Extracellular matrix remodeling in oral submucous fibrosis: its stage-specific modes revealed by immunohistochemistry and in situ hybridization.
BACKGROUND
Oral submucous fibrosis (OSF) is a chewing habit-related pre-cancerous condition of the oral mucosa affecting predominantly south Asians. It is histopathologically characterized by epithelial atrophy and fibrosis of the subepithelial connective tissue. Fibrosis extends all the way into the muscle layer, leading to difficulty in mouth opening. However, the dynamics of extracellular matrix (ECM) remodeling with OSF progression is largely unknown.


METHODS
Forty biopsy specimens of OSF and 10 of normal buccal mucosa were examined for expression/deposition modes of eight ECM molecules by histochemistry, immunohistochemistry, and in situ hybridization.


RESULTS
In the early stage of OSF, tenascin, perlecan, fibronectin, collagen type III were characteristically enhanced in the lamina propria and the submucosal layer. In the intermediate stage, the ECM molecules mentioned above and elastin were extensively and irregularly deposited around muscle fibers. In the advanced stage, such ECM depositions decreased and were entirely replaced with collagen type I only. Their gene expression levels varied with progression of fibrosis, but the mRNA signals were confirmed in fibroblasts in the submucosal fibrotic areas.


CONCLUSIONS
The results indicate that the ECM remodeling steps in OSF are similar to each phase of usual granulation tissue formation. Restricted mouth opening may be a result of loss of variety of ECM molecules including elastin into the homogeneity of collagen type I replacing muscle fibers.
Utsunomiya
Hiroko
H
Division of Oral Pathology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Niigata 951-8514, Japan.
Tilakaratne
Wanninayake M
WM
Oshiro
Kazufumi
K
Maruyama
Satoshi
S
Suzuki
Makoto
M
Ida-Yonemochi
Hiroko
H
Cheng
Jun
J
Saku
Takashi
T
D016022:Case-Control Studies; D018450:Disease Progression; D004549:Elastin / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism / Q000473:pathology*; D016326:Extracellular Matrix Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D024022:Fibrillar Collagens / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D005353:Fibronectins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D015870:Gene Expression; D019812:Heparan Sulfate Proteoglycans / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007797:Laminin / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D009061:Mouth Mucosa / Q000473:pathology; D009914:Oral Submucous Fibrosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D019063:Tenascin / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics
D016326:Extracellular Matrix Proteins; D024022:Fibrillar Collagens; D005353:Fibronectins; D019812:Heparan Sulfate Proteoglycans; D007797:Laminin; D019063:Tenascin; C071927:perlecan; D004549:Elastin