星型胶质细胞分泌的Hevin蛋白在神经病理性疼痛中的作用机制研究

Chronic neuropathic pain is a serious health problem and especially difficult to treat. It is generally believed that neuropathic pain is an expression of neural plasticity in primary sensory neurons (peripheral sensitization) and CNS (e.g., spinal cord dorsal horn) neurons (central sensitization). Recent progress in pain research field has also pointed to a central role for spinal cord microglia and astrocytes in neuropathic pain. Peripheral nerve injury induces robust spinal glial cells activation. Activated glial cells produce the proinflammatory cytokines and chemokines to facilitate spinal cord synaptic transmission and promote neuropathic pain. During development astrocytes promote synapse formation and regulate synaptic connectivity in the CNS through secreted signals, such as thrombospondin-4 (TSP4) and Hevin. After nerve injury TSP4 is mainly up-regulated in spinal astrocytes and contributes to the development of neuropathic pain. On the other hand, the role of astrocyte-secreted synaptogenic protein Hevin in chronic pain is unknown. In this study, we will test the hypothesis that spinal cord astrocytic Hevin contributes to the development and maintenance of neuropathic pain caused by peripheral nerve injury. Combined with the methods of electrophsciology, virus microinjection, immunohistrochemistry, pharmacology and behaviorology in wild-type and Hevin KO mice, we will investigate (1) the role of astrocytic Hevin in the transition from acute to chronic neuropathic pain,(2) the mechanism of hevin for enhancing the excitability of spinal cord sensory neurons,(3) the role of Hevin in microglial activation, (4) whether hevin–neutralizing antibody can reduce neuropathic pain? These proposed studies may not only reveal the role of astrocytes in neuropathic pain, but also provides new ideas and methods for the treatment of neuropathic pain.

慢性神经病理性疼痛是一种严重的健康问题，既是临床治疗的难点，也是疼痛研究的热点。外周神经损伤后可以激活脊髓小胶质细胞和星型胶质细胞，活化的胶质细胞释放的多种炎性趋化因子、细胞因子可以增强脊髓中间神经元的兴奋性,在神经病理性疼痛的产生和维持中发挥重要作用。本课题将对星型胶质细胞分泌的细胞外基质蛋白Hevin在神经病理性疼痛中的作用和机制开展研究。通过Hevin KO小鼠的行为学和电生理学分析，Hevin蛋白和抗体的体内外实验和以及病毒感染脊髓星型胶质细胞等方法，研究1）Hevin蛋白在神经损伤引发的急性痛转变为慢性痛的过程中起什么作用？2）Hevin增强脊髓感觉神经元兴奋性的机制是什么？3）Hevin对小胶质细胞活化的影响和机制？4）Hevin 抗体是否可以用来治疗神经病理性疼痛？该研究不仅有助于揭示星型胶质细胞在维持神经病理性疼痛中的作用，还将为治疗神经病理性疼痛提供新的思路和手段。

神经病理性痛是严重的健康问题。神经损伤后活化的胶质细胞参与神经元突触可塑性的改变，是神经病理性痛发生和维持的重要病理基础。本项目对星型胶质细胞分泌的细胞外基质蛋白Hevin在神经病理性疼痛中的作用和机制开展研究。通过Hevin KO小鼠的行为学和电生理学分析，Hevin蛋白和抗体的体内外实验和以及病毒感染脊髓星型胶质细胞等方法，研究了四个问题：1）Hevin蛋白在神经损伤引发的急性疼痛转变为慢性疼痛的过程中起什么作用？2）Hevin增强脊髓感觉神经元兴奋性的机制是什么？3）Hevin是否可以直接作用于小胶质细胞以及在小胶质细胞上引起何种变化？4）Hevin 抗体是否可以用来治疗神经病理性疼痛？现已如期完成所有研究计划，主要发现有1）确定了星型胶质细胞分泌的Hevin促进了神经病理性疼痛的发展，Hevin KO 小鼠的神经病理性疼痛病程明显缩短；2）Hevin通过增强NMDA受体介导的电流来增强脊髓感觉神经元兴奋性的突触传递；3）Hevin可以通过结合小胶质细胞的TLR4来参与神经病理性疼痛的维持。4）鞘内注射Hevin 抗体可以缓解神经病理性疼痛模型小鼠的机械过敏。已经完成合同规定的任务目标，主要成果包括：1）与本项目直接相关的研究成果发表在JCI Insight（中科院一区，IF 9.484），申请人是单独第一作者和共同通讯作者。另外申请人还以（共同）通讯作者发表基金号标注的SCI论文18篇，其中中科院一区论文3篇，中科院二区论文10篇，平均影响因子6.5575。2）以第一完成人获得高等学校科学研究优秀成果自然科学二等奖和江苏省科技进步三等奖。3）毕业硕士研究生5名，博士研究生1名；出站博士后1名。