XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:145-1

Investigação

145-1

Influence of 17β-estradiol on gene expression of Paracoccidioides brasiliensis during mycelia to yeast transition

Authors:

Jata Shankar (CIMR - California Institute for Medical ResearchSCVMC - Santa Clara Valley Medical CenterSU - Stanford University) ; Karl V. Clemons (CIMR - California Institute for Medical ResearchSCVMC - Santa Clara Valley Medical CenterSU - Stanford University) ; Laurence F. Mirels (CIMR - California Institute for Medical ResearchSCVMC - Santa Clara Valley Medical CenterSU - Stanford University) ; Jomar P. Monteiro (CIMR - California Institute for Medical ResearchSCVMC - Santa Clara Valley Medical CenterSU - Stanford University) ; Thomas D. Wu (GI - Genentech, Inc.) ; David A. Stevens (CIMR - California Institute for Medical ResearchSCVMC - Santa Clara Valley Medical CenterSU - Stanford University)

Abstract

Infection by Paracoccidioides brasiliensis is initiated by inhalation of conidia or mycelial (M) fragments by the host, which subsequently differentiate into yeast (Y). Epidemiological studies indicate a predominance of paracoccidioidomycosis in adult men compared to women. Furthermore, in vitro and in vivo studies suggest that the female hormone (17β-estradiol, E2) plays an important role in regulating morphological transition, inhibiting M to Y transition. In our current studies we have examined the molecular mechanism of how E2 inhibits M to Y transition. We assessed temporal gene expression in P. brasiliensis (Pb01) by evaluating transcript levels in the presence or absence of E2 at various time points through 9 days of the M to Y transition. We employed an 11,000 element random-shear genomic DNA microarray previously developed in our laboratory and verified the results using RT-PCR. Overall, the abundance of transcripts exhibited a general decline during the M to Y transition in both controls and E2-treated cultures. In comparison with controls, E2 treatment altered transcript levels by at least twofold in genes represented by 550 array elements, with 331 showing up-regulation and 219 showing down-regulation at one or more time points. We sequenced these clones to identify the underlying genes and biological function. Genes with lower initial expression after exposure to E2 belonged to pathways involved in heat shock response (hsp-70), energy metabolism, and several retrotransposons. The Y-specific genes mannosyltransferase and Y20 demonstrated lower, delayed expression in E2-treated cultures. Hydrophobin, an M-specific gene, maintained higher expression in the presence of E2 relative to controls. A number of genes potentially involved in signaling, such as palmitoyltransferase (erf2), RhoA GTPase activating protein, phosphatidylinositol-4-kinase, and a predicted serine/threonine-protein kinase were down-regulated by E2. One exception was an arrestin domain-containing protein, which showed increased expression. In addition, genes related to ubiquitin-mediated protein degradation, and oxidative metabolism genes were up-regulated by E2. This study showed that E2 delays or blocks expression of some transcripts that are potentially involved in M to Y transition and continued analysis of these data is ongoing.

Keyword: Paracoccidioides, form transition, estradiol, gene expression, microarray

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