Yin Q, Kemp G J, Yu L G, Wagstaff S C, Frostick S P
Department of Musculoskeletal Science, University of Liverpool, UK.
Neuroscience. 2001;105(3):779-83. doi: 10.1016/s0306-4522(01)00216-0.
Neurotrophin-4 acts as a potent survival factor for subpopulations of motoneurons. To investigate its effect on Schwann cell sheath and axonal proteins during peripheral nerve regeneration, sciatic nerves in adult rats were transected and repaired, and fibrin glue containing neurotrophin-4 injected around the repair site. At 5, 15, 30 and 60 days after repair, 5-mm nerve segments distal to the repair were collected, and western blotting was used to measure myelin-associated glycoprotein, myelin basic protein and low-molecular-weight neurofilament protein. In control groups these dramatically declined at 5 and 15 days then increased from 30 and 60 days. However, in the neurotrophin-4 group there was a significant increase (to several times basal values) in myelin-associated glycoprotein and myelin basic protein at 5-15 days. The relatively small increases (<7%) in Schwann cell numbers suggest that this is mainly due to increased synthesis per cell. The neurotrophin-4 group also showed a small but significant increase at 15 days in low-molecular-weight neurofilament protein, which however remained much lower than basal. We conclude that neurotrophin-4 regulates the expression of myelin-associated glycoprotein, myelin basic protein, and to a lesser extent low-molecular-weight neurofilament protein, during peripheral nerve regeneration.
神经营养因子-4作为运动神经元亚群的一种强效存活因子。为了研究其在周围神经再生过程中对雪旺细胞鞘和轴突蛋白的影响，将成年大鼠的坐骨神经切断并修复，并在修复部位周围注射含神经营养因子-4的纤维蛋白胶。在修复后5、15、30和60天，收集修复部位远端5毫米的神经节段，并用蛋白质印迹法检测髓鞘相关糖蛋白、髓鞘碱性蛋白和低分子量神经丝蛋白。在对照组中，这些蛋白在5天和15天时急剧下降，然后从30天和60天开始增加。然而，在神经营养因子-4组中，髓鞘相关糖蛋白和髓鞘碱性蛋白在5至15天时显著增加（达到基础值的数倍）。雪旺细胞数量相对较小的增加（<7%）表明，这主要是由于每个细胞合成增加所致。神经营养因子-4组在15天时低分子量神经丝蛋白也有小幅但显著的增加，然而仍远低于基础水平。我们得出结论，神经营养因子-4在周围神经再生过程中调节髓鞘相关糖蛋白、髓鞘碱性蛋白的表达，并在较小程度上调节低分子量神经丝蛋白的表达。
