O'Brien L, Shelley K, Towfighi J, McPherson A
Proc Natl Acad Sci U S A. 1980 Apr;77(4):2260-4. doi: 10.1073/pnas.77.4.2260.
Paracrystalline inclusions known as Hirano bodies characteristically appear in the hippocampal region of the brains of humans exhibiting senile and presenile dementias as well as several other neurodegenerative diseases. We present evidence that the currently accepted model for those structures based on alternating filament sheets is not correct, but that Hirano bodies are stacked sheets of membrane-bound ribosomal particles derived from partially degraded rough endoplasmic reticulum or Nissl substance. Using fluorescence staining with acridine orange and ethidium bromide, were have shown that the bodies contain RNA. Spatial filtering of electron micrographs by Fourier techniques shows that the individual particles that make up the arrays have a characteristic shape previously reported for the large subunit of eukaryotic ribosomes. The storage of these ribosomal particles in inclusion bodies may indicate a quiescent state of protein synthesis in the cells. This withdrawal of synthetic mechanisms in the hippocampus may have significant consequences in the loss of ability to consolidate short-term to long-term memory.
被称为 Hirano 小体的类晶体包涵体，典型地出现在患有老年性和早老性痴呆以及其他几种神经退行性疾病的人类大脑海马区。我们提供的证据表明，目前基于交替丝状片层的这些结构模型是不正确的，Hirano 小体是由部分降解的粗面内质网或尼氏体衍生而来的膜结合核糖体颗粒堆叠片层。通过吖啶橙和溴化乙锭荧光染色，我们已表明这些小体含有 RNA。利用傅里叶技术对电子显微镜图像进行空间滤波显示，构成阵列的单个颗粒具有先前报道的真核核糖体大亚基的特征形状。这些核糖体颗粒在包涵体中的储存可能表明细胞中蛋白质合成处于静止状态。海马体中合成机制的这种退缩可能对短期记忆巩固为长期记忆的能力丧失产生重大影响。
