Kasa P, Papp H, Pakaski M
Alzheimer's Disease Research Centre, Department of Psychiatry, University of Szeged, Somogyi B. ut 4, H-6720, Szeged, Hungary.
Brain Res. 2001 Aug 3;909(1-2):159-69. doi: 10.1016/s0006-8993(01)02679-8.
The axonal transport of presenilin-1 was investigated in a spinal cord-sciatic nerve-neuromuscular junction model system in the rat. The technique of unilateral sciatic nerve ligation, using double ligatures, was combined with immunohistochemical staining and Western blotting to examine the axonal transport of the protein. Immunohistochemical studies involving the use of polyclonal antibodies for either the N-terminal or the C-terminal domain of presenilin-1 furnished evidence that both fragments may be present not only in the neuronal cell bodies, but also in the motoric and sensory axons and the motoric axon terminals at the neuromuscular junctions. After double ligation of the sciatic nerve for 6, 12 or 24 h, progressive immunostaining of presenilin-1 occurred above the upper ligature and to a lesser extent below the lower ligature. Double staining of the sciatic nerve for presenilin-1 and for amyloid precursor protein revealed overlapping immunoreactivity. Western blotting confirmed the accumulation of the approximately 20-kDa C-terminal and approximately 25-kDa N-terminal fragments and the full-length 45-kDa holoprotein of presenilin-1 both above and below the ligature. It is concluded that besides the larger amounts of C-terminal and N-terminal fragments, a smaller quantity of intact presenilin-1 may be present and conveyed bidirectionally in the sciatic nerve of the rat. These results lend further support to the suggestion that presenilin-1 may leave the trans-Golgi network and be found in the axons and axon terminals of the various neurons.
在大鼠的脊髓 - 坐骨神经 - 神经肌肉接头模型系统中研究了早老素 -1 的轴突运输。采用双侧结扎的单侧坐骨神经结扎技术，结合免疫组织化学染色和蛋白质印迹法来检测该蛋白的轴突运输。涉及使用早老素 -1 N 端或 C 端结构域的多克隆抗体的免疫组织化学研究提供了证据，表明这两个片段不仅可能存在于神经元细胞体中，还可能存在于运动和感觉轴突以及神经肌肉接头处的运动轴突终末中。在坐骨神经双侧结扎 6、12 或 24 小时后，早老素 -1 在上方结扎线以上逐渐出现免疫染色，在下方结扎线以下程度较轻。对坐骨神经进行早老素 -1 和淀粉样前体蛋白的双重染色显示出重叠的免疫反应性。蛋白质印迹法证实了在结扎线上下均存在约 20 kDa 的 C 端片段、约 25 kDa 的 N 端片段以及全长 45 kDa 的早老素 -1 全蛋白的积累。得出的结论是，除了大量的 C 端和 N 端片段外，大鼠坐骨神经中可能存在少量完整的早老素 -1 并进行双向运输。这些结果进一步支持了早老素 -1 可能离开反式高尔基体网络并存在于各种神经元的轴突和轴突终末中的观点。
