Am. J. Respir. Cell Mol. Biol., Volume 19, Number 6, December, 1998 929-935

Trafficking of Newly Synthesized Surfactant Protein A in Isolated Rat Alveolar Type II Cells

Kazuhiro Osanai, Robert J. Mason, and Dennis R. Voelker

National Jewish Medical and Research Center; and Department of Medicine, Anna Perahia Adatto Clinical Research Center, Denver, Colorado

We examined the synthesis, transport, and localization of surfactant protein A (SP-A) in primary cultures of alveolar type II cells. In type II cells maintained in culture for 6 h, 39% of the SP-A pool detected with an enzyme-linked immunosorbent assay (ELISA) was found in lamellar bodies (LBs). After 24 h in culture, 53% of the cellular SP-A pool was found in LBs. The absolute amount of SP-A in the LB compartment was almost identical at 6 and 24 h of culture. In contrast to the results obtained with ELISA, ³⁵S labeling of newly synthesized SP-A revealed that less than 7% of the cellular SP-A pool was in LBs at either 6 or 24 h of culture. In the 6-h cultures, 17% of the total (i.e., cells and media) [³⁵S]SP-A pool was extracellular. In the 24-h cultures, 70% of the [³⁵S]SP-A pool was extracellular. The secretion of [³⁵S]SP-A was blocked by brefeldin A at all times. When medium containing newly secreted [³⁵S]SP-A was incubated with alveolar type II cells maintained in culture for 24 h, the protein was taken up and incorporated into the LB fraction. More than 80% of the internalized SP-A was associated with the LB compartment after a 6 h incubation. The uptake of [³⁵S]SP-A was blocked at 4°C and was promoted by addition of unlabeled SP-A at 37°C. These findings support a pathway of extracellular routing of SP-A prior to its accumulation in LBs in cultured type II cells.

This article has been cited by other articles:

				K. Osanai, R. Oikawa, J. Higuchi, M. Kobayashi, K. Tsuchihara, M. Iguchi, H. Jongsu, H. Toga, and D. R. Voelker A Mutation in Rab38 Small GTPase Causes Abnormal Lung Surfactant Homeostasis and Aberrant Alveolar Structure in Mice Am. J. Pathol., November 1, 2008; 173(5): 1265 - 1274. [Abstract] [Full Text] [PDF]

				A. V. Andreeva, M. A. Kutuzov, and T. A. Voyno-Yasenetskaya Regulation of surfactant secretion in alveolar type II cells Am J Physiol Lung Cell Mol Physiol, August 1, 2007; 293(2): L259 - L271. [Abstract] [Full Text] [PDF]

				N. Gupta, Y. Manevich, A. S. Kazi, J.-Q. Tao, A. B. Fisher, and S. R. Bates Identification and characterization of p63 (CKAP4/ERGIC-63/CLIMP-63), a surfactant protein A binding protein, on type II pneumocytes Am J Physiol Lung Cell Mol Physiol, September 1, 2006; 291(3): L436 - L446. [Abstract] [Full Text] [PDF]

				J. E. Crowther and L. S. Schlesinger Endocytic pathway for surfactant protein A in human macrophages: binding, clathrin-mediated uptake, and trafficking through the endolysosomal pathway Am J Physiol Lung Cell Mol Physiol, February 1, 2006; 290(2): L334 - L342. [Abstract] [Full Text] [PDF]

				S. H. Guttentag, A. Akhtar, J.-Q. Tao, E. Atochina, M. E. Rusiniak, R. T. Swank, and S. R. Bates Defective Surfactant Secretion in a Mouse Model of Hermansky-Pudlak Syndrome Am. J. Respir. Cell Mol. Biol., July 1, 2005; 33(1): 14 - 21. [Abstract] [Full Text] [PDF]

				R. Ridsdale and M. Post Surfactant lipid synthesis and lamellar body formation in glycogen-laden type II cells Am J Physiol Lung Cell Mol Physiol, October 1, 2004; 287(4): L743 - L751. [Abstract] [Full Text] [PDF]

				F. Brasch, J. Birzele, M. Ochs, S.H. Guttentag, O.D. Schoch, A. Boehler, M.F. Beers, K.M. Muller, S. Hawgood, and G. Johnen Surfactant proteins in pulmonary alveolar proteinosis in adults Eur. Respir. J., September 1, 2004; 24(3): 426 - 435. [Abstract] [Full Text] [PDF]

				F. Brasch, G. Johnen, A. Winn-Brasch, S. H. Guttentag, A. Schmiedl, N. Kapp, Y. Suzuki, K. M. Muller, J. Richter, S. Hawgood, et al. Surfactant Protein B in Type II Pneumocytes and Intra-Alveolar Surfactant Forms of Human Lungs Am. J. Respir. Cell Mol. Biol., April 1, 2004; 30(4): 449 - 458. [Abstract] [Full Text] [PDF]

				J. B. Cowland, O. E. Sorensen, M. Sehested, and N. Borregaard Neutrophil Gelatinase-Associated Lipocalin Is Up-Regulated in Human Epithelial Cells by IL-1{beta}, but Not by TNF-{alpha} J. Immunol., December 15, 2003; 171(12): 6630 - 6639. [Abstract] [Full Text] [PDF]

				C. D. Foster, P. X. Zhang, L. W. Gonzales, and S. H. Guttentag In Vitro Surfactant Protein B Deficiency Inhibits Lamellar Body Formation Am. J. Respir. Cell Mol. Biol., August 1, 2003; 29(2): 259 - 266. [Abstract] [Full Text] [PDF]

				J. A. Platt, N. Kraipowich, F. Villafane A., and J. C. DeMartini Alveolar Type II Cells Expressing Jaagsiekte Sheep Retrovirus Capsid Protein and Surfactant Proteins Are the Predominant Neoplastic Cell Type in Ovine Pulmonary Adenocarcinoma Vet. Pathol., May 1, 2002; 39(3): 341 - 352. [Abstract] [Full Text] [PDF]

				M. Ochs, G. Johnen, K.-M. Muller, T. Wahlers, S. Hawgood, J. Richter, and F. Brasch Intracellular and Intraalveolar Localization of Surfactant Protein A (SP-A) in the Parenchymal Region of the Human Lung Am. J. Respir. Cell Mol. Biol., January 1, 2002; 26(1): 91 - 98. [Abstract] [Full Text] [PDF]

				L. I. Gobran and S. A. Rooney Regulation of SP-B and SP-C secretion in rat type II cells in primary culture Am J Physiol Lung Cell Mol Physiol, December 1, 2001; 281(6): L1413 - L1419. [Abstract] [Full Text] [PDF]

				O. Gurel, M. Ikegami, Z. C. Chroneos, and A. H. Jobe Macrophage and type II cell catabolism of SP-A and saturated phosphatidylcholine in mouse lungs Am J Physiol Lung Cell Mol Physiol, June 1, 2001; 280(6): L1266 - L1272. [Abstract] [Full Text] [PDF]

				K. Osanai, M. Iguchi, K. Takahashi, Y. Nambu, T. Sakuma, H. Toga, N. Ohya, H. Shimizu, J. H. Fisher, and D. R. Voelker Expression and Localization of a Novel Rab Small G Protein (Rab38) in the Rat Lung Am. J. Pathol., May 1, 2001; 158(5): 1665 - 1675. [Abstract] [Full Text] [PDF]

				J. M. Shannon, T. Pan, L. D. Nielsen, K. E. Edeen, and R. J. Mason Lung Fibroblasts Improve Differentiation of Rat Type II Cells in Primary Culture Am. J. Respir. Cell Mol. Biol., March 1, 2001; 24(3): 235 - 244. [Abstract] [Full Text] [PDF]

				K. G. Davidson, A. D. Bersten, H. A. Barr, K. D. Dowling, T. E. Nicholas, and I. R. Doyle Lung function, permeability, and surfactant composition in oleic acid-induced acute lung injury in rats Am J Physiol Lung Cell Mol Physiol, December 1, 2000; 279(6): L1091 - L1102. [Abstract] [Full Text] [PDF]

				M. Traebert, O. Hattenhauer, H. Murer, B. Kaissling, and J. Biber Expression of type II Na-Pi cotransporter in alveolar type II cells Am J Physiol Lung Cell Mol Physiol, November 1, 1999; 277(5): L868 - L873. [Abstract] [Full Text] [PDF]

				J. J. Conkright, J. P. Bridges, C.-L. Na, W. F. Voorhout, B. Trapnell, S. W. Glasser, and T. E. Weaver Secretion of Surfactant Protein C, an Integral Membrane Protein, Requires the N-terminal Propeptide J. Biol. Chem., April 27, 2001; 276(18): 14658 - 14664. [Abstract] [Full Text] [PDF]

				R. J. Mason, M. C. Lewis, K. E. Edeen, K. McCormick-Shannon, L. D. Nielsen, and J. M. Shannon Maintenance of surfactant protein A and D secretion by rat alveolar type II cells in vitro Am J Physiol Lung Cell Mol Physiol, February 1, 2002; 282(2): L249 - L258. [Abstract] [Full Text] [PDF]