Developmental changes of neutral glycosphingolipids as receptors for pulmonary surfactant protein SP-A in the alveolar epithelium of murine lung.
A dramatic change in the glycosphingolipid composition in murine lung occurred between 1 day and 1 week after birth. GlcCer and LacCer were the predominant neutral glycosphingolipids prenatally and 1 day after birth, and the concentrations of globo- and ganglio-series glycosphingolipids increased abruptly from 1 week after birth, reaching maxima at 2-3 weeks. To explore the functional significance of the change, we examined the role of neutral glycosphingolipids as receptors for the murine pulmonary surfactant protein, SP-A, and found that SP-A bound to LacCer, Gg3Cer, and Gg1Cer, but not to Gb3Cer, Gb4Cer, IV3GalNAc alpha-Gb4Cer, sulfatide, or several gangliosides. On TLC-blotting with 125I-labeled SP-A, the binding of SP-A to Gg3Cer and Gg4Cer was 5 times higher than that to LacCer, and on immunohistochemical staining Gg4Cer and Gg3Cer was mainly observed in the alveolar epithelium. Thus, the capacity to retain SP-A of glycolipid receptors per gram dry weight of lung at 1 week after birth was 1.6 times higher than that at 1 day after birth, and reached a maximum 3 weeks after birth. These findings suggest that the enhanced synthesis of the ganglio-series neutral glycosphingolipids 1 week after birth results in an increase in the binding capacity for SP-A on the epithelial cell surface of alveoli.
Momoeda
K
K
Department of Anesthesiology, Faculty of Medicine, University of Tokyo.
Hirota
K
K
Utsuki
T
T
Tsuchida
Y
Y
Hanaoka
K
K
Iwamori
M
M
D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006028:Glycosphingolipids / Q000737:chemistry / Q000378:metabolism*; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D011247:Pregnancy; D011510:Proteolipids / Q000378:metabolism*; D011650:Pulmonary Alveoli / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*
D006028:Glycosphingolipids; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D011956:Receptors, Cell Surface; C067774:surfactant protein A receptor