Abstract
BackgroundItraconazole is currently used to treat paracoccidioidomycosis. The mechanism of action of azoles has been elucidated in some fungi, although little is known regarding its mechanism of action in Paracoccidioides spp. The present work focused on identification of regulated transcripts using representational difference analysis of Paracoccidioides spp. yeast cells treated with itraconazole for 1 and 2 h.ResultsParacoccidioides Pb01 genes up-regulated by itraconazole included genes involved in cellular transport, metabolism/energy, transcription, cell rescue, defense and virulence. ERG11, ERG6, ERG3, ERG5 and ERG25 were up-regulated at multiple time points. In vivo infection experiments in mice corroborated the in vitro results. Ergosterol levels and distribution were evaluated in Paracoccidioides Pb18 yeast cells, and the results demonstrate that both factors were changed in the fungus treated with itraconazole.ConclusionTo our knowledge, this is the first transcriptional analysis of Paracoccidioides spp. exposed to a triazole drug. Here acetyl seems to be intensively produced from different metabolic pathways to produce ergosterol by the action of ergosterol synthesis related enzymes, which were also affected in other fungi. Among the genes affected, we identified genes in common with other fungi, as well as genes unique to Paracoccidioides Pb01. Those genes could be considered target to new drugs. Voltage-gated Ca2+ alpha subunit (CAV), Tetracycline resistance protein (TETA) and Hemolisyn-iii channel protein (HLYiii) were found only here and a probably involvement with resistence to itraconazole could be investigated in the future. However our findings do not permit inference to current clinical practice.
Highlights
Itraconazole is currently used to treat paracoccidioidomycosis
224 up- and 208 down-regulated expressed sequence tags (ESTs) were obtained from yeast cells after incubation with itraconazole for 1 h, containing 55 singlets and 26 contigs for up-regulated transcripts and three singlets and 20 contigs for downregulated ones
The ESTs obtained were submitted to the National Center for Biotechnology Information (NCBI) database under accession numbers: LIBEST_028165 Paracoccidioides Pb01 itraconazole 1 h up Library, LIBEST_028164 Paracoccidioides Pb01 itraconazole 1 h down Library, LIBEST_028167 Paracoccidioides Pb01 itraconazole 2 h up Library and LIBEST_028166 Paracoccidioides Pb01 itraconazole 2 h down Library
Summary
The mechanism of action of azoles has been elucidated in some fungi, little is known regarding its mechanism of action in Paracoccidioides spp. The present work focused on identification of regulated transcripts using representational difference analysis of Paracoccidioides spp. yeast cells treated with itraconazole for 1 and 2 h. Paracoccidioides spp., a complex of several phylogenetic species, is the agent of paracoccidioidomycosis (PCM). Itraconazole is a triazole antifungal drug, which are multi-ringed synthetic compounds containing three nitrogen atoms in the azole ring. The triazole drugs inhibit the synthesis of ergosterol, an essential component of fungal cell membranes, and cause abnormalities in the membrane permeability and cell death [6]. Itraconazole and related azole derivatives act by blocking the ergosterol biosynthesis pathway through the inhibition of the fungal cytochrome P450 enzyme lanosterol demethylase (Erg11) [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
