Differential expression of annexins I and II in bovine bronchial epithelial cells.
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)
Vishwanatha
J K
JK
Department of Biochemistry and Molecular Biology, College of Medicine, University of Nebraska Medical Center, Omaha 68198-4525.
Muns
G
G
Beckmann
J D
JD
Davis
R G
RG
Rubinstein
I
I
D000818:Animals; D017305:Annexin A1 / Q000378:metabolism*; D017306:Annexin A2 / Q000378:metabolism*; D015153:Blotting, Western; D001980:Bronchi / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D004848:Epithelium / Q000378:metabolism; D007124:Immunoenzyme Techniques; D066298:In Vitro Techniques
D017305:Annexin A1; D017306:Annexin A2; D003907:Dexamethasone