Connective tissue influences on patterns of epithelial architecture and keratinization in skin and oral mucosa of the adult mouse

Abstract

Epithelial-mesenchymal interactions play an important role during embryogenesis but it is uncertain whether such interactions influence the maintenance of epithelial structure in the adult. To examine this problem, separated epithelial and connective tissue components of skin and mucosae from various regions of adult mice were homo-or heterotypically recombined and transplanted to histo-compatible hosts. The patterns of tissue architecture and keratinization of the resultant epithelia were examined for changes indicative of mesenchymal influences on the epithelial phenotype. Each type of epithelium, in some recombinations, fully conserved its normal pattern of phenotypic expression indicating that subepithelial connective tissue from all regions is permissive and that regionally-specific connective tissue influences are not necessary for conservation of epithelial specificity. In other recombinations, however, the epithelium acquired features of tissue architecture or keratinization typical of the epithelium normally associated with the connective tissue component, indicating directive influences from the connective tissue. The patterns of epithelial response observed suggest that there may be separate connective tissue influences on epithelial architecture and cyto-differentiation and that there is a regionally-related variation in the competence of epithelia to respond to these influences.

Engineered Keratinized Oral Mucosa Decreased C. albicans Transition Through the Production of Keratins 10, 14, 16, and 19 by Oral Epithelial Cells

“…The epithelial cell monolayer produced greater amounts of differentiating K10 than did the kEHOM and nkEHOM following contact with C. albicans. This is in agreement with previously reported results indicating that K10 expression varies with cell type [39], developmental stage [40], tissue differentiation [41], and pathological changes [42]. Given the effect of C. albicans on K10 production, we investigated the effect on proliferative and basal layer K14 and showed that the yeast did not affect K14 production.…”

Tissue Engineering of Skin

“…Even though clinical evidence is lacking, it may very well be possible to obtain oral site-differentiated epithelium by culturing keratinocytes from different places in the oral cavity. On the other hand, it has previously been shown, in several studies, that the dermis does indeed play a role in epidermal morphology and cytodifferentiation (Karring et al, 1975;Mackenzie and Hill, 1984;Hill and Mackenzie, 1984). Instead of culturing, the authors transplanted the epithelium and underlying connective tissue in various combinations among histocompatible hosts to various sites.…”

Recapitulation of oral mucosal tissues in long‐term organotypic culture

“…Cultured keratinocytes show full differentiation only if associated with a connective tissue or with fibroblasts (Rheinwald and Green, 1975;Mackenzie and Hill, 1984;Mackenzie and Dabelsteen, 1987). Native collagen alone may promote keratinocyte attachment and proliferation, but not differentiation (Holbrook and Hennings, 1983).…”

“…Melby and Karasek (1973) proposed two mechanisms to explain the influence of connective tissue on epithelial cells: 1) the connective tissue provides a physical substrate for attachment and orientation of epidermal basal cells; and 2) the connective tissue cells synthesize diffusible proteins that influence both growth and differentiation of epithelial cells. That diffusible factors of dermal origin facilitate growth and differentiation of the epithelial cells has long been considered relevant (Karring et al, 1975;Mackenzie and Fusenig, 1983;Mackenzie and Hill, 1984;Coulomb, 1989;Mackenzie et al, 1993). Mackenzie and Fusenig (1983) showed that even if keratinocytes have no direct contact with connective tissue, they still show full differentiation, thereby demonstrating that diffusible dermal products contribute to the differentiation of cultured keratinocytes.…”

“…It has been known for decades that for isolated keratinocytes to form a structurally complete epithelium, the cells must be associated with a connective tissue matrix or with fibroblasts (Rheinwald and Green, 1975;Mackenzie and Hill, 1984;Mackenzie et al, 1993). Here we report that collagen type I gels can be modified by cultured fibroblasts, and that these modified matrices will modulate the appropriate epithelial structure from cultured keratinocytes.…”