Transforming growth factor-beta1 and basic fibroblast growth factor modulate osteocalcin and osteonectin/SPARC syntheses in vitamin-D-activated pulp cells.
Vitamin D deficiency elicits hypocalcified dentin. However, little is known about the action of vitamin D on the syntheses of dentin matrix proteins. In this study, we examined the effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on the expressions of osteocalcin and osteonectin/secreted protein, acidic and rich in cysteine (SPARC), by human pulp cells in the presence or absence of transforming growth factor-beta1 (TGF-beta1) or basic fibroblast growth factor (bFGF). 1,25(OH)2D3 markedly increased osteocalcin at protein and mRNA levels. The osteocalcin level induced by 1,25(OH)2D3 was decreased and increased by TGF-beta1 and bFGF, respectively. 1,25(OH)2D3 suppressed SPARC synthesis at protein and mRNA levels. TGF-beta1, but not bFGF, increased SPARC synthesis in the presence of 1,25(OH)2D3. SPARC, but not osteocalcin, increased DNA synthesis in pulp cells. These findings suggest that 1,25(OH)2D3 and growth factors interactively regulate the expression of osteocalcin and SPARC in pulp cells, and that SPARC can stimulate DNA synthesis by pulp cells.
Shiba
H
H
Department of Periodontology and Endodontology, Hiroshima University Faculty of Dentistry, Japan. bashihi@hiroshima-u.ac.jp
Uchida
Y
Y
Kamihagi
K
K
Sakata
M
M
Fujita
T
T
Nakamura
S
S
Takemoto
T
T
Kato
Y
Y
Kurihara
H
H
D000704:Analysis of Variance; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002135:Calcium-Binding Proteins / Q000096:biosynthesis*; D002417:Cattle; D004247:DNA / Q000096:biosynthesis; D003782:Dental Pulp / Q000187:drug effects / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D006133:Growth Substances / Q000378:metabolism*; D006801:Humans; D015675:Osteocalcin / Q000096:biosynthesis; D015676:Osteonectin / Q000096:biosynthesis; D012333:RNA, Messenger / Q000032:analysis; D014074:Tooth Calcification / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000378:metabolism
D002135:Calcium-Binding Proteins; D006133:Growth Substances; D015676:Osteonectin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D015675:Osteocalcin; D004247:DNA; D002117:Calcitriol