| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Clinic of Neonatology, University Children's Hospital Charité, Humboldt-Universität Berlin, 10098 Berlin; and 2 University Children's Hospital, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
Surfactant protein (SP) A and
SP-A-mediated lipid uptake by isolated type II cells were investigated
with biochemical and morphological methods. Inhibition of coated-pit
function by potassium depletion severely reduced both SP-A and
SP-A-mediated lipid internalization. Lipid uptake in the absence of
SP-A was not affected. With confocal laser scanning microscopy and
immunoelectron microscopy, SP-A and lipid predominantly (60%)
colocalized in intracellular vesicles carrying early endosomal markers
(EEA1) 5 min after endocytosis but were negative for the late endosomal
or lysosomal marker LAMP-1. As estimated by subcellular fractionation,
at this time point, 23% of the internalized SP-A and 45% of
internalized lipid were localized within light (<0.38 M sucrose)
fractions, which contain lamellar bodies and are positive for EEA1. The
remaining label was predominantly found within EEA1-positive and plasma
membrane-containing subfractions (
1 M sucrose). We suggest that in
isolated type II cells in vitro, SP-A and lipid are taken up together
via the coated-pit pathway and that at early time points, both
components reside in the same early endosomal compartment.
early endosome; lamellar body; coated vesicle
This article has been cited by other articles:
|
|
 |
|
  C. Moulakakis and C. Stamme Role of clathrin-mediated endocytosis of surfactant protein A by alveolar macrophages in intracellular signaling Am J Physiol Lung Cell Mol Physiol, March 1, 2009; 296(3): L430 - L441. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. R. Bates, A. S. Kazi, J.-Q. Tao, K. J. Yu, D. S. Gonder, S. I. Feinstein, and A. B. Fisher Role of P63 (CKAP4) in binding of surfactant protein-A to type II pneumocytes Am J Physiol Lung Cell Mol Physiol, October 1, 2008; 295(4): L658 - L669. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Jain, C. Dodia, A. B. Fisher, and S. R. Bates Pathways for clearance of surfactant protein A from the lung Am J Physiol Lung Cell Mol Physiol, December 1, 2005; 289(6): L1011 - L1018. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. L. H. Poelma, L. J. Zimmermann, W. A. van Cappellen, J. J. Haitsma, B. Lachmann, and J. F. van Iwaarden Distinct effects of SP-B and SP-C on the uptake of surfactant-like liposomes by alveolar cells in vivo and in vitro Am J Physiol Lung Cell Mol Physiol, November 1, 2004; 287(5): L1056 - L1065. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. L. Poelma, M. R. Ju, S. C. Bakker, L. J. Zimmermann, B. F. Lachmann, and J. F. van Iwaarden A Common Pathway for the Uptake of Surfactant Lipids by Alveolar Cells Am. J. Respir. Cell Mol. Biol., May 1, 2004; 30(5): 751 - 758. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Wissel, C. Schulz, M. Rudiger, M. Krull, P. A. Stevens, and R. R. Wauer Chlamydia pneumoniae Affect Surfactant Trafficking and Secretion Due to Changes of Type II Cell Cytoskeleton Am. J. Respir. Cell Mol. Biol., September 1, 2003; 29(3): 303 - 313. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Ruckert, S. R. Bates, and A. B. Fisher Role of clathrin- and actin-dependent endocytotic pathways in lung phospholipid uptake Am J Physiol Lung Cell Mol Physiol, June 1, 2003; 284(6): L981 - L989. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Fehrenbach, C. Bube, J. M. Hohlfeld, P. Stevens, T. Tschernig, H. G. Hoymann, N. Krug, and H. Fehrenbach Surfactant Homeostasis Is Maintained In Vivo during Keratinocyte Growth Factor-induced Rat Lung Type II Cell Hyperplasia Am. J. Respir. Crit. Care Med., May 1, 2003; 167(9): 1264 - 1270. [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]
|
|
|
|
|
|
H. Wissel, A. Lehfeldt, P. Klein, T. Muller, and P. A. Stevens Endocytosed SP-A and surfactant lipids are sorted to different organelles in rat type II pneumocytes Am J Physiol Lung Cell Mol Physiol, August 1, 2001; 281(2): L345 - L360. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
