N-cadherin expression during periodontal ligament cell differentiation in vitro.
BACKGROUND
When confluent periodontal ligament (PDL) cells were cultured in the presence of dexamethasone (Dex), ascorbic acid (AA), and beta-glycerophosphate (GP), they underwent sequential differentiation, demonstrating distinct morphological characteristics. At 1 week, localized cell proliferation led to the formation of multilayers of cells. As cell differentiation progressed, they formed nodules by deposition of matrix in the clusters of cells at 2 weeks, and mineralized the nodules at 3 weeks. These changes implicate extensive cell-to-cell interactions. Cadherins are known to play an important role in establishing cell contacts during tissue formation.


METHODS
To determine whether cadherins are involved in PDL cell differentiation, and the formation and mineralization of nodules by the cells in vitro, we investigated the expression of N-cadherin using immunofluorescence labeling and Northern blot analysis.


RESULTS
Immunolabeling showed that N-cadherin was expressed in PDL cells in the stages of nodule formation and mineralization. Northern blot analysis demonstrated a 3-fold increase in the expression of N-cadherin mRNA in the stages. However, neither E-cadherin nor P-cadherin was expressed.


CONCLUSIONS
Our data suggest that N-cadherin may play an important role in PDL cell differentiation and the formation of mineralized nodules by PDL cells.
Lin
W L
WL
Department of Oral Biology, State University of New York at Buffalo, 14214, USA.
Chien
H H
HH
Cho
M I
MI
D000469:Alkaline Phosphatase / Q000235:genetics; D000818:Animals; D015152:Blotting, Northern; D015820:Cadherins / Q000145:classification / Q000235:genetics*; D002113:Calcification, Physiologic / Q000235:genetics; D002448:Cell Adhesion / Q000235:genetics; D002450:Cell Communication / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D002455:Cell Division; D002478:Cells, Cultured; D003094:Collagen / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D058574:Integrin-Binding Sialoprotein; D015675:Osteocalcin / Q000235:genetics; D015676:Osteonectin / Q000235:genetics; D053495:Osteopontin; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012795:Sialoglycoproteins / Q000235:genetics
D015820:Cadherins; C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; D015676:Osteonectin; D010750:Phosphoproteins; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D015675:Osteocalcin; D053495:Osteopontin; D003094:Collagen; D000469:Alkaline Phosphatase