人发角蛋白神经导管诱导兔胫神经修复时NGF和p75的表达及分布

目的研究人发角蛋白(HHK)神经导管诱导兔胫神经缺损再生修复时神经生长因子(NGF)及其低亲和受体p75的表达及分布。方法取正常胫神经、缝线连接的胫神经和HHK导管桥接的胫神经术后不同时期的切口部位及相邻组织制作石蜡切片,用免疫组化法对切片进行染色。结果正常胫神经组织中无NGF阳性染色。术后76 d,HHK周围的新生组织中NGF免疫组化染色表现为强阳性,而缝线周围的组织中无阳性着色。术后100 d,与正常胫神经组织无显著差异。正常胫神经组织中无p75阳性染色。术后76 d,导管组HHK周围较成熟的神经组织中p75免疫组化染色为弱阳性,而新生组织中为强阳性。术后100 d,导管组的p75免疫组化染色与正常神经组织无显著差别。结论HHK及其降解产物能诱导NGF和p75的产生,为神经再生创造良好的微环境;而缝线无此诱导作用。在新生神经组织中NGF和p75含量多,较成熟的神经组织中含量少。

Expression and distribution of NGF and p75 during rabbit tibial nerve repair induced by human hair keratin conduits

Objective To study the expression and distribution of nerve growth factor (NGF) and low-affinity neurophin re-ceptor p75 during human hair keratin conduit-induced repair of rabbit tibial nerves. Methods Rabbit tibial nerves were tran-sected and connected by either routine suture or by conduits made of human hair keratin (HHK), and after different time peri-ods, paraffin-embedded sections of the nerve tissue at the damaged sites and the adjacent tissues, with normal rabbit tibial nerve sections as control, were prepared for immunohistochemistry. Results No positive NGF staining was observed in nor-mal tibial nerve tissues, but 76 days after the surgery, strong NGF positivity was detected in the newly generated nerve tissue around the HHK implants until 100 days after the surgery, which was absent in the tissues around the suture. As for p75, there was no positive staining observed in normal tibial nerve tissue. Light positive p75 staining was found in the mature nerve tis-sues around the HHK implants, where the newly generated tissues were strongly p75-positive during the period between 76-and loo-days after surgery. Conclusions HHK and its degenerative product, but not routine suture, can induce the produc-tion of NGF and p75 to create a favorable micro-environment for nerve regeneration. More NGF and p75 are produced in newly generated neurons than in mature ones.