白假丝酵母CFL1基因通过转录调控参与氧化压力应答

CFL1 regulates oxidative stress response genes in transcriptional levels in Candida albicans

摘要:

【背景】CFL1基因是白假丝酵母高铁还原酶基因，介导胞外铁离子的还原，在白假丝酵母胞内铁稳态的维持方面发挥着重要作用。【目的】研究CFL1基因调节氧化压力应答的分子机制。【方法】采用液体培养及巨噬细胞模型，测定CFL1缺失对氧化压力耐受性和杀伤巨噬细胞能力的影响；使用羟基自由基清除剂二甲基亚砜(DMSO)分析其对缓解氧化压力敏感性的影响；采用实时荧光定量PCR分析CFL1缺失对氧化压力应答基因表达的影响；采用过氧化氢酶(CAT)活性测定方法研究CFL1缺失对CAT1基因表达的影响；通过构建WT-CAT1-GFP和cfl1Δ/Δ-CAT1-GFP菌株分析过氧化氢酶基因过表达对cfl1Δ/Δ氧化压力敏感性的影响。【结果】白假丝酵母CFL1基因的缺失会造成杀伤巨噬细胞能力的减弱，氧化压力应答基因表达的下降。过氧化氢酶基因的过表达则能恢复与野生型几乎一致的氧化压力水平。【结论】CFL1基因通过转录调控参与白假丝酵母氧化压力应答过程。

关键词:白假丝酵母，氧化压力，CFL1基因，转录调控

Abstract:

[Background] CFL1 is one of the ferric reductase genes in Candida albicans, and mediates the reduction of iron in the cell surface to maintain iron stability in the cell. [Objective] To study the sensitivity and mechanism of CFL1 to oxidative stress. [Methods] We analyzed the growth and the ability to kill macrophages under the oxidative stress condition by means of liquid culture and macrophages model. Dimethyl sulfoxide (DMSO) was added to verify if it released the oxidative stress. The quantitative real-time PCR was used to analyze the expression of oxidative stress response genes in cfl1Δ/Δ. We constructed the strain WT-CAT1-GFP and cfl1Δ/Δ-CAT1-GFP to test if the over-expression of catalase changed the sensitivity. [Results] The deletion of CFL1 caused the decrease of the ability to kill macrophages and the expression of oxidative stress response genes. Besides, it resulted in the down-expression of catalase. However, the over-expression of catalase in cfl1Δ/Δ could recover nearly the same ability of oxidative stress response as the wild type. [Conclusion] CFL1 regulates the oxidative stress response genes in the transcriptional levels.

Key words:Candida albicans, oxidative stress, CFL1 gene, transcriptional regulation