IADR Abstract Archives
New haploid Candida albicans model to uncover novel drug targets
Objectives: Candida albicans is the major fungal pathogen in humans. There are only a few antifungal agents available for Candida infections. Recently we discovered a novel antifungal small molecule SM21, which demonstrated promising antifungal activity in vitro and in vivo. However, mechanism by which SM21 exerts its fungicidal effects on C. albicans remains unknown. In the present study, we used novel haploid form of C. albicans as a model system to uncover the drug target of SM21.
Methods: A standard C. albicans haploid strain, GZY803, was employed to examine the transcriptomics profiles in response to SM21 treatment. RNA from SM21 treated cultures were extracted for sequencing. Subsequent bioinformatics analysis identified altered pathways in SM21 exposed cultures. In parallel, SM21 resistant haploid strains were developed by sequential exposure of parent GZY803 strain to the antifungal agents. DNA and RNA sequencing analysis of the resistant strains were also performed to understand the mechanism of resistance. Growth curve analysis and ATP production measurement were conducted to confirm the bioinformatics findings from sequencing data.
Results: RNAseq analysis C. albicans transcriptome identified a significant reduction in ATP generation and transmembrane transport when treated with SM21. Enhanced cytochrome assembly was also reported in SM21 exposed cultures. Downstream experiments further confirmed inhibition at mitochondrial activity in the SM21 treated C. albicans. On the other hand, resistant strains showed an increase in Secreted aspartic proteins (SAPs) expression. This probably is to compensate for the loss of amino acid synthesis at mitochondrial level.
Conclusions: The new haploid C. albicans haploid model has uncovered the inhibition of mitochondrial activity as the mechanism of action of SM21. These new findings will aid the development of SM21 as a novel antifungal molecule, which could bring enormous benefits to million patients suffering from Candida related infections.
Methods: A standard C. albicans haploid strain, GZY803, was employed to examine the transcriptomics profiles in response to SM21 treatment. RNA from SM21 treated cultures were extracted for sequencing. Subsequent bioinformatics analysis identified altered pathways in SM21 exposed cultures. In parallel, SM21 resistant haploid strains were developed by sequential exposure of parent GZY803 strain to the antifungal agents. DNA and RNA sequencing analysis of the resistant strains were also performed to understand the mechanism of resistance. Growth curve analysis and ATP production measurement were conducted to confirm the bioinformatics findings from sequencing data.
Results: RNAseq analysis C. albicans transcriptome identified a significant reduction in ATP generation and transmembrane transport when treated with SM21. Enhanced cytochrome assembly was also reported in SM21 exposed cultures. Downstream experiments further confirmed inhibition at mitochondrial activity in the SM21 treated C. albicans. On the other hand, resistant strains showed an increase in Secreted aspartic proteins (SAPs) expression. This probably is to compensate for the loss of amino acid synthesis at mitochondrial level.
Conclusions: The new haploid C. albicans haploid model has uncovered the inhibition of mitochondrial activity as the mechanism of action of SM21. These new findings will aid the development of SM21 as a novel antifungal molecule, which could bring enormous benefits to million patients suffering from Candida related infections.