清大生醫學院學士後醫學系黃建銘助理教授與研究團隊成員

Assistant Professor Jian-Ming Huang of the School of Medicine, College of Life Sciences and Medicine, National Tsing Hua University, with research team member

論文標題Paper Title

Ouabain, ATPase inhibitor, potentially enhances the effect of polyhexamethylene biguanide on Acanthamoeba castellanii

學術期刊刊名Journal Name

國際寄生蟲學雜誌—藥物與抗藥性The International Journal for Parasitology – Drugs and Drug Resistance

研究團隊 Research Team

主持人Principle Investigator：

黃建銘 助理教授Jian-Ming Huang, Assistant Professor

國立清華大學生命科學暨醫學院 學士後醫學系

School of Medicine, College of Life Sciences and Medicine, National Tsing Hua University(NTHU)

參與者Participants:：

摘要

Abstract

棘阿米巴（Acanthamoeba）是一種廣泛存在於自然及人造環境中的自由生活阿米巴原蟲，可引起肉芽腫性阿米巴腦炎及棘阿米巴角膜炎（AK）等嚴重疾病。AK主要影響隱形眼鏡使用者，若未及時治療，可能導致失明。現行治療以PHMB眼藥水為主，但對耐藥株效果有限。本研究發現鈉P型ATPase（ACA1_065450）與棘阿米巴囊化有關，並可透過ATPase抑制劑Ouabain降低囊化率。未來期望結合Ouabain與PHMB開發更有效的AK治療策略。

Acanthamoeba is a free-living amoeba widely found in natural and artificial environments and can cause serious infections such as granulomatous amoebic encephalitis and Acanthamoeba keratitis (AK). AK mainly affects contact lens wearers and can lead to blindness if untreated. Current treatment relies on polyhexamethylene biguanide (PHMB) eye drops but is often ineffective against drug-resistant strains. Our study identified that the sodium P-type ATPase (ACA1_065450) is closely associated with the encystation process. Furthermore, inhibiting ATPase activity with ouabain reduced encystation rates. We aim to develop an improved treatment strategy by combining ouabain with PHMB to enhance AK management.

研究成果Result/Contributions

棘阿米巴能在不良環境下形成抵抗外界攻擊的囊體，造成臨床治療困難。然而，囊化的分子機制尚未完全釐清。透過本研究，我們首先鑑定出棘阿米巴中鈉P型ATPase（ACA1_065450）基因表現量與囊化過程密切相關。在不同誘導囊化條件（如MgCl₂或NaCl）下，P型ATPase的表現明顯上升。此外，利用ATPase抑制劑Ouabain處理棘阿米巴後，發現其囊化率顯著下降，顯示Na⁺/K⁺離子泵對囊體形成具有關鍵調控作用。由於PHMB對部分耐藥棘阿米巴效果不佳，我們提出Ouabain結合PHMB的新穎治療策略，期望能夠有效破壞棘阿米巴的生存機制，減緩疾病進展。本研究不僅了解對棘阿米巴囊化機制的理解，也為開發新型AK治療提供了可能方向，對提升臨床治療效果具有重要意義。

Acanthamoeba can form cysts under unfavorable conditions, making clinical treatment challenging. However, the detailed molecular mechanisms of encystation remain poorly understood. In this study, we identified that the sodium P-type ATPase (ACA1_065450) gene plays a critical role in the encystation process of Acanthamoeba. The expression of P-type ATPase was significantly upregulated under encystation-inducing conditions, such as treatment with MgCl₂ or NaCl. Moreover, when treated with ouabain, an ATPase inhibitor, the cyst formation rate was markedly reduced, suggesting that the Na⁺/K⁺ ion pump is essential for cyst development. Given that PHMB alone is less effective against some drug-resistant strains, we propose a novel therapeutic strategy combining ouabain and PHMB to more effectively target Acanthamoeba survival mechanisms. This research not only advances our understanding of Acanthamoeba's encystation mechanisms but also provides a promising direction for developing more effective AK treatments, with potential clinical benefits for improving patient outcomes.

論文連結 Paper Link

https://doi.org/10.1016/j.ijpddr.2024.100550