体内直接人胰岛素原基因转移对糖尿病小鼠治疗作用的研究

Therapeutic effect of human proinsulin gene transfer in vivo on diabetic mice

目的 研究人胰岛素原基因表达质粒直接转移至糖尿病小鼠体内后对其血糖和血浆胰岛素水平的影响。 方法 将人胰岛素原基因和大鼠磷酸烯醇式丙酮酸羧激酶 (PEPCK)启动子的重组质粒 p N - PEPCK- INS经脂质体介导 ,直接转入糖尿病小鼠体内 ,监测空腹血糖并测定血浆胰岛素水平 ,PCR法鉴定基因转入。 结果 人胰岛素原基因转移组小鼠血浆胰岛素为 (49.2 9± 14 .5 6 )ml U / L ,显著高于生理盐水对照组 (37.5 6± 8.4 ) m l U / L (P<0 .0 5 )和质粒 PL NC对照组 (33.5 4±13.35 ) ml U / L (P<0 .0 5 ) ,生理盐水组与质粒 PL NCX组差别无显著性 (P>0 .0 5 ) ,人胰岛素原基因转移组空腹血糖显著低于基因转入前 (P<0 .0 5 )。生理盐水组和质粒 PL NCX组空腹血糖基因转入前后差异无显著性。

Objective To study the effect of human proinsulin gene transfer on vivo in blood glucose and plasma insulin level in diabetic mice. Methods A recombinant plasmid pN PEPCK INS containing human proinsulin gene was mixed with cationic liposome and then injected into the diabetic mice via tail veins. Fasting blood glucose (FBG) was monitored everyday. The mice were sacrificed at the 4 th day after the injection and the insulin levels in plasma were monitored by radioimmunoassay (RIA). DNA was isolated from the liver and lung tissues of each mouse. Polymerase chain reaction (PCR) was then performed and the products were analyzed by electrophoresis. Results PCR products proved that human proinsulin gene was transferred into the tissues of the diabetic mice. FBG of those mice showed a significant decrease at the 4 th day after the injection ( P < 0.05 ). Besides, the insulin levels in plasma were significantly higher than those of control mice( P < 0.05 ). Conclusion Human proinsulin gene can be successfully transferred into diabetic mice and leads to the increase of insulin level in plasma and the decrease of FBG.