法尼醇在促氟康唑耐药白念珠菌凋亡中的作用机制

The mechanism of farniol induced apoptosis of fluconazole resistant Candida albicans

目的:初步探讨法尼醇促进氟康唑耐药白念珠菌凋亡的可能机制。方法:采用药物浓度梯度法构建氟康唑耐药的白念珠菌株,经鉴定后设为氟康唑耐药组;氟康唑敏感的白念珠菌株作为对照组。在2组中加入终浓度为200μmol/L的法尼醇,孵育24 h后采用四甲基偶氮唑盐(methylthiazolyl tetrazolium,MTT法)比色法检测加入法尼醇后氟康唑耐药与敏感白念珠菌的增殖情况。应用流式细胞仪、激光共聚焦显微镜等,检测并比较2组菌株的胱天蛋白酶3(caspase 3)的活化程度、菌株内还原型谷胱甘肽的含量及细胞内活性氧类(reactive oxygen species,ROS)含量,进而比较不同组菌株在细胞凋亡、细胞内氧化还原及氧化应激水平上的差异。结果:与对照组比较,加入法尼醇后,氟康唑耐药的白念珠菌株增殖下降,其差异具有统计学意义(P=0.0057)。氟康唑耐药组白念珠菌内的还原型谷胱甘肽的含量下降,细胞内ROS含量及胱天蛋白酶3活性上升,且差异均具有统计学意义(分别P=0.011、P=0.023、P=0.036)。结论:法尼醇通过减少耐药菌株细胞内还原型谷胱甘肽的含量,增加胞内ROS含量,增强胱天蛋白酶3活性,使耐药白念珠菌抗氧化能力下降并促使真菌发生细胞凋亡。

Objective To investigate the possible mechanism of fenitol induced apoptosis in fluconazole resistant Candida albicans.Methods The Candida albicans strains were exposed to fluconazole in concentration gradient to establish the drug resistance strain and the fluconazole-sensitive Candida albicans strains was used as control in the study.The proliferation of fluconazole resistance and sensitive Candida albicans in the presence of fenitol were examined by methylthiazolyl tetrazolium(MTT)method.The extent of apoptosis and status of intracellular redox and oxidative balance were measured by flow cytometry technology,laser confocal microscopy,the activation of caspase 3 enzyme activation and intracelluar reduced glutathione and reactive oxygen species(ROS).Results The proliferation of fluconazole resistant Candida albicans significantly decreased after the addition of fenitol(P=0.0057).The reduced glutathione content in Candida albicans significantly decreased(P=0.011),while the intracellular ROS and caspase-3 activity increased at the same time(P=0.023,P=0.036).Conclusions Farnesol shifts balance of redox reactions in drug-resistant Candida albicans,promoting apoptosis and inhibiting the proliferation of drug-resistant Candida albicans.