Title: Lung surfactant protein D (SP-D) response and regulation during acute and chronic lung injury.
Authors: Gaunsbaek, Maria Quisgaard; Rasmussen, Karina Juhl; Beers, Michael F; Atochina-Vasserman, Elena N; Hansen, Soren
Published In Lung, (2013 Jun)
Abstract: Surfactant protein D (SP-D) is a collection that plays important roles in modulating host defense functions and maintaining phospholipid homeostasis in the lung. The aim of current study was to characterize comparatively the SP-D response in bronchoalveolar lavage (BAL) and serum in three murine models of lung injury, using a validated ELISA technology for estimation of SP-D levels.Mice were exposed to lipopolysaccharide, bleomycin, or Pneumocystis carinii (Pc) and sacrificed at different time points.In lipopolysaccharide-challenged mice, the level of SP-D in BAL increased within 6 h, peaked at 51 h (4,518 ng/ml), and returned to base level at 99 h (612 ng/ml). Serum levels of SP-D increased immediately (8.6 ng/ml), peaked at 51 h (16 ng/ml), and returned to base levels at 99 h (3.8 ng/ml). In a subacute bleomycin inflammation model, SP-D levels were 4,625 and 367 ng/ml in BAL and serum, respectively, 8 days after exposure. In a chronic Pc inflammation model, the highest level of SP-D was observed 6 weeks after inoculation, with BAL and serum levels of 1,868 and 335 ng/ml, respectively.We conclude that serum levels of SP-D increase during lung injury, with a sustained increment during chronic inflammation compared with acute inflammation. A quick upregulation of SP-D in serum in response to acute airway inflammation supports the notion that SP-D translocates from the airways into the vascular system, in favor of being synthesized systemically. The study also confirms the concept of using increased SP-D serum levels as a biomarker of especially chronic airway inflammation.
PubMed ID: 23435873
MeSH Terms: Acute Lung Injury/blood; Acute Lung Injury/chemically induced; Acute Lung Injury/metabolism*; Acute Lung Injury/microbiology; Animals; Bleomycin; Bronchoalveolar Lavage Fluid/chemistry; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Immunohistochemistry; Lipopolysaccharides; Lung Injury/blood; Lung Injury/chemically induced; Lung Injury/metabolism*; Lung Injury/microbiology; Lung/metabolism*; Lung/microbiology; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Nude; Pneumocystis carinii; Pneumonia, Pneumocystis/blood; Pneumonia, Pneumocystis/metabolism*; Pneumonia, Pneumocystis/microbiology; Pulmonary Surfactant-Associated Protein D/blood; Pulmonary Surfactant-Associated Protein D/metabolism*; Time Factors