Rohn T T, Head E, Su J H, Anderson A J, Bahr B A, Cotman C W, Cribbs D H
Institute for Brain Aging and Dementia, University of California at Irvine, 92697-4540, USA.
Am J Pathol. 2001 Jan;158(1):189-98. doi: 10.1016/S0002-9440(10)63957-0.
Although evidence suggests that neurofibrillary tangles (NFTs) and neuronal cell loss are prominent features of Alzheimer's disease (AD), the relationship between the two remains unknown. In the present study, the relationship between the activation of apoptotic mechanisms and NFT formation in AD was investigated using a caspase-cleavage site-directed antibody to fodrin, an abundant neuronal cytoskeleton protein. This antibody recognized cleavage products of fodrin after digestion by caspase-3, but did not recognize full-length fodrin. In vitro analysis of this fodrin caspase-cleavage product (CCP) antibody demonstrates that it is a specific probe for the detection of apoptotic but not necrotic pathways in cultured neurons. To determine whether caspases cleave fodrin in vivo, tissue sections from controls and AD were immunostained for fodrin (CCPs). Although no staining was observed in control cases, labeling of neurons was observed in the hippocampus of all AD cases, which increased as a function of disease progression. To determine a possible relationship between caspase activation and NFT formation, double-labeling experiments with fodrin CCP and PHF-1 were performed. Co-localization of these markers was observed in many neurons, and quantitative analysis showed that as the extent of NFT formation increased, there was a significant corresponding increase in fodrin CCP immunolabeling (r = 0.84). Taken together, these results provide evidence for the activation of apoptotic mechanisms in neurons in the AD brain and suggest that there is an association between NFT formation and the activation of apoptotic pathways in AD.
尽管有证据表明神经纤维缠结（NFTs）和神经元细胞丢失是阿尔茨海默病（AD）的突出特征，但两者之间的关系仍然不明。在本研究中，使用针对血影蛋白（一种丰富的神经元细胞骨架蛋白）的半胱天冬酶切割位点定向抗体，研究了AD中凋亡机制激活与NFT形成之间的关系。该抗体识别半胱天冬酶-3消化后血影蛋白的切割产物，但不识别全长血影蛋白。对这种血影蛋白半胱天冬酶切割产物（CCP）抗体的体外分析表明，它是检测培养神经元中凋亡而非坏死途径的特异性探针。为了确定半胱天冬酶在体内是否切割血影蛋白，对对照和AD的组织切片进行血影蛋白（CCPs）免疫染色。虽然在对照病例中未观察到染色，但在所有AD病例的海马中均观察到神经元标记，且其随疾病进展而增加。为了确定半胱天冬酶激活与NFT形成之间的可能关系，进行了血影蛋白CCP和PHF-1的双重标记实验。在许多神经元中观察到这些标记的共定位，定量分析表明，随着NFT形成程度的增加，血影蛋白CCP免疫标记有显著相应增加（r = 0.84）。综上所述，这些结果为AD脑神经元中凋亡机制的激活提供了证据，并表明AD中NFT形成与凋亡途径激活之间存在关联。
