Regulation of ALP activity by TNF-alpha on human dental pulp.
In this study, we examined the effects of TNF-alpha on Bone morphogenetic protein (BMP-2), Smads (which play intracellular signaling of BMPs) expression and alkaline phosphatase (ALP) activity of human dental pulp (HDP) cells to clarify the mechanism of tertiary dentin formation. The quantity of RT-PCR product for BMP-2 from the HDP cells stimulated by TNF-alpha is increased. However, ALP activity was not increased on the cells incubated with TNF-alpha. On the other hand, ALP activity was significantly increased on HDP cells treated with Ammonium Pyrrolidinedithiocarbamate (PDTC, NF- kappaB inhibitor) groups and combined supplementation of TNF-alpha and PDTC groups. Furthermore, we examined the effect of TNF-alpha and PDTC on Smad7 expression using RT-PCR and western blot analysis. Smad7 expression in HDP cells was increased by TNF-alpha, but decreased by PDTC treatment. These results suggest that NF- kappaB and Smad7 play an important role in the down regulation of ALP activity by TNF-alpha on HDP cells.
Okabe
Tatsu
T
Department of Endodontics, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan. okabe@mascat.nihon-u.ac.jp
Matsushima
Kiyoshi
K
D000469:Alkaline Phosphatase / Q000187:drug effects* / Q000378:metabolism; D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000187:drug effects / Q000378:metabolism; D003782:Dental Pulp / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D016328:NF-kappa B / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D051785:Smad Proteins / Q000187:drug effects / Q000378:metabolism; D013859:Thiocarbamates / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000187:drug effects / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000975:Antioxidants; C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016328:NF-kappa B; D011759:Pyrrolidines; D051785:Smad Proteins; D013859:Thiocarbamates; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; C020972:pyrrolidine dithiocarbamic acid; D000469:Alkaline Phosphatase