【摘要】 目的　观察香烟烟雾提取物 (CSE)和酪氨酸激酶抑制剂 (tyrophostin 2 5 )对气道上皮细胞(AEC)酪氨酸磷酸化程度、细胞Src蛋白 (c Src)及 β 连环素 (β cat)表达的影响 ,探讨细胞酪氨酸磷酸化程度及β cat在吸烟致AEC损伤和修复中的作用及调控机制。方法　体外培养猪AEC ,将培养细胞分成 3组 :N组 :加无血清培养基 ;C组 :在无血清培养基上分别加CSE ;CT组 :加tyrophostin 2 5及CSE。每组随机检测 30 0个AEC中 β cat免疫细胞化学染色的分布规律 ;利用图像分析技术 ,每组随机检测30个AEC的酪氨酸磷酸化程度、c Src、β catmRNA的变化。 结果　C组加入 2 0 %的CSE作用 4h和 2 4h后 ,AEC蛋白质酪氨酸磷酸化程度分别是N组的 1 5 1倍和 3 44倍 (P <0 0 0 0 1) ,胞膜上 β cat阳性表达率分别为 2 6 7%和 38 7% ,较N组 (分别为 83 3%和 81 3 % )明显下降 (P <0 0 0 10 )。与N组比较C组胞质中c Src的浓度分别降低了 47 9%和 5 1 4% (P <0 0 0 0 1) ;CT组酪氨酸磷酸化程度及胞膜上 β cat表达的变化接近N组。而C组和CT组 β catmRNA含量均较N组有明显下降 (P <0 0 0 0 1)。结论　上皮细胞的蛋白质酪氨酸磷酸化程度的变化可能介导了香烟对气道上皮细胞的损伤 ,而 β cat蛋白质可逆性磷酸化对粘附连接的结构和更多还原

【Abstract】 Objective To explore the possible mechanism of injury by smoking and its repairing, the effects of cigarette smoke extract on the expression of β catenin(β cat),c Src and level of phosphoric tyrosine in airway epithelial cells (AEC). Methods Pig AECs were cultured in vitro After CSE and tyrphostin 25 exposure, (1) the expression of β cat was determined by immunocytochemical stain in 300 randomly selected AECs of each group, (2) the level of phosphoric tyrosine, content of c Src and β cat mRNA in AECs were evaluated by immunocytochemical stain, in situ hybridization and image analysis in 30 randomly selected AECs of each group Results After exposure to CSE for 4 hours and 24 hours, the levels of phosphoric tyrosine were 1 51 and 3 44 times of that of the control groups of the same time ( P <0 0001) respectively; the ratio of positive stain of β cat on membrane was markedly lower than that in the control groups (78 3% vs 83 3%, 77 7% vs 81 3%, P <0 0001), and the cytoplasmic content of c Src decreased 47 9% and 51 4% ( P <0 0001) compared with the control groups of the same time, respectively While dealt with CSE and tyrphostin 25 together, the level of phosphoric tyrosine, the expression of β cat and c Src resembled those in normal control Contends of β cat mRNA decreased in the both two situations ( P <0 0010) Conclusion CSE decreased the membranous expression of β cat and increased the level of tyrosine phosporylation of AECs The change of β cat expression might mediate the airway epithelial injuries caused by smoking, and tyrphostin 25 might prevent such injuries through inhibiting the tyrosine kinase更多还原