ABSTRACT
During a study of indoor fungal colonisation, several isolates of Stachybotrys chartarum were recovered, and the effects of metabolites from four isolates on lung epithelial Type II cells and alveolar macrophages were studied in vitro. All the isolates showed toxic effects on both cell types, and they differed only in the extent of the changes induced. In Type II cells, the number of alkaline phosphatase positive cells was reduced, the pattern of Maclura pomifera agglutinin (MPA) binding was changed, and acid phosphatase activity in alveolar macrophages was diminished. In both cell types, the production of monocyte chemotactic protein-1 (MCP-1) and tumour necrosis factor-alpha (TNF-alpha) was changed, and parameters related to antioxidant status (superoxide dismutase, glutathione peroxidase, glutathione) were decreased.
Subject(s)
Epithelial Cells/drug effects , Macrophages, Alveolar/drug effects , Mycotoxins/toxicity , Pulmonary Alveoli/drug effects , Stachybotrys/chemistry , Acid Phosphatase/metabolism , Alkaline Phosphatase/metabolism , Animals , Cells, Cultured , Dose-Response Relationship, Drug , Epithelial Cells/metabolism , Macrophages, Alveolar/metabolism , Mycotoxins/isolation & purification , Plant Lectins/metabolism , Pulmonary Alveoli/metabolism , Rabbits , RatsABSTRACT
Damp dwellings represent suitable conditions for extended indoor moulds. A cellulolytic micromycete Stachybotrys chartarum (Ehrenb.) Hughes is considered to be a tertiary colonizer of surfaces in affected buildings. Known adverse health effects of S. chartarum result from its toxins--trichothecenes or atranones, as well as spirolactams. Mechanism of their potential pathological effects on the respiratory tract has not yet been sufficiently clarified. The cytotoxic effects of complex chloroform-extractable endo- (in biomass) and exometabolites (in cultivation medium) of an indoor S. chartarum isolate of an atranone chemotype, grown on a liquid medium with yeast extract and sucrose at 25 degrees C for 14 d, on lung tissue were evaluated in the 3-day experiment. For the purpose, 4 mg of toxicants were intratracheally instilled in 200 g Wistar male rats. A trichothecene mycotoxin diacetoxyscirpenol was used as the positive control. Bronchoalveolar lavage (BAL) parameters--viability and phagocytic activity of alveolar macrophages (AM), activity of lactate dehydrogenase, acid phosphatase and cathepsin D in cell-free BAL fluid (BALF), as well as in BAL cells, were measured. Acute exposure to the metabolites caused statistically significant changes, indicating lung tissue injury in the experimental animals. Decreased AM viability and increased activity of lysosomal enzyme cathepsin D in BAL cells after fungal exometabolite exposure were the most impressive. As toxic principles were found predominantly in the growth medium, toxins were more likely responsible for lung cell damage than e.g. fungal cell wall components. S. chartarum toxic metabolites can contribute to the ill health of occupants of mouldy building after inhalation of contaminated aerosol.
