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Invest Ophthalmol Vis Sci. 2020 Mar 9;61(3):15. doi: 10.1167/iovs.61.3.15.
To investigate whether the distribution of intermediate filament protein desmin is related to the different patterns of innervation in the human extraocular muscles (EOMs).
EOM samples were analyzed with immunohistochemistry using antibodies against desmin, vimentin, different myosin heavy chain (MyHC) isoforms, and fetal and adult acetylcholine receptor (AChR) subunits. Neuromuscular junctions (NMJs) were identified with α-bungarotoxin or with antibodies against neurofilament and synaptophysin.
Desmin was present in the vast majority of myofibers, but it was weakly present or absent in a limited area in the close vicinity of the single en plaque NMJs in less than half of these myofibers. Desmin was either present or lacking in MyHCsto/I myofibers displaying multiple en grappe endings but present in MyHCsto/I myofibers receiving spiral nerve endings. In MyHCeom myofibers displaying multiterminal en plaque endings, desmin was either present or absent irrespective of AChR subunits or EOM layer. Vimentin did not substitute for the lack of desmin.
The results indicate that the human EOMs have a more complex cytoskeletal organization than other muscles and suggest additional signalling mechanisms from the NMJs to the myofibers.
研究中间丝蛋白结蛋白的分布是否与人类眼外肌（EOM）不同的神经支配模式有关。
使用针对结蛋白、波形蛋白、不同肌球蛋白重链（MyHC）同工型以及胎儿和成人乙酰胆碱受体（AChR）亚基的抗体，通过免疫组织化学分析 EOM 样本。神经肌肉接头（NMJ）用α-银环蛇毒素或神经丝和突触素抗体来识别。
结蛋白存在于绝大多数肌纤维中，但在不到一半的这些肌纤维中，靠近单个斑块 NMJ 的附近有限区域内，结蛋白的存在较弱或缺失。结蛋白存在或缺失于显示多个 en grappe 末端的 MyHCsto/I 肌纤维中，但存在于接收螺旋神经末梢的 MyHCsto/I 肌纤维中。在显示多末端斑块 NMJ 的 MyHCeom 肌纤维中，结蛋白的存在或缺失与 AChR 亚基或 EOM 层无关。波形蛋白不能替代结蛋白的缺乏。
这些结果表明，人类 EOMs 的细胞骨架组织比其他肌肉更为复杂，并提示 NMJ 向肌纤维发出额外的信号转导机制。
