Nakanishi H, Tsukuba T, Kondou T, Tanaka T, Yamamoto K
Department of Pharmacology, Kyushu University Faculty of Dentistry, Fukuoka, Japan.
Exp Neurol. 1993 Jun;121(2):215-23. doi: 10.1006/exnr.1993.1088.
The accumulation and localization of cathepsins E and D in the rat hippocampus and neostriatum during the neurodegenerating process induced by transient forebrain ischemia were investigated by immunoprecipitation and by immunohistochemistry using discriminative antibodies specific for each enzyme. While significant amounts of cathepsin D were found in both the hippocampus and the neostriatum of normal rats, cathepsin E was barely detectable in these tissues. No significant change in their levels was found in these tissues of postischemic rats for up to 3 days after transient forebrain ischemia. After 7 days of the treatment, cathepsin E was markedly increased in both tissues. Although the cathepsin D content in these tissues was also increased at this stage, the rate of increase was much less than that of cathepsin E. At the light microscopic level, the increased immunoreactivity for each enzyme was mainly found in reactive glial cells and degenerating neurons in the hippocampal CA1 subfield at 7 days postischemia. In the neostriatal dorsolateral portion, cathepsin D immunoreactivity was also increased in both reactive glial cells and degenerating neurons, whereas increased immunoreactivity of cathepsin E was only identified in reactive glial cells at 7 days postischemia. It was also found by double-immunostaining technique that the cathepsin E-positive glial cells were largely reactive microglial cells, whereas the cathepsin D-positive glial cells were associated mainly with reactive astrocytes. These results suggest that the accumulation of both cathepsins E and D in the regions of selective neuronal vulnerability may be associated with the postischemic development of intense gliosis and also probably neurodegenerative responses.
采用免疫沉淀法以及使用针对每种酶的特异性鉴别抗体进行免疫组织化学方法，研究了短暂性前脑缺血诱导的神经退行性变过程中，组织蛋白酶E和D在大鼠海马体和新纹状体中的积累及定位情况。正常大鼠的海马体和新纹状体中均发现有大量的组织蛋白酶D，而在这些组织中几乎检测不到组织蛋白酶E。短暂性前脑缺血后，缺血大鼠这些组织中的蛋白酶水平在3天内未发现显著变化。治疗7天后，两种组织中的组织蛋白酶E均显著增加。尽管此时这些组织中的组织蛋白酶D含量也有所增加，但其增加速率远低于组织蛋白酶E。在光学显微镜水平上，缺血7天后，每种酶增加的免疫反应性主要见于海马CA1亚区的反应性胶质细胞和变性神经元中。在新纹状体背外侧部分，组织蛋白酶D的免疫反应性在反应性胶质细胞和变性神经元中均增加，而组织蛋白酶E增加的免疫反应性在缺血7天时仅见于反应性胶质细胞中。通过双重免疫染色技术还发现，组织蛋白酶E阳性胶质细胞主要是反应性小胶质细胞，而组织蛋白酶D阳性胶质细胞主要与反应性星形胶质细胞相关。这些结果表明，组织蛋白酶E和D在选择性神经元易损区域的积累可能与缺血后强烈的胶质细胞增生以及可能的神经退行性反应的发展有关。
