Fluidizing effects of C-reactive protein on lung surfactant membranes: protective role of surfactant protein A.

A. SAENZ; A. LOPEZ-SANCHEZ; J. MOJICA-LAZARO; L. MARTINZ-CARO; N. NIN; LUIS A. BAGATOLLI; C. CASALS

FASEB JOURNAL

FEDERATION AMER SOC EXP BIOL

Lugar: Bethesda; Año: 2010 vol. 24 p. 3662 - 3662

0892-6638

e purpose of this study was to investigate how surfactant membranes can be perturbed by C-reactive protein (CRP) and whether surfactant protein A (SP-A) might overcome CRP-induced surfactant membrane alterations. The effect of CRP on surfactant surface adsorption was evaluated in vivo after intratracheal instillation of CRP into rat lungs. Insertion of CRP into surfactant membranes was investigated through monolayer techniques. The effect of CRP on membrane structure was studied through differential scanning calorimetry and fluorescence spectroscopy and microscopy using large and giant unilamellar vesicles. Our results indicate that CRP inserts into surfactant membranes and drastically increases membrane fluidity, resulting in surfactant inactivation. At 10% CRP/phospholipid weight ratio, CRP causes disappearance of liquid-ordered/liquid-disordered phase coexistence distinctive of surfactant membranes. SP-A, the most abundant surfactant lipoprotein structurally similar to C1q, binds t