The effects of enamel matrix derivative (EMD) on osteoblastic cells in culture and bone regeneration in a rat skull defect.
OBJECTIVE
Enamel matrix derivative (EMD) has been clinically used to promote periodontal tissue regeneration. The purpose of the present study is to clarify EMD affects on osteoblastic cells and bone regeneration.


METHODS
Mouse osteoblastic cells (ST2 cells and KUSA/A1 cells) are used in culture experiments. After cells were treated with EMD, cell growth was evaluated with DNA measurement, 5-bromo-2'-deoxyurydine (BrdU) incorporation assay. Measurement of alkaline phosphatase (ALP) activity and mineralized-nodule (MN) formation, Northern blotting analysis and zymography are also performed. In addition, EMD was applied to a rat skull defect and the defect was radiographically and histologically evaluated 2 weeks after the application.


RESULTS
EMD did not stimulate ST2 cell growth; however, it enhanced KUSA/A1 cell proliferation. Although EMD stimulated ALP activity in both the cells, ALP activity in KUSA/A1 cells was affected to a much greater degree. Corresponding to the increase in ALP activity, MN formation in KUSA/A1 cells was enhanced by EMD. EMD stimulated osteoblastic phenotype expression of KUSA/A1 cells such as type I collagen, osteopontin, transforming growth factor beta 1 and osteocalcin. EMD treatment also stimulated matrix metalloproteinase production in KUSA/A1 cells. Although the effects of EMD on osteoblastic cells depend on cell type, the overall effect of EMD on osteoblastic cells is stimulatory rather than inhibitory. Finally, EMD application to a rat skull defect accelerated new bone formation.


CONCLUSIONS
These results indicate that EMD affects osteoblastic cells and has potential as a therapeutic material for bone healing.
Yoneda
Satoshi
S
Masticatory Function Control, Tokyo Medical and Dental University, Yushima, Tokyo, Japan. kome.mfc@tmd.ac.jp
Itoh
Daisuke
D
Kuroda
Shinji
S
Kondo
Hisatomo
H
Umezawa
Akihiro
A
Ohya
Keiichi
K
Ohyama
Takashi
T
Kasugai
Shohei
S
D000469:Alkaline Phosphatase / Q000032:analysis; D000704:Analysis of Variance; D000818:Animals; D001847:Bone Diseases / Q000188:drug therapy*; D001861:Bone Regeneration / Q000187:drug effects*; D002113:Calcification, Physiologic / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D024042:Collagen Type I / Q000032:analysis; D004247:DNA / Q000032:analysis; D003746:Dental Enamel Proteins / Q000494:pharmacology*; D020782:Matrix Metalloproteinases / Q000032:analysis; D051379:Mice; D010006:Osteoblasts / Q000145:classification / Q000187:drug effects*; D015675:Osteocalcin / Q000032:analysis; D053495:Osteopontin; D010641:Phenotype; D010750:Phosphoproteins / Q000032:analysis; D051381:Rats; D012795:Sialoglycoproteins / Q000032:analysis; D012886:Skull / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000032:analysis; D053773:Transforming Growth Factor beta1
D024042:Collagen Type I; D003746:Dental Enamel Proteins; D010750:Phosphoproteins; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; C506897:Spp1 protein, rat; C508961:Tgfb1 protein, mouse; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C109069:enamel matrix proteins; D015675:Osteocalcin; D053495:Osteopontin; D004247:DNA; D000469:Alkaline Phosphatase; D020782:Matrix Metalloproteinases