He Qian-Ru, Cong Meng, Chen Qing-Zhong, Sheng Ya-Feng, Li Jian, Zhang Qi, Ding Fei, Gong Yan-Pei
Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China.
Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China.
Neural Regen Res. 2016 Dec;11(12):2025-2030. doi: 10.4103/1673-5374.197148.
The expression of nerve cell adhesion molecule L1 in the neuronal growth cone of the central nervous system is strongly associated with the direction of growth of the axon, but its role in the regeneration of the peripheral nerve is still unknown. This study explored the problem in a femoral nerve section model in rats. L1 and semaphorin 3A mRNA and protein expressions were measured over the 4-week recovery period. Quantitative polymerase chain reaction showed that nerve cell adhesion molecule L1 expression was higher in the sensory nerves than in motor nerves at 2 weeks after injury, but for the expression of semaphorin 3A. Western blot assay results demonstrated that nerve cell adhesion molecule L1 expression was higher in motor nerves than in the sensory nerves at the proximal end after injury, but its expression was greater in the sensory nerves at 2 weeks. Semaphorin 3A expression was higher in the motor nerves than in the sensory nerves at 3 days and 1 week after injury. Nerve cell adhesion molecule L1 and semaphorin 3A expressions at the distal end were higher in the motor nerves than in the sensory nerves at 3 days, 1 and 2 weeks. Immunohistochemical staining results showed that nerve cell adhesion molecule L1 expression at the proximal end was greater in the sensory nerves than in the motor nerves; semaphorin 3A expression was higher in the motor nerves than in the sensory nerves at 2 weeks after injury. Taken together, these results indicated that nerve cell adhesion molecules L1 and semaphorin 3A exhibited different expression patterns at the proximal and distal ends of sensory and motor nerves, and play a coordinating role in neural chemotaxis regeneration.
神经细胞黏附分子L1在中枢神经系统神经元生长锥中的表达与轴突生长方向密切相关，但其在周围神经再生中的作用尚不清楚。本研究在大鼠股神经切断模型中探讨了这一问题。在4周的恢复期内检测L1和信号素3A的mRNA和蛋白表达。定量聚合酶链反应显示，损伤后2周感觉神经中神经细胞黏附分子L1的表达高于运动神经，但信号素3A的表达情况则相反。蛋白质印迹分析结果表明，损伤后近端运动神经中神经细胞黏附分子L1的表达高于感觉神经，但其在2周时感觉神经中的表达更高。损伤后3天和1周，运动神经中信号素3A的表达高于感觉神经。损伤后3天、1周和2周，运动神经远端神经细胞黏附分子L1和信号素3A的表达高于感觉神经。免疫组织化学染色结果显示，近端感觉神经中神经细胞黏附分子L1的表达高于运动神经；损伤后2周，运动神经中信号素3A的表达高于感觉神经。综上所述，这些结果表明神经细胞黏附分子L1和信号素3A在感觉神经和运动神经的近端和远端呈现不同的表达模式，并在神经趋化性再生中发挥协同作用。
