测鳞状分化标记物小脯氨酸丰富蛋白mRNA的表达、荧光素酶报告基因分析β-连环素／Tcf信号的激活状态。结果显示,锂能诱导猪气道上皮细胞出现鳞状形态、增加小脯氨酸丰富蛋白mRNA和外皮蛋白的表达、促进GSK3的抑制性丝氨酸磷酸化和β-连环素的细胞核内转位;锂能激活β-连环素／Tcf信号,但该作用出现于鳞状分化标记物增加之后。上述结果提示,GSK3可能参与猪气道上皮细胞的鳞状分化。

Role of glycogen synthase kinase 3 in squamous differentiation of pig airway epithelial cells: A primary study

To investigate if glycogen synthase kinase 3 (GSK3) is involved in squamous differentiation of airway (tracheobronchial) epithelial cells, primary pig airway epithelial cells were treated with lithium chloride, a highly selective inhibitor of GSK3. Change in morphology of cells was monitored under microscopy, and expression of beta-catenin, phosphorylated GSK3 and involucrin, a squamous differentiation marker, were dectected by Western blotting, while expression of mRNA of another squamous differentiation marker, small proline-rich protein, was detected by RT-PCR. Further, luciferase reporter assay was used to assess the activation of beta-catenin/Tcf signaling. The results demonstrated that lithium was able to induce a squamous morphology of the cells, and to enhance the expression of involucrin and small proline-rich protein mRNA. Moreover, lithium increased inhibitory phosphorylation of GSK3, augmented nuclear translocation of beta-catenin in a dose- and time-dependent manner. Activation of beta-catenin/Tcf signaling was observed after the elevation of squamous differentiation markers. Taken together, these data suggest that GSK3 is possibly involved in squamous differentiation of pig airway epithelial cells.