| [PMID]: | 22037357 |
| [Au] Autor: | Hite RD; Grier BL; Waite BM; Veldhuizen RA; Possmayer F; Yao LJ; Seeds MC |
| [Ad] Endereço: | Section Head-Pulmonary, Critical Care, Allergy and Immunologic Diseases, Wake Forest University School of Medicine, 1 Medical Ctr. Blvd., Winston-Salem, NC 27157-1054, USA. dhite@wfubmc.edu |
| [Ti] Título: | Surfactant protein B inhibits secretory phospholipase A2 hydrolysis of surfactant phospholipids. |
| [So] Source: | Am J Physiol Lung Cell Mol Physiol;302(2):L257-65, 2012 Jan 15. |
| [Is] ISSN: | 1522-1504 |
| [Cp] País de publicação: | United States |
| [La] Idioma: | eng |
| [Ab] Resumo: | Hydrolysis of surfactant phospholipids (PL) by secretory phospholipases A(2) (sPLA(2)) contributes to surfactant damage in inflammatory airway diseases such as acute lung injury/acute respiratory distress syndrome. We and others have reported that each sPLA(2) exhibits specificity in hydrolyzing different PLs in pulmonary surfactant and that the presence of hydrophilic surfactant protein A (SP-A) alters sPLA(2)-mediated hydrolysis. This report tests the hypothesis that hydrophobic SP-B also inhibits sPLA(2)-mediated surfactant hydrolysis. Three surfactant preparations were used containing varied amounts of SP-B and radiolabeled tracers of phosphatidylcholine (PC) or phosphatidylglycerol (PG): 1) washed ovine surfactant (OS) (pre- and postorganic extraction) compared with Survanta (protein poor), 2) Survanta supplemented with purified bovine SP-B (1-5%, wt/wt), and 3) a mixture of dipalmitoylphosphatidylcholine (DPPC), 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC), and 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) (DPPC:POPC:POPG, 40:40:20) prepared as vesicles and monomolecular films in the presence or absence of SP-B. Hydrolysis of PG and PC by Group IB sPLA(2) (PLA2G1A) was significantly lower in the extracted OS, which contains SP-B, compared with Survanta (P = 0.005), which is SP-B poor. Hydrolysis of PG and PC in nonextracted OS, which contains all SPs, was lower than both Survanta and extracted OS. When Survanta was supplemented with 1% SP-B, PG and PC hydrolysis by PLA2G1B was significantly lower (P < 0.001) than in Survanta alone. When supplemented into pure lipid vesicles and monomolecular films composed of PG and PC mixtures, SP-B also inhibited hydrolysis by both PLA2G1B and Group IIA sPLA2 (PLA2G2A). In films, PLA2G1B hydrolyzed surfactant PL monolayers at surface pressures ≤30 mN/m (P < 0.01), and SP-B lowered the surface pressure range at which hydrolysis can occur. These results suggest the hydrophobic SP, SP-B, protects alveolar surfactant PL from hydrolysis mediated by multiple sPLA(2) in both vesicles (alveolar subphase) and monomolecular films (air-liquid interface). |
| [Mh] Termos MeSH primário: |
Fosfolipases A2 do Grupo IA/metabolismo
Fosfolipases A2 do Grupo IB/metabolismo
Fosfolipídeos/metabolismo
Proteína B Associada a Surfactante Pulmonar/metabolismo
Surfactantes Pulmonares/metabolismo
|
| [Mh] Termos MeSH secundário: |
Lesão Pulmonar Aguda/metabolismo
Lesão Pulmonar Aguda/patologia
Animais
Bovinos
Hidrólise
Interações Hidrofóbicas e Hidrofílicas
Fosfatidilcolinas/metabolismo
Fosfatidilgliceróis/metabolismo
Proteína A Associada a Surfactante Pulmonar/metabolismo
Surfactantes Pulmonares/química
Síndrome do Desconforto Respiratório do Adulto/patologia
Ovinos
|
| [Pt] Tipo de publicação: | JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T |
[Nm] Nome de substância:
| 0 (Phosphatidylcholines); 0 (Phosphatidylglycerols); 0 (Phospholipids); 0 (Pulmonary Surfactant-Associated Protein A); 0 (Pulmonary Surfactant-Associated Protein B); 0 (Pulmonary Surfactants); EC 3.1.1.4 (Group IA Phospholipases A2); EC 3.1.1.4 (Group IB Phospholipases A2) |
| [Em] Mês de entrada: | 1202 |
| [Cu] Atualização por classe: | 161019 |
[Lr] Data última revisão:
| 161019 |
| [Sb] Subgrupo de revista: | IM |
| [Da] Data de entrada para processamento: | 111101 |
| [St] Status: | MEDLINE |
| [do] DOI: | 10.1152/ajplung.00054.2011 |
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