Am. J. Respir. Cell Mol. Biol., Vol 12, No. 3, 03 1995, 280-286.
Differential expression of annexins I and II in bovine bronchial epithelial cells
JK Vishwanatha, G Muns, JD Beckmann, RG Davis and I Rubinstein
Department of Biochemistry and Molecular Biology, College of Medicine, University of Nebraska Medical Center, Omaha 68198-4525.
Annexins I and II have been proposed to participate in regulation of
inflammation and cell proliferation. In the present study, we examined the
expression of annexins I and II in various levels of the bovine respiratory
tract and in cultured bovine bronchial epithelial cells. Immunoblot
analysis of whole-tissue extracts revealed low-level expression of annexins
I and II in bronchial mucosa mainstem to fourth generation. In contrast,
high levels of annexins I and II (15- to 20- fold higher than in the
bronchial mucosa) were seen in the distal lung parenchyma.
Immunohistochemical staining of tracheobronchial tissue sections with
anti-annexin I antibody revealed an uneven positive reaction of about 30 to
40% of the columnar differentiated ciliated and secretory cells, with no
obvious positivity within the nondifferentiated basal epithelial cell
layer. In contrast, anti- annexin II antibody reacted nearly uniformly
within the basal cell layer, with no obvious decoration of the
differentiated cell types. These results were confirmed by immunoblot
analysis of annexin I and II in density fractionated populations of basal
and secretory/ciliated epithelial cells. Both annexins I and II were
expressed at constitutive levels in bovine bronchial epithelial cells grown
in glucocorticoid- and serum-free medium, and dexamethasone increased
expression of both proteins in a concentration-dependent manner. We
conclude that annexins I and II are differentially expressed in the
differentiated ciliated cells and undifferentiated basal cells.(ABSTRACT
TRUNCATED AT 250 WORDS)
