糖尿病大鼠海马超微结构及蛋白质组学研究

目的 研究早期糖尿病大鼠海马超微结构及蛋白质表达谱变化,探寻糖尿病对中枢神经系统早期损害可能的机制.方法 将15只6～8周龄、体重200～250g雄性sD大鼠按随机数字表法分为对照组及糖尿病组.腹腔注射链脲佐菌素(STZ)55mg/kg制备糖尿病模型,5周后用透射电镜观察海马超微结构,采用双向凝胶电泳技术分离海马总蛋白,基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)鉴定差异蛋白质.结果 超微病理学观察结果:成模5周时糖尿病组海马神经元固缩,毛细血管管周足突水肿明显;对照组大鼠神经元、毛细血管未见明显异常改变.蛋白质组学研究结果:建立早期糖尿病大鼠海马蛋白质的双向凝胶电泳图谱;质谱鉴定8个差异表达大于2倍的蛋白质,其中线粒体细胞色素b-cl复合物亚型、14-3-3蛋白β/α、胶质纤维酸性蛋白(GFAP)、鸟苷酸结合蛋白g(0)α亚基表达上调,线粒体ATP合成酶d亚基、线粒体硫氧还蛋白依赖性过氧化物还原酶、内质网蛋白(ERP29)表达下调,内吞蛋白只在对照组表达.结论 早期糖尿病大鼠海马已出现病理改变,这种改变可能与氧化应激损伤导致能量代谢异常有关,与老化及神经变性疾病相关的蛋白质可能参与了糖尿病中枢神经系统损害的发病.

Ultrastructure observation and proteomic analysis of differentially expressed proteins in hippocampus of early diabetic rats

Objective To investigate the alteration of ultrastructure and protein expression profile in hippocampus of early diabetic rats,and to explore the possible mechanism of brain damage caused by diabetes.Methods 15 male SD rats(6-8 week-old,200-250g)were randomly divided to control group and diabetes group.Diabetic rat model wag established by peritoneal injection of STZ 55 mg/kg.After 5 weeks of treatment,ultrastructure of hippocampus were observed by transmission electron microscope(TEM);twodimensional gel electrophoresis(2-DE)technology Was applied to isolate proteins in hippocampus.MALDITOF-MS was used to identify the differentially expressed protein.Results Pyknosis of nuclei and obvious swelling in end foot of astrocytes were noted in hippocampus of diabetes group under TEM.Eight differential proteins were identified by MALDI-TOF-MS:Cytochrome b-cl complex subunit,mitochondrial,14-3-3proteinβ/α,GFAP and Guanine nucleotide-binding protein G(0)subunit a were up-regulated and ATP synthase subunit d mitochondrial,Thioredoxin-dependent peroxide reductase mitochondrial,and ERP29 were down-regulated in diabetic rat:Endophilin-Al was only expressed in control group. Conclusions Pathological changes found in hippocampus of early diabetic rats may be related to abnormal energy metabolism caused by oxidative stress,and proteins related to aging and degenerative diseases are probably involved in the pathology.