XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:93-1

Poster (Painel)

93-1	Autophagy in Paracoccidioides brasiliensis during mycelium to yeast transition
Authors:	Sarah Pedroso (UNIVAP - UNIVERSIDADE DO VALE DO PARAIBA) ; Claudia Campos (UNIVAP - UNIVERSIDADE DO VALE DO PARAIBA) ; Flavia Morais (UNIVAP - UNIVERSIDADE DO VALE DO PARAIBAUNIP - UNIVERSIDADE PAULISTA)

Abstract

Autophagy is a highly conserved eukaryotic process which allows cells to degrade macromolecules and organelles through the action of lysosomal/vacuole compartments. This process is involved in many biological events such as development, differentiation and adaptation, being crucial for survival of several microorganisms exposed to stress conditions. The human pathogenic fungus Paracoccidioides brasiliensis, the etiological agent of a deep mycosis, paracoccidioidomycosis, needs to undergo mycelium to yeast dimorphism inside the host to establish disease, which is triggered by a thermal stress when fungus changes from 25Ã‚Â°C to 37Ã‚ÂºC. In P. brasiliensis, many genes involved in autophagy undergo expression induction/repression during mycelium to yeast transition, which may be related to adaptation of the fungus to human host environment. In this work, P. brasiliensis, isolate 18, were cultivated in liquid medium after temperature shift from 25Ã‚Â°C to 36Ã‚Â°C for 7 days, in presence or absence of the drugs N-ethylmaleimide or 3-methyladenine, two inhibitors of autophagy, in order to establish the involvement of this process during dimorphism. P. brasiliensis mycelia cells cultivated at 25Ã‚Â°C during 7 days did not exhibit autophagic vacuoles in presence of monodansylcadaverine, a specific in vivo marker for autophagic vacuoles. However, the temperature rise from 25Ã‚Â°C to 37Ã‚Â°C in the presence of monodansylcadaverine, induced abundant autophagic vacuoles in P. brasiliensis cells during the first 24 hours. Both N-ethylmaleimide and 3-methyladenine blocked the mycelium to yeast transition by either death or stagnation of the culture, respectively. When 3-methyladenine was used, few autophagic vacuoles could be observed by monodansylcadaverine staining. These results suggest that autophagy is involved in P. brasiliensis dimorphism, which could mean that this process might be also involved in P. brasiliensis pathogenicity and virulence.਀匀甀瀀瀀漀爀琀攀搀戀礀䘀愀瀀攀猀瀀⸀

Keyword: autophagy, dimorphism, pathogenicity

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