Pype Stefan, Moechars Dieder, Dillen Lieve, Mercken Marc
Johnson & Johnson Pharmaceutical Research & Development, a division of Janssen Pharmaceutica, Turnhoutseweg, Beerse, Belgium.
J Neurochem. 2003 Feb;84(3):602-9. doi: 10.1046/j.1471-4159.2003.01556.x.
Alzheimer's disease (AD) is marked by the presence of neurofibrillary tangles and amyloid plaques in the brain of patients. To study plaque formation, we report on further quantitative and qualitative analysis of human and mouse amyloid beta peptides (Abeta) from brain extracts of transgenic mice overexpressing the London mutant of human amyloid precursor protein (APP). Using enzyme-linked immunosorbant assays (ELISAs) specific for either human or rodent Abeta, we found that the peptides from both species aggregated to form plaques. The ratios of deposited Abeta1-42/1-40 were in the order of 2-3 for human and 8-9 for mouse peptides, indicating preferential deposition of Abeta42. We also determined the identity and relative levels of other Abeta variants present in protein extracts from soluble and insoluble brain fractions. This was done by combined immunoprecipitation and mass spectrometry (IP/MS). The most prominent peptides truncated either at the carboxyl- or the amino-terminus were Abeta1-38 and Abeta11-42, respectively, and the latter was strongly enriched in the extracts of deposited peptides. Taken together, our data indicate that plaques of APP-London transgenic mice consist of aggregates of multiple human and mouse Abeta variants, and the human variants that we identified were previously detected in brain extracts of AD patients.
阿尔茨海默病（AD）的特征是患者大脑中存在神经原纤维缠结和淀粉样斑块。为了研究斑块形成，我们报告了对过表达人类淀粉样前体蛋白（APP）伦敦突变体的转基因小鼠脑提取物中的人类和小鼠淀粉样β肽（Aβ）进行的进一步定量和定性分析。使用针对人类或啮齿动物Aβ的酶联免疫吸附测定（ELISA），我们发现这两种物种的肽都会聚集形成斑块。人类沉积的Aβ1-42/1-40比率约为2-3，小鼠肽的比率约为8-9，表明Aβ42优先沉积。我们还确定了可溶性和不可溶性脑部分蛋白质提取物中存在的其他Aβ变体 的身份和相对水平。这是通过免疫沉淀和质谱联用（IP/MS）完成的。在羧基末端或氨基末端截短的最突出的肽分别是Aβ1-38和Aβ11-42，后者在沉积肽的提取物中大量富集。综上所述，我们的数据表明，APP-伦敦转基因小鼠的斑块由多种人类和小鼠Aβ变体的聚集体组成，我们鉴定出的人类变体先前在AD患者的脑提取物中也被检测到。
