Activity of Pulmonary Surfactant Protein-D (SP-D) in Vivo Is Dependent on Oligomeric Structure
Pulmonary surfactant protein-D (SP-D) is a member of the collectin family of C-type lectins that is synthesized in many tissues including respiratory epithelial cells in the lung. SP-D is assembled predominantly as dodecamers consisting of four homotrimeric subunits each. Association of these subunits is stabilized by interchain disulfide bonds involving two conserved amino-terminal cysteine residues …
Reversibility of Pulmonary Abnormalities by Conditional Replacement of Surfactant Protein D (SP-D) in Vivo
Surfactant protein D (SP-D) gene-targeted mice develop severe pulmonary disease associated with emphysema, pulmonary lipidosis, and foamy macrophage infiltrations. To determine the potential reversibility of these abnormalities, transgenic mice were developed in which SP-D was conditionally replaced in the respiratory epithelium of SP-D/ mice. SP-D was not detected in the absence of doxycycline. Treatment with …
Surfactant protein D influences surfactant ultrastructure and uptake by alveolar type II cells
Surfactant protein D (SP-D) is a member of the collectin family of the innate host defense proteins. In the lung, SP-D is expressed primarily by type II cells. Gene-targeted SP-D-deficient [SP-D(−/−)] mice have three- to fivefold higher surfactant lipid pool sizes. However, surfactant synthesis and secretion by type II cells and catabolism by alveolar macrophages …
Intratracheal Recombinant Surfactant Protein D Prevents Endotoxin Shock in the Newborn Preterm Lamb
Rationale: The susceptibility of neonates to pulmonary and systemic infection has been associated with the immaturity of both lung structure and the immune system. Surfactant protein (SP) D is a member of the collectin family of innate immune molecules that plays an important role in innate host defense of the lung. Objectives: We tested whether …
Correction of Pulmonary Abnormalities in Sftpd/ Mice Requires the Collagenous Domain of Surfactant Protein D
Surfactant protein D (SP-D) is a member of the collectin family of innate defense proteins. Members of this family share four distinct structural domains: an N-terminal crosslinking domain, a collagenous domain, a neck region, and a carbohydrate recognition domain. In this study, the function of the collagenous domain was evaluated by expressing a SP-D collagen …
Surfactant protein-D regulates the postnatal maturation of pulmonary surfactant lipid pool sizes
Surfactant protein (SP)-D plays an important role in host defense and pulmonary surfactant homeostasis. In SP-D-deficient (Sftpd−/−) mice, the abnormal large surfactant forms seen at the ultrastructural level are taken up inefficiently by type II cells, resulting in an over threefold increase in the surfactant pool size. The mechanisms by which SP-D influences surfactant ultrastructure …
Surfactant Protein-D Inhibits Lung Inflammation Caused by Ventilation in Premature Newborn Lambs
Rationale: Premature newborns frequently require manual ventilation for resuscitation during which lung injury occurs. Although surfactant protein (SP)-D regulates pulmonary inflammation, SP-D levels are low in the preterm lung. Commercial surfactants for treatment of respiratory distress syndrome do not contain SP-D. Objectives: To determine whether addition of recombinant human SP-D (rhSP-D) to commercial surfactant influences …
Surfactant Protein D Deficiency Increases Lung Injury during Endotoxemia
Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), are major causes of acute respiratory failure with high rates of morbidity and mortality. Although surfactant protein (SP)-D plays a critical role in pulmonary innate immunity and several clinical studies suggest that this protein may be implicated in the pathophysiology of ARDS, …
Supramolecular Assembly of Human Pulmonary Surfactant Protein SP-D.
Pulmonary surfactant protein D (SP-D) is a glycoprotein from the collectin family that is a component of the lung surfactant system. It exhibits host defense and immune regulatory functions in addition to contributing to the homeostasis of the surfactant pool within the alveolar airspaces. It is known that the SP-D monomer forms trimers, which further …
