人胎儿表皮干细胞的体外分离培养及基因转染

目的：探讨人胎儿表皮干细胞体外分离培养的方法以及作为体外基因转染靶细胞的可行性。方法：利用Ⅳ型胶原快速贴附法分离人胎儿表皮干细胞，以人胎儿成纤维细胞条件培养液配制表皮干细胞培养基，通过角蛋白19（K19）和整合素β1免疫组化染色、细胞周期分析及克隆形成率测定，对培养细胞进行鉴定。采用脂质体介导法，以含血管内皮细胞生长因子165（VEFG165）基因片段的真核表达载体pcDNA3.1(pcDNA3.1/VEGF165)转染培养细胞；采用病毒载体介导法，以含报告基因绿色荧光蛋白（GFP）的重组腺相关病毒载体（raav/GFP)转染培养细胞。应用免疫组化染色及荧光显微镜观察检测转染效果。结果：人胎儿表皮干细胞呈明显克隆性生长、克隆形成率高，G1期细胞比例明显高于普通基底层角质细胞，K19和整合素β1免疫组化染色呈强阳性。pcDNA3.1/VEGF165转染的表皮干细胞VEGF165免疫组化染色阳性，raav/GFP转染的表皮干细胞呈现强荧光。结论：利用Ⅳ型胶原快速贴附法及人胎儿成纤维细胞条件培养基，可初步实现人胎儿表皮干细胞的分离培养。以质体为介导或以腺相关病毒为载体进行人胎儿表皮干细胞的体外基因转染是可行的。

The in vitro isolation, culture and transfection of human fetal epidermal stem cells

OBJECTIVE: To explore the in vitro methods of isolation and culture of human fetal epidermal stem cells (HFESCs) and the feasibility of the cultured cells as the target cells for gene transfection. METHODS: The HFESCs were isolated by means of type IV collagen rapid adhering method. The culture medium for HFESCs was prepared according to that for human fetal fibroblasts. The cultured cells were identified by immunohistochemistry staining of keratin-19 and integrin-beta1, cell cycle analysis and clone forming rate determination. Then the cultured cells were gene transfected in vitro by liposome mediating method in which eukaryon expression vector pcDNA3.1/VEGF165 containing vascular endothelial growth factor 165 (VEGF165) were transfected into cultured cells, or by virus vector mediating method in which recombinant adenovirus accompanied vector (raav) containing green fluorescent protein (GFP) (raav/GFP) were transfected into the cultured cells, respectively. The results of in vitro gene transfection of HFESCs were observed by immunohistochemisty staining and fluorescence microscope. RESULTS: HFESCs grew well and formed large clones with higher cloning efficiency and higher ratio of G1 cells than keratinocytes. The cultured cells were strongly positive with immunohistochemistry staining of keratin-19 and integrin-beta1. After being gene-transfected by pcDNA3.1/VEGF165, the VEGF165 of HFESCs showed positive immunohistochemistry staining property, while the HFESCs transfected by raav/GFP exhibited strong fluorescence. CONCLUSION: HFESCs could be isolated and cultured in vitro by means of rapid adherence to type IV collagen. It seemed feasible that HFESCs were gene transfected with liposome or adeno-associated virus as the vector.