McGeer P L, Akiyama H, Kawamata T, Yamada T, Walker D G, Ishii T
Kinsmen Laboratory of Neurological Research, Department of Psychiatry, University of British Columbia, Vancouver, Canada.
J Neurosci Res. 1992 Mar;31(3):428-42. doi: 10.1002/jnr.490310305.
Immunohistochemical staining with antibodies directed against four segments of the amyloid precursor protein (APP) was studied by light and electron microscopy in normal and Alzheimer (AD) brain tissue. The segments according to the Kang et al. sequence were: 18-38 (T97); 527-540 (R36); 597-620 (1-24 of beta-amyloid protein [BAP], R17); and 681-695 (R37) (Kang et al. [1987]: Nature 325:733-736). The antibodies recognized full length APP in Western blots of extracts of APP transfected cells. They stained cytoplasmic granules in some pyramidal neurons in normal appearing tissue from control and AD cases. In AD affected tissue, the antibodies to amino terminal sections of APP stained tangled neurons and neuropil threads, and intensely stained dystrophic neurites in senile plaques. By electron microscopy, this staining was localized to abnormal filaments. The antibody to the carboxy terminal segment failed to stain neurofibrillary tangles or neuropil threads; it did stain some neurites with globular swellings. It also stained globular and elongated deposits in senile plaque areas. The antibody against the BAP intensely stained extracellular material in senile plaques and diffuse deposits. By electron microscopy, the antibodies all stained intramicroglial deposits. Some of the extracellular and intracellular BAP-positive deposits were fibrillary. Communication between intramicroglial and extracellular fibrils was detected in plaque areas. These data suggest the following sequence of events. APP is normally concentrated in intraneuronal granules. In AD, it accumulates in damaged neuronal fibers. The amino terminal portion binds to abnormal neurofilaments. Major fragments of APP are phagocytosed and processed by microglia with the BAP portion being preserved. The preserved BAP is then extruded and accumulates in extracellular tissue.
运用针对淀粉样前体蛋白（APP）四个片段的抗体进行免疫组织化学染色，通过光学显微镜和电子显微镜对正常脑组织和阿尔茨海默病（AD）脑组织进行了研究。根据Kang等人的序列，这些片段分别为：18 - 38（T97）；527 - 540（R36）；597 - 620（β淀粉样蛋白[BAP]的1 - 24，R17）；以及681 - 695（R37）（Kang等人[1987]：《自然》325:733 - 736）。这些抗体在APP转染细胞提取物的蛋白质免疫印迹中可识别全长APP。它们在对照和AD病例外观正常的组织中的一些锥体神经元中对细胞质颗粒进行了染色。在AD受累组织中，针对APP氨基末端部分的抗体对缠结的神经元和神经原纤维丝进行了染色，并对老年斑中的营养不良性神经突进行了强烈染色。通过电子显微镜观察，这种染色定位于异常细丝。针对羧基末端片段的抗体未能对神经原纤维缠结或神经原纤维丝进行染色；它确实对一些有球状肿胀的神经突进行了染色。它还对老年斑区域的球状和细长沉积物进行了染色。针对BAP的抗体对老年斑中的细胞外物质和弥漫性沉积物进行了强烈染色。通过电子显微镜观察，所有抗体都对小胶质细胞内沉积物进行了染色。一些细胞外和细胞内BAP阳性沉积物呈纤维状。在斑块区域检测到小胶质细胞内和细胞外纤维之间的通讯。这些数据提示了以下事件序列。APP通常集中在神经元内颗粒中。在AD中，它在受损的神经纤维中积累。氨基末端部分与异常神经丝结合。APP的主要片段被小胶质细胞吞噬和加工，BAP部分得以保留。然后保留的BAP被挤出并在细胞外组织中积累。
