Proteomic And Genomic Analysis, Identification Of Differential Protein And Gene Expression Of Fluconazole Resistance In Laboratory Candida Albicans

Drug resistance is the major problem in achieving successful Candida infections treatment. However, molecular investigations have provided evidence that multifactorial and multistep alterations are involved in acquired fluconazole resistance of Candida albicans. It is necessary to develop a more systematical and detailed understanding of the complexity of drug resistance. Therefore, comparative proteomic and genomic analysis for proteins and genes altered during the development of fluconazole resistance were performed. We first established the model of fluconazole-resistance C. albicans. Then we established and optimized the 2-DE methods. Satisfactory 2-DE maps including resolution and reproducibility were obtained. Using this approach we identified 24 different classes of proteins in fluconazole-resistant strains whose expression were either increased or decreased comparing with fluconazole-susceptible strains. The differentially expressed pattern of certain protein (Ald5p, Cdcl9p, Gap1p, Grp2p, Mdh1p, Mir1p, Ynk1p, and Potl4p) was in agreement with previous reports in both experimentally induced and clinically acquired azole resistance strains. Majority of the differentially expressed proteins (Adhlp, Fbalp, Gpm1p, Idhlp, Mls1p, Pgk1p, Qcr7p, Rps5p, Ssa4p, Tsa1p, Tpi1p, Zuo1p, IPF4328, and IPF16253) were found for the first time to be potentially novel fluconazole-resistant proteins. Measurement of mitochondrial membrane potential and reactive oxygen species provided further confirmation that the metabolism shift and reduced susceptibility to stress damage might contribute to fluconazole resistance in C. albicans. cDNA microarray technique was used to study the difference in gene expression between this pair of C. albicans. The results suggested that overexpression of CDR1, CDR2, and alterations in sterol synthesis as the major cause of acquired resistance. We identified differentially expressed genes involved in morphology and virulence, e.g. EFG1, SNF1, and HST7, which reflected the alteration of virulence in fluconazole-resistant C. albicans. We demonstrated the utility of proteomic analysis combined with microarray techniques for studying the molecular profiling of acquired fluconazole resistance in C. albicans. These differentially expressed proteins and genes provide materials for further investigation on the molecular mechanism of acquired fluconazole resistance in C. albicans.