Surfactant proteins A and D in Eustachian tube epithelium.

https://arctichealth.org/en/permalink/ahliterature58617
Source
Am J Physiol Lung Cell Mol Physiol. 2001 Sep;281(3):L660-7
Publication Type
Article
Date
Sep-2001
Author
R. Paananen
R. Sormunen
V. Glumoff
M. van Eijk
M. Hallman
Author Affiliation
Biocenter Oulu, University of Oulu, FIN-90014 Oulu, Finland. rpaanane@cc.oulu.fi
Source
Am J Physiol Lung Cell Mol Physiol. 2001 Sep;281(3):L660-7
Date
Sep-2001
Language
English
Publication Type
Article
Keywords
Animals
Blotting, Western
Bronchoalveolar Lavage Fluid - chemistry
Epithelial Cells - cytology - metabolism
Eustachian Tube - anatomy & histology - cytology - metabolism
Glycoproteins - metabolism
In Situ Hybridization
Irrigation
Microscopy, Electron
Microscopy, Immunoelectron
Proteolipids - metabolism
Pulmonary Surfactant-Associated Protein A
Pulmonary Surfactant-Associated Protein D
Pulmonary Surfactant-Associated Proteins
Pulmonary Surfactants - metabolism
Research Support, Non-U.S. Gov't
Swine
Tissue Distribution
Abstract
Surfactant protein (SP) A and SP-D are collectins that have roles in host defense. The Eustachian tube (ET) maintains the patency between the upper airways and the middle ear. Dysfunction of local mucosal immunity in ET may predispose infants to recurrent otitis media. We recently described preliminary evidence of the expression of SP-A and SP-D in the ET. Our present aim was to establish the sites of SP-A and SP-D expression within the epithelium of the ET in vivo. With in situ hybridization, electron microscopy, and immunoelectron microscopy, the cells responsible for SP-A and SP-D expression and storage were identified. SP-A expression was localized within the ET epithelium, and the protein was found in the electron-dense granules of microvillar epithelial cells. Being concentrated in the epithelial lining, only a few cells revealed intracellular SP-D, and it was not associated with granules. The SP-A and SP-D immunoreactivities in ET lavage fluid, as shown by Western blot analyses, were similar to those in bronchoalveolar lavage fluid. We propose that there are specialized cells in the ET epithelium expressing and secreting SP-A and SP-D. SP-A and SP-D may be important for antibody-independent protection of the middle ear against infections.
PubMed ID
11504694 View in PubMed
Less detail