Masliah E, Cole G, Shimohama S, Hansen L, DeTeresa R, Terry R D, Saitoh T
Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla 92093.
J Neurosci. 1990 Jul;10(7):2113-24. doi: 10.1523/JNEUROSCI.10-07-02113.1990.
Decreased levels of protein kinase C (PKC) and a reduction in the in vitro phosphorylation of a Mr 86,000 protein (P86), the major PKC substrate, are biochemical characteristics of brain tissue from patients with Alzheimer's disease (AD) (Cole et al., 1988). In the current study, we utilized antibodies against individual isozymes of PKC to assess the degree of involvement of different PKC isoforms in AD. The concentration of PKC(beta II) was lower in particulate fractions prepared from AD hippocampal and cortical tissue than in controls and higher in AD cytosol fractions from the cortex than in controls. Immunohistochemical studies in AD neocortex revealed reduced numbers of anti-PKC(beta II)-immunopositive neurons and diminished staining intensity. In contrast, AD hippocampal neurons in CA3-CA4 were more intensely stained with anti-PKC(beta II) antiserum than were controls. The concentration of PKC(beta I) was lower in particulate fractions prepared from AD hippocampus than in controls and was higher in soluble fractions prepared from AD cortex than in controls. The concentration of PKC(alpha) was lower in AD particulate fractions than in controls in the hippocampus. Immunohistochemistry with PKC(alpha) antiserum revealed moderately intense neuron staining and an intense staining of glial cells in AD neocortex. The concentrations and histochemical distributions of PKC(gamma) were not altered in the disease. PKC immunoreactivity was also found in neuritic plaques. The staining patterns of neuritic plaques with different isoform antibodies varied considerably. Anti-PKC(alpha) faintly stained entire plaques and surrounding glial cells; anti-PKC(beta I) stained dystrophic plaque neurites; and anti-PKC(beta II) stained the amyloid-containing portions of plaques.
蛋白激酶C（PKC）水平降低以及主要PKC底物——分子量为86,000的蛋白质（P86）的体外磷酸化减少，是阿尔茨海默病（AD）患者脑组织的生化特征（Cole等人，1988年）。在本研究中，我们使用针对PKC各同工酶的抗体来评估不同PKC同工型在AD中的参与程度。从AD海马体和皮质组织制备的微粒体部分中，PKC（βII）的浓度低于对照组，而在来自皮质的AD胞质溶胶部分中则高于对照组。AD新皮质的免疫组织化学研究显示，抗PKC（βII）免疫阳性神经元数量减少且染色强度减弱。相比之下，CA3 - CA4区的AD海马神经元用抗PKC（βII）抗血清染色比对照组更强烈。从AD海马体制备的微粒体部分中，PKC（βI）的浓度低于对照组，而从AD皮质制备的可溶性部分中则高于对照组。AD海马体微粒体部分中PKC（α）的浓度低于对照组。用PKC（α）抗血清进行的免疫组织化学显示，AD新皮质中神经元染色中等强度，胶质细胞染色强烈。PKC（γ）的浓度和组织化学分布在疾病中未发生改变。在神经炎性斑块中也发现了PKC免疫反应性。用不同同工型抗体对神经炎性斑块进行染色的模式差异很大。抗PKC（α）使整个斑块和周围胶质细胞微弱染色；抗PKC（βI）使营养不良性斑块神经突染色；抗PKC（βII）使斑块中含淀粉样蛋白的部分染色。
