目的研究糖尿病小鼠脑内Ｔａｕ蛋白是否过度磷酸化并观察ＡＰＰ１７肽的作用。方法用链脲佐菌素诱发小鼠糖尿病模型，并皮下注射ＡＰＰ１７肽对糖尿病小鼠进行保护。４周后，取脑组织做ＡＴ８、Ｔａｕ１、ＰＰ２Ｂ及用ＰＰ２Ｂ脱磷酸后的Ｔａｕ１免疫组化染色。结果糖尿病小鼠脑内ＡＴ８阳性反应神经元数目多，胞浆和突起深染，而正常小鼠及ＡＰＰ１７肽保护的糖尿病小鼠脑内阳性反应神经元数目少，染色淡；糖尿病小鼠海马内ＰＰ２Ｂ阳性反应神经元数目比正常小鼠明显减少，用ＡＰＰ１７肽保护后染色结果与正常小鼠接近。结论糖尿病小鼠脑内出现Ｔａｕ蛋白的过度磷酸化，即在丝氨酸２０２／苏氨酸２０５位点被磷酸化，ＰＰ２Ｂ表达减少可能是导致Ｔａｕ蛋白过度磷酸化的主要原因。用ＡＰＰ１７肽可使ＰＰ２Ｂ表达正常而保护Ｔａｕ蛋白不被过度磷酸化。 Objective To investigate whether Tau protein in diabetic mice is hyperphosphorylated and to observe the effect of APP17 peptide. Methods Diabetic mice were induced by streptozotocin (STZ) and diabetic mice were injected subcutaneously with APP17 peptide. After 4 weeks, brain tissue was taken as AT 8, Tau 1, PP 2 2B and Tau 1 immunohistochemistry with PP 2-dephosphorylated. Results The number of AT8positive neurons in the brain of diabetic mice was more than that in the cytoplasm and protuberances of diabetic mice, while the number of positive neurons in diabetic mice protected by normal mice and APP17 peptide was less, The number of PP2B-positive neurons in the hippocampus decreased significantly compared with that in normal mice. The staining results with APP17 peptide were similar to those in normal mice. Conclusion Tau protein hyperphosphorylation, which is phosphorylated at serine 202 / threonine 205 site, may be the main reason leading to hyperphosphorylation of Tau protein in diabetic mice. PP17 peptide with PP  2B expression can be normal and protect Tau protein is not over-phosphorylation.