IADR Abstract Archives
Effects of TNF-alpha in activation of MAP4K4 for mineralization of dental pulp stem cells
Objectives: The purposes of this study were to investigate the effects of TNFα on human dental pulp stem cells and the related mechanism.
Methods: The materials and methods used in this study were to treat dental pulp stem cells with TNF-α for different time periods to see the effects on the expression of ALP by staining and the activation of ALP was also measured. Then, dental pulp stem cells were treated with TNFα and the effects were observed by measuring the cytoplasm level of MAP4K4 and p-MAP4K4 through indirect ELISA. For understanding the mechanism of signal transduction, MAPK inhibitor was added to make sure the expression of ALP activity.
Results: Our results indicated that by treating with TNFα for a long period, the mineralization of dental pulp stem cells were inhibited, but the mineralization expression is enhanced after short time treatment with TNFα. With ELISA analysis, TNF-α was found to promote the activation of MAP4K4. When MAPK siRNA was inserted, the expression of ALP activity was found to be downregulated, with or without adding TNF-α in the culture medium.
Conclusions: It is concluded that short time treatment with TNF-α would promote the mineralized differentiation of dental pulp stem cells via MAP4K4 signaling pathway, but long time treatment with TNF-α may inhibit cell mineralization and eventually lead to cell necrosis and apoptosis.
Methods: The materials and methods used in this study were to treat dental pulp stem cells with TNF-α for different time periods to see the effects on the expression of ALP by staining and the activation of ALP was also measured. Then, dental pulp stem cells were treated with TNFα and the effects were observed by measuring the cytoplasm level of MAP4K4 and p-MAP4K4 through indirect ELISA. For understanding the mechanism of signal transduction, MAPK inhibitor was added to make sure the expression of ALP activity.
Results: Our results indicated that by treating with TNFα for a long period, the mineralization of dental pulp stem cells were inhibited, but the mineralization expression is enhanced after short time treatment with TNFα. With ELISA analysis, TNF-α was found to promote the activation of MAP4K4. When MAPK siRNA was inserted, the expression of ALP activity was found to be downregulated, with or without adding TNF-α in the culture medium.
Conclusions: It is concluded that short time treatment with TNF-α would promote the mineralized differentiation of dental pulp stem cells via MAP4K4 signaling pathway, but long time treatment with TNF-α may inhibit cell mineralization and eventually lead to cell necrosis and apoptosis.