|
KMID : 0358920010280020238
|
|
Journal of the Korean Academy of Pedodontics
2001 Volume.28 No. 2 p.238 ~ p.246
|
|
|
The effect of BMP regulated Smad protein on alkaline phosphatase gene expression
|
|
Kim Nan-Jin
Ryoo Hyun-Mo
Kim Hyun-Jung
Kim Young-Jin
Nam Soon-Hyeun
|
|
|
Abstract
|
|
|
Bone morphogenetic proteins(BMPs), members of the transforming growth factor β(TGF-β) superfamily were first identified as the factors that induce ectopic bone formation in vivo, when implanted into muscular tissue. Especially BMP-2 inhibits terminal differentiation of C2C12 myoblasts and converts them into osteoblast lineage cells. In the molecular mechanism of the signal transduction of TGF-β and related factors, intracellular signaling proteins were identified as Smad. In previous study, it has been reported that Smad 1 and Smad 5, which belong to the R-Smad family mediate BMP signaling, were involved in the induction of osteoblast differentiation in C2C12 cells.
To understnad the role of Smads involved in osteogenic transdifferentiation in C2C12 cell, in present study, after we stably transfected C2C12 cells with each.
Smad(Smad 1, Smad 5) expression vector, cultured for 3 days and stained for alkaline phophatase activity. ALP activity positive cells appeared in the Smad 1, Smad 5 stably transfected cell even in the abscence of BMP.
After transiently co-transfected C2C12 cells with each Smad expression vector and ALP promoter, it was excence of MBP. These result suggested that both Smad 1 and Smad 5 were involved in the intracellular BMP signals which induce osteoblast differentiation in C2C12 cells.
The effect of BMP on C2C12 cells with Smad 1, Smad 5 transfected were studied by using northern blot analysis. the treatment of BMP upregulated ALP mRNA level in three groups, especially upregulation of ALP was larger in Smad 1, Smad 5 transfected cell than control group.
Pretreatment with cycloheximide(10㎍/ml), a protein synthesis inhibitor resulted in blocking the ALP gene expression even in BMP(100ng/ml) treated cell. These results suggested that Smad increased the level of ALP mRNA via the synthesis of a certain transcriptional regulatory protein.
|
|
|
KEYWORD
|
|
|
BMP, TGF-β superfamily, osteoblast, Smad, alkaline phosphatase, Signal transduction
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|
|