title: Association of caspase-14 and filaggrin expression with keratinization of the oral mucosa and reconstruction culture rat models.
abstract: OBJECTIVE
  Keratinization of the oral mucosa, such as the gingiva, has been shown to be important for periodontal health. Caspase-14 is a protease that plays a role in keratinization of the epidermis. The objective of this study was to investigate whether the expression of caspase-14 is intimately linked with keratinization and to examine the effect of the main component of green tea on the improvement of keratinization in rat oral mucosal preparations.
  
  
  METHODS
  Histological and immunohistochemical analyses and quantitative mRNA measurements of caspase-14 and its substrate filaggrin were performed using different types of rat epithelial tissue and organotypic reconstruction culture models derived from epithelial cells and fibroblasts taken from the rat oral mucosa.
  
  
  RESULTS
  In the skin, palate, buccal mucosa and esophagus, the degree of keratinization appeared to be associated with expression of cytokeratin 10. The relative protein and mRNA expression levels of caspase-14 and filaggrin were consistent with the degree of keratinization in the following order: skin > palate > buccal mucosa > esophagus. The culture models of palatal and buccal mucosa retained a stratified epithelial structure. Expression of caspase-14 appeared to be stronger in the palatal model than in the buccal model. Remarkably, epigallocatechin-3-gallate (EGCG) improved the localization of cytokeratins and increased the expression of caspase-14 and filaggrin. This expression was more intense in the palatal model than in the buccal model, indicating that both models maintain the intrinsic properties of keratinization of the mucosa from where the cultured cells were derived.
  
  
  CONCLUSIONS
  These results suggest that keratinization is closely associated with expression of caspase-14 and filaggrin. Our reconstruction models are promising tools for drug evaluation and show that EGCG is beneficial for improving both keratinization and expression of the linked protease in the oral mucosa.
authors: Department of Odontology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka, 814-0193, Japan.
authors: H
authors: H
authors: Murakami
authors: K
authors: K
authors: Okamura
authors: S
authors: S
authors: Aoki
authors: R
authors: R
authors: Sakagami
authors: J
authors: J
authors: Yamazaki
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D053456:Caspase 14 / Q000032:analysis* / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D018929:Cell Culture Techniques; D004847:Epithelial Cells / Q000737:chemistry; D004848:Epithelium / Q000737:chemistry; D004947:Esophagus / Q000166:cytology; D005347:Fibroblasts / Q000737:chemistry; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins / Q000032:analysis* / Q000187:drug effects; D053550:Keratin-10 / Q000032:analysis / Q000187:drug effects; D007633:Keratins; D023421:Models, Animal; D009061:Mouth Mucosa / Q000737:chemistry*; D010159:Palate / Q000166:cytology; D010750:Phosphoproteins / Q000032:analysis*; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000166:cytology; D046509:Tissue Culture Techniques
chemical_list: D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins; D010750:Phosphoproteins; D011480:Protease Inhibitors; D053550:Keratin-10; D007633:Keratins; D002392:Catechin; C045651:epigallocatechin gallate; D053456:Caspase 14
keywords: caspase-14; filaggrin; keratinization; oral mucosa