Effects of Stachybotrys chartarum atra conidia and isolated toxin on LungSurfactant production and homeostasis

Abstract

This study evaluated the effects of Stachybotrys chartarum conidia and a trichothecene, isosatratoxin-F, on choline incorporation into DSPC by fetal rabbit alveolar type II cells and on alveolar surfactant subtypes in mice. Exposure of fetal rabbit type II cells to S. chartarum conidia at concentrations of 10(3) to 10(6) conidia ml(-1) significantly depressed [3H] choline incorporation after 24 h of exposure. Exposure of the rabbit cells to 10(5) to 10(6) conidia ml(-1) also resulted in significantly depressed [3H] choline uptake after 48 h. Additionally, fetal rabbit alveolar type II cells exposed to isosatratoxin-F in concentrations ranging from 10(-9) to 10(-4) M showed a significant reduction in [3H] choline incorporation into DSPC. Alveolar surfactant phospholipid concentrations in the different metabolic subfractions of lung lavage fluid of mice intratracheally exposed to either 50 microl of 10(7) ml(-1) S. chartarum conidia or 50 microl 10(-7) M isosatratoxin-F showed some significant changes at 12, 24, 48, and 72 h post-exposure, compared to the surfactant subfractions of control mice which were either untreated, exposed to saline or to 50 microl of 10(-7) ml(-1) Cladosporium cladosporioides conidia. In both the S. chartarum- and the isosatratoxin-F-treated mice, exposure significantly increased P10, P100, and S100 phospholipid concentrations, while the P60 phospholipid concentrations were depressed. In contrast, C. cladosporioides-treated mice showed only one significant change in subfraction phospholipid concentration: P60 was depressed at 48 h post-exposure. These results reveal that alveolar type II cells are sensitive to exposure to S. chartarum conidia and to isosatratoxin F. Sensitivity is manifest by alterations in the normal metabolic processing of alveolar surfactant. In exposed mice, this effect appears to involve a significant increase in newly secreted surfactant and an accumulation of the used surfactant forms.

Indoor Mold, Toxigenic Fungi, andStachybotrys chartarum: Infectious Disease Perspective

“…Early studies showed that surfactant production is up-regulated in type II alveolar cells exposed to pollutants (98,120,311). Subsequent work has shown that alveolar type II cells, macrophages, and surfactant production and composition are affected by exposure to fungal spores and their mycotoxins, including Cladosporium and Stachybotrys species (181,249,250,255,378; W. G. Sorenson, Proc. Int.…”

Localization of Satratoxin-G in Stachybotrys chartarum Spores and Spore-Impacted Mouse Lung Using Immunocytochemistry

“…Each mouse used for the study was inoculated intratracheally with 50 µl of S. chartarum spores, (1.4 × 10 6 spores/ml in physiological saline = 75,000 spores/animal = 3,000 spores/g BW) (Mason et al, 1998). The mice were placed back into their cages immediately after instillation.…”

Analysis of Fungal Spore Mycotoxin and the Relationship Between Spore Surface Area and Mycotoxin Content Utilizing a Protein Translation Inhibition Assay

“…Schulz et al concluded that there is a health hazard due to toxic effects after the inhalation of high concentrations of spores from the filamentous fungi [20]. It has also been known for some time that toxins produced by Stachybotrys chartarum can accumulate to very high levels in the conidia and that spores laden with toxins can affect lung function [21,22,23]. However, the role that mycotoxins have in the manifestation of the aforementioned ailments is currently unknown, and studies aimed at mycotoxin inhalation exposure are lacking.…”