Abstract
Transforming growth factor beta (TGF-beta) may regulate the biological activities of dental pulp cells. We found that human dental pulp cells expressed TGF-beta1, TGF-beta2, and a little amount of TGF-beta3 messenger RNA (mRNA). The exposure of pulp cells to TGF-beta2 induced the phosphorylation of Smad2/3, Smad1/5/8, and extracellular regulated-kinase 1/2 (ERK1/2) as observed by Western blotting. Exposure to TGF-beta2 decreased the alkaline phosphatase (ALP) mRNA expression and enzyme activity. Pretreatment of pulp cells with SB431542 (an inhibitor of TGF-beta ALK-4, ALK-5, and ALK-7 receptors) but not U0126 (a MEK1 inhibitor) prevented the inhibition of viable cell number, ALP activity, and mRNA expression by TGF-beta2 in dental pulp cells. These results suggest that TGF-beta may affect the growth and differentiation of dental pulp cells via an autocrine fashion by activation of the ALK/Smad2/3-signal transduction pathways. TGF-beta2 possibly regulates the differentiation of pulp cell at specific stages synergistically with other factors.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Alkaline Phosphatase / metabolism
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Benzamides / pharmacology
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Cell Differentiation
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Cell Proliferation
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Dental Pulp / cytology
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Dental Pulp / metabolism*
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Dioxoles / pharmacology
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Enzyme Inhibitors / pharmacology
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Extracellular Signal-Regulated MAP Kinases / physiology
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Humans
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MAP Kinase Kinase Kinases / physiology
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MAP Kinase Signaling System / physiology*
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Protein Isoforms
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Protein Serine-Threonine Kinases / antagonists & inhibitors
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Protein Serine-Threonine Kinases / metabolism*
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Receptor, Transforming Growth Factor-beta Type I
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Receptors, Transforming Growth Factor beta / antagonists & inhibitors
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Receptors, Transforming Growth Factor beta / metabolism*
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Smad Proteins, Receptor-Regulated / metabolism*
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Transforming Growth Factor beta1 / biosynthesis
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Transforming Growth Factor beta2 / biosynthesis
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Transforming Growth Factor beta2 / physiology*
Substances
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4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide
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Benzamides
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Dioxoles
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Enzyme Inhibitors
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Protein Isoforms
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Receptors, Transforming Growth Factor beta
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Smad Proteins, Receptor-Regulated
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Transforming Growth Factor beta1
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Transforming Growth Factor beta2
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Protein Serine-Threonine Kinases
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Extracellular Signal-Regulated MAP Kinases
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MAP Kinase Kinase Kinases
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Receptor, Transforming Growth Factor-beta Type I
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TGFBR1 protein, human
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Alkaline Phosphatase