Differential expression of annexins I and II in bovine bronchial epithelial cells

• Published in: American journal of respiratory cell and molecular biology Vol. 12; no. 3; pp. 280 - 286
• Main Authors: Vishwanatha, JK, Muns, G, Beckmann, JD, Davis, RG, Rubinstein, I
• Format: Journal Article
• Language: English
• Published: United States Am Thoracic Soc 01.03.1995; American Thoracic Society
• Subjects: Animals; Annexin A1 - metabolism; Annexin A2 - metabolism; Blotting, Western; Bronchi - metabolism; Cattle; Cells, Cultured; Dexamethasone - pharmacology; Epithelium - metabolism; Immunoenzyme Techniques; In Vitro Techniques
• ISSN: 1044-1549; 1535-4989
• DOI: 10.1165/ajrcmb.12.3.7873194

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.