Mei Yikun, Jiang Tong, Zou Yun, Wang Yuanyuan, Zhou Jia, Li Jinyang, Liu Lin, Tan Jingcong, Wei Luqi, Li Jingquan, Dai Huanqin, Peng Yibing, Zhang Lixin, Lopez-Ribot Jose L, Shapiro Rebecca S, Chen Changbin, Liu Ning-Ning, Wang Hui
Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
The Center for Microbes, Development and Health, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
Front Microbiol. 2020 Jun 3;11:996. doi: 10.3389/fmicb.2020.00996. eCollection 2020.
Due to the increasing prevalence of pathogenic fungal infections, the emergence of antifungal resistant clinical isolates worldwide, and the limited arsenal of available antifungals, developing new antifungal strategies is imperative. In this study, we screened a library of 1068 FDA-approved drugs to identify hits that exhibit broad-spectrum antifungal activity. Robenidine, an anticoccidial agent which has been widely used to treat coccidian infections of poultry and rabbits, was identified in this screen. Physiological concentration of robenidine (8 μM) was able to significantly inhibit yeast cell growth, filamentation and biofilm formation of - the most extensively studied human fungal pathogen. Moreover, we observed a broad-spectrum antifungal activity of this compound against fluconazole resistant clinical isolates of , a wide range of other clinically relevant fungal pathogens. Intriguingly, robenidine-treated cells were hypersensitive to diverse cell wall stressors, and analysis of the cell wall structure by transmission electron microscopy (TEM) showed that the cell wall was severely damaged by robenidine, implying that this compound may target the cell wall integrity signaling pathway. Indeed, upon robenidine treatment, we found a dose dependent increase in the phosphorylation of the cell wall integrity marker Mkc1, which was decreased after prolonged exposure. Finally, we provide evidence by RNA-seq and qPCR that Rlm1, the downstream transcription factor of Mkc1, may represent a potential target of robenidine. Therefore, our data suggest that robenidine, a FDA approved anti-coccidiosis drug, displays a promising and broadly effective antifungal strategy, and represents a potentially repositionable candidate for the treatment of fungal infections.
由于致病性真菌感染的患病率不断上升、全球抗真菌耐药临床分离株的出现以及可用抗真菌药物的种类有限，开发新的抗真菌策略势在必行。在本研究中，我们筛选了一个包含1068种美国食品药品监督管理局（FDA）批准药物的文库，以鉴定具有广谱抗真菌活性的药物。在该筛选中，我们发现了罗苯尼丁，一种已广泛用于治疗家禽和兔球虫感染的抗球虫药。罗苯尼丁的生理浓度（8 μM）能够显著抑制酿酒酵母（一种研究最为广泛的人类真菌病原体）的细胞生长、丝状化和生物膜形成。此外,我们观察到该化合物对白色念珠菌的氟康唑耐药临床分离株以及多种其他临床相关真菌病原体具有广谱抗真菌活性。有趣的是，经罗苯尼丁处理的白色念珠菌细胞对多种细胞壁应激源高度敏感，通过透射电子显微镜（TEM）对细胞壁结构进行分析表明，罗苯尼丁严重破坏了细胞壁，这意味着该化合物可能靶向细胞壁完整性信号通路。事实上，在罗苯尼丁处理后，我们发现细胞壁完整性标志物Mkc1的磷酸化呈剂量依赖性增加，而在长时间暴露后则降低。最后，我们通过RNA测序（RNA-seq）和定量聚合酶链反应（qPCR）证明，Mkc1的下游转录因子Rlm1可能是罗苯尼丁的潜在靶点。因此，我们的数据表明，罗苯尼丁这种FDA批准的抗球虫病药物，显示出一种有前景且广泛有效的抗真菌策略，并且是治疗真菌感染的潜在可重新定位的候选药物。
