Department of Biology, Texas A&M University, College Station, Texas, USA.
Antimicrob Agents Chemother. 2012 Jul;56(7):3758-66. doi: 10.1128/AAC.00212-12. Epub 2012 Apr 16.
Therapeutic treatment for systemic mycoses is severely hampered by the extremely limited number of antifungals. The difficulty of treatment of fungal infections in the central nervous system is further compounded by the poor central nervous system (CNS) penetration of most antifungals due to the blood-brain barrier. Only a few fungistatic azole drugs, such as fluconazole, show reasonable CNS penetration. Here we demonstrate that sertraline (Zoloft), the most frequently prescribed antidepressant, displays potent antifungal activity against Cryptococcus neoformans, the major causative agent of fungal meningitis. In in vitro assays, this neurotropic drug is fungicidal to all natural Cryptococcus isolates tested at clinically relevant concentrations. Furthermore, sertraline interacts synergistically or additively with fluconazole against Cryptococcus. Importantly, consistent with our in vitro observations, sertraline used alone reduces the brain fungal burden at an efficacy comparable to that of fluconazole in a murine model of systemic cryptococcosis. It works synergistically with fluconazole in reducing the fungal burden in brain, kidney, and spleen. In contrast to its potency against Cryptococcus, sertraline is less effective against strains of Candida species and its interactions with fluconazole against Candida strains are often antagonistic. Therefore, our data suggest the unique application of sertraline against cryptococcosis. To understand the antifungal mechanisms of sertraline, we screened a whole-genome deletion collection of Saccharomyces cerevisiae for altered sertraline susceptibility. Gene ontology analyses of selected mutations suggest that sertraline perturbs translation. In vitro translation assays using fungal cell extracts show that sertraline inhibits protein synthesis. Taken together, our findings indicate the potential of adopting this antidepressant in treating cryptococcal meningitis.
治疗系统性真菌感染的治疗方法受到抗真菌药物数量极其有限的严重阻碍。由于血脑屏障的存在,大多数抗真菌药物很难穿透中枢神经系统,这使得真菌性中枢神经系统感染的治疗更加复杂。只有少数抑菌性唑类药物,如氟康唑,具有合理的中枢神经系统穿透能力。在这里,我们证明了舍曲林(Zoloft),最常被开的抗抑郁药,对新型隐球菌具有很强的抗真菌活性,新型隐球菌是真菌性脑膜炎的主要病原体。在体外实验中,这种神经递质药物对所有天然新型隐球菌分离株均具有杀菌作用,浓度与临床相关。此外,舍曲林与氟康唑联合使用对隐球菌具有协同或累加作用。重要的是,与我们的体外观察结果一致,单独使用舍曲林可降低系统性隐球菌病小鼠模型中的脑部真菌负担,其疗效可与氟康唑相当。它与氟康唑联合使用可协同降低脑部、肾脏和脾脏中的真菌负担。与对新型隐球菌的效力相比,舍曲林对念珠菌属菌株的作用较弱,其与氟康唑的相互作用通常是拮抗的。因此,我们的数据表明舍曲林可用于治疗隐球菌病。为了了解舍曲林的抗真菌机制,我们筛选了酿酒酵母全基因组缺失文库,以寻找对舍曲林敏感性改变的突变株。对选定突变的基因本体分析表明,舍曲林扰乱了翻译。使用真菌细胞提取物进行的体外翻译实验表明,舍曲林抑制蛋白质合成。综上所述,我们的研究结果表明,采用这种抗抑郁药治疗隐球菌性脑膜炎具有一定的潜力。