Amyotrophic lateral sclerosis : on the decreased transcription activity of ribosomal RNA gene and cell degeneration

本文观察了肌萎缩侧索硬化（ALS）患者前角细胞粗面内质网、分子伴侣和高尔基体等蛋白质合成系统的形态学改变，以及核糖体（r）RNA基因转录活性的变化。本研究阐明了运动神经元损伤后rRNA基因转录活性迅速降低，导致胞质rRNA含量减少。ALS患者前角细胞内分子伴侣KDEL的定位变化早于高尔基体的断裂和尼氏物质的减少。肌萎缩侧索硬化前角细胞rER池不规则扩张，池上附着的核糖体数量减少。因此，ALS患者前角细胞的蛋白质合成系统由上游向下游退化。

Morphological changes of the protein synthesizing system including rough ER, molecular chaperon and Golgi apparatus, and transcription activity of ribosomal (r) RNA gene in the anterior horn cells of the patients with amyotrophic lateral sclerosis (ALS) were examined. The present research elucidated that the activity of the transcription of rRNA gene reduced very quickly after insults on the motor neurons, which induced decrease of cytoplasmic rRNA. Localization of molecular chaperon, KDEL, changed earlier than the fragmentation of the Golgi apparatus and decrease of Nissl substance in the anterior horn cells of the patients with ALS. The cisterns of the rER of the anterior horn cells of ALS were dilated irregularly, and the number of the attached ribosomes on the cistern decreased. Thus the protein synthesizing system in the anterior horn cells in ALS patients degenerated from upper stream to downstream.