大肠杆菌病兔实质器官TLR4的分布规律

发布时间：2018-06-01 07:44

本文选题：TLR4 + 大肠杆菌内毒素　；参考：《山东农业大学》2015年硕士论文

【摘要】：家兔的腹泻病尤其是以大肠杆菌引起的4~8周龄仔兔的腹泻,严重危害了养兔业的发展。该病发病率、死亡率高,损失大,治愈率低的特点,引起了世界各国养兔者的普遍关注。大肠杆菌的致病性主要取决于其血清型,内毒素和吸附性三个因素。大肠杆菌(Escherichia coli,E.coli)存在许多可以使人或动物致病的血清型,即使处于同一疫区的血清型也存在不同之处;大肠杆菌的内毒素是存在于大肠杆菌外膜中的脂多糖,是主要的致病因素;菌毛是与大肠杆菌吸附性密切相关的毒力因子,是大肠杆菌侵入机体的前提条件。大肠杆菌在病兔体内裂解后释放出的脂多糖,被Toll样受体家族中的TLR4识别并结合,通过以TLR4/NF-κB为主的一系列信号通路,促进各种炎症因子的释放,如白介素(inter-leukin,IL)-1B、IL-6、IL-8、肿瘤坏死因子(tumor necrosis factor,TNF)-A,在抗大肠杆菌感染的炎症过程中起到重要作用。本实验利用免疫组化的方法对不同发病时期病兔实质器官中TLR4进行定位定量的分析,从而比较出不同器官,不同发病时期TLR4的分布规律以及各实质器官对大肠杆菌敏感性的高低。各实质器官中TLR4表达量的高低可以从侧面说明各实质器官在抗感染过程中产生的炎症因子的多少、重要性的大小以及自身的感染程度。本实验的研究为仔兔的大肠杆菌病提供了一定的理论依据。心脏中TLR4的表达分布于心肌纤维中;肝脏中TLR4的表达分布在肝细胞、库普弗细胞、内皮细胞,但胆管上皮细胞或其它细胞的细胞质和细胞膜中也可见TLR4的表达;脾脏中TLR4的表达主要分布在白髓中的淋巴小结和动脉周围淋巴组织鞘,在小梁处也可见到受体表达;肺脏中TLR4的表达主要分布于肺泡管、肺泡周围,但也有少量分布于细支气管黏膜处;肾脏中TLR4的表达主要分布于肾小管周围的毛细血管、肾小管上皮,肾小球中也有表达。无论是健康动物还是发病动物,心、肝、脾、肺、肾中都有TLR4的表达,但是其表达量的高低水平不同;脾、肾中TLR4的表达量明显高于心、肺、肝中TLR4表达量。而且处于同一发病阶段的不同动物由于存在自身差异,导致其机体内TLR4的表达量也略有不同。在不同的发病阶段,不同的实质器官在抗感染的过程中起到了极其重要的作用。在发病第1天,肾、肝、肺中TLR4的表达量达到各自的峰值,在机体抵抗大肠杆菌入侵时起重要作用;发病第3天,脾中TLR4的表达量达到其峰值,发挥其重要作用;发病第5天,心中TLR4的表达量达到其峰值。心中TLR4的表达量,第5天大肠杆菌感染组与正常对照组及第1、3、7天大肠杆菌感染组存在显著性差异(P0.05);肝中TLR4的表达量,第1天大肠杆菌感染组与正常对照组及第3、5、7天大肠杆菌感染组差异显著(P0.05);脾中TLR4的表达量,第3天大肠杆菌感染组与正常对照组及第1、5、7天大肠杆菌感染组差异显著(P0.05);肺中TLR4的表达量,第1天大肠杆菌感染组与正常对照组及第3、5、7天大肠杆菌感染组差异显著(P0.05);肾中TLR4的表达量,第1、5天大肠杆菌感染组与正常对照组及第3、7天大肠杆菌感染组存在显著性差异(P0.05)。因为心、肝、脾、肺、肾本身所存在的TLR4受体的数量不一,所以在同一发病时期中,各实质器官中TLR4受体的表达量之间也存在差异。根据各实质器官中TLR4表达量的峰值以及达到峰值的发病时期,可以推算出各实质器官对大肠杆菌侵入的敏感程度:肾肝肺脾心。
[Abstract]:Diarrhea in rabbits, especially the diarrhea caused by Escherichia coli, caused by diarrhea in 4~8 weeks old rabbits, seriously endangers the development of rabbit industry. The disease incidence, high mortality, high loss and low cure rate have caused widespread concern in the world of rabbits. The main pathogenic factors of Escherichia coli depend on the three causes of its serotype, endotoxin and adsorbability. Escherichia coli (E.coli) has many serotypes that can cause human or animal disease, even in the serotypes in the same epidemic area. The endotoxin in Escherichia coli is the lipopolysaccharide in the outer membrane of the Escherichia coli, the main cause of the disease, and the pilus is closely related to the adsorption of Escherichia coli. The force factor is the precondition for the Escherichia coli invading the body. The lipopolysaccharide released by the Escherichia coli after the lysis of the sick rabbit is identified and combined by TLR4 in the Toll like receptor family. It promotes the release of various inflammatory factors through a series of signaling pathways dominated by TLR4/NF- kappa B, such as inter-leukin (IL) -1B, IL-6, IL-8, and tumor necrosis. Tumor necrosis factor (TNF) -A plays an important role in the inflammatory process of Escherichia coli infection. This experiment uses immunohistochemical method to locate and quantify the TLR4 in the parenchyma organs of rabbits at different onset times, thus comparing the distribution of different organs, the distribution of TLR4 in different onset periods and the major organs to large organs. The high or low sensitivity of Enterobacteriaceae. The level of TLR4 expression in the various parenchyma organs can be described from the side to explain the number of inflammatory factors, the magnitude of importance and the degree of their own infection. This study provides a theoretical basis for the colibacillosis in the rabbit. The table of TLR4 in the heart. The expression of TLR4 in the liver is distributed in hepatocytes, Kupffer cells, and endothelial cells, but the expression of TLR4 in the cytoplasm and membrane of the bile duct epithelial cells or other cells is also visible; the expression of TLR4 in the spleen is mainly distributed in the lymph nodes in the white pulp and the peri arterial lymphatic sheath, and is also visible on the trabeculae. The expression of TLR4 in the lung is mainly distributed in the alveolar duct and around the alveoli, but also in the bronchioles. The expression of TLR4 in the kidney is mainly distributed in the capillaries around the renal tubules, in the renal tubules and in the glomeruli, both in the healthy and in the animals, in the heart, in the liver, in the spleen, in lung, and in the kidney. The expression of TLR4 is different, but the expression of TLR4 in the spleen and kidney is significantly higher than the expression of TLR4 in the heart, lung and liver. And the different animals in the same stage of the disease have a slight difference in the expression of TLR4 in the body. In the first day of disease, the expression of TLR4 in the kidney, liver and lung reached its peak value and played an important role in the body's resistance to the invasion of Escherichia coli. The expression of TLR4 in the spleen reached its peak and played an important role in the spleen for third days, and the expression of TLR4 in the heart reached its peak value for fifth days. Heart TLR 4 of the expression amount, fifth days of colibacilli infection group and normal control group and 1,3,7 day infection group of Escherichia coli (P0.05), the expression of TLR4 in the liver, first days of Escherichia coli infection group and normal control group and 3,5,7 day Escherichia coli infection group significant difference (P0.05), the expression of TLR4 in the spleen, third days of Escherichia coli infection group The difference between the normal control group and the 1,5,7 day colibacilli infection group was significant (P0.05), the expression of TLR4 in the lung, the first day colibacilli infection group and the normal control group and the 3,5,7 day colibacilli infection group were significantly different (P0.05), the expression of TLR4 in the kidney, the Escherichia coli infection group and the normal control group, and the infection of the Escherichia coli day 3,7 day on day 3,7. There is a significant difference in the group (P0.05). Because the number of TLR4 receptors in the heart, the liver, the spleen, the lung and the kidney itself is different, so there is also a difference in the expression of the TLR4 receptors in the parenchymal organs during the same period. Organ sensitivity to E. coli invasion: kidney, liver, lung, spleen and heart.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.291

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