Mycologic endocrinology

Abstract

The interactions of fungi and chemical messenger molecules, hormones or pheromones, are addressed in this chapter. These interactions include mammalian fungal pathogens, also plant pathogens, or nonpathogenic fungi, which can result in functional responses in receptor- or nonreceptor-mediated fashions. Endogenous ligands in the fungi have been demonstrated to be important for mating in a number of systems. Mammalian hormones have been demonstrated to have stimulatory or inhibitory effects on growth in organisms such as Candida albicans, Paracoccidioides brasiliensis, Saccharomyces cerevisiae, Rhizopus nigricans, Aspergillus fumigatus, Coccidioides, and dermatophytic fungi. A number of fungi have been shown to have specific binding proteins for corticosteroid, estrogen, and progesterone that are stereospecific and possess high affinity. In some instances, the interactions of a mammalian hormone with the organism, in vivo, affects pathogenesis. Genome expression profiles of C. albicans in the presence of estradiol or progesterone, and S. cerevisiae with progesterone, indicate major up-regulation of various drug resistance pumps, such as CDR1 and CDR2, can affect antifungal susceptibility. Azole antifungal interactions occur with fungal hormone binding proteins. Azoles also can block mammalian steroidogenesis. The finding of the interactions of mammalian hormones with fungi and subsequent functional responses by the fungi, suggest that hormonal interactions with fungal systems have been conserved throughout evolution and have an important role in fungal pathogenesis, as well as in the overall biology of the organisms.