scholarly journals Requirement of a bone morphogenetic protein for the maintenance and stimulation of osteoblast differentiation

2006 ◽  
Vol 69 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Snjezana Martinovic ◽  
Fran Borovecki ◽  
Vera Miljavac ◽  
Veronika Kisic ◽  
Drazen Maticic ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Osteoblast Differentiation ◽  
Morphogenetic Protein ◽  
Stimulation Of

Harmine promotes osteoblast differentiation through bone morphogenetic protein signaling

2011 ◽  
Vol 409 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Takayuki Yonezawa ◽  
Ji-Won Lee ◽  
Ayaka Hibino ◽  
Midori Asai ◽  
Hironori Hojo ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Osteoblast Differentiation ◽  
Protein Signaling ◽  
Bone Morphogenetic Protein Signaling ◽  
Morphogenetic Protein

Characterization of bone morphogenetic protein-6 signaling pathways in osteoblast differentiation

1999 ◽  
Vol 112 (20) ◽  
pp. 3519-3527 ◽  
Author(s):  
T. Ebisawa ◽  
K. Tada ◽  
I. Kitajima ◽  
K. Tojo ◽  
T.K. Sampath ◽  
...  
Keyword(s):  
Bone Morphogenetic Protein ◽  
Osteoblast Differentiation ◽  
Transforming Growth Factor ◽  
C2c12 Cells ◽  
Nuclear Accumulation ◽  
Type I ◽  
Type Ii ◽  
Weakly Bound ◽  
Bmp Receptors ◽  
Morphogenetic Protein

Bone morphogenetic protein (BMP)-6 is a member of the transforming growth factor (TGF)-(β) superfamily, and is most similar to BMP-5, osteogenic protein (OP)-1/BMP-7, and OP-2/BMP-8. In the present study, we characterized the endogenous BMP-6 signaling pathway during osteoblast differentiation. BMP-6 strongly induced alkaline phosphatase (ALP) activity in cells of osteoblast lineage, including C2C12 cells, MC3T3-E1 cells, and ROB-C26 cells. The profile of binding of BMP-6 to type I and type II receptors was similar to that of OP-1/BMP-7 in C2C12 cells and MC3T3-E1 cells; BMP-6 strongly bound to activin receptor-like kinase (ALK)-2 (also termed ActR-I), together with type II receptors, i.e. BMP type II receptor (BMPR-II) and activin type II receptor (ActR-II). In addition, BMP-6 weakly bound to BMPR-IA (ALK-3), to which BMP-2 also bound. In contrast, binding of BMP-6 to BMPR-IB (ALK-6), and less efficiently to ALK-2 and BMPR-IA, together with BMPR-II was detected in ROB-C26 cells. Intracellular signalling was further studied using C2C12 and MC3T3-E1 cells. Among the receptor-regulated Smads activated by BMP receptors, BMP-6 strongly induced phosphorylation and nuclear accumulation of Smad5, and less efficiently those of Smad1. However, Smad8 was constitutively phosphorylated, and no further phosphorylation or nuclear accumulation of Smad8 by BMP-6 was observed. These findings indicate that in the process of differentiation to osteoblasts, BMP-6 binds to ALK-2 as well as other type I receptors, and transduces signals mainly through Smad5 and possibly through Smad1.

scholarly journals Statin-induced Ras Activation Integrates the Phosphatidylinositol 3-Kinase Signal to Akt and MAPK for Bone Morphogenetic Protein-2 Expression in Osteoblast Differentiation

2006 ◽  
Vol 282 (7) ◽  
pp. 4983-4993 ◽  
Author(s):  
Nandini Ghosh-Choudhury ◽  
Chandi Charan Mandal ◽  
Goutam Ghosh Choudhury
Keyword(s):  
Bone Morphogenetic Protein ◽  
Osteoblast Differentiation ◽  
Dominant Negative ◽  
Bone Morphogenetic Protein 2 ◽  
Regulatory Subunit ◽  
Type I ◽  
Dependent Manner ◽  
Phosphatidylinositol 3 Kinase ◽  
Morphogenetic Protein ◽  
Phosphatidylinositol 3

Lovastatin promotes osteoblast differentiation by increasing bone morphogenetic protein-2 (BMP-2) expression. We demonstrate that lovastatin stimulates tyrosine phosphorylation of the p85 regulatory subunit of phosphatidylinositol 3-kinase (PI3K), leading to an increase in its kinase activity in osteoblast cells. Inhibition of PI3K ameliorated expression of the osteogenic markers alkaline phosphatase, type I collagen, osteopontin, and BMP-2. Expression of dominant-negative PI3K and PTEN, an inhibitor of PI3K signaling, significantly attenuated lovastatin-induced transcription of BMP-2. Akt kinase was also activated in a PI3K-dependent manner. However, our data suggest involvement of an additional signaling pathway. Lovastatin-induced Erk1/2 activity contributed to BMP-2 transcription. Inhibition of PI3K abrogated Erk1/2 activity in response to lovastatin, indicating the presence of a signal relay between them. We provide, as a mechanism of this cross-talk, the first evidence that lovastatin stimulates rapid activation of Ras, which associates with and activates PI3K in the plasma membrane, which in turn regulates Akt and Erk1/2 to induce BMP-2 expression for osteoblast differentiation.

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