人胰岛素样生长因子1基因转染脂肪源性干细胞的效应

Effects of human insulin-like growth factor 1 gene trasfection on adiposederived stem cells

背景:人胰岛素样生长因子1基因对脂肪源性干细胞的增殖和分化也可能会产生有效作用。目的:验证人胰岛素样生长因子1基因转染对体外培养的脂肪源性干细胞的效应。方法:构建含人胰岛素样生长因子1基因的双顺反子真核表达载体pIRES2-EGFP-hIGF-1,利用阳离子脂质体Lipofectamine2000介导转染体外培养的人脂肪源性干细胞。观察基因转染后细胞增殖及形态的变化,倒置荧光显微镜观测标记基因增强绿色荧光蛋白的表达并计算转染效率,酶联免疫吸附试验检测培养上清中人胰岛素样生长因子1的浓度,免疫组织化学染色及RT-PCR检测人胰岛素样生长因子1的表达,流式细胞仪检测转染前后细胞周期的变化。结果与结论:测序及酶切证实真核表达载体pIRES2-EGFP-hIGF-1构建正确。体外培养的脂肪源性干细胞为多种形态并存,转染后6h检测到有EGFP的表达,至60h达到高峰,转染效率为(16±3)%。细胞上清中人胰岛素样生长因子1的浓度在60h达到22.65μg/L。免疫组织化学染色及RT-PCR均检测到人胰岛素样生长因子1的表达。转染后的细胞分裂增殖加快,细胞群体倍增时间缩短,S期细胞比例增多。证实人胰岛素样生长因子1基因可有效转染脂肪源性干细胞并表达人胰岛素样生长因子1蛋白质,同时可促进细胞增殖。

BACKGROUND： Human insulin-like growth factor I gene produces effects on the proliferation and differentiation of adipose-derived stem cells. OBJECTIVE： To investigate the possible effects of human insulin-like growth factor 1 gene transfection on the adipose-derived stem ceils cultured in vitro. METHODS： The cDNA for human insulin-like growth factor 1 was cloned into the recombinant eukaryotic expression plasmid plRES2-EGFP-hlGF-I. The adipose-derived stem cells were derived from adipose tissue and cultured in vitro, and then the plasmid was transfected into cells by Lipofectamine 2000. After gene transfection, changes in cell proliferation and morphology were observed. Through the use of inverted fluorescent microscopy, the marker gene coding enhanced green fluorescent protein was observed and the transfection efficiency was determined. The human insulin growth factor 1 concentration in the supernatant fluids was measured by ELISA. The expression of human insulin-like growth factor 1 was detected by immunohistochemical staining and RT-PCR The changes in cell cycle before and after transfection were assessed by flow cytometry. RESULTS AND CONCLUSION： The recombinant eukaryotic expression plasmid plRES2-EGFP-hlGF-1 was confirmed by gene sequencing and enzyme digestion. The adipose-derived stem cells cultured in vitro were in multiple shapes. The expression of enhanced green fluorescent protein was detected for the first time at 6 hours after transfection and peaked at 60 hours, with transfection efficacy of 16±3%. The concentration of insulin-like growth factor 1 in the supernatant fluid was 22.65 pg/L at 60 hours after transfection. Human insulin growth factor 1 expression was detected by immunohistochemical staining and RT-PCR. Division and proliferation of the cells were accelerated after gene transfection, leading to the decrease of the population doubling time, and the increase of the percentage of stem ceils in the S stage. These results indicate that human insulin growth factor 1 gene can be transfected efficiently into the adipose-derived stem cells by fiposome and human insulin-like growth factor 1 protein can be secreted into the supernatant fluid, therefore accelerating the proliferation of the cells.