Abstract
Rationale: Surfactant protein D (SP-D) is a collectin family member with demonstrated immunomodulatory properties in vitro. We hypothesized that SP-D modulates inflammation during noninfectious lung injury in vivo. Objectives: To investigate the association of alveolar SP-D and injury, we studied the responses of transgenic mice expressing varying levels of SP-D to intratracheal bleomycin (ITB). Methods: Eight-week old C57/BL6 SP-D-deficient (-/-) mice and syngeneic wild-type (WT) controls or Swiss Black SP-D-overexpressing (SP-D OE) mice and littermate controls received either ITB or saline and were followed for up to 21 d. Measurements and Results: Kaplan-Meier analysis demonstrated a dose-dependent decrease in survival in ITB SP-D (-/-) mice receiving 2 U/kg bleomycin, with a 14-d mortality of 100% versus 0% mortality for WT receiving 2 U/kg ITB or SP-D (-/-) mice given saline (p < 0.05). At 8 d, ITB SP-D (-/-) mice had greater respiratory distress (frequency/tidal volume) and weight loss than ITB WT mice. Furthermore, bronchoalveolar lavage cellularity, pulmonary parenchymal inflammation, and tissue 3-nitrotyrosine (NO2 Y) were increased to a greater extent in ITB SP-D (-/-) mice. By 21 d, compared with all groups, ITB SP-D (-/-) survivors had increased Trichrome staining and tissue hydroxyproline levels. As proof of principle, SP-D OE mice were highly resistant to bleomycin-induced morbidity and mortality at doses up to 3 U/kg. Conclusions: These data provide new in vivo evidence for an antiinflammatory role for SP-D in response to noninfectious, subacute lung injury via modulation of oxidative-nitrative stress.
Original language | English (US) |
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Pages (from-to) | 869-877 |
Number of pages | 9 |
Journal | American journal of respiratory and critical care medicine |
Volume | 172 |
Issue number | 7 |
DOIs | |
State | Published - Oct 1 2005 |
Keywords
- Bleomycin
- Collectins
- Innate immunity
- Lung
- Nitric oxide
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine