BMC Microbiol. 2007 Jan 23;7:5.
Verruculogen associated with Aspergillus fumigatus hyphae
and conidia modifies the electrophysiological properties of
human nasal epithelial cells.
Khoufache K, Puel O, Loiseau N, Delaforge M, Rivollet D,
Coste A, Cordonnier C, Escudier E, Botterel F, Bretagne S.
Laboratoire de Parasitologie-Mycologie, Hôpital Henri Mondor
(AP-HP), Université Paris 12, and UMR BIPAR 956, Créteil,
France. k_khoufache@yahoo.fr
k_khoufache@yahoo.fr
BACKGROUND: The role of Aspergillus fumigatus mycotoxins in
the colonization of the respiratory tract by conidia has not
been studied extensively, even though patients at risk from
invasive aspergillosis frequently exhibit respiratory epithelium
damage. In a previous study, we found that filtrates of
Aspergillus fumigatus cultures can specifically alter the
electrophysiological properties of human nasal epithelial cells
(HNEC) compared to those of non pathogenic moulds.
RESULTS: We fractionated the organic phase of filtrate from
3-day old Aspergillus fumigatus cultures using
high-performance liquid chromatography. The different fractions
were tested for their ability to modify the electrophysiological
properties of HNEC in an in vitro primary culture model.The
fraction collected between 20 and 30 min mimicked the effects of
the whole filtrate, i.e. decrease of transepithelial resistance
and increase of potential differences, and contained secondary
metabolites such as helvolic acid, fumagillin, and verruculogen.
Only verruculogen (10(-8) M) had effects similar to the whole
filtrate. We verified that verruculogen was produced by a
collection of 67 human, animal, plant and environmental
Aspergillus fumigatus isolates. Using MS-MS analysis, we
found that verruculogen was associated with both mycelium and
conidia extracts.
CONCLUSION: Verruculogen is a secondary metabolite that
modifies the electrophysiological properties of HNEC. The role
of these modifications in the colonization and invasion of the
respiratory epithelium by Aspergillus fumigatus on first
contact with the epithelium remains to be determined.
PMID: 17244350 |
