孤束核在内毒素致大鼠炎症中的作用及其机制研究

发布时间：2018-08-15 18:53

【摘要】：炎症是临床常见的一个病理过程，可以生于机体各部位的组织和各器官，例如毛囊炎、扁桃体炎、肺炎、肝炎、肾炎等。急性炎症平时具有红、肿、热、痛、机能掩藏等变化。这些变化实质上是机体与致炎因子进行抗争的结果。这种抗争始终存在在炎症过程。致炎因子，一方面引发组织细胞的损坏，使局部组织细胞变性、坏死；另一方面，诱导增加机体抗病机能，促进致炎因子的清除，修复受损的组织，从而使内环境和外环境之间以及机体的内环境达到新的均衡。但是，当炎症反应过于激烈的时候反而会对机体产生伤害。许多慢性病如类风湿性关节炎、克隆氏病等都与不当的炎症反应有关。新近发现的胆碱能抗炎通路（cholinergic anti-inflammatory pathway）可以有效减少多种促炎因子的释放，对全身和局部炎症均具有明显的抑制作用。胆碱能抗炎症通路是当发生炎症反应时，在炎症部位的炎症信息会通过迷走神经及其递质乙酰胆碱（Acetylcholine,Ach）与免疫系统相互作用，从而完成抗炎作用。迷走传出神经及其递质Ach参与了抗炎反应，表明炎症反应中迷走传出神经位于迷走神经背核（DMV）内的节前神经元被激活，而迷走背核、孤束核和最后区这三个核团在解剖学中位置相邻,功能相关性较大,且之间具有密切的纤维联系,所以将它们合称为迷走复合体(DVC)。周围免疫信息可通过两种途径传达到脑，一是血液中的细胞因子通过缺乏血脑屏障的最后区（AP）入脑，由AP直接传递至DMV,或由AP经孤束核（NTS）间接传递至DMV[1]。二为细胞因子通过迷走传入神经将炎症信息传至NTS,由NTS传到DMV[2]。我们实验室前期工作发现内毒素炎症大鼠脑干DMV、AP和NTS的c-Fos表达均显著增强，表明AP和NTS参与了炎症反应。胆碱能抗炎通路中炎症信号主要是通过缺乏血脑屏障的AP入脑还是通过迷走传入神经传至NTS或两者兼之，还不明确。G. E. Hermann等大鼠注射LPS致炎后，右侧NTS、DMV的c-Fos表达要显著高于左侧。SimonsCT等的研究发现外周炎症信息主要通过左侧迷走神经传入NTS。这些结果提示神经系统对炎症的调节是否存在一侧优势，那么，左右两侧NTS对炎症反应是否存在着差异，相关研究尚未见报道。已有发现，NTS内观察到大量的pERK样免疫反应阳性神经元，ERK1/2通路在内脏感觉、运动的信号转导过程中都发挥了重要作用，但对孤束核内ERK1/2通路在炎症反应中是否活化而影响炎症反应还未见报道。因此，本文采用内毒素炎症模型，分别利用电生理技术和免疫组化方法记录迷走神经放电和DMV、AP神经元的c-Fos表达，探讨NTS在在炎症反应中的作用及DMV、NTS和AP在炎症反应的相关性，以进一步探究DMV、NTS和AP在胆碱能抗炎通路中所起的作用。本研究分为三部分：第一部分，损毁双侧NTS后观察内毒素炎症模型中，大鼠肿瘤坏死因子（TNF-α）水平、白细胞数目、迷走神经放电，动脉血压以及DMV和AP内c-Fos的表达情况。实验分为三组：假损毁双侧NTS+LPS组、损毁双侧NTS+LPS组以及损毁双侧NTS+生理盐水组。结果与讨论：损毁双侧+LPS组和损毁双侧+生理盐水组相比，TNF-α水平显著升高，AP和DMV的c-Fos表达均增强，但差异不显著，说明注射LPS引起了大鼠的炎症反应；损毁双侧+LPS组和假损毁双侧+LPS组相比，TNF-α水平显著升高，AP和DMV的c-Fos表达量减少，但差异不显著，说明NTS参与了抗炎症反应。第二部分，分别损毁左、右两侧NTS后，再注射LPS致炎，观察大鼠肿瘤坏死因子（TNF-α）水平、白细胞个数、迷走神经放电、动脉血压以及DMV和AP内C-Fos的表达情况。实验分为四组：损毁左侧+LPS组、假损毁左侧+LPS组、损毁右侧+LPS组以及假损毁右侧+LPS组。结果与讨论：损毁左侧+LPS组和假损毁左侧+LPS组相比，TNF-α水平显著升高，，差异极显著，DMV的c-Fos表达量显著降低。损毁右侧+LPS组和假损毁右侧+LPS组相比，TNF-α水平无明显变化，DMV的c-Fos表达量显著升高，说明左、右侧NTS在抗炎症反应中作用不同。左侧NTS参与抗炎症反应，而右侧NTS可能对炎症反应作用较小。第三部分，观察PD98059对LPS致大鼠炎症AP和DMV内c-Fos表达的影响。实验分为两组：注射PD98059+LPS组和注射生理盐水+LPS组。结果与讨论：注射PD98059以后，DMV的c-Fos表达量显著减少，这说明了NTS内ERK1/2通路参与了炎症反应，也进一步表明NTS参与了将炎症信息传至DMV的过程。
[Abstract]:Inflammation is a common clinical pathological process, which can be produced in various parts of the body and organs, such as folliculitis, tonsillitis, pneumonia, hepatitis, nephritis and so on. Acute inflammation usually has red, swollen, hot, painful, functional concealment and other changes. These changes are essentially the result of the body's struggle with inflammatory factors. Inflammatory factors, on the one hand, cause damage to tissues and cells, causing degeneration and necrosis of local tissues and cells; on the other hand, induce and increase the body's anti-disease function, promote the clearance of inflammatory factors, repair damaged tissues, so as to achieve a new balance between the internal and external environment and the internal environment of the body. Many chronic diseases such as rheumatoid arthritis and Crohn's disease are associated with inappropriate inflammation.
The recently discovered cholinergic anti-inflammatory pathway can effectively reduce the release of a variety of pro-inflammatory factors and significantly inhibit systemic and local inflammation. Acetylcholine (Ach) interacts with the immune system to complete the anti-inflammatory effect. Vagus efferent nerve and its transmitter Ach participate in the anti-inflammatory response, indicating that the presegmental neurons located in the dorsal vagal nucleus (DMV) are activated in the inflammatory response, while the three nuclei of the dorsal vagal nucleus, the nucleus tractus solitarius and the final region are anatomically activated. Peripheral immune information can be transmitted to the brain in two ways: one is that cytokines in the blood enter the brain through the last area (AP), which lacks the blood-brain barrier, and are transmitted directly from AP to DMV, or from AP through the nucleus tractus solitarius (NTS). We found that the expression of DMV, AP and C-Fos in the brain stem of endotoxin-induced inflammation rats were significantly increased, suggesting that AP and NTS were involved in the inflammatory response. It is not clear whether AP with blood-brain barrier enters the brain through the vagal afferent nerve to NTS or both. The expression of c-Fos in the right NTS and DMV is significantly higher than that in the left after LPS injection in rats such as G.E. Hermann. SimonsCT and other studies have found that peripheral inflammation information mainly enters NTS through the left vagal nerve. It has been found that a large number of pERK-like immunoreactive neurons have been observed in NTS, and ERK1/2 pathway plays an important role in the signal transduction of visceral sensation and movement, but it is not found in the solitary tract. The activation of ERK1/2 pathway in the nucleus has not been reported to affect the inflammatory response. In this study, endotoxin inflammation model was used to record the vagal discharge and the expression of c-Fos in DMV and AP neurons by electrophysiological and immunohistochemical methods, respectively, to explore the role of NTS in the inflammatory response and the role of DMV, NTS and AP in the inflammatory reaction. The correlation should be further explored to explore the role of DMV, NTS and AP in cholinergic anti-inflammatory pathway.
This study is divided into three parts.
The first part was to observe the levels of tumor necrosis factor-alpha (TNF-alpha), white blood cell count, vagal discharge, arterial blood pressure and the expression of c-Fos in DMV and AP in the endotoxin inflammation model of rats after bilateral NTS lesion. The experiment was divided into three groups: sham lesion of bilateral NTS+LPS group, lesion of bilateral NTS+LPS group and lesion of bilateral NTS+normal saline group. Compared with bilateral + LPS group and bilateral + normal saline group, the levels of TNF-alpha increased significantly, while the expression of c-Fos of AP and DMV increased, but the difference was not significant, indicating that LPS injection induced inflammation in rats; the levels of TNF-alpha increased significantly, and the expression of c-Fos of AP and DMV decreased compared with bilateral + LPS group and sham + LPS group. Less, but the difference is not significant, indicating that NTS is involved in the anti-inflammatory response.
The second part was to observe the levels of tumor necrosis factor-alpha (TNF-alpha), the number of white blood cells, vagal discharges, arterial blood pressure and the expression of C-Fos in DMV and AP. The experiment was divided into four groups: left + LPS group, left + LPS group, right + LPS group and right + LPS group. RESULTS AND DISCUSSION: Compared with the left + LPS group and the false + LPS group, the levels of TNF-alpha were significantly increased, and the expression of c-Fos in DMV was significantly decreased. The levels of TNF-alpha in the right + LPS group and the false + LPS group were not significantly changed, and the expression of c-Fos in DMV was significantly increased, suggesting that NTS in the left and right sides was anti-inflammatory. The left NTS is involved in the anti-inflammatory response, while the right NTS may have less effect on the inflammatory response.
In the third part, the effects of PD98059 on the expression of c-Fos in LPS-induced inflammatory AP and DMV were observed. The experiment was divided into two groups: PD98059+LPS injection group and normal saline+LPS injection group. The process of transmitting inflammatory information to DMV.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R363

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