Role of lung surfactant in phagocytic clearance of apoptic cells by macrophages during the development of pulmonary inflammation and fibrosis.
Wang L; Scabilloni J; Rojanasakul Y; Antonini J; Zhang Z; Castranova V; Mercer RR
FASEB J 2002 Mar; 16(5):A1151
Two of the common features of inflammatory lung diseases are the increased production of lung surfactant and induction cell apoptosis in the lungs. However, the relationship between these two events has not been addressed. To investigate the role of surfactants in pulmonary inflammation and apoptosis, we instilled Survanta (I.S-12 mg) into the lungs of rats and determined the levels of alveolar macrophage (AMS) and panoptic lung cells by TUNEL assay. Our results show that high-dose treatments of Survanta (> 6 mg) caused an increase in macrophage influx and apoptic cell number 4 weeks after the treatment. In vitro studies using lavaged AMs showed that Survanta did not enhance apoptosis induced by DMSO over control level. We then examined the ability of AMs to clear apoptic cells with or without Survanta. AMs were able to clear apoptic cells more efficiently in the absence of surfactant than in the presence of surfactant at 6 h (7S% vs. 38 degrees/0). These results suggest that excessive accumulation of lung surfactant can impair or overwhelm the phagocyte function of AMs and that this impairment may lead to an uncontrolled increase in apoptotic cells.
Lung-disease; Lung; Pulmonary-disorders; Pulmonary-function-tests; In-vitro-study; Laboratory-animals; Animal-studies
Abstract; Conference/Symposia Proceedings
Other Occupational Concerns; Pulmonary System Disorders
The FASEB Journal, Experimental Biology 2002, New Orleans, Louisiana, April 20-24, 2002