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Differential expression of integrins and laminin‐5 in normal oral epithelia
Author(s) -
THORUP ALIS KARABULUT,
DABELSTEEN ERIK,
SCHOU SØREN,
GIL SUSANA G.,
CARTER WILLIAM G.,
REIBEL JESPER
Publication year - 1997
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1699-0463.1997.tb05049.x
Subject(s) - laminin , integrin , epithelium , basement membrane , biology , extracellular matrix , pathology , connective tissue , cell adhesion molecule , microbiology and biotechnology , population , cell , medicine , biochemistry , genetics , environmental health
β1 and β4 integrins are receptors on epithelial cells mediating cell‐extracellular matrix adhesion. Furthermore, α2β1 and α3β1 contribute to cell‐cell adhesion. Laminin‐5 in epithelial basement membranes (BMs) is a ligand for α6β4 and α3β1. Expression of different integrins and laminin‐5 was studied in oral epithelium to characterize regional variations in these adhesion molecules. Monoclonal antibodies directed against α2‐α6β1/α6β4 and laminin‐5 were examined in cryopreserved biopsies of normal mucosa by immunohistochemistry. Laminin‐5 was expressed as a line along the BMs. The junctional epithelium showed a unique phenotype: Laminin‐5 was detected in the internal BM at the tooth surface and in the external BM, where excessive laminin‐5 was seen in the stroma. α6β4 was expressed in all cells of the junctional epithelium. Integrins α4β1 and α5β1 were not detected in the epithelia, whereas α2β1 and α3β1 showed differential expression. Epithelia with well‐developed rete pegs and connective tissue papillae showed polarized α3β1 expression along the BM in the rete pegs, in contrast to negative expression at the tips of the connective tissue papillae. A variation in the suprabasal distribution of α2β1 and α3β1 was observed between epithelia from different regions. α2β1 and α3β1 were detected in basal/parabasal cells in keratinized epithelia, whereas there was increased suprabasal expression in nonkeratinized mucosa. These results indicate inhomogeneity in the basal cell population of oral squamous epithelia and differential expression of integrins, which may reflect differences in the underlying stroma. Laminin‐5 deposits in the stroma underneath the junctional epithelium may indicate subclinical gingival inflammation.