肌肉注射大鼠胰岛素原基因治疗糖尿病大鼠的研究  

Effect of rat proinsulin gene therapy by intramuscular injection on blood glucose in streptozotocin-induced diabetic rats

作　　者：顾永辉[1] 蒋琳[2] 唐伟[2] 茅晓东[2] 刘超[2] 

机构地区：[1]江苏省省级机关医院内科,江苏南京210024 [2]南京医科大学第一附属医院内分泌科．江苏南京210029

出　　处：《南京医科大学学报（自然科学版）》2008年第1期42-46,共5页Journal of Nanjing Medical University(Natural Sciences)

摘　　要：目的:研究肌肉注射大鼠胰岛素原基因重组表达质粒转基因治疗对糖尿病大鼠血糖和胰岛素分泌的影响。方法:链脲佐菌素(STZ)诱导SD大鼠糖尿病模型,经肌肉注射将大鼠胰岛素原基因重组表达质粒pCMV/proinsulin DNA裸质粒直接导入糖尿病大鼠体内,与转染同等剂量pCMV空载质粒的对照组比较,观察糖尿病大鼠血糖的影响以及体内胰岛素表达的变化。结果:①接受肌肉注射重组质粒的治疗组(A组)糖尿病大鼠血糖下降约4mmol/L,且能维持1～2周,血浆胰岛素水平明显升高,并持续表达2周;②肌肉注射胰岛素原基因治疗后,治疗组血糖明显低于接受pCMV空载质粒对照组(B组)和糖尿病对照组(DM组)(P<0.05),治疗组胰岛素浓度也明显高于这两个对照组(P<0.05);③肌肉注射治疗组大鼠的骨骼肌能检测到大鼠胰岛素原基因mRNA的表达,而对照组则为阴性;治疗组大鼠胰腺胰岛素原基因mRNA的表达量也明显高于对照组;④免疫组化结果显示,肌肉注射治疗组大鼠骨骼肌组织可见胰岛素表达,而对照组则无表达;治疗组胰腺组织胰岛素含量较对照组明显增高。结论:糖尿病大鼠裸质粒肌肉注射转基因治疗可获得胰岛素的有效表达,并有效降低糖尿病大鼠的血糖水平。Objective：To study the effect of rat proinsulin gene therapy by intramuscular injection on blood glucose and insulin secretion in streptozotocin-induced diabetic rats. Methods：Recombinant eukaryotic cell expression plasmid of rat proinsulin gene pCMV/proinsulin was transferred into streptozotocin-induced diabetic rats by intramuscular injection. The treatment group （Group A） was injected with pCMV/proinsulin naked plasmid DNA 100 μg,whereas the corresponding control group（Group B） was treated with similar amount of pCMV DNA. Normal group and DM group were also observed at the same time. Blood glucose levels and plasma insulin levels were determined by hypersensitive radioimmunoassay. RT-PCR was used to determine the alteration of proinsulin mRNA expression in skeletal muscles and pancreas. Sections of skeletal muscles and pancreas in each group were also observed. Results： （1）The blood glucose level in Group A was decreased about 4 mmol/L and maintained for 1-2 weeks. The serum insulin level increased significantly after pCMV/proinsulin gene therapy. The blood glucose in Group A was significantly lower than Group B and DM Group （P 〈 0.05）,while serum insulin was higher than that of two groups （P 〈 0.05）. （2）Proinsulin mRNA expression could be detected in skeletal muscle cells of Group A, but no detected in that of Group B and DM Group. It was also showed that proinsulin mRNA expression was higher in pancreas of Group A than Group B and DM Group. （3）Immunohistochemistry studies showed that insulin staining was positive in the sections of skeletal muscles of Group A,whereas the same results were not obtained in Group B and DM Group. And insulin staining was more intensive in pancreas of Group A than that of Group B. Conclusion：Direct injection of naked plasmids encoding rat proinsulin gene intramuscularly led to the reduction of blood glucose level, suggesting that proinsulin gene therapy offers a potential approach to diabetes.

关 键 词：糖尿病 胰岛素原基因 基因治疗 肌肉注射 裸质粒 

分 类 号：R587.1[医药卫生—内分泌]