Involvement of MT1-MMP and TIMP-2 in human periodontal disease.
OBJECTIVE
Periodontal disease is characterized by an increased collagen metabolism. Although membrane type-1 matrix metalloproteinase (MT1-MMP) plays a critical role in collagen degradation, its involvement in human periodontitis remains to be determined.


METHODS
MT1-MMP and TIMP-2 expression and distribution were evaluated in gingival tissue samples derived from 10 healthy and 12 periodontitis-affected human subjects. MT1-MMP and TIMP-2 expression were assessed through Western-blot of tissue homogenates. The main cell types involved in MT1-MMP and TIMP-2 production were evaluated by means of immunohistochemistry.


RESULTS
Both MT1-MMP and TIMP-2 were significantly increased in periodontitis-affected gingival tissues when compared to healthy gingiva. Moreover, the balance between MT1-MMP and its inhibitor TIMP-2 was altered in periodontitis-affected tissues, suggesting an imbalance in this proteolytic axis. Immunohistochemistry demonstrated the expression of MT1-MMP in fibroblasts and macrophages in gingival tissues. MT1-MMP was detected in cells in close association with the gingival collagen matrix. TIMP-2 expression was identified in fibroblasts, macrophages and epithelial cells.


CONCLUSIONS
Our observations show an increased expression of MT1-MMP and TIMP-2 in periodontitis-affected gingival tissues. The altered balance between these two molecular mediators of collagen remodeling suggests their involvement in human periodontal disease.
Oyarzún
A
A
Faculty of Odontology, Universidad Finis Terrae.
Arancibia
R
R
Hidalgo
R
R
Peñafiel
C
C
Cáceres
M
M
González
M-J
MJ
Martínez
J
J
Smith
P C
PC
D016022:Case-Control Studies; D005881:Gingiva / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D010518:Periodontitis / Q000201:enzymology* / Q000473:pathology; D012016:Reference Values; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*
D019716:Tissue Inhibitor of Metalloproteinase-2; D053511:Matrix Metalloproteinase 14