[Hedgehog pathway is associated with the proliferation and differentiation of osteoblasts].
OBJECTIVE
The purpose of this study was to evaluate the effects of Hedgehog signaling pathway on osteoblast proliferation and differentiation.


METHODS
Primary osteoblasts harvested from newborn rat calvarial bone were cultured for 21 days. The temporary expression of Shh and Ihh was detected by RT-PCR. The culture medium was then treated with either a recombinant Shh N-terminals protein (N-Shh) or cyclopamine (cy), a Hedgehog inhibitor. The proliferation of osteoblasts was quantified by MTT and FCM. The osteoblast differentiation and matrix mineralization were evaluated by ALP and Alizarin-Red staining. The expression of Ptch and Smo was quantified by real-time PCR.SAS 8.0 software package was used for statistical analysis.


RESULTS
Osteoblast expressed both Shh and Ihh. The expression level of Shh decreased with culture time while the amount of Ihh expression increased. N-Shh treatment increased the cell population and the number of cells in S phase (P<0.05. N-Shh also promoted ALP activities (P<0.05) and bone matrix calcification. Moreover, N-Shh application led to an increase in Ptch and Smo mRNA level (P<0.05). Treatment with cy, on the other side, inhibited osteoblast proliferation and differentiation(P<0.05).


CONCLUSIONS
Heghehog signaling pathway is actively involved in regulating osteoblast proliferation and differentiation.
Han
Lei
L
Department of Orthodontics, College of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China. pinedream@163.com
Zhang
Xiao-ling
XL
Li
Xuan
X
Tang
Guo-hua
GH
D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D053823:Hedgehog Proteins; D010006:Osteoblasts; D051381:Rats; D015398:Signal Transduction; D014704:Veratrum Alkaloids
D053823:Hedgehog Proteins; D014704:Veratrum Alkaloids; C000541:cyclopamine