APP17肽改善糖尿病小鼠脑组织Tau蛋白过度磷酸化

背景:Tau蛋白的过度磷酸化是痴呆的一个因素,国外学者研究发现APP17肽对其可能产生影响。目的:观察注射APP17肽后糖尿病小鼠Tau蛋白Ser202/Thr205磷酸化的变化。设计:随机对照实验。单位:首都医科大学病理学教研室,首都医科大学宣武医院脑老化研究室。材料:实验在首都医科大学病理学教研室、北京市宣武医院脑老化研究室完成。选用8周龄雄性昆明小鼠18只,体质量28～32g,随机分为3组:对照组,糖尿病组,APP17肽治疗组,每组6只小鼠。方法:用链脲佐菌素选择性地破坏胰岛β-细胞,诱发小鼠糖尿病模型,并皮下注射APP17肽给予治疗。4周后取脑组织进行AT-8(抗Ser202/Thr205特异单抗)免疫组化染色。主要观察指标:①形态学观察。②AT-8分布。③免疫组化染色定量分析。结果:糖尿病组AT-8阳性反应细胞广泛分布于压后颗粒皮层、海马、丘脑、下丘脑等部位,而对照组及APP17肽治疗组仅在压后颗粒皮层、海马可见阳性反应细胞,且着色淡。结论:糖尿病脑内多个区域的神经元可能存在较多的AT-8阳性细胞,而APP17肽可能使AT-8阳性反应细胞出现的部位和数量正常化。

Improved effect of APP17 peptide on overexpression of phosphorylated Tau protein in brain tissues of mice with diabetes mellitus

BACKGROUND: Overexpression of phosphorylated Tau protein is a factor of dementia, and scholars abroad find that APP17 peptide may have effect on it.OBJECTIVE: To observe changes of phosphorylated Tau protein Ser202/Thr205 of mice with diabetes mellitus (DM) after injection of APP17 peptide.DESIGN: Randomized control study.SETTING: Department of Pathology, Capital University of Medical Sciences; Department of Brain Aging, Xuanwu Hospital, Capital University of Medical Sciences.MATERIALS: The experiment was carried out in the Pathological Department of Capital University of Medical Sciences and Brain Aging Department of Beijing Xuanwu Hospital. A total of 18 male Kunming mice of 8 weeks old and weighing 28-32 g were randomly divided into control group, DM group and APP17 peptide group with 6 in each group.METHODS: DM models were induced by streptozotocin (STZ) through selectively destroying β-islet cells; meanwhile, APP17 peptide was intraperitoneally injected into mice. Four weeks later, brain tissue underwentimmunohistochemical staining with AT-8 (Ser202/Thr205, a special monoclonal antibody).MAIN OUTCOME MEASURES: ① Morphological observation; ② AT-8 distribution; ③ quantitative analysis of immunohistochemical staining.RESULTS: Positive AT-8 cells in DM group were distributed in retrosplenial cortex, hippocampus, thalamus, hypothalamus, etc.; however, those incontrol and APP17 peptide groups were only distributed in retrosplenial cortex and hippocampus, and poorly stained.CONCLUSION: Positive AT-8 cells may be widely distributed in neurons of brains of DM mice; however, APP17 peptide may normalize the expression of positive AT-8 cells.