探討斑馬魚的Atox1在細胞內抗氧化反應所扮演的角色

銅離子是動物體內必要的微量元素，它可以作為不同酵素的輔因子提供酵素活性。在低濃度狀況下，銅離子可以幫助細胞正常生長，但是當銅離子過度堆積時會造成毒性，進而產生疾病甚至導致癌症。Atox1是一個金屬離子伴護蛋白，在銅離子恆定中扮演著重要的角色。它可將銅離子送往ATP7A及ATP7B以利銅離子的運輸。近期研究也發現，Atox1還可以成為轉錄因子（transcription factor, TF）調控SOD-3的基因轉錄。但是對於Atox1直接參與抗氧化的機制尚不明確，所以本篇研究中，我利用斑馬魚來研究Atox1蛋白在斑馬魚發育中抗氧化機制所扮演的角色。利用顯微注射Atox1 Morpholino的方式，觀察斑馬魚在缺乏Atox1蛋白的狀況下對於其抗氧化能力的影響。當Atox1蛋白表現量下降時，由DCFH-DA染色可以檢測出斑馬魚體內堆積較多的活性氧化物。此外Acridine Orange染色也可以發現，斑馬魚胚胎發育早期若缺乏Atox1蛋白，斑馬魚體內會引發較多的凋亡細胞。由此可知，缺乏Atox1蛋白可能使體內活性氧化物堆積，進而促使細胞凋亡的發生。因此，Atox1蛋白在斑馬魚發育中扮演著重要的抗氧化角色。

關鍵字

銅離子；氧化壓力；活性氧化物； Atox1

並列摘要

Copper is an essential element in living organisms as it is an important cofactor for many enzymes. At low concentration, copper is required for normal cell growth, whereas it is extremely toxic at a higher concentration. Atox1, a copper metallochaperone, plays an important role in the copper homeostasis. Atox1 transfers copper to the copper exporting P-type ATPases ATP7A and ATP7B. Recently, a novel function for Atox1 as a transcription factor (TF) for SOD-3 was reported. However, the relationship between Atox1 and antioxidant activity is not clear. In this study, zebrafish was used as an animal model to investigate the role of Atox1 in cellular redox reaction during zebrafish embryonic development. The Atox1-defieicnt zebrafish was established by using Atox1-MO to knockdown Atox1 expression. Upon Atox1 knockdown, increased reactive oxygen species (ROS) was measured in zebrafish embryo by DCFH-DA. In addition, Acridine Orange staining showed that Atox1 knockdown induced cell death in zebrafish embryo. These results revealed that Atox1 deficiency enhances ROS accumulation and apoptosis. Thus, an anti-oxidative and an anti-apoptotic role of Atox during zenrafish embryonic development is established.

並列關鍵字

Copper ； oxidative stress ； ROS ； Atox1 ； zebrafish

參考文獻

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探討斑馬魚的Atox1在細胞內抗氧化反應所扮演的角色

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