摘要目的 探讨磷脂转运蛋白(PLTP)在烟草提取物(CSE)诱导大鼠Ⅱ型肺泡上皮细胞株RLE-6TN发生上皮间质转化(EMT)中的作用.方法 体外培养RLE-6TN细胞株24 h,分为4组,每组3孔,分别加入0％、0.25％、0.5％和1％ CSE培养2d,检测E-钙黏蛋白和波形蛋白mRNA表达以及细胞和CSE共培养3d检测PLTP、EMT相关蛋白(E-钙黏蛋白、N-钙黏蛋白和波形蛋白)的表达量.将siRNA-PLTP转染入RLE-6TN中,Western blot法检测CSE对转染后PLTP和EMT相关蛋白的影响.结果 不同浓度的CSE作用后,E-钙黏蛋白mRNA分别为1.01±0.05、0.74±0.05、0.65±0.03、0.30±0.08,呈浓度依赖下降;波形蛋白mRNA在1％ CSE组(1.88±0.49)表达与对照组(1.01±0.20)相比增加.PLTP蛋白含量分别为0.42±0.02、0.89±0.25、1.08 ±0.18、1.61±0.06;E-钙黏蛋白蛋白含量分别为1.61±0.04、1.08 ±0.10、0.63±0.08、0.68±0.17;N-钙黏蛋白蛋白含量分别为0.60±0.15、0.57±0.26、0.88±0.30、1.94±0.54;波形蛋白蛋白含量分别为0.61±0.05、0.98±0.16、1.07±0.14、1.34±0.19.1％组与对照组比较差异有统计学意义(均P＜0.05).siRNA-PLTP和CSE处理细胞后,E-钙黏蛋白蛋白表达量较对照组明显增加(P＜0.05),N-钙黏蛋白和波形蛋白蛋白表达量较对照组明显降低(P＜0.05),siRNA-PLTP可部分逆转CSE诱导RLE-6TN细胞发生上皮间质转化.结论 PLTP能促进烟草诱导RLE-6TN发生上皮间质转化.

abstractsObjective To investigate the effect of phospholipid transfer protein(PLTP) on cigarette smoke extract(CSE) induced epithelial-mesenchymal transition(EMT) in rat alveolar Type Ⅱ cells (RLE-6TN).Methods CSE of different concentrations (0％,0.25％,0.5％ and 1％) was co-cultured for 2 or 3days with RLE-6TN,either pre-treated or not pre-treated with siRNA-PLTP for 6 h.Expression levels of E-cadherin mRNA and Vimentin mRNA were examined by RT-PCR,while expression levels of PLTP,E-cadherin,N-cadherin and Vimentin were examined by Western blot.Results Our results showed that the expression of E-cadherin mRNA decreased in CSE-treated groups:1.01 ± 0.05,0.74 ± 0.05,0.65 ± 0.03,0.30 ±0.08 respectively at different concentrations of CSE (0 ％,0.25％,0.5 ％,and 1.0％);while the level of Vimentin mRNA increased significantly in 1％ CSE treated cells (1.88 ± O.49),compared with control cells (1.01 ±0.20).Treatment with CSE at different concentrations (0％,0.25％,0.5％ and 1％) showed that the protein levels of PLTP were 0.42 ± 0.02,0.89 ± 0.25,1.08 ± 0.18,1.61 ± 0.06 respectively;those of E-cadherin were 1.61 ± 0.04,1.08 ± 0.10,0.62 ± 0.08,0.68 ± 0.17,respectively;those of N-cadherin were 0.60 ± 0.14,0.57 ± 0.26,0.88 ± 0.30,1.94 ± 0.54,respectively;and those of Vimentin were 0.61 ± 0.05,0.98 ± 0.16,1.07 ± 0.14,1.34 ± 0.19,respectively;all P ＜ 0.05 when the 1％ CSE group was compared with the control group.EMT induced by CSE was significantly inhibited by siRNA-PLTP.Conclusion PLTP may be involved in CSE induced EMT of rat alveolar cells.