Smad3 Differently Affects Osteoblast Differentiation Depending upon its Differentiation Stage

Kaji, Hiroshi; Naito, Junko; Sowa, Hideaki; Sugimoto, Toshitsugu; Chihara, Kazuo

doi:10.1055/s-2006-955085

Cited by 40 publications

(41 citation statements)

References 26 publications

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“…9) On the other hand, TGF-β1 blocked osteogenesis by a variety of mechanisms depending on cell density, TGF-β1 concentration and differentiation stage of the cells. [10][11][12] TGF-β1 also blocked odontogenesis by downregulation of dentin sialophosphoprotein. 13) The mitogen-activated protein kinase (MAPK) pathway has been proposed to negatively regulate Smad pathway and osteoblast mineralization.…”

Section: Introductionmentioning

confidence: 92%

Dual Nature of TGF-β1 in Osteoblastic Differentiation of Human Periodontal Ligament Cells

Ochiai

Yamamoto

Yokoyama

et al. 2010

J. Hard Tissue Biology.

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This study investigated the effect of various treatments with TGF-β1 in osteogenic differentiation of human periodontal ligament (HPDL) cells.HPDL cells were treated with single 1 ng/ml, 100 ng/ml or multiple (12-h intervals) 1 ng/ml TGF-β1. Alkaline phosphatase (ALP) activity was detected by ALP activity staining at 4 days. Phospho-Smad3 was detected by western blotting and transcription of osteogenic differentiation markers (RUNX2, ALPL, IBSP: bone sialoprotein, BGLAP: osteocalcin) were determined by real-time PCR at various culture periods. Cells were pretreated with or without SB505124, a TGF-β/Smad pathway inhibitor, for 1 h before 1 ng/ml TGF-β1 treatment at 12-h intervals. ALP activity and phosphorylated Smad3 were detected.Single treatment with 1 ng/ml TGF-β1 significantly induced Smad3 phosphorylation, subsequent ALP upregulation and transcription of osteogenic differentiation markers, compared to these inductions with 100 ng/ml TGF-β1 treatment. In multiple treatments with 1 ng/ml TGF-β1 at 12-h intervals, only the first treatment significantly induced Smad3 phosphorylation but not the succeeding treatments. Inductive effects of single 1 ng/ml TGF-β1 in osteogenic differentiation were almost completely abolished by multiple treatments. Furthermore, multiple treatments with 1 ng/ml TGF-β1 did not induce ALP activity although the TGF-β/Smad pathway was inhibited by SB505124.Single treatment with low dose TGF-β1 significantly induced osteogenic differentiation. Multiple treatments inhibited osteogenic differentiation despite inhibition of TGF-β/Smad pathway. These findings suggest that TGF-β1 both positively and negatively regulates osteogenic differentiation and the inhibitory effect may be mediated by the non-Smad signaling pathway in HPDL cells.

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Section: Introductionmentioning

confidence: 92%

Dual Nature of TGF-β1 in Osteoblastic Differentiation of Human Periodontal Ligament Cells

Ochiai

Yamamoto

Yokoyama

et al. 2010

J. Hard Tissue Biology.

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“…cDNA synthesis, reverse transcription, and PCR were performed as previously described [49]. The amplified DNA was separated on 2% agarose gels and stained with ethidium bromide.…”

Section: Rna Extraction and Semi-quantitative Rt-pcrmentioning

confidence: 99%

Small molecule-based disruption of the Axin/β-catenin protein complex regulates mesenchymal stem cell differentiation

Gwak

Hwang

Park³

et al. 2011

Cell Res

110

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The Wnt/β-catenin pathway plays important roles in the differentiation of multiple cell types, including mesenchymal stem cells. Using a cell-based chemical screening assay with a synthetic chemical library of 270 000 compounds, we identified the compound SKL2001 as a novel agonist of the Wnt/β-catenin pathway and uncovered its molecular mechanism of action. SKL2001 upregulated β-catenin responsive transcription by increasing the intracellular β-catenin protein level and inhibited the phosphorylation of β-catenin at residues Ser33/37/Thr41 and Ser45, which would mark it for proteasomal degradation, without affecting CK1 and GSK-3β enzyme activities. Biochemical analysis revealed that SKL2001 disrupted the Axin/β-catenin interaction, which is a critical step for CK1-and GSK-3β-mediated phosphorylation of β-catenin at Ser33/37/Thr41 and Ser45. The treatment of mesenchymal stem cells with SKL2001 promoted osteoblastogenesis and suppressed adipocyte differentiation, both of which were accompanied by the activation of Wnt/β-catenin pathway. Our findings provide a new strategy to regulate mesenchymal stem cell differentiation by modulation of the Wnt/β-catenin pathway.

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“…We showed previously that Smad3, a crucial TGF-␤-signaling molecule, promotes alkaline phosphatase (ALP) activity in mouse osteoblastic MC3T3-E1 cells (5,6), and Borton et al (7) have found that mice with targeted disruption of Smad3 exhibit osteopenia caused by decreased bone formation, suggesting that the Smad3 molecule is a promoter of bone formation. Moreover, we demonstrated that TGF-␤-responsive ERK1/2 and c-Jun N-terminal kinase (JNK) cascades negatively regulate Smad3-induced transcriptional activity and ALP activity in osteoblasts (8).…”

mentioning

confidence: 99%

Parathyroid Hormone-responsive Smad3-related Factor, Tmem119, Promotes Osteoblast Differentiation and Interacts with the Bone Morphogenetic Protein-Runx2 Pathway

Hisa

Inoue

Hendy

et al. 2011

Journal of Biological Chemistry

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The mechanisms whereby the parathyroid hormone (PTH) exerts its anabolic action on bone are incompletely understood. We previously showed that inhibition of ERK1/2 enhanced Smad3-induced bone anabolic action in osteoblasts. These findings suggested the hypothesis that changes in gene expression associated with the altered Smad3-induced signaling brought about by an ERK1/2 inhibitor would identify novel bone anabolic factors in osteoblasts. We therefore performed a comparative DNA microarray analysis between empty vector-transfected mouse osteoblastic MC3T3-E1 cells and PD98059-treated stable Smad3-overexpressing MC3T3-E1 cells. Among the novel factors, Tmem119 was selected on the basis of its rapid induction by PTH independent of later increases in endogenous TGF-␤. The levels of Tmem119 increased with time in cultures of MC3T3-E1 cells and mouse mesenchymal ST-2 cells committed to the osteoblast lineage by BMP-2. PTH stimulated Tmem119 levels within 1 h as determined by Western blot analysis and immunocytochemistry in MC3T3-E1 cells. MC3T3-E1 cells stably overexpressing Tmem119 exhibited elevated levels of Runx2, osteocalcin, alkaline phosphatase, and ␤-catenin, whereas Tmem119 augmented BMP-2-induced Runx2 levels in mesenchymal cells. Tmem119 interacted with Runx2, Smad1, and Smad5 in C2C12 cells. In conclusion, we identified a Smad3-related factor, Tmem119, that is induced by PTH and promotes differentiation in mouse osteoblastic cells. Tmem119 is an important molecule in the pathway downstream of PTH and Smad3 signaling in osteoblasts.Bone remodeling is controlled by bone resorption and subsequent osteoblastic bone formation. Insights into the mechanisms of osteoclastic bone resorption have led to the development of reagents that potently suppress bone resorption for the treatment of osteoporosis. On the other hand, the impairment of osteoblastic bone formation is considered to be the main driving force in age-related, glucocorticoid-induced, and diabetes-related osteoporosis. However, many aspects of osteoblastic bone formation remain to be understood. Intermittent parathyroid hormone (PTH) 3 is one of the most potent anabolic agents; it stimulates de novo osteoblastic bone formation and is superior to bisphosphonates in the treatment of osteoporosis (1, 2). The anabolic action of PTH is exerted partly through local growth factors and transcriptional regulators as well by as an anti-apoptotic action in osteoblasts (3, 4). However, the precise mechanisms by which PTH exerts its anabolic action on bone are incompletely understood.We showed previously that Smad3, a crucial TGF-␤-signaling molecule, promotes alkaline phosphatase (ALP) activity in mouse osteoblastic MC3T3-E1 cells (5, 6), and Borton et al. (7) have found that mice with targeted disruption of Smad3 exhibit osteopenia caused by decreased bone formation, suggesting that the Smad3 molecule is a promoter of bone formation. Moreover, we demonstrated that TGF-␤-responsive ERK1/2 and c-Jun N-terminal kinase (JNK) cascades negatively regulate Smad3-ind...

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Smad3 Differently Affects Osteoblast Differentiation Depending upon its Differentiation Stage

Cited by 40 publications

References 26 publications

Dual Nature of TGF-β1 in Osteoblastic Differentiation of Human Periodontal Ligament Cells

Dual Nature of TGF-β1 in Osteoblastic Differentiation of Human Periodontal Ligament Cells

Small molecule-based disruption of the Axin/β-catenin protein complex regulates mesenchymal stem cell differentiation

Parathyroid Hormone-responsive Smad3-related Factor, Tmem119, Promotes Osteoblast Differentiation and Interacts with the Bone Morphogenetic Protein-Runx2 Pathway

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