德国：新发现有助于阿尔茨海默氏症早期诊断

德国研究人员日前在患阿尔茨海默氏症的实验鼠脑细胞内部发现了一种致病蛋白。研究人员认为，这一发现或有助于阿尔茨海默氏症的提早诊断与治疗。

阿尔茨海默氏症是最常见的痴呆症类型。患者大脑中β淀粉样蛋白出现异常蓄积，脑细胞受损，记忆力下降，目前尚无有效疗法。德国波恩大学３月２８日发表声明说，该校研究人员与哥廷根大学研究人员在患阿尔茨海默氏症的实验鼠脑神经细胞内部也发现了β淀粉样蛋白。

“令人吃惊的是，在两个月大的患病实验鼠体内，这种β淀粉样蛋白不是在神经细胞外部蓄积，而是直接在细胞内蓄积，”研究人员库马尔说。

研究人员还发现，随着病情进一步发展，β淀粉样蛋白在神经细胞外部的蓄积逐渐增多，年龄超过１２个月的患病实验鼠大脑内，β淀粉样蛋白主要蓄积在神经细胞外部。

研究人员认为，β淀粉样蛋白在脑神经细胞内部的早期蓄积表明，在脑神经细胞外还未出现β淀粉样蛋白蓄积时，阿尔茨海默氏症就已经出现。这一发现或有助于提早诊断、治疗阿尔茨海默氏症，从而尽可能延缓病情恶化。

原文链接：

---

Early intraneuronal accumulation and increased aggregation of phosphorylated Abeta in a mouse model of Alzheimer’s disease

The progressive accumulation of extracellular amyloid plaques in the brain is a common hallmark of Alzheimer’s disease (AD). We recently identified a novel species of Aβ phosphorylated at serine residue 8 with increased propensity to form toxic aggregates as compared to non-phosphorylated species. The age-dependent analysis of Aβ depositions using novel monoclonal phosphorylation-state specific antibodies revealed that phosphorylated Aβ variants accumulate first inside of neurons in a mouse model of AD already at 2 month of age. At higher ages, phosphorylated Aβ is also abundantly detected in extracellular plaques. Besides a large overlap in the spatiotemporal deposition of phosphorylated and non-phosphorylated Aβ species, fractionized extraction of Aβ from brains revealed an increased accumulation of phosphorylated Aβ in oligomeric assemblies as compared to non-phosphorylated Aβ in vivo. Thus, phosphorylated Aβ could represent an important species in the formation and stabilization of neurotoxic aggregates, and might be targeted for AD therapy and diagnosis.

来源：新华网