Expression patterns of E-cadherin, involucrin, and connexin gap junction proteins in the lining epithelia of inflamed gingiva

Abstract

The structural integrity and functional differentiation of the lining epithelium were studied in relation to inflammatory changes associated with destructive periodontitis. In the different regions of lining epithelia from clinically healthy gingiva and periodontitis, comparisons were made of the expression patterns of E-cadherin, which is critical in intercellular adhesion; of proteins associated with gap junction communication channels; and of involucrin, which is a key marker of differentiation in stratified epithelia. Filamentous actin (F-actin), which is important in cell structural integrity, attachment, and migration, was also examined. Semiquantitative immunohistochemical analysis revealed that in both clinically healthy gingiva and lesions of advanced periodontitis, expression patterns of E-cadherin, involucrin, and connexins 26 and 43 were similar, with a statistically significant reduction in staining intensity from the external oral epithelium, through the gingival sulcus, to the junctional epithelium or pocket epithelium, respectively. Furthermore, there was a striking reduction in staining for E-cadherin, involucrin, and both connexins in the pathological lining epithelium of the periodontal pocket. These changes were associated with marked alterations of filamentous actin expression, collectively indicating profound perturbation of the epithelial structure. The data reported support the concept that the ability of the pathological lining epithelium to function as an effective barrier against the ingress of microbial products into the tissues is severely compromised.

Expression pattern of adhesion molecules in junctional epithelium differs from that in other gingival epithelia

“…In the present study of the human gingival epithelium, connexin 43 was present in the oral gingival epithelium and sulcular epithelium. Although the relationship between gap junctions and E‐cadherin function has been characterized (24), the present study supported the presence of gap junction structures formed with connexin 43 in the gingival epithelium.…”

“…In contrast, in almost all cases, E‐cadherin was scarcely found in the junctional epithelium, although in previous studies, there has been a discrepancy concerning the presence of E‐cadherin in the junctional epithelium. For example, E‐cadherin was weakly expressed in human junctional epithelium of clinically healthy gingiva (24), while it was absent in the junctional epithelium of either rats or mice (25). The absence of E‐cadherin indicates that integrated adherens junctions are not generally present in the junctional epithelium, despite the presence of α‐catenin, γ‐catenin and P‐cadherin.…”

Lysophosphatidic acid regulates adhesion molecules and enhances migration of human oral keratinocytes

“…This allows detrimental entrance of bacteria and their products into the tissues. In sites with periodontal inflammation, the expression of adhesion molecules is significantly reduced and this can, in itself, constitute a pathogenic factor . E‐cadherin is widely expressed in the epithelia in the human oral cavity .…”

Breaking the Gingival Epithelial Barrier: Role of the Aggregatibacter actinomycetemcomitans Cytolethal Distending Toxin in Oral Infectious Disease

“…Ye et al [107] reported a relatively high level of expression of E-cadherin in the basal cell layer of healthy human gingiva. Therefore, E-cadherin was used as a marker to examine the effects of the recombinant Aa Cdt on adherens junctions in situ [105].…”