Clioquinol influences cell membrane, attenuates virulence factors, induces apoptosis to inhibit <i>Candida albicans</i> growth

<b>Aim:</b> To investigate the antifungal mechanism of clioquinol and indicate that clioquinol has potential as a novel therapeutic antifungal agent. <b>Materials &amp; methods:</b> Analyze differentially expressed genes of <i>Candida albicans</i> treated with clioquinol using RNA-sequencing. The effects on cell wall and membrane features, virulence factors, apoptosis-induced cell death were also investigated. <b>Results:</b> The differentially expressed genes of <i>C. albicans</i> after treated with clioquinol focused on cell wall and membrane synthesis, antioxidant system and energy metabolism. Clioquinol did not change cell wall components levels while it decreased squalene epoxidase activity to influence the ergosterol biosynthesis in cell membrane. It also decreased cellular surface hydrophobicity and induced β-glucan unmasking to attenuate virulence factors. Meanwhile, clioquinol influenced enzyme activities involved in antioxidant system, citrate cycle, oxidative phosphorylation and decreased the ATP levels. Clioquinol induced apoptosis in <i>C. albicans</i> to exert its fungicidal activity. It induced reactive oxygen species and calcium ion elevation, leading to loss of mitochondrial membrane potential, cytochrome C release, metacaspase activation, thereby triggering apoptosis. <b>Conclusion:</b> Clioquinol exerted anti-<i>C. albicans</i> activity through influencing cell membrane, attenuating virulence factors and inducing apoptosis. Clioquinol changed gene expressions involved in cell wall and membrane synthesis, antioxidant system and energy metabolism in <i>Candida albicans</i>. Clioquinol influenced the ergosterol biosynthesis in cell membrane and attenuated virulence factors in <i>C. albicans</i>. Clioquinol influenced gene expressions and enzyme activities involved in antioxidant system, citrate cycle and oxidative phosphorylation. Meantime it decreased the ATP levels. Clioquinol induce apoptosis in <i>C. albicans</i> through influencing reactive oxygen species and calcium ion levels. The study provided more evidences for the antifungal mechanism of clioquinol. Clioquinol emerges as promising candidates for the development of novel antifungal therapies.**研究目的**：探究氯碘羟喹（clioquinol）的抗真菌作用机制，并阐明其作为新型治疗性抗真菌制剂的应用潜力。 **材料与方法**：采用RNA测序（RNA-sequencing）技术分析经氯碘羟喹处理的白色念珠菌（*Candida albicans*）的差异表达基因，同时探究其对真菌细胞壁、细胞膜特性、毒力因子以及凋亡诱导细胞死亡的影响。 **研究结果**：经氯碘羟喹处理后的白色念珠菌差异表达基因主要富集于细胞壁与细胞膜合成、抗氧化系统以及能量代谢相关通路。氯碘羟喹未改变细胞壁组分水平，但可通过降低鲨烯环氧酶活性，影响细胞膜中麦角固醇的生物合成。其同时可降低细胞表面疏水性，并诱导β-葡聚糖暴露增强，从而减弱毒力因子活性。此外，氯碘羟喹可调控抗氧化系统、三羧酸循环、氧化磷酸化相关酶的活性，并降低细胞内ATP水平。氯碘羟喹可诱导白色念珠菌发生凋亡以发挥杀菌作用，具体机制为：诱导活性氧与钙离子水平升高，进而引发线粒体膜电位丧失、细胞色素C释放及半胱天冬酶激活，最终触发细胞凋亡。 **结论**：氯碘羟喹可通过影响细胞膜功能、减弱毒力因子活性以及诱导细胞凋亡，发挥抗白色念珠菌作用。其可调控白色念珠菌中与细胞壁/细胞膜合成、抗氧化系统及能量代谢相关的基因表达，影响细胞膜麦角固醇的生物合成并减弱真菌毒力；同时可调控抗氧化系统、三羧酸循环及氧化磷酸化相关的基因表达与酶活性，降低细胞内ATP水平，并通过调控活性氧与钙离子水平诱导白色念珠菌凋亡。本研究为阐明氯碘羟喹的抗真菌作用机制提供了更多实验依据，氯碘羟喹有望成为新型抗真菌治疗药物的开发候选对象。