Regulation of differentiation and keratin protein expression by vitamin A in primary cultures of hamster tracheal epithelial cells

Abstract

Hamster tracheal epithelial (HTE) cells maintained in primary culture show the induction of specific keratin species under vitamin A-deficient conditions. A comparison was made between the morphology and the expression of keratins in HTE cells in vivo and in primary culture with and without vitamin A. HTE cells cultured in serum-free, vitamin A-supplemented medium formed a simple cuboidal, ciliated monolayer and produced four simple epithelial keratins (7, 8, 18, and 19). In contrast, vitamin A-deficient HTE cells, which were squamous-like and stratified in culture, produced a more complex keratin pattern, with the induction of four additional keratin species (5, 6, 14, and 17). A keratin pair whose expression serves as a marker of stratified epithelia was induced, as well as a single keratin species unique to lesions of squamous metaplasia in vitamin A-deficient hamster tracheal organ cultures. Thus it appears that HTe cells retain the ability to respond to a deficiency in vitamin A through squamous differentiation and increased keratin production when removed from the intact organ and maintained in primary culture in a chemically defined medium. This system may be useful for the study of mechanisms underlying the squamous differentiation of respiratory epithelial cells in the development of bronchogenic tumors.

Rehabilitation of Surgically Traumatized Paranasal Sinus Mucosa using Retinoic Acid

“…epithelial cells. 2,[8][9][10][11][12][13] The role of RA in paranasal sinus mucosal wound healing has been reviewed recently. 5 Although our prior studies examined the role of RA in promoting regeneration of ciliated epithelium in the surgically demucosalized sinus, this study investigated the ability of RA to rescue deciliated mucosa that has already regenerated after surgical trauma.…”

Paranasal Sinus Mucosal Regeneration: The Effect of Topical Retinoic Acid

“…Additionally, in a study by Edmondson et al, systemic vitamin A deprivation in hamsters resulted in squamous metaplasia of pseudostratified ciliated tracheal epithelium with loss of goblet cells, resulting in loss of mucus-secreting capability and an overall disruption of the mucociliary microenvironment. 6 In this pilot study, we examined the effect of topical vitamin A (retinoic acid) on healing sinus mucosa. Patients with chronic sinus disease often have inflamed polypoid mucosa that can be stripped away easily during functional endoscopic sinus surgery, even when great care is taken to preserve the mucosal lining.…”

Contribution of in vitro culture methods for respiratory epithelial cells to the study of the physiology of the respiratory tract

“…The epithelial nature of the cultured cells can be demonstrated by their morphology (polarization, microvilli, tight junctions), positive reactions with epithelial specific antibodies (anti-keratins), as illustrated in figure 1, and by redifferentiation into a normal respiratory type epithelium on de-epithelialized trachea implanted in athymic mice [33,34,48]. The expression of keratins in culture depends on the culture conditions and more specifically on the presence or absence of vitamin A [49,50]. The pattern of keratins expressed is related to cell morphology and this may therefore be important in studies concerning differentiation, metaplasia and carcinogenesis.…”