Modulations of the epithelial phenotype and functional activity of cultured bovine tracheal gland cells: dependence on the culture medium and passage number

Abstract

Bovine tracheal gland (BTG) cells in culture show an epithelial-fibroblastoid transition after several passages. To investigate these BTG cell phenotype changes, we studied the effects of both the culture medium and passage number on the expression of epithelial cytoskeletal proteins and glandular serous cell markers. We also analyzed the intracellular cAMP level in the basal state and after adrenergic stimulation. Three culture media were used: 1) serum-free defined medium (SFDM); 2) medium supplemented with 2% Ultroser G; and 3) medium supplemented with 10% fetal calf serum (FCS). Using immunofluorescence microscopy, we showed that, in the first 4 passages whatever the culture conditions, BTG cells expressed immunoreactivities to cytokeratin filaments and desmoplakins I and II, whereas vimentin filaments were not detected. After four passages, BTG cells cultured in 10% FCS or 2% Ultroser G became progressively fibroblastoid and showed immunoreactivities to both vimentin and cytokeratin intermediate filaments. No immunoreactivity to vimentin filaments was observed on BTG cells cultured in a SFDM. Using biochemical analysis, we showed that basal levels of cAMP in cultured BTG cells and lysozyme secretion by these cells vary according to the culture medium and passage number. It was higher in BTG cells cultured in a SFDM compared to that recovered from cells cultured in medium supplemented with Ultroser G or FCS. Whatever the culture medium, BTG cells responded to stimulation by isoproterenol. However, the results of stimulation in a SFDM were higher than in Ultroser G or FCS supplemented medium. We conclude that the BTG epithelial cell organization and the regulation of biosynthesis of secretory proteins by these cells in culture depend on both the culture medium and passage number.(ABSTRACT TRUNCATED AT 250 WORDS)

Innate Immunity in the Vagina (Part I): Estradiol Inhibits HBD2 and Elafin Secretion by Human Vaginal Epithelial Cells

“…used primary VEC that were obtained from enzymatically digested tissue and grown in vitro for at least 2 weeks before treatment. Previous studies have shown that the phenotype of FRT epithelial cells in culture changes with increasing passage number . In contrast, we used freshly isolated VEC that were in culture for a maximum of 72 hrs.…”

Localization of the cystic fibrosis transmembrane conductance regulator in airway secretory glands

“…Fresh bovine tracheae were obtained from a local abattoir. Isolation and culture conditions of bovine tracheal submucosal gland (BTG) [20] and human tracheal submucosal gland (HTG) [21] cells have previously been described.…”