Aging-related alterations in the distribution of Ca(2+)-dependent PKC isoforms in rabbit hippocampus.
Aging-related alterations in the distribution of Ca(2+)-dependent PKC isoforms in rabbit hippocampus.
复制标题
兔海马中 Ca(2) 依赖性 PKC 异构体分布的衰老相关变化。
DOI：
10.1002/hipo.20000
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发表时间：
2004
期刊：
影响因子：
3.5
通讯作者：
Disterhoft,JF
中科院分区：
文献类型：
--
作者：
VanderZee,EA;Palm,IF;O'Connor,M;Maizels,ET;Hunzicker-Dunn,M;Disterhoft,JF
在年轻（3 个月大；n = 11）和老年（36 个月大；n = 14）受试者的兔子海马中检查了 Ca2+ 依赖性蛋白激酶 C (cPKC) 亚型（PKCα、β1、β2 和 γ）的免疫细胞化学和亚细胞定位。详细的免疫细胞化学分析显示，衰老兔子的主细胞体和相关树突以及肺门区域的中间神经元中的 PKCβ1、β2 和 γ 免疫反应性显着增加。衰老层中 PKCα 和 γ 阳性中间神经元的数量显着下降。 PKCα 在主细胞中受影响最小，仅显示颗粒细胞中的免疫染色增加。在大多数衰老兔子的海马部分区域中都可以看到弱 PKC 阳性主细胞与浓染细胞混合在一起，这表明 PKC 免疫反应性的衰老相关变化程度在神经元之间存在差异。老化齿状回分子层和颗粒下层 PKC 表达的变化表明该区域 PKC 阳性传入神经发生了重组。蛋白质印迹分析显示，所有亚型的沉淀部分中 PKC 均显着损失，并且胞质 PKC 水平有增加的趋势。然而，任何 PKC 同工型的 PKC 总含量均未发现显着变化。蛋白质印迹显示沉淀部分中活化 C 激酶 (RACK1) 的 PKC 锚定蛋白受体同时急剧丧失。这些发现表明，RACK1 的缺失导致衰老兔海马体中 PKC 系统的失调。增强的 PKC 免疫反应性可能与 PKC 与锚定蛋白 RACK1 的蛋白质-蛋白质相互作用减少有关，从而导致抗体更接近抗原位点。总之，结果表明衰老兔子的记忆缺陷（部分）是由海马神经元亚细胞 PKC 定位失调引起的。 © 2004 Wiley-Liss, Inc.
The immunocytochemical and subcellular localization of the Ca2+‐dependent protein kinase C (cPKC) isoforms (PKCα, β1, β2, and γ) was examined in rabbit hippocampus of young (3 months of age; n = 11) and aging (36 months of age; n = 14) subjects. Detailed immunocytochemical analyses revealed a significant increase in PKCβ1, β2, and γ immunoreactivity in principal cell bodies and associated dendrites, and interneurons of the hilar region in the aging rabbits. The number of PKCα‐ and γ‐positive interneurons in the aging stratum oriens declined significantly. PKCα was least affected in principal cells, showing an increase in immunostaining in granule cells only. Weakly PKC‐positive principal cells intermingled between densely stained ones were seen in parts of the hippocampus in most of the aging rabbits, showing that the degree of aging‐related alterations in PKC‐immunoreactivity varies between neurons. Changes in PKC expression in the molecular and subgranular layer of the aging dentate gyrus suggested a reorganization of PKC‐positive afferents to this region. Western blot analysis revealed a significant loss of PKC in the pellet fraction for all isoforms, and a tendency for increased levels of cytosolic PKC. However, no significant changes were found in total PKC content for any PKC isoform. A concurrent dramatic loss of the PKC anchoring protein receptor for activated C kinase (RACK1) in the pellet fraction was shown by Western blotting. These findings suggest that the loss of RACK1 contributes to the dysregulation of the PKC system in the aging rabbit hippocampus. The enhanced PKC‐immunoreactivity might relate to reduced protein‐protein interactions of PKC with the anchoring protein RACK1 leading to increased access of the antibodies to the antigenic site. In conclusion, the results suggest that memory deficits in aging rabbits are (in part) caused by dysregulation of subcellular PKC localization in hippocampal neurons. © 2004 Wiley‐Liss, Inc.