O'Barr S, Schultz J, Rogers J
L.J. Roberts Center, Sun Health Research Institute, Sun City, AZ 85372, USA.
Neurobiol Aging. 1996 Jan-Feb;17(1):131-6. doi: 10.1016/0197-4580(95)02024-1.
To investigate the role of the apopotosis-related protooncogene bcl-2 in Alzheimer's disease (AD), we compared levels of its protein product, designated Bcl-2, in AD and nondemented (ND) age-matched control neocortical samples. The 26 kD Bcl-2 protein is increased in expression by more than three-fold in AD compared to ND samples as detected by immunoblots. Immunohistochemical analyses give similar results. In AD patients Bcl-2 immunoreactivity is dense and profuse and appears to occur on reactive astrocytes, whereas Bcl-2 immunoreactivity of astrocytes in ND patients is light and sparse. Staining of both gray and white matter is observed but is most prominent in the latter. Increased expression of Bcl-2 by astrocytes may partially underlie their resistance to loss in AD. By contrast, neuronal Bcl-2 immunoreactivity is more sparse and equivocal, perhaps reflecting the vulnerability of this cell type to apoptotic mechanisms in AD. High levels of Bcl-2 in glial cells may aid in cell survival of reactive astrocytes resulting in either beneficial or deleterious effects on neuronal viability.
为研究凋亡相关原癌基因bcl - 2在阿尔茨海默病（AD）中的作用，我们比较了AD患者与年龄匹配的非痴呆（ND）对照者新皮质样本中其蛋白产物（称为Bcl - 2）的水平。免疫印迹检测显示，与ND样本相比，AD中26 kD的Bcl - 2蛋白表达增加了三倍多。免疫组织化学分析给出了类似的结果。在AD患者中，Bcl - 2免疫反应性密集且丰富，似乎出现在反应性星形胶质细胞上，而ND患者星形胶质细胞的Bcl - 2免疫反应性则微弱且稀少。灰质和白质均有染色，但在白质中最为明显。星形胶质细胞中Bcl - 2表达增加可能部分是其在AD中抵抗丢失的原因。相比之下，神经元Bcl - 2免疫反应性更稀少且不明确，这可能反映了这种细胞类型在AD中对凋亡机制的易感性。神经胶质细胞中高水平的Bcl - 2可能有助于反应性星形胶质细胞的存活，从而对神经元活力产生有益或有害的影响。
