Proteomics and β-hydroxybutyrylome reveal the novel mechanisms underlying fluconazole resistance in Candida albicans.

BACKGROUND

The rising incidence of fluconazole-resistant C. albicans presents a substantial challenge to global health, especially in resource-limited settings.

AIM: To delineate the proteomic and β-hydroxybutyrylome changes associated with fluconazole resistance and identify potential novel therapeutic approaches.

METHODS

We performed comprehensive proteomic and β-hydroxybutyrylome analyses on fluconazole-resistant and -susceptible C. albicans strains. Lysine β-hydroxybutyrylation levels were quantified using Western blotting (WB), and the synergistic interactions between β-hydroxybutyrate (BHB) and fluconazole were evaluated through checkerboard assays.

RESULTS

Proteomic profiling exhibited significant dysregulation of acylation-modulating enzymes, notably downregulation of histone acetyltransferase RTT109 and upregulation of deacetylase HDA1. WB confirmed pronounced suppression of β-hydroxybutyrylation in the resistant strain. Combination therapy reduced the minimum inhibitory concentration values of fluconazole and BHB by 64-fold and 4-fold, respectively, indicating a synergistic interaction. β-hydroxybutyrylome profiling identified 27 significantly upregulated sites on 27 proteins and 91 downregulated sites on 86 proteins in the resistant strain, consistent with WB data. Bioinformatic analyses implicated alterations in β-hydroxybutyrylation of metabolic pathway proteins as a key mechanism underlying the development of fluconazole resistance.

CONCLUSION

Fluconazole-resistant C. albicans poses a growing threat. This study links reduced β-hydroxybutyrylation to fluconazole resistance and highlights post-translational modifications as potential therapeutic targets.