RGD-CAP (betaig-h3) exerts a negative regulatory function on mineralization in the human periodontal ligament.
In our previous studies, RGD-CAP/betaig-h3 was isolated from a fiber-rich fraction of cartilage and was found to have a negative function on mineralization of hypertrophic chondrocytes. However, the expression and biological function of RGD-CAP in the periodontal ligament (PDL) are not known. We hypothesized that RGD-CAP could be expressed in the PDL and regulate its mineralization. To test this, we investigated the expression of RGD-CAP in human PDL and the effects of RGD-CAP on mineralization of cultured PDL cells. RGD-CAP was detected in the human PDL as multimeric proteins greater than 200 kDa. The RGD-CAP mRNA level decreased in cultured PDL cells exposed to 10(-8) M dexamethasone or 10(-8) M 1alpha,25-dihydroxyvitamin D(3) when these steroids increased alkaline phosphatase (ALP) activity. Furthermore, exogenous RGD-CAP suppressed the ALP activity and bone nodule formation of cultured PDL cells. These findings suggest that RGD-CAP in the PDL modulates the mineralization which affects adjacent alveolar bone metabolism.
Ohno
S
S
Department of Orthodontics, Hiroshima University Faculty of Dentistry, Japan. shigebon@hiroshima-u.ac.jp
Doi
T
T
Fujimoto
K
K
Ijuin
C
C
Tanaka
N
N
Tanimoto
K
K
Honda
K
K
Nakahara
M
M
Kato
Y
Y
Tanne
K
K
D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism; D000539:Alveolar Process / Q000378:metabolism; D015153:Blotting, Western; D002117:Calcitriol / Q000494:pharmacology; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis; D003907:Dexamethasone / Q000494:pharmacology; D015536:Down-Regulation; D016326:Extracellular Matrix Proteins; D006801:Humans; D058574:Integrin-Binding Sialoprotein; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000494:pharmacology; D012795:Sialoglycoproteins / Q000096:biosynthesis; D014074:Tooth Calcification / Q000187:drug effects* / Q000235:genetics*; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein
D000469:Alkaline Phosphatase; D002117:Calcitriol; D024042:Collagen Type I; D003907:Dexamethasone; D016326:Extracellular Matrix Proteins; D058574:Integrin-Binding Sialoprotein; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein; C546871:IBSP protein, human