Role of lung surfactant in phagocytic clearance of apoptotic cells by macrophages in rats.
Authors
Wang-LY; Scabilloni-JF; Antonini-JM; Castranova-V; Rojanasakul-Y; Roberts-JR; Zhang-Z; Mercer-RR
Source
Lab Invest 2006 May; 86(5):458-466
Abstract
Two of the common features of inflammatory lung diseases are the increased production of pulmonary surfactant and the induction of lung cell apoptosis. However, the relationship between these two events has not been addressed. To investigate the role of surfactant in pulmonary inflammation and apoptosis, we instilled natural lung surfactant (Survanta) (1.6-12.5 mg) into the rat lungs and determined the number of alveolar macrophages (AMs) and apoptotic lung cells. High-dose treatments of Survanta (>6.25 mg/rat) caused an increase in macrophage cell influx and lung cell apoptosis at 4 weeks post-treatment. In vitro studies using lavaged macrophages showed Survanta did not cause apoptosis. We then examined the role of Survanta on ability of macrophages phagocytizing apoptotic cells. This study demonstrated that macrophages were able to eliminate apoptotic cells more efficiently in the absence of surfactant than in its presence. In vivo, high doses of Survanta decreased the ability to clear exogenously instilled apoptotic cells or bacteria. Taken together, our results suggest that excessive accumulation of lung surfactant by Survanta treatment can impair or overwhelm the phagocytic clearance function of AMs and that this impairment may lead to increased presence of apoptotic cells in the lung and bacterial survival.Laboratory Investigation (2006) 86, 458-466.
Keywords
Lung-disorders; Surfactants; Phagocytes; Laboratory-animals; Animals; Animal-studies; Lung-disease; Diseases; Pulmonary-system-disorders; In-vitro-studies; In-vivo-studies
Contact
Dr L Wang, MD, PhD, Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA
Document Type
Journal Article
Email Address
lmw6@cdc.gov
Priority Area
Work Environment and Workforce: Emerging Technologies
Source Name
Laboratory Investigation
