title: [Biological effect of inhibition of Notch signaling pathway on human dental pulp cells].
abstract: OBJECTIVE
  To investigate the effect of Notch signaling pathway on human dental pulp cells.
  
  
  METHODS
  The γ-secretase inhibitor N-[N-(3, 5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester(DAPT) was applied to inhibit the Notch signaling pathway of human dental pulp cells. The solvent dimethly sulfoxide (DMSO) served as the negative control.Senescence conditions were evaluated by cells morphology changes, the alkaline phosphatase (ALP) expression and its activity, senescence-associated β-galactosidase (SA-β-Gal) expression and the senescence related gene p53 expression.
  
  
  RESULTS
  After inhibition of the Notch signaling pathway, morphology changes, including flatter cells, larger plasma area, were seen in the 10th passage human dental pulp cells. ALP expression and activity showed a significant decrease at the 8th passage after inhibition (35.36 ± 2.55) U/g, compared with the negative control group[(49.76 ± 4.30) U/g] (t = 4.989, P = 0.008).SA-β-Gal-positive cells could be seen as early as the 8th passage and more positive cells were evident at the 10th passage. The relative expression level of p53 gene was elevated in the 10th passage cells (1.7 ± 0.4) compared with the negative control group(1.0) (t = 3.581, P = 0.012).
  
  
  CONCLUSIONS
  Human dental pulp cells became senescent at earlier passages after inhibition of Notch signaling pathway.Notch signaling pathway may affect life cycle of human dental pulp cells.
authors: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Xiaoying
authors: X
authors: Zou
authors: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China. Email: doctorzhuang@163.com.
authors: Heng
authors: H
authors: Zhuang
authors: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Lin
authors: L
authors: Yue
authors: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors: Xuejun
authors: X
authors: Gao
mesh_terms: D002478:Cells, Cultured; D003782:Dental Pulp / Q000378:metabolism*; D004847:Epithelial Cells; D006801:Humans; D051880:Receptors, Notch / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D051880:Receptors, Notch