Mucin synthesis and secretion by cultured tracheal cells: effects of collagen gel substratum thickness

Abstract

We previously demonstrated that human tracheobronchial epithelial (TBE) cells synthesize mucin and form mucous granules in culture when they are maintained on a collagen gel (CG) substratum, but not on a plastic tissue culture surface or a thin collagen-coated surface (Wu et al., Am. J. Respir. Cell Mol. Biol., 3:467-478; 1990). This observation led us to examine the effects of CG thickness on cell growth and differentiation in primary human/monkey TBE cell cultures. Using the same CG preparation, culture dishes with different thicknesses of CG substratum were prepared. In general, equivalent degrees of cell attachment and proliferation were observed in all cultures maintained on a collagen gel, independent of the thicknesses of CG substratum. However, a greater degree of mucin synthesis and secretion by the cells was observed as the thickness of the CG substratum was increased. Cultures maintained on a thick collagen gel (1 mm) exhibited greater apical membrane complexity, more pseudostratification, and more mucous granules than did cultures maintained on a thin CG substratum. The optimal culture surface for airway mucous cell differentiation contains more than 1-mm thickness of collagen gel substratum.

In vitro Nasal Cell Culture Systems for Drug Transport Studies

“…However, the effect of collagen during the nasal cell culture is still controversial. It was reported that collagen gel, of which thickness was more than 1 mm could produce more pseudostratified cells (Robinson and Wu, 1993). However, in other reports (Werner and Kissel, 1995;Wu et al, 1985), collagen-coated supports provided similar or less cell growth and differentiation compared to uncoated supports.…”

Staphylococcus aureus adherence to nasal epithelial cells in a physiological in vitro model

“…The type of surface on which the cells are grown influences receptors as well as cellular architecture, two factors regulating gene expression and leading ultimately to the presentation of specific phenotypic characteristics (14). In addition, it appears that the epithelial cells will respond to secretory products from fibroblasts embedded in collagen gels (28,34).…”

“…However, increasing evidence suggests the need to further enhance in vitro culture systems with extracellular matrix (ECM) proteins to more closely simulate physiological environments. ECM (e.g., collagen I and IV, fibronectin, and laminin) are vital components of the cellular microenvironment in vivo and their use in vitro has been shown to promote cell growth and enhance expression of cell-specific morphology and function (28,34). Collagen I has been used to promote cell attachment and spreading, to expand cell populations rapidly, to grow cells in serum-free or serum-poor conditions, to investigate cell adherence, and to improve survival of primary ceils in culture.…”

Biocompatible hydrogel supports the growth of respiratory epithelial cells: Possibilities in tracheal tissue engineering

“…However, this could be improved by the adoption of certain strategies, such as the culturing of epithelial cells on a thicker threedimensional hydrogel matrix, 35 the use of the hydrogel matrix with the controlled release of agents known to induce a higher mucosecretory function, 36 the addition of a conditioned medium from respiratory fibroblasts, and the coculture of respiratory epithelial cells with respiratory fibroblasts 37 on our hydrogel matrix. These strategies could enable us to build epithelial tissue that closely resembles the composition of the natural epithelium.…”