| First Author | Stahlman MT | Year | 2000 |
| Journal | Lab Invest | Volume | 80 |
| Issue | 3 | Pages | 395-403 |
| PubMed ID | 10744075 | Mgi Jnum | J:61159 |
| Mgi Id | MGI:1354506 | Doi | 10.1038/labinvest.3780044 |
| Citation | Stahlman MT, et al. (2000) Lamellar body formation in normal and surfactant protein B-deficient fetal mice. Lab Invest 80(3):395-403 |
| abstractText | Surfactant protein B (SP-B) -/- mice die of lethal respiratory distress syndrome shortly after birth. Alveolar type II epithelial cells in SP-B-deficient mice are characterized by a complete absence of lamellar bodies, the intracellular storage form of pulmonary surfactant, and the presence of inclusions containing numerous small vesicles and electron-dense masses. The present study was undertaken to characterize the formation of these inclusions during fetal lung development and clarify their relationship to lamellar bodies. In wild-type and SP-B +/- mice, small lamellar bodies with loosely organized lamellae and distinct limiting membranes were first detected on day 16 to 16.5 of gestation. SP-B -/- mice were readily identified on day 16 by the absence of immature lamellar bodies, the appearance of vesicular inclusions similar to those previously described in late gestation SP-B -/- mice, and the accumulation of misprocessed SP-C protein. Vesicular inclusions were rarely detected in SP-B +/- mice and were never detected in wild-type littermates. Classical multivesicular bodies were observed fusing with lamellar bodies in wild-type mice, and with the vesicular inclusions in SP-B -/- mice that occasionally contained a few membrane lamellae. On day 18, the airways of SP-B -/- mice lacked tubular myelin and were filled with vesicles and electron-dense masses, suggesting that the contents of the vesicular inclusions were secreted. Taken together, these observations suggest that vesicular inclusions in SP-B -/- mice are disorganized lamellar bodies in which the absence of SP-B leads to failure to package surfactant phospholipids into concentric lamellae. |
