Lee Robin E B, Liu Teresa T, Barker Katherine S, Lee Richard E, Rogers P David
Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
J Antimicrob Chemother. 2005 May;55(5):655-62. doi: 10.1093/jac/dki105. Epub 2005 Apr 6.
The aim of this study was to identify changes in the gene expression profile of Candida albicans upon exposure to the hydroxypyridone anti-infective agent ciclopirox olamine in an effort to better understand its mechanism of action.
C. albicans SC5314 was exposed to either medium alone or ciclopirox olamine at a concentration equivalent to the IC50 (0.24 mg/L) for 3 h. RNA was isolated and gene expression profiles were compared using DNA microarrays. Differential expression of select genes was confirmed by real-time reverse transcription (RT)-PCR. Mutants disrupted for CDR2 and both CDR1 and CDR2, as well as a clinical isolate overexpressing CDR1 and CDR2, were examined for changes in susceptibility to ciclopirox olamine.
A total of 49 genes were found to be responsive to ciclopirox olamine, including 36 up-regulated genes and 13 down-regulated genes. These included genes involved in small molecule transport (HGT11, HXT5, ENA22, PHO84, CDR4), iron uptake (FRE30, FET34, FTR1, FTR2, SIT1) and cell stress (SOD1, SOD22, CDR1, DDR48). Mutants disrupted for CDR2 and both CDR1 and CDR2, as well as a clinical isolate overexpressing CDR1 and CDR2, showed no change in susceptibility to ciclopirox olamine compared with the respective parent.
Consistent with the hypothesis that ciclopirox olamine acts as an iron chelator, it induced changes in expression of many genes involved in iron uptake. Despite induction of the multidrug efflux pump genes CDR1 and, to a lesser extent, CDR2 by ciclopirox olamine, these genes do not affect susceptibility to this agent.
本研究旨在确定白色念珠菌暴露于羟基吡啶酮抗感染剂环吡酮胺后基因表达谱的变化，以便更好地理解其作用机制。
将白色念珠菌SC5314分别暴露于单独培养基或浓度相当于IC50（0.24mg/L）的环吡酮胺中3小时。分离RNA并使用DNA微阵列比较基因表达谱。通过实时逆转录（RT）-PCR确认选定基因的差异表达。检测CDR2以及CDR1和CDR2均被破坏的突变体，以及过表达CDR1和CDR2的临床分离株对环吡酮胺敏感性的变化。
共发现49个基因对环吡酮胺有反应，包括36个上调基因和13个下调基因。这些基因包括参与小分子转运（HGT11、HXT5、ENA22、PHO84、CDR4）、铁摄取（FRE30、FET34、FTR1、FTR2、SIT1）和细胞应激（SOD1、SOD22、CDR1、DDR48）的基因。CDR2以及CDR1和CDR2均被破坏的突变体，以及过表达CDR1和CDR2的临床分离株，与各自亲本相比，对环吡酮胺的敏感性没有变化。
与环吡酮胺作为铁螯合剂的假设一致，它诱导了许多参与铁摄取的基因表达的变化。尽管环吡酮胺诱导了多药外排泵基因CDR1以及程度较轻的CDR2，但这些基因不影响对该药物的敏感性。
