Fas基因转染瘢痕疙瘩成纤维细胞并诱导其凋亡的实验研究

目的探讨瘢痕疙瘩成纤维细胞抗Fas单克隆抗体(mAb)诱导的凋亡,是否能通过正常Fas基因转染使凋亡率得以提高。方法利用分子克隆技术将人Fas cDNA插入真核表达载体pcDNA3.1多克隆位点之间,以脂质体介导法将目的基因导入瘢痕疙瘩成纤维细胞,Fas mAb诱导凋亡;通过琼脂糖凝胶电泳、HE染色和流式细胞仪检测瘢痕疙瘩成纤维细胞凋亡的情况。结果转基因的瘢痕疙瘩成纤维细胞经Fas mAb作用后,在形态学上出现典型的细胞核固缩、碎裂;琼脂糖凝胶电泳显现特征性的“梯状”带;流式细胞仪检测凋亡率明显增加。对照组未见上述结果。结论瘢痕疙瘩成纤维细胞Fas诱导的凋亡异常,是由于Fas凋亡通道的“上游事件”无功能Fas蛋白造成,与通道下游无关。瘢痕疙瘩成纤维细胞凋亡异常可能是Fas基因突变引起,其与瘢痕疙瘩形成有密切关系。

Apoptosis of keloid-derived fibroblasts induced by Fas gene transfection

Objective To observe the effect of Fas gene transfection on the apoptosis of keloid-derived fibroblasts. Methods The full-length cDNA of Fas was inserted into the multicloning site of the expression vector pcDNA-3.1 by molecular cloning technique, and the recombinant plasmid was transfected into the keloid-derived fibroblasts via lipofectin. Fas monoclonal anti-body (mAb) was used to induce the apoptosis of the cells, which was evaluated with HE staining, DNA agarose gel elec-trophoresis and flow cytometry. Results The expression plasmid pcDNA-3.1-Fas was constructed successfully. Fas mAb in-duced apoptosis of these fibroblasts transfected with Fas gene, with the typical features of fibroblast apoptosis observed in the treated cells (e.g. typical apoptotic cell nuclei, DNA ladder and high apoptosis rate as determined by flow cytometer), but not in the control cells. Conclusion Blockage of upstream apoptosis pathway in keloid-derived fibroblasts is due to nonfunction of Fas protein, and mutation of Fas gene may be the pathogenesis of keloids.