以斑馬魚作為研究心臟修復及藥物對心律影響的模型

Zebrafish: a predictive model for assessing cardiac repair and pharmacological effects on cardiac rhythm

黃威彰(Wei-Chang Huang)

指導教授 ： 莊永仁

國立清華大學/生命科學院/生物資訊與結構生物研究所/博士(2013年)

https://doi.org/10.6843/NTHU.2013.00578

摘要

心血管疾病對人類的健康造成極大威脅，在已開發國家造成的死亡人數比率相當高，其致死率甚至超過癌症。其中，心肌梗塞是常見的心血管疾病，病患因缺血及缺氧造成了梗塞血管下游心臟肌肉細胞的壞死，最終會導致心衰竭及死亡；至目前為止，臨床上仍難有積極的方法去促進受損心肌的修復再生。而另一種致命的心血管疾病，心律不整，則肇因心臟的異常電生理活動，與心肌梗塞亦具關聯性，發作時相當危險，常會導致心臟驟停和病人猝死。因而開發治療心血管疾病的藥物及方法，是刻不容緩的事。
斑馬魚為一近年來興起的模式生物，常被用來模擬人類疾病發生過程。斑馬魚擁有許多的優點，包括: 便宜並且易飼養；胚胎透明且在母體外發育，利於觀察；斑馬魚的基因組已被解碼定序完成。更重要的是，斑馬魚保留有和人類似的心血管循環系統，斑馬魚因而常被運用在心血管研究。在我們的研究中，利用斑馬魚研究系統獨特的優勢，我們開發出兩個重要的心血管功能評估平台：一為斑馬魚心臟修復模組，另一是斑馬魚心電圖監控模組。在第一部分的心臟修復模組，我們研究固醇類消炎藥物對傷口修復的影響，我們發現抑制發炎反應會妨礙斑馬魚的心臟修復，顯著地抑制血管新生和細胞複製。在第二部分的心電圖模組，我們則開發了即時活體斑馬魚心電圖技術，並且利用此技術測試我們開發出的新型麻醉配方，我們發現新配方能有效減少麻醉劑對生物造成的嚴重副作用:心跳速度降低及心律不整。新配方因而能有效地延長麻醉時間及降低實驗動物死亡率。
綜而言之，我們用斑馬魚建立了一個新穎且獨特的心血管分析平台，未來能用它來快速篩選出潛在的促進或是抑制心臟修復的藥物; 而獨特的斑馬魚心電圖技術則能夠協助篩選出潛在可能引起心律失常的危險藥物。把兩者結合，這樣的整合式平台除了能用於心血管疾病研究和臨床前藥物的篩選，未來並且有淺力成為商業化的專業委託實驗平台。

關鍵字

斑馬魚 ； 心肌梗塞 ； 心臟再生 ； 發炎反應 ； 心律不整 ； 麻醉 ； 心電圖

並列摘要

Cardiovascular diseases have been the leading cause of death worldwide for a long time. Ischemic heart disease such as myocardial infarction is a common type of cardiovascular diseases. During myocardial infarction, blood supply to the heart is decreased due to occlusion of coronary arteries. The subsequent shortage of nutrients and oxygen lead to cardiomyocytes death in the infarction region. If a patient survives from a myocardial infarction episode, the resulting scar tissues in the heart muscles may interfere the synchronized beating of the heart and will cause heart failure. On the other hand, cardiac arrhythmia is another life-threatening condition which may occur after heart attack or result from abnormal electrical activities in the heart. Similar to myocardial infarction, cardiac arrhythmia may lead to acute heart arrest and sudden death. There are increased efforts on research aiming to either prevent or treat this class of diseases.
As an emerging model organism for human diseases, several features of zebrafish (Danio rerio), such as its rapid and external development, easily tractable genetics, conserved cardiovascular system, and transparency, make it ideal for cardiovascular research. Giving these unique advantages over other animal models, we used zebrafish to establish two major assessment platforms for biomedical research: one is cardiac repair model and the other is zebrafish electrocardiography model.
In the first part of this thesis work, we found that applying the steroid anti-inflammatory drug during injury would hinder the cardiac repair capacity of zebrafish. The disrupted wound healing process accompanied with decreased angiogenesis and cell proliferation. In the second part of our work, we developed a new combinative formula of anesthetics for long-term anesthesia of zebrafish. This novel approach has minimized adverse effects in cardiac function, and its advantages are demonstrated by cardiac rhythm analysis using both the adult zebrafish and isolated heart electrocardiogram systems.
In conclusion, we established a zebrafish-based assessment module for cardiovascular diseases that could enhance cardiac repair research in the future. The unique zebrafish electrocardiogram system may also enable cardiotoxicity profiling. Integration of the zebrafish cardiac repair model and ECG system serves not only as a comprehensive platform for cardiovascular research, but also as commercial CRO tools for pre-clinical drug screening.

並列關鍵字

Zebrafish ； Myocardial infarction ； Heart regeneration ； Inflammation ； Cardiac arrhythmias ； Anesthesia ； Electrocardiography

參考文獻

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