Expression of MT1-MMP during deciduous tooth resorption in odontoclasts.
Membrane type 1-matrix metalloproteinase (MT1-MMP) is a membrane-bound matrix metalloproteinase capable of mediating pericellular proteolysis of extracellular matrix components. In osteoclasts, the localization of MT1-MMP has been reported at the tips of specialized membrane protrusions (podosomes and lamellipodia) so that osteoclasts might use MT1-MMP to perform focal proteolysis and move through the extracellular matrix to the bone surface. The objectives of this study were to investigate an association of MT1-MMP in physiological root resorption of the deciduous tooth by reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot analysis, and to identify MT1-MMP-producing cell during deciduous tooth resorption by in situ hybridization and immunohistochemistry. RT-PCR and Northern blot analysis revealed the exclusively high expression of MT1-MMP mRNA in bovine root-resorbing tissue, which lies between the root of the deciduous tooth and its permanent successor. Expression of MT1-MMP mRNA was seen in odontoclasts aligning in the surface layer of the root-resorbing tissue at sites of root resorption. Furthermore, immmunohistochemistry also confirmed the localization of MT1-MMP protein to the odontoclasts. The present identification of MT1-MMP in odontoclasts during deciduous tooth resorption might be relevant to the migration activity that these cells have to gain access to the root surface.
Linsuwanont-Santiwong
Busayarat
B
Department of Pediatric Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
Takagi
Yuzo
Y
Ohya
Keiichi
K
Shimokawa
Hitoyata
H
D000818:Animals; D002417:Cattle; D015870:Gene Expression; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D010010:Osteoclasts / Q000378:metabolism* / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D014091:Tooth Resorption / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*
D012333:RNA, Messenger; D053509:Matrix Metalloproteinase 13; D020778:Matrix Metalloproteinase 2; D053511:Matrix Metalloproteinase 14