NGF突变体在治疗糖尿病多发性神经病变中的作用及机制研究

Nerve growth factor (NGF) could be used for the treatment of diabetic peripheral neuropathy (DPN) and improve sensory neuropathy, but pain-inducing side effect greatly limits the clinical application of NGF. In our previous study, we found that a missense recessive mutation in NGF, NGFR100W, could promote the survival and differentiation of neurons, but doesn’t cause acute pain. And instead of p75NTR, the NGFR100W acting with TrkA is the potential mechanism underlying this function, suggesting NGFR100W could be used for the treatment of DPN. This project will establish NGFR100W gene knock-in mouse model and test whether it shows significant loss of perception to deep pain by kinds of methods; Y maze is used to detect the effect of NGFR100W on cognitive function; Western blot,immunofluorescence and qPCR are used to detect the effect of p75NTR and TrkA mediated signaling pathways on pain and cognitive function. Furthermore, the type I and type II diabetic DPN mouse model are treated with recombinant NGFR100W to verify the therapeutic effect and mechanism of NGFR100W for the treatment of DPN using ethological, histological and molecular biological methods. This study will.provide the theoretical basis for using NGFR100W to treat DPN and overcome pain-inducing side effects by NGF.

神经生长因子(NGF)可用于治疗糖尿病周围神经病变(DPN)，改善感觉神经病变症状，但其疼痛副作用极大限制了临床应用。我们前期研究发现，一种NGF错义隐性突变体NGFR100W不会引起急性疼痛感，且促进神经元存活和分化，机理可能是NGFR100W作用于TrkA，而不是p75NTR有关，由此推测NGFR100W可代替NGF用于治疗DPN。本项目将构建NGFR100W基因敲入小鼠模型，通过各种疼痛测试方法检测其是否出现深部痛觉的缺失，通过Y迷宫实验等检测对认知功能影响；通过Western blot、免疫荧光、qPCR等探讨在该模型中p75NTR和TrkA介导的信号通路对痛觉和认知功能的影响；进一步用重组NGFR100W处理I型和II型DPN小鼠模型，通过行为学、组织学、分子生物学等验证其作用效果和机理。本课题为NGFR100W用于治疗DPN等疾病，克服NGF引起的疼痛副作用提供理论基础。

神经生长因子(Nerve growth factor，NGF)是神经营养因子家族的重要成员，可促进神经功能发挥。在本课题研究中，我们构建了NGFR100W基因突变小鼠模型，探究NGF的促神经功能。研究发现NGFR100W突变基因小鼠出现疼痛功能的选择性丧失，并且发现该NGFR100W突变基因小鼠通过抑制NGF分泌，促进神经元显著丢失。另外，在NGFR100W突变体工作的基础上，我们进一步构建了外周神经损伤（PNI)大鼠模型，探究外源性补充NGF对神经损伤修复的影响。我们发现外源性补充NGF可通过调控p75NTR/AMPK/mTOR信号通路，增强SCs的自噬，从而促进SCs清除髓鞘碎片，最终促进PNI后神经修复。以上结果揭示了NGF不仅可调控外周神经疼痛感受功能，而且有利于促进PNI后的神经功能修复。