Multipronged approach to promote functional axonal regeneration in the spinal cord after injury

项目总结 成熟的中枢神经系统损伤后缺乏成功的再生是由于固有的和 环境障碍。尽管在这一领域取得了进展，但克服这些障碍将导致 强健的功能性轴突再生和恢复仍然是一个巨大的挑战。我们以初步数据为基础 并假设损伤后反复出现的DREADD介导的神经元激活是增强 功能性轴突再生。此外，我们将检验神经元激活增加轴突的假设。 通过激活mTOR和增加动态微管来再生。我们将把我们的假设 用成年背根神经节神经元体外培养和活体背根压碎、背柱 脊髓损伤(SCI)/周围神经移植(PNG)，以及不完全颈髓损伤/PNG模型。在目标1中，我们 将阐明重复的、化学生成的神经元激活如何促进轴突再生。在目标2中，我们将 评估神经元激活--单独或与增加动态微管的手法联合使用 和mTOR激活-促进功能性轴突再生。总而言之，我们将：1)阐明机制 神经元激活如何促进生长的背后，潜在地确定新的治疗靶点；2)确定 在不同的损伤模型(背根挤压，SCI)中神经元激活促进再生的程度； 3)确定神经元激活在不同的神经元群体中是否具有不同或相似的影响(DRG与 中枢神经系统)；4)测试是否使用独特的、多方面的方法促进有意义的轴突再生 A)使用化学生成神经元激活--可能伴随着动态微管的进一步增加 和/或mTOR激活-增强轴突生长反应；b)提供更多的生长许可 损伤后的环境(即用软骨素酶减轻胶质瘢痕的抑制基质； 将PNG移植到脊髓损伤腔内；软骨素酶消化限制可塑性的神经周网络)。 在这些实验完成后，我们将找到新的治疗途径来促进功能 脊髓损伤后修复。

PROJECT SUMMARY The lack of successful regeneration after injury in the mature central nervous system is due to intrinsic and environmental obstacles. Though progress in the field has been made, overcoming these barriers to result in robust functional axon regeneration and recovery is still a significant challenge. We build upon preliminary data and hypothesize that recurrent DREADD-mediated neuronal activation after injury is a means to enhance functional axon regeneration. Additionally, we will test the hypothesis that neuronal activation increases axon regeneration via both mTOR activation and increasing dynamic microtubules. We will these our hypotheses both in vitro using adult dorsal root ganglion neuron cultures and in vivo using dorsal root crush, dorsal columns spinal cord injury (SCI)/peripheral nerve graft (PNG), and incomplete cervical SCI/PNG models. In Aim 1, we will elucidate how repeated, chemogenetic neuronal activation enhances axon regeneration. In Aim 2, we will assess if neuronal activation – alone or in combination with manipulations that increase dynamic microtubules and mTOR activation – promotes functional axon regeneration. Collectively, we will: 1) elucidate mechanisms behind how neuronal activation enhances growth, potentially identifying new therapeutic targets; 2) determine the extent to which neuronal activation enhances regeneration in different injury models (dorsal root crush, SCI); 3) determine if neuronal activation has disparate or similar effects in different populations of neurons (DRG vs. CNS); 4) test whether meaningful axonal regeneration is facilitated using a unique, multi-faceted approach that: a) uses chemogenetic neuronal activation – possibly along with further increasing dynamic microtubules and/or mTOR activation – to enhance the axonal growth response; b) provides a more growth-permissive environment after an injury (i.e. mitigation of the inhibitory matrix of the glial scar with chondroitinase; transplantation of a PNG into an SCI cavity; chondroitinase digestion of plasticity-limiting perineuronal nets). After the completion of these experiments, we will have identified novel therapeutic avenues to foster functional repair after SCI.