阻断血小板激活因子信号通路对脊髓损伤后反应性胶质增生和神经功能恢复影响的研究

发布时间：2018-04-21 21:40

  本文选题：胶质瘢痕 + 星形胶质细胞　； 参考：《吉林大学》2015年博士论文

【摘要】：背景： 反应性胶质增生，亦称为胶质瘢痕形成，是中枢神经系统在受到损伤后继发的一种特殊的细胞反应。此病理过程的主要参与者包括激活的星形胶质细胞，激活的小胶质细胞和细胞外间质成分。在中枢神经损伤发生后，损伤急性期炎症反应所生成的化学因子和细胞因子通过血-脑屏障或血-脊髓屏障进入神经系统，先后将小胶质细胞和星形胶质细胞激活，最终导致胶质增生的发生。在此过程中生成的胶质瘢痕一方面可以局限炎症反应的范围，支持损伤组织，减轻细胞毒性反应；另一方面它却可以阻碍神经再生和神经髓鞘再生。但是，激活反应先行胶质增生的机制目前尚不明确。血小板激活因子（PAF）是一种内源性磷脂多能性介质，它在免疫系统和神经系统中都发挥着重要作用。一方面它可以维持细胞的正常生理活动，另一方面它可以造成病理反应。研究已经证明过量表达的PAF与许多中枢神经系统的疾病都有关系，而应用PAF拮抗剂可以缓解一部分神经系统疾病的症状。在本研究中我们假设PAF信号通路可以在脊髓损伤后启动反应性胶质增生，而阻断PAF信号通路则可以抑制胶质瘢痕形成，改善损伤后神经功能恢复情况。 研究目的： 通过实验探究阻断PAF信号通路对小鼠脊髓损伤后反应性胶质增生和神经功能恢复的影响。 实验方法： 测量体重、行为学等指标证明WT和PAFR敲除小鼠在大体发育上没有显著差异；用免疫荧光染色和Western Blot观察WT和PAFR敲除小鼠的脊髓族中内星形胶质细胞和小胶质细胞的含量与分布；在WT小鼠脊髓中注射外源性PAF观察PAF对星形胶质细胞及小胶质细胞增殖、激活的影响；用Rotarod test和Griptest等行为学实验测量脊髓损伤的PAFR敲除小鼠在损伤后特定时间点的神经功能恢复情况；用Western Blot和免疫荧光染色测量和观察脊髓损伤后PAFR敲除小鼠脊髓组织内各种细胞因子如白细胞介素-6、特定蛋白与中间丝蛋白如GFAP的表达量和分布情况，从而说明小胶质细胞和星形胶质细胞在脊髓受损伤后的激活情况；用免疫荧光染色观察脊髓损伤之后小鼠的神经轴突脱髓鞘/再生的情况；用行为学实验测量对WT损伤小鼠系统性地使用PAFR拮抗剂治疗后小鼠神经功能恢复情况。 结果： （a）小胶质细胞和星形胶质细胞可以被外源性PAF剂量依赖性激活；（b）在脊髓损伤后，，PAFR敲除小鼠的神经功能恢复要显著优于WT小鼠；（c）虽然在脊髓损伤后PAFR敲除小鼠和WT小鼠的小胶质细胞和星形胶质细胞都被激活，但是PAFR敲除小鼠脊髓组织中IL-6，GFAP，波形蛋白和硫酸软骨蛋白多糖（CSPGs）表达量并未显著升高；（d）PAFR小鼠在脊髓损伤后轴突回缩更少；（e）就与对照组比较而言，在亚急性期和慢性期接受PAF拮抗剂治疗的WT小鼠的功能恢复程度与在急性期接受治疗的WT小鼠的恢复程度相比显著提高。 结论： PAF信号通路参与脊髓损伤后反应性胶质增生的激活；阻断此信号通路可以改善损伤后的功能恢复还可以在一定程度上促进神经再生。
[Abstract]:Background:
Reactive gliosis, also known as glial scar formation, is a special cell response to the central nervous system secondary to injury. The main participants in this pathological process include activated astrocytes, activated microglia and extracellular matrix. After the armature injury of the middle armature, the acute inflammatory reaction is damaged. The chemical and cytokine generated by the formation of the blood brain barrier or the blood spinal cord barrier enter the nervous system and activate the microglia and astrocytes successively and eventually lead to the occurrence of glial proliferation. In this process, the formation of glial scar can limit the scope of the inflammatory reaction, support the damaged tissue, and reduce the cytotoxicity. Sexual reaction; on the other hand, it can impede nerve regeneration and regeneration of the myelin sheath. However, the mechanism that activates the activation of glial proliferation is not yet clear. Platelet activating factor (PAF) is an endogenous phospholipid pluripotent medium, which plays an important role in both the immune system and the nervous system. On the one hand, it can maintain cells. The normal physiological activity, on the other hand, can cause a pathological response. Studies have shown that excessive expression of PAF is associated with many diseases in the central nervous system, and the application of PAF antagonists can relieve some of the symptoms of a nervous system disease. In this study, we hypothesized that the PAF signal pathway could initiate reactivity after spinal cord injury. Glial hyperplasia, and blocking the PAF signaling pathway can inhibit glial scar formation and improve the recovery of nerve function after injury.
The purpose of the study is:
To explore the effects of blocking PAF signaling pathway on reactive gliosis and neurological function recovery after spinal cord injury in mice.
Experimental methods:
Measurement of weight, behavior and other indicators showed that there was no significant difference in the gross development of WT and PAFR knockout mice; the content and distribution of astrocytes and microglia in the spinal cord of WT and PAFR knockout mice were observed by immunofluorescence staining and Western Blot, and the exogenous PAF was injected into the astrocytes in the spinal cord of WT mice to observe the astrocytes. The effects of proliferation and activation of cells and microglia; measurement of neural function recovery at specific time points after injury in PAFR knockout mice with spinal cord injury by Rotarod test and Griptest; and Western Blot and immunofluorescence staining to measure and observe all kinds of cell causes in the spinal cord tissue of PAFR knockout mice after spinal cord injury. The expression and distribution of interleukin -6, specific protein and intermediate silk protein, such as GFAP, were used to demonstrate the activation of microglia and astrocytes after the injury of the spinal cord. Immunofluorescence staining was used to observe the demyelination / regeneration of the axon after spinal cord injury, and the behavior test was used to measure WT. The injured mice were systematically treated with PAFR antagonist to restore neurological function.
Result锛

本文编号：1784203