胰岛素样生长因子-1受体在糖尿病小鼠脑内的分布

目的:观察糖尿病小鼠脑内胰岛素样生长因子-1受体(IGF-1R)的分布及APP17肽对其分布的影响,为多肽对糖尿病脑病和AD的治疗提供理论依据。方法:雄性昆明小鼠体质量28～32g,鼠龄8周,共18只。随机分为3组,正常对照组(C组)、糖尿病对照组(DM组)和APP17肽治疗组(APP17peptide+DM组)。用链脲佐菌素诱发小鼠糖尿病模型,并皮下注射APP17肽(β-淀粉样肽前体蛋白319～335)给予治疗。4周后取脑组织进行IGF-1R免疫组化染色。结果:糖尿病组IGF-1R阳性反应细胞广泛分布于皮质、海马、丘脑、下丘脑等部位,而正常对照组及APP17肽治疗组仅在皮质、海马可见阳性反应细胞,DM组与C组、APP17peptide+DM组海马阳性反应细胞数分别为(22.3±1.7),(14.5±1.4),(15.2±1.1)个/10倍物镜。后两组与DM组比较差异有显著性意义(F=0.1,0.2,P<0.001)。C组与DM+APP17peptide组小鼠海马IGF-1R免疫组化红、绿、蓝像素值分别为86±8,101±6,130±5(F=3.3,0.6,0.5,P<0.01)和84±6,102±6,132±6(F=1.2,6.0,7.0,P<0.01),且着色淡。结论:糖尿病小鼠脑内多个区域存在较多的IGF-1R阳性神经元,而APP17肽能使IGF-1R阳性反应细胞出现的部位和数量正常化。

Expression of insulin-like growth factor-1 receptor in diabetic mouse brain

AIM:To observe the expression of insulin like growth factor 1 receptor (IGF-1R) in the brain of diabetic mice and to provide theoretical basis for treatment of diabetic encephalopathy and Alzheimer disease (AD). METHODS:Eighteen male Kunming mice were randomly divided into normal control group(C group),diabetic control group (DM group),and APP17 peptide treated diabetic group(APP17 peptide+ DM group).Diabetic mouse models were induced by strepozotocin injection,and β amyloid precursor protein 319-335 (APP17 peptide) was subcutaneously injected for the treatment.Brain tissue was taken 4 weeks later for IGF 1R immunohistochemical staining. RESULTS:IGF 1R positive neurons were widely distributed in the cortex,hippocampus, and thalamus,etc.of the diabetic mice,and the cytoplasm was darkly stained.In contrast, positive cells in the hippocampaus were lightly stained in normal mice and the APP17 peptide treated diabetic mice.The number of Hi positive cells in DM, control and APP17 peptide+DM groups were 22.3±1.7, 14.5±1.4, and 15.2±1.1 respectively under 10 power object lens. CONCLUSION:IGF 1R positive neurons abounds in some areas of diabetic mouse brain and APP17 peptide can normalize their distribution and quantity.