Please use this identifier to cite or link to this item:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/21248
Title: | 以外源物誘發小鼠模式探討原發性膽汁性膽管炎疾病機轉 Study on the Initiation Mechanisms of Primary Biliary Cholangitis by Xenobiotic Induced Mouse Model |
Authors: | Yu-Wen Wang 王禹文 |
Advisor: | 莊雅惠(Ya-Hui Chuang) |
Keyword: | 原發性膽汁性膽管炎,自體免疫疾病,外源物,膽管上皮細胞,腸內菌, primary biliary cholangitis,autoimmune disease,xenobiotics,cholangiocytes,microbiota, |
Publication Year : | 2019 |
Degree: | 碩士 |
Abstract: | 原發性膽汁性膽管炎 (Primary biliary cholangitis;PBC) 為一好發於中年婦女之慢性肝臟自體免疫疾病,患者體內免疫細胞浸潤於門脈區並破壞肝臟末端小膽管,導致慢性膽汁鬱積。臨床上發病之女性人數為男性的十倍,除了導因於性染色體與性激素的差異,女性亦更常接觸清潔劑、保養品及化妝品而暴露於PBC潛在誘發因子下。此外,飲食、衛生條件及環境物質皆會影響腸內菌叢 (microbiota) 組成,當這些微生物的衍生物經肝門靜脈由腸道移動至肝臟後,被細胞上 pattern recognition receptors (PRRs) 辨認後,會啟動下游的免疫反應。本研究利用外源物誘發之小鼠模式探討PBC 疾病致病機轉。為了瞭解環境中外源物在PBC中的角色,我們讓兩種性別的小鼠暴露於等量的 2-OA-OVA 以誘發自體免疫性膽管炎並檢測其免疫反應,發現刺激十一週後公鼠與母鼠皆出現自體免疫性膽管炎症狀但母鼠門脈區淋巴球浸潤及發炎情形較公鼠嚴重。且在刺激三週時皆可測得小鼠膽管上皮細胞凋亡。接著,我們採集三週小鼠糞便分析腸內菌叢組成,發現致敏化後菌叢組成改變,其中,未致敏化的公鼠具較多保護性菌叢。我們也分析細胞上辨識腸內不同微生物的Toll-like receptors (TLR) 表現量,測得經致敏化的小鼠膽管中TLR7 與 TLR9顯著升高。最後,為了瞭解菌群組成改變在 PBC 疾病中的致病機轉,我們在誘發母鼠自體免疫性膽管炎前先餵食小鼠非致病性大腸桿菌株 (DH5α strain) 以干擾小鼠腸內菌,發現給予外源性細菌的小鼠五週後肝臟內浸潤的免疫細胞顯著升高且發炎情形嚴重,保護性的TLR5 表現量亦顯著降低。以上實驗結果顯示外源物刺激引起的腸內菌失衡會誘發膽管上皮細胞進行細胞凋亡,進而導致PBC的發生。 Primary biliary cholangitis (PBC) is a chronic liver autoimmune disease characterized by immune-mediated destruction of the intrahepatic bile ducts. PBC presents a female predominance with almost 10:1. Aside from the impact of sex chromosome and sex hormones, female tend to experience greater exposure to chemicals such as detergents, facial care products, and cosmetics, which are potential triggers of PBC. Diets, personal hygiene, and environmental xenobiotics affect the gut microbiota. Products of gut microbiota circulate through the gut-liver axis and provoke immune responses in the liver. In the study, we investigated the mechanisms of PBC by the xenobiotic induced PBC mouse model. To investigate the role of environmental xenobiotics in PBC, we exposed mice of both genders to equivalent 2-octynoic acid conjugated to ovalbumin (2-OA-OVA) to induce autoimmune cholangitis and monitored their immune responses. The results showed that both male and female mice immunized with 2-OA-OVA developed autoimmune cholangitis while female mice had higher lymphocytes infiltration and liver inflammation than males at 11 weeks post-immunization. Besides, apoptosis of cholangiocytes in 2-OA-OVA immunized mice were observed at 3 weeks post-immunization. Furthermore, we collected feces to analyze the gut microbiota of mice. We found the gut microbiota structure altered after immunization. Notably, naïve male mice maintained a protective gut microbiome. We then analyzed the expression levels of toll-like receptors (TLRs), which could recognize microbial components, and found expression levels of TLR7 and TLR9 in bile ducts were significantly upregulated after immunization. To research the impact of alternation of gut microbiota in the PBC pathogenesis, we disturbed the gut microbiota before 5 weeks 2-OA-OVA immunization by feeding mice with non-pathogenic E. coli (DH5α) and found that mice given exogenous bacteria had an increased cell infiltration and decreased protective TLR5 in the liver. Our results suggested that in xenobiotics exposure, dysbiosis of gut microbiota induce apoptosis of cholangiocytes, which led to the initiation of PBC. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/21248 |
DOI: | 10.6342/NTU201903780 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 醫學檢驗暨生物技術學系 |
Files in This Item:
File | Size | Format | |
---|---|---|---|
ntu-108-1.pdf Restricted Access | 3.61 MB | Adobe PDF |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.