目的 探讨转铁蛋白受体1(TfR1)在淀粉样蛋白前体（APP）/早老素1（PS1）转基因小鼠脑内异常表达情况及其对阿尔茨海默病（AD）神经元的保护作用。方法 首先，利用免疫荧光及Western blotting技术检测出生后1月（P1M）至P12M各发育时间点，APP/PS1转基因小鼠与野生型小鼠大脑TfR1的表达情况；其次，取APP/PS1转基因与野生型新生小鼠原代海马神经元培养，培养12 d后利用TfR1 shRNA质粒干扰TfR1基因的表达，利用Western blotting技术检测干扰后细胞TfR1的表达变化；ELISA技术检测TfR1干扰前后细胞β-淀粉样蛋白(Aβ)_1-42的分泌量；利用微管相关蛋白2(MAP2)标记神经元突起，观察TfR1干扰前、后神经元突起的生长变化；最后，利用FM1-43染色观察由TfR1介导的轴质运输中囊泡的运输情况。 结果 在APP/PS1转基因小鼠生长发育过程中，随着年龄的增长TfR1的表达呈现先增加后减少的趋势，在P6M之后明显降低，且与对照组相比差异有显著性；TfR1 shRNA 干扰后可以使原代神经元细胞内TfR1基因沉默，使其突起明显变细、变长并影响囊泡的运输。与对照组相比，TfR1基因在APP/PS1转基因小鼠原代神经元中表达量减少，荧光减弱。 结论 APP、PS1基因突变可导致TfR1的表达下降；APP/PS1转基因小鼠原代神经元经TfR1 shRNA干扰Aβ_1-42分泌量增多，影响神经元突起的生长，使轴质运输速率减慢，囊泡的活动减缓，加重AD病情。故TfR1的表达可以对神经元起到保护作用。

Objective To investigate the neuroprotection effect of transferrin receptor 1(TfR1) in Alzheimer’s disease(AD). Methods Immunofluorescence and Western blotting were used to detect the expression of TfR1 in the amyloid precursor protein（APP）/presenilin-1（PS1）transgenic mice from postnatal 0 day(P0) to P360. With primary cultured hippocampal neurons, TfR1 expression and amyloid betapeptides (Aβ) secretion were detected with Western blotting and ELISA assay, respectively. The cultured neurons and their processes were labeled with TfR1 and microtubule associated protein 2 (MAP2) immunolabeling, and the TfR1-mediated axonal vesicles were observed with FM1-43 staining, after TfR1 shRNA interference. Results TfR1 expression in AD mice (APP/PS1 transgenic mice) decreased significantly after postnatal 6 months (P 6 M) compared with the wild type(WT) mice. Similarly, in cultured cells, after TfR1 gene silence, the neuronal processes became long and thin, and the axonal vesicle transportation was blocked. Conclusion APP and PS1 gene mutation can decrease expression of TfR1. TfR1 shRNA interference can increase the amount of Aβ_1-42 secretion and impact neurite growth and axonal vesicle transportation. Therefore, we conclude that TfR1 may play an important role in neuroprotection.