Detection of collagenase mRNA in odontoclasts of bovine root-resorbing tissue by in situ hybridization.
The odontoclast, which is morphologically similar to osteoclast, is thought to play a major role in root resorption of deciduous teeth. High collagenolytic activity has been detected in the root resorbing tissue. In order to identify collagenase-producing cells and the role of collagenase in root resorption of deciduous tooth, in situ hybridization of collagenase mRNA in bovine root-resorbing tissue sections was performed using a digoxigenin-labeled, nonradioactive RNA probe. Collagenase mRNA expression was clearly observed in odontoclasts in addition to the macrophages, fibroblasts, odontoblasts, and cementoblasts. Multinuclear odontoclasts showed intense tartrate-resistant acid phosphatase (TRAP) activity. We also examined interleukin-1 (IL-1) mRNA expression in the root-resorbing tissue by in situ hybridization. IL-1 transcripts were found to be expressed in odontoclasts, fibroblasts, and macrophages suggesting that IL-1 might be an important factor for promoting root resorption. These results suggest that the collagenase produced by odontoclasts may play a key role in dentin collagen degradation in root resorption.
Okamura
T
T
Department of Pedodontics, School of Dentistry, Tokyo Medical and Dental University, Japan.
Shimokawa
H
H
Takagi
Y
Y
Ono
H
H
Sasaki
S
S
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D002417:Cattle; D002478:Cells, Cultured; D017364:Collagenases / Q000096:biosynthesis / Q000235:genetics*; D003739:Dental Cementum / Q000201:enzymology; D005347:Fibroblasts / Q000201:enzymology; D017403:In Situ Hybridization; D007375:Interleukin-1 / Q000096:biosynthesis / Q000235:genetics; D008264:Macrophages / Q000201:enzymology; D009804:Odontoblasts / Q000201:enzymology; D010010:Osteoclasts / Q000201:enzymology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012391:Root Resorption / Q000201:enzymology*
D007375:Interleukin-1; D012333:RNA, Messenger; D000135:Acid Phosphatase; D017364:Collagenases