TITLE:
Stachybotrys chartarum (atra) spore extract alters surfactant protein expression and surfactant function in isolated fetal rat lung epithelial cells, fibroblasts and human A549 cells
AUTHORS:
Gail F. Pollard, Anthony Shaw, Michael Sowa, Thomas Rand, James A. Thliveris, James E. Scott
KEYWORDS:
Fetal Lung; Surfactant; Surface Tension; Black Mould; Captive Bubble Surfactometer; Surfactant Proteins
JOURNAL NAME:
Open Journal of Pediatrics,
Vol.3 No.3,
August
27,
2013
ABSTRACT:
Moulds, notably Stachybotrys chartarum (atra),
are constant contributors to air pollution particularly to air quality in
buildings. The spores themselves or their volatile organic products are present
in variable amounts in almost all environments, particularly in buildings
affected by flooding. These moulds and products can account for the sick
building syndrome and have been tied to such occurrences as the outbreak of
pulmonary hemosiderosis and hemorrhage in infants in Cleveland, Ohio. The
present study was designed to investigate the effects of S. chartarum extracts on surfactant protein expression, surfactant
quality and cell survival in the developing lung. S. chartarum extracts were incubated with cultures of several cell
types; isolated fetal lung type II cells and fetal lung fibroblasts, and human
lung A549 cells, a continuously growing cell line derived from
surfactant producing type II alveolar cells. MTT formazan assays were employed
to test cell viability. The synthesis and release of the predominant surfactant
protein A (SP-A), which is involved in the regulation of surfactant turnover
and metabolism, and surfactant protein B (SP-B) involved in shuttling phospholipids
between surfactant subcompartments was also assessed. Antibodies to these
proteins and western blotting results were used to assess the quantity of protein produced by the various cell
types. A novel approach utilizing captive bubble surfactometry was employed to
investigate the quality of surfactant in terms of surface tension and bubble
volume measurements. Electron microscopy was used to
examine changes in cellular structure of control and S. chartarum-treated cells. Results of the study showed that
exposure to the S. chartarum extracts
had deleterious effects on fetal lung epithelial cell viability and their
ability to produce pulmonary surfactant. S.
chartarum extracts also induced deleterious changes to the developing fetal
lung cells in terms of expression of SP-A and SP-B as well as to the surface
tension reducing abilities of the pulmonary surfactant. Ultrastructurally,
spore toxin associated changes were apparent in the isolated lung cells most
notably in the lamellar bodies of fetal rat lung alveolar type II and human
A549 cells. This study has demonstrated the potential damage to surfactant
production and function which may be induced by inhaling S. chartarum toxins.