TLR2在比格犬慢性缺血性脑白质脱髓鞘中的表达研究

发布时间：2018-01-19 14:45

本文关键词： TLR2 脑白质脱髓鞘慢性脑缺血少突胶质前体细胞少突胶质细胞　出处：《西南医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的:研究TLR2蛋白在慢性缺血性脑白质脱髓鞘病变中的表达情况及探讨TLR2蛋白是否参与缺血性脑白质脱髓鞘病变及可能的参与机制。方法:将16只成年比格犬按照随机化原则分为假手术组(A组)和实验组,其中实验组使用血管结扎法制作成比格犬脑缺血动脉模型,依据脑缺血轻中重不同程度分为B组、C组、D组。选取实验动物双侧侧脑室边缘部位脑白质作为检测标本,采用HE染色和LFB染色法分别观察各组脑白质的病理变化和标准化评分后比较各组脑白质脱髓鞘病变程度。使用免疫组化方法检测标本中TLR2、NG2、CNPase表达水平情况。采用Spearman秩相关分析法分析TLR2与CNPase之间的相关性。结果:(1)HE染色中假手术组脑白质染色均匀,细胞形态正常,无脱髓鞘改变;实验B、C、D组可见不同程度的神经纤维排列紊乱,细胞肿胀、核固缩。LFB染色后可见假手术组髓鞘形态正常,染色均匀;实验组见明显脱髓鞘改变:B组脑白质脱髓鞘病变相对较轻,表现髓鞘形态紊乱,染色不均;C组可见髓鞘肿胀、断裂,有明显的液泡形成;D组脑白质脱髓鞘病变最为严重,可见有髓纤维消失,脂质空泡形成,不显色。(2)采用Hideaki标准化评分评估脱髓鞘病变程度。其中假手术组为0.63±0.52分值最低,其次实验B组的分值为1.25±0.46和实验C组的分值为1.63±0.52,实验组D为1.88±0.64分值最高。假手术组与实验B组、C组和D组比较差异均具有统计学意义(P0.05)。(3)免疫组化检测显示:1)TLR2蛋白表达水平情况:在假手术组为0.148±0.058表达水平最低,而实验B组为0.185±0.023、实验C组为0.185±0.025和实验D组为0.191±0.016表达水平最高。与假手术组相比,实验B、C、D组TLR2蛋白表达水平明显增高且两者比较差异具有统计学意义(P0.05)。2)NG2表达情况:在假手术组为0.147±0.021表达水平最低,在实验B组为0.169±0.017,实验C组为0.170±0.016、实验D组为0.177±0.018表达水平最高。实验B、C、D组与假手术组相比,NG2表达水平增高,两者比较具有统计学差异P0.05)。3)CNPase表达水平情况:在假手术组中CNPase的表达水平为0.287±0.032最高,而在实验D组为0.213±0.015表达水平最低,其他在实验B、C组中CNPase的表达水平分别为0.225±0.025和0.222±0.026。与假手术组相比,实验B、C、D组CNPase表达水平有所降低,两者比较差异具有统计学意义(P0.05)。(4)通过对TLR2与CNPase的表达情况进行Spearman秩相关性分析结果显示:TLR2与CNPase的表达水平成负相关(r=-0.382,P0.01)。结论TLR2蛋白参与了慢性缺血性脑白质脱髓鞘病变,推测机制可能是TLR2蛋白的表达水平上调一方面引起CNPase蛋白表达水平下调,少突胶质细胞的减少;另一方面阻碍少突胶质前体细胞分化成熟从而影响髓鞘再生引起脱髓鞘病变。
[Abstract]:Objective: to study the expression of TLR2 protein in chronic ischemic white matter demyelinating lesions and to explore whether TLR2 protein is involved in ischemic white matter demyelinating lesions and its possible mechanism. Sixteen adult Beagle dogs were randomly divided into sham-operated group (. Group A) and experimental group. The experimental group was made into the model of cerebral ischemia artery by vascular ligation. According to the light, moderate and heavy cerebral ischemia, the experimental group was divided into group B and C. Group D: the white matter of bilateral ventricular margin was selected as the test specimen. The pathological changes and standardized scores of white matter in each group were observed by HE staining and LFB staining respectively. The degree of demyelinating lesions in white matter of each group was compared. The TLR2 in the samples was detected by immunohistochemical method. NG2. CNPase expression level. Spearman rank correlation analysis was used to analyze the correlation between TLR2 and CNPase. In HE staining, white matter staining was uniform in sham-operation group. The morphology of the cells was normal and no demyelinating changes were observed. The nerve fibers were disordered, the cells were swollen, and the myelin sheath in the sham operation group was normal and even after the pyknosis. LFB staining. In the experimental group, obvious demyelinating changes were observed in the white matter of brain in group B, the lesions were relatively light, and the morphology of myelin was disordered and the staining was uneven. In group C, myelin swelling, rupture and vacuole formation were observed. In group D, the lesions of white matter demyelination were the most serious, myelinated fibers disappeared and lipid vacuoles were formed. The degree of demyelinating lesions was evaluated by Hideaki standard score, and the lowest score was 0.63 卤0.52 in the sham operation group. Secondly, the score of group B was 1.25 卤0.46 and that of group C was 1.63 卤0.52, and that of group D was 1.88 卤0.64. The difference between group C and group D was statistically significant (P0.05, P < 0.05). The expression of TLR2 protein was the lowest in sham-operated group (0.148 卤0.058). The highest expression level was found in group B (0.185 卤0.023), group C (0.185 卤0.025) and group D (0.191 卤0.016). C. The expression of TLR2 protein in group D was significantly increased and the difference was statistically significant (P 0.05. 2). The expression of NG2 was the lowest in sham-operated group (0.147 卤0.021). The highest expression level was found in group B (0.169 卤0.017), group C (0.170 卤0.016) and group D (0.177 卤0.018). Compared with sham operation group, the expression of NG2 in group D was higher than that in group D. There was statistical difference between the two groups in the expression of CNPase: the expression level of CNPase was the highest in sham-operated group (0.287 卤0.032). The lowest level of expression was 0.213 卤0.015 in group D, and the other was in experiment B. The expression levels of CNPase in group C were 0.225 卤0.025 and 0.222 卤0.026, respectively. The expression of CNPase in group D was decreased. The difference between the two is statistically significant (P0.05. 4). The results of Spearman rank correlation analysis on the expression of TLR2 and CNPase showed that there was a negative correlation between the expression level of CNPase and the expression level of CNPase. Conclusion TLR2 protein is involved in chronic ischemic white matter demyelination. It is suggested that the up-regulation of TLR2 protein may cause down-regulation of CNPase protein expression and decrease of oligodendrocyte on the one hand. On the other hand, it hinders the differentiation and maturation of oligodendrocyte precursor cells, thus affecting myelin regeneration and demyelinating lesions.
【学位授予单位】：西南医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R744.5

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