Shibata N, Hirano A, Kobayashi M, Dal Canto M C, Gurney M E, Komori T, Umahara T, Asayama K
Department of Pathology, Tokyo Women's Medical College, Japan.
Acta Neuropathol. 1998 Feb;95(2):136-42. doi: 10.1007/s004010050777.
This investigation deals with the immunocytochemical localization of Cu/Zn superoxide dismutase (SOD) in the spinal cord neurons of transgenic mice that overexpress Gly93Ala mutant human Cu/Zn SOD and demonstrate clinicopathological features similar to human amyotrophic lateral sclerosis (ALS) with Cu/Zn SOD mutation. At low magnification of light microscopy, the gray and white matter of the spinal cord of Gly93Ala mice showed more intense Cu/Zn SOD immunoreactivity than that of control mice. At higher magnification, the cytoplasm of control mice neurons displayed a distinct staining for Cu/Zn SOD, whereas the surrounding neuropil was only weakly stained. In contrast, the intensity of Cu/Zn SOD immunoreactivity in the cytoplasm of the majority of Gly93Ala mice neurons was similar to that in the neuropil. Almost all neuronal hyaline inclusions (NHIs) of Gly93Ala mice were positively immunostained by antibodies to Cu/Zn SOD, ubiquitin and phosphorylated neurofilament protein (NFP), the intensities of which were much higher in the NHIs than in the surrounding cytoplasm. In control mice, significant Cu/Zn SOD precipitation was not observed to be limited to any particular region of the neuronal cytoplasm. Intracytoplasmic vacuoles in the neuronal soma and processes of Gly93Ala mice were not stained by any of these antibodies. These results indicate that Cu/Zn SOD colocalizes with ubiquitin and phosphorylated NFP in NHIs of mice expressing mutant Cu/Zn SOD; similar findings have been shown for Lewy body-like inclusions of familial ALS patients with Cu/Zn SOD mutation. Moreover, our results point to the possibility that Cu/Zn SOD mutation may have a role in the abnormal Cu/Zn SOD accumulation in the NHIs, in association with motor neuron degeneration.
本研究探讨了在过度表达Gly93Ala突变型人铜锌超氧化物歧化酶（SOD）且表现出与铜锌SOD突变型人类肌萎缩侧索硬化症（ALS）相似临床病理特征的转基因小鼠脊髓神经元中铜锌超氧化物歧化酶（SOD）的免疫细胞化学定位。在光学显微镜低倍放大下，Gly93Ala小鼠脊髓的灰质和白质显示出比对照小鼠更强的铜锌SOD免疫反应性。在高倍放大下，对照小鼠神经元的细胞质对铜锌SOD呈现明显染色，而周围的神经纤维网仅呈弱阳性染色。相比之下，大多数Gly93Ala小鼠神经元细胞质中铜锌SOD免疫反应性的强度与神经纤维网中的相似。几乎所有Gly93Ala小鼠的神经元透明包涵体（NHIs）都被抗铜锌SOD、泛素和磷酸化神经丝蛋白（NFP）的抗体阳性免疫染色，其强度在NHIs中比周围细胞质中高得多。在对照小鼠中，未观察到明显的铜锌SOD沉淀局限于神经元细胞质的任何特定区域。Gly93Ala小鼠神经元胞体和突起中的胞质空泡未被这些抗体中的任何一种染色。这些结果表明，在表达突变型铜锌SOD的小鼠的NHIs中，铜锌SOD与泛素和磷酸化NFP共定位；对于患有铜锌SOD突变的家族性ALS患者的路易小体样包涵体也有类似发现。此外，我们的结果指出，铜锌SOD突变可能与运动神经元变性相关，在NHIs中异常铜锌SOD积累中起作用。
