TMEM16A钙激活氯离子通道在Fisher大鼠甲状腺滤泡上皮细胞的表达及其电生理特性研究

 目的：探讨跨膜蛋白16A（TMEM16A）钙激活氯离子通道在Fisher大鼠甲状腺滤泡上皮（FRT）细胞的表达及其电生理特性。方法：构建pUB6/V5-TMEM16A真核表达载体。脂质体方法转染TMEM16A至FRT细胞，同时优化脂质体和载体的量和比例，获得最佳转染效率和表达效果，杀稻瘟菌素（blasticidin）进行抗生素筛选，获取稳定表达TMEM16A的FRT细胞株。RT-PCR和免疫荧光检测TMEM16A于FRT细胞的表达情况；倒置荧光显微镜下观察TMEM16A在FRT细胞中的表达和定位；应用全细胞膜片钳技术和卤族元素敏感的荧光蛋白YFP-H148Q/I152L检测TMEM16A钙激活氯离子通道的功能。结果：BamHⅠ和XbaⅠ双酶切的琼脂糖凝胶电泳和测序结果表明目的基因TMEM16A成功克隆到真核表达载体pUB6/V5中；RT-PCR和免疫荧光实验结果表明经杀稻瘟菌素筛选后的FRT细胞在mRNA和蛋白水平表达TMEM16A，倒置显微镜下观察结果表明TMEM16A在FRT细胞膜上有表达；应用全细胞膜片钳技术和卤族元素敏感的荧光蛋白YFP-H148Q/I152L证实稳定表达于FRT细胞的TMEM16A具有经典的钙激活氯离子通道特性。结论：FRT细胞可高效表达TMEM16A。TMEM16A是钙激活氯离子通道的分子基础。

Expression of TMEM16A as a calcium-activated chloride channel in Fischer rat thyroid follicular epithelial cells and its electrophysiologic pro-perties

AIM：To investigate the expression of transmembrane protein 16A(TMEM16A) in Fischer rat thyroid follicular epithelial (FRT) cells and its electrophysiologic properties. METHODS：The eukaryotic expression vector of pUB6/V5-TMEM16A was constructed and transfected into FRT cells by liposome-mediated transfection. In order to obtain the high efficiency of gene transfection and expression, the quantity and ratio of lipid/DNA complexes were optimized. The FRT cells stably expressing TMEM16A were gained by the selection with blasticidin and confirmed by the techniques of RT-PCR and immunofluorescence. The expression and location of TMEM16A in the FRT cells were observed under an inverted fluorescence microscope. TMEM16A protein was associated with calcium-dependent chloride current, as measured with halide-sensitive fluorescent protein and patch-clamp technique. RESULTS：The results of double digestion and sequencing indicated that TMEM16A was cloned into pUB6/V5. The results of RT-PCR and immunofluorescence confirmed that TMEM16A was expressed in the FRT cells after transfection with TMEM16A. The classical calcium-activated chloride channel currents were recorded in the FRT cells stably expressing TMEM16A by the technique of patch-clamp and halide-sensitive fluorescent protein YFP-H148Q/I152L. CONCLUSION：The protein expression of TMEM16A in the FRT cells was observed. TMEM16A is the molecular identity of calcium-activated chloride channels.