以SCA17基因轉殖小鼠模式探討神經發炎病理機制及潛力藥物

Investigation of neuroinflammatory pathogenesis and therapeutics using SCA17 transgenic mice

鍾妤涵(Chung Yu-Han)

指導教授 ： 謝秀梅

國立臺灣師範大學/理學院/生命科學系/碩士(2017年)

https://doi.org/10.6345/NTNU202202940

摘要

['第十七型脊髓小腦共濟失調症是一種體染色體顯性遺傳的神經退化疾病，主要病因是在TATA-box binding protein (TBP)基因上有不正常的CAG三核苷酸重複擴增，經過轉錄及轉譯後會形成polyglutamine片段，造成不溶性蛋白的堆積。第十七型脊髓小腦共濟失調症病人有小腦萎縮、癡呆、肌張力障礙及癲癇等症狀。近年來的研究顯示，microglia (小膠質細胞)涉及多種神經相關疾病，活化的microglia會釋放一些物質如：NO、TNF-α或IL-6作用於astrocyte或神經使得神經發炎現象產生。我們先前的研究，在SCA17基因轉殖小鼠可以觀察到astrocyte (星狀膠細胞)顯著增加，而在本研究中也發現SCA17小鼠小腦中的發炎相關因子如：IL-1β、NFκB、iNOS及IL-6有上升的趨勢。小腦組織切片培養是一個適合用來了解不同細胞間的溝通及網絡的方法，因此，我們以小腦組織切片培養這個平台去評估有抗發炎效果的藥物。在SCA17小鼠小腦組織切片培養中我們發現NTNU008、NTNU037和NTNU063能改善Purkinje cell排列及生長情形，也看到microglia的表現有顯著下降。接下來，我們以小量動物預實驗確認藥物的效果，用藥四週結果發現雖然在行為上並未改善，但在病理分析中可見Purkinje cell丟失獲得改善，microgliosis現象也有顯著下降，周邊系統中IL-6的含量也有下降趨勢。我們選擇NTNU008和NTNU063進入大量動物試驗，藥物處理八週後並無影響小鼠體重，在行為的結果也顯示不會造成小鼠的焦慮程度，雖然在滾輪測試中並沒有看到改善平衡及協調能力，但在步態分析中有顯著的改善站立時間、跨步速度及跑動時間。在病理分析的結果中，也有顯著改善腦中及周邊系統的發炎反應。因此，我們認為，這些研究結果說明以對抗神經發炎為目標之藥物對SCA17的治療具有發展的潛力。']

關鍵字

第十七型脊髓小腦共濟失調症 ； SCA17基因轉殖小鼠 ； 神經發炎 ； 小膠質細胞 ； 抗發炎藥物

並列摘要

['Spinocerebellar ataxia 17 (SCA17) is an autosomal dominate neurodegenerative disease. Major pathogenesis is resulted from abnormal expansion of CAG repeats in the polyglutamine (polyQ) tract of the TATA-binding protein (TBP) gene. The symptoms of SCA17 patients include cerebellar ataxia, dementia, dystonia and seizures. In recent years, studies have demonstrated that microglia are involved in many neurological diseases. The activated microglia could secret some molecules such as nitric oxide (NO), TNF-α or IL-6, which effect astrocytes and neurons and lead to neuroinflammation. Our previous studies have shown that the levels of astrocytes are significantly increased in SCA17 transgenic mice. In this study, we find some inflammatory molecules levels increased in SCA17 transgenic mice. Organotypic slice culture is a well semi in vivo system because it maintains the interactions of different cell types as in an organ. Therefore, we have used this system to evaluate the drugs which could anti-inflammation in BV2 cells. The results showed NTNU008, NTNU037 and NTNU063 could improve the Purkinje cell growth, and we also find the Iba1 expression reduced on organotypic slice culture. These three drugs were applied to small scale SCA17 mice to verify their efficacy in vivo. Treatment result showed mouse coordination was not improved from the rotarod task evaluation. But we found the Iba1 levels in cerebellum of SCA17 transgenic mice decreased. Next, we confirmed the treatment efficacy of NTNU008 and NTNU063 in vivo in a large scale animal test. The results showed the treatment significantly improved footprinting of SCA17 mice. These two drugs also reduced the levels of microglia and astrocyte. These results provide potential neurotherapeutics for SCA17 targeting on neuroninflammation.']

並列關鍵字

Spinocerebellar ataxia 17 ； SCA17 transgenic mice ； neuroinflammation ； microglia ； anti-inflammation

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