氧化还原失衡对单增李斯特菌毒力基因转录水平的影响

Redox imbalance influences the transcription of virulence genes in Listeria monocytogenes

保持氧化还原平衡对生物体维持其正常生理活动具有重要作用。单增李斯特菌是可以自身合成谷胱甘肽(glutathione,GSH)的革兰氏阳性菌,GSH可影响该菌毒力基因的转录。为了研究氧化还原平衡对于单增李斯特菌毒力基因转录水平的影响,利用氧化剂H_2O_2和还原剂GSH分别对单增李斯特菌进行氧化和还原应激,qRT-PCR检测毒力基因hly、actA和plcB的转录水平变化,结果表明,22 mmol/L H_2O_2和10 mmol/L低浓度GSH均能诱导毒力基因转录水平的显著上调,而22 mmol/L高浓度GSH则抑制毒力基因的转录,表明在单增李斯特菌的氧化还原平衡调节能力范围之内,有效打破其氧化还原平衡,无论是氧化应激,还是还原应激,都可以促进其毒力基因的转录。

Balance of oxidation-reduction is important for organisms to maintain normal physiological activities.Listeria monocytogenes is a unique Gram-positive bacterium which contains a gene encoding a multi-domain fusion protein for synthesizing glutathione(GSH).In order to study the influence of oxidation and reduction to transcription of virulence genes,oxidizer H 2O 2 and reducer GSH were added to cultural media to create the oxidizing and reducing environment for Listeria monocytogenes,respectively,The transcription levels of virulence genes hly,actA and plcB were checked by using RT-qPCR method.The results showed that both 22 mmol/L H 2O 2 and 10 mmol/L GSH treatments induced robust transcription of virulence genes while 22 mmol/L GSH treatment repressed the transcriptions,suggesting that within the ability of Listeria monocytogenes to adjust the balance of oxidation-reduction,effective breaking the balance by oxidative or reductive stress promotes virulence gene transcription.