局部释放夫拉平度调控局部星形胶质细胞和炎症反应促进脊髓损伤修复

发布时间：2018-05-10 07:35

本文选题：脊髓损伤 + 纳米微球　；参考：《浙江大学》2017年博士论文

【摘要】：脊髓损伤(SCI)是最具毁灭性的创伤之一,目前的处理获得功能恢复非常有限。SCI给每一位患者的家庭和社会都带来了沉重的负担,探寻其疗法非常重要。SCI后,损伤局部遭受严重的炎症反应。炎症因子与SCI修复密切相关,其中许多因子已被证明可以直接促进或者抑制SCI修复。大鼠SCI之后局部炎症因子蛋白水平的程序性变化却并未得到解析。故我们在第一章以大鼠为模型研究损伤脊髓局部微环境的炎症因子程序性变化。我们发现大鼠SCI后7个可能利于和11个可能阻碍SCI修复的炎症因子在损伤后有差异性的变化。其中,4个利于SCI修复的炎症因子水平在损伤后下降,9个阻碍SCI修复的炎症因子水平在损伤后升高。这为后期临床前研究中针对SCI药物筛查,和临床上的治疗和预后提供了基础生物学数据。SCI后细胞周期病理性激活,不仅导致神经元和少突胶质细胞死亡,且引起小胶质细胞、星形胶质细胞及其前体细胞的增殖和激活。有研究发现,夫拉平度在大鼠SCI后减少病灶体积和星形胶质细胞的增殖,降低神经元和少突胶质细胞的凋亡,促进了运动功能的恢复。而星形胶质细胞是重要的炎症因子来源。故第二章探究夫拉平度是否能够抑制星形胶质细胞炎症因子的合成。我们发现,夫拉平度抑制星形胶质细胞的炎症因子合成、增殖和划痕愈合,且不影响神经元的存活,提示其很可能可以促进SCI修复。在SCI研究中,夫拉平度现有的两种给药方式都有缺憾:全身性高剂量给药有副作用;缓释微泵鞘内给药成本较高,且有组织相容性风险。有研究在大鼠SCI中发现,甲强龙PLGA纳米微球局部给药比全身性给药更有效。故我们在第三章制作夫拉平度PLGA微球局部缓释制剂,并研究其对SCI修复的效果。结果表明,合成的夫拉平度微球有长达三天的缓释。夫拉平度微球明显减少了星形胶质细胞的促炎因子合成,同时提高了 IL-10合成。在体内,夫拉平度微球减少了星形胶质细胞、神经元和巨噬细胞的细胞周期相关蛋白的表达,提高了脊髓大体组织结构的完整性,降低了胶质瘢痕和脊髓空洞形成,同时促进了神经的存活和再生。夫拉平度微球在损伤点提高了 GM-CSF蛋白水平,降低了 IP-10水平。最终,夫拉平度微球也促进了 SCI大鼠的运动功能恢复。总之,通过PLGA微球局部释放夫拉平度通过调控局部星形胶质细胞和炎症反应促进了脊髓损伤的修复。我们的研究展示了通过PLGA微球局部缓释夫拉平度的方法,提示SCI后促进功能恢复的潜在临床应用前景。
[Abstract]:Sci (spinal cord injury) is one of the most devastating injuries. The recovery of the current treatment is very limited. Sci imposes a heavy burden on the family and society of every patient. After exploring the treatment of sci, it is very important. The local injury suffers from severe inflammatory reactions. Inflammatory factors are closely related to SCI repair, many of which have been shown to directly promote or inhibit SCI repair. The procedural changes in local inflammatory factor protein levels after SCI in rats were not analyzed. In Chapter 1, we used the rat model to study the programmed changes of inflammatory cytokines in the local microenvironment of spinal cord injury. We found that there were different changes in 7 and 11 inflammatory factors after SCI. Four of the inflammatory cytokines that were conducive to SCI repair decreased after injury, and 9 that hindered SCI repair increased after injury. This provides basic biological data for the screening of SCI drugs, clinical treatment and prognosis in the later preclinical study. The pathological activation of cell cycle after sci not only leads to the death of neurons and oligodendrocytes, but also to microglia. Proliferation and activation of astrocytes and their precursors. It has been found that fluapine reduces the volume of focus and the proliferation of astrocytes and the apoptosis of neurons and oligodendrocytes after SCI in rats and promotes the recovery of motor function. Astrocytes are an important source of inflammatory cytokines. The second chapter is to investigate whether Flappine can inhibit the synthesis of astrocytic inflammatory factors. We found that flapidium inhibits the synthesis of inflammatory cytokines proliferation and scratch healing of astrocytes and does not affect the survival of neurons suggesting that it may promote SCI repair. In the SCI study, there are two existing methods of administration of Fraphidu: systemic high dose administration has side effects, and sustained release micropump intrathecal delivery cost is high, and there is a risk of histocompatibility. Some studies have found that methylenolone PLGA nanoparticles are more effective in local administration than systemic administration in rat SCI. Therefore, in chapter 3, we prepared the local sustained release preparation of PLGA microspheres, and studied its effect on SCI repair. The results showed that the synthesized microspheres had sustained release for up to three days. Flampindu microspheres significantly reduced the pro-inflammatory factor synthesis of astrocytes and increased IL-10 synthesis. In vivo, Flampindu microspheres reduced the expression of cell cycle related proteins in astrocytes, neurons and macrophages, increased the integrity of the gross structure of the spinal cord, and reduced the formation of glial scars and syringomyelia. It also promotes nerve survival and regeneration. The level of GM-CSF protein was increased and the level of IP-10 was decreased at the point of injury. In the end, the flattened microspheres also promoted the recovery of motor function in SCI rats. In conclusion, the local release of flapidium through PLGA microspheres promotes the repair of spinal cord injury by regulating local astrocytes and inflammatory responses. Our study demonstrated the method of local sustained release of PLGA microspheres and suggested the potential clinical application of promoting functional recovery after SCI.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R651.2

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