人β-NGF基因在COS-7细胞中的表达及其生物学活性的研究

study on the expression and biological activity of the expression products of the human β-NGF cDNA in COS-7 cell line

目的研究人β-神经生长因子(β-NGF)cDNA在真核细胞中的表达及其表达产物的活性。方法将质粒pGEM-β-NGF进行酶切并回收β-NGF cDNA片段，构建重组真核表达载体pcDNA3-β-NGF。利用脂质体Lipofectamine方法转染COS-7细胞，对阳性克隆COS-7细胞的mRNA和培养上清分别进行Northern blot分析和观察对PC12细胞突起生长的作用。结果β-NGF基因在COS-7细胞中获得表达。阳性克隆COS-7细胞培养上清能够促进PC12细胞突起生长。结论目的基因在COS-7细胞中成功表达β-NGF蛋白，并具有良好的生物学活性。

Aim To study the expression of β-NGF gene in the mammlian cells and the biological activity of its expression products. Methods The β-nerve growth factor (β-NGF) cDNA which obtained from the plasmid pGEM-β-NGF by enzyme digestion analysis was cloned into the expression vector pcDNA3 to construct the recombinant plasmid pcDNA3-β-NGF. COS-7 cell line grown to log phase was transfected using lipofectamine reagent. The expression level of β-NGF mRNA and the biological activity were analyzed by Northern blot and observation of neurite outgrowth of PC12 cell line stimulated by supernatant, respectively. Results The β-NGF gene was expressed successfully in COS-7 cell lines. The culture supernatant of the positive COS-7 cells transfected with pcDNA3-β-NGF could stimulate the neurite outgrowth of PC12 cell line. Conclusion The target gene expressed successfully in the transfected COS-7 cell line and had good biological activity.