Ac-SDKP经HSP27调节锌指蛋白而抑制肺上皮细胞-间质转化

目的:探讨N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸(Ac-SDKP)是否通过抑制热休克蛋白27(heat-shock protein 27,HSP 27)的表达,进而抑制锌指蛋白SNAI1、SNAI2的表达,而发挥阻抑转化生长因子(TGF)-β1诱导的人肺泡Ⅱ型上皮细胞向间质细胞(肌成纤维细胞)的转化以及Ⅰ型、Ⅲ型胶原蛋白的表达。方法:激光共聚焦检测TGF-β1诱导的人肺泡Ⅱ型上皮细胞向肌成纤维细胞转化中HSP27及SNAI1、SNAI2蛋白的共定位表达;real-time PCR法检测HSP27、SNAI1和SNAI2 mRNA的表达;Western blotting法检测HSP27、SNAI1、SNAI2和Ⅰ型、Ⅲ型胶原蛋白的表达,以及转染HSP27干扰质粒后SNAI1、SNAI2蛋白及Ⅰ型、Ⅲ型胶原蛋白表达的变化。结果:与对照组相比,TGF-β1刺激组HSP27、SNAI1、SNAI2及Ⅰ型、Ⅲ型胶原蛋白表达增强;给予Ac-SDKP干预后,HSP27、SNAI1、SNAI2及Ⅰ型、Ⅲ型胶原蛋白表达明显降低,差异有统计学意义。用HSP27的干扰质粒转扰细胞后,SNAI1、SNAI2及Ⅰ型、Ⅲ型胶原蛋白表达降低,其中SNAI1和Ⅰ型、Ⅲ型胶原蛋白的表达与TGF-β1刺激组比较差异有统计学意义。这与Ac-SDKP干预的结果相似。结论:Ac-SDKP能够通过对HSP27表达的调节,降低锌指蛋白SNAI1和SNAI2的表达,进而抑制肺泡Ⅱ型上皮细胞向肌成纤维细胞的转化及胶原蛋白的合成。

Inhibitory effect of N-acetyl-seryl-aspartyl-lysyl-proline on epithelial-mes-enchymal transition by heat-shock protein 27/zinc finger proteins

AIM: To detect whether N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) inhibits epithelial-mesenchymal transition in A549 cells induced by TGF-β1 through suppressing the expression of heat shock protein 27 (HSP27) and zinc finger proteins Snail (including SNAI1and SNAI2) which ultimately inhibited the deposition of type I and type III collagens. METHODS: The colocalizations of HSP27 and SNAI1/SNAI2 respectively on A549 alveolar epithelial cells induced by TGF-β1 were measured by confocal microscopy. The expression of HSP27, SNAI1 and SNAI2 at mRNA level was detected by real-time PCR. Western blotting analysis was used to detect the expression of HSP27, SNAI1 and SNAI2 on epithelial-mesenchymal transition in A549 cells induced by TGF-β1 and also the deposition of type I and type III collagens in A549 cells transfected with HSP27shRNA prior to TGF-β1 stimulation.RESULTS: Compared with control group, TGF-β1 increased the expression of HSP27, SNAI1, SNAI2, type I and type III collagen, which decreased significantly followed by Ac-SDKP intervention. The expression of SNAI1, type I and type III collagen decreased significantly after transfected with HSP27shRNA in A549 cells, which had the similar effect on Ac-SDKP intervention.CONCLUSION: Ac-SDKP inhibits the transition of cultured A549 cells to myofibroblasts and attenuates collagen synthesis by suppressing the expression of HSP27 and zinc finger proteins SNAI1 and SNAI2.