title: TNF-α and LPS activate angiogenesis via VEGF and SIRT1 signalling in human dental pulp cells.
abstract: OBJECTIVE
  To assess whether SIRT1 and VEGF are responsible for tumour necrosis factor-α (TNF-α) and lipopolysaccharide (LPS)-induced angiogenesis and to examine the molecular mechanism(s) of action in human dental pulp cells (HDPCs).
  
  
  METHODS
  Immortalized HDPCs obtained from Prof. Takashi Takata (Hiroshima University, Japan) were treated with LPS (1 μg mL(-1) ) and TNF-α (10 ng mL(-1) ) for 24 h. mRNA and protein levels were examined by RT-PCR and Western blotting, respectively. Migration and tube formation were examined in human umbilical vein endothelial cells (HUVECs). The data were analysed by one-way anova. Statistical analysis was performed at α = 0.05.
  
  
  RESULTS
  LPS and TNF-α upregulated VEGF and SIRT1 mRNA and protein levels. Inhibition of SIRT1 activity by sirtinol and SIRT1 siRNA or inhibition of the VEGF receptor by CBO-P11 significantly attenuated LPS + TNF-α-stimulated MMPs production in HDPCs, as well as migration and tube formation in HUVECs (P < 0.05). Furthermore, sirtinol, SIRT1 siRNA and CBO-P11 attenuated phosphorylation of Akt, extracellular signal-regulated kinase (ERK), p38 and c-Jun N-terminal kinase (JNK) and the nuclear translocation of NF-κB p65. Pre-treatment with inhibitors of p38, ERK, JNK, PI3K and NF-κB decreased LPS + TNF-α-induced VEGF and SIRT1 expression, MMPs activity in HDPCs and angiogenesis (P < 0.05) in HUVECs.
  
  
  CONCLUSIONS
  TNF-α and LPS led to upregulation of VEGF and SIRT1, and subsequent upregulation of MMP-2 and MMP-9 production, and promote angiogenesis via pathways involving PI3K, p38, ERK, JNK and NF-κB. The results suggest that inhibition of SIRT1 and VEGF might attenuate pro-inflammatory mediator-induced pulpal disease.
authors.affiliation: Department of Prosthodontics, Dongatn Sacred Heart Hospital, Hallym University, Dongtan, Korea.
authors.forename: M R
authors.initials: MR
authors.lastname: Shin
authors.affiliation: Department of Oral Medicine, School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: S K
authors.initials: SK
authors.lastname: Kang
authors.affiliation: Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: S C
authors.initials: SC
authors.lastname: Hong
authors.affiliation: Department of Oral and Maxillofacial Pathology, Research Center for Tooth and Periodontal Regeneration (MRC), School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: E-C
authors.initials: EC
authors.lastname: Kim
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000187:drug effects; D001549:Benzamides / Q000494:pharmacology; D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology / Q000378:metabolism*; D016228:Endothelial Growth Factors / Q000494:pharmacology; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D009284:Naphthols / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010456:Peptides, Cyclic / Q000494:pharmacology; D010766:Phosphorylation; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D056564:Sirtuin 1 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: C486377:AKTIP protein, human; D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D001549:Benzamides; D016228:Endothelial Growth Factors; D008070:Lipopolysaccharides; D009284:Naphthols; D010456:Peptides, Cyclic; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; C478485:cyclo-VEGI; C439060:sirtinol; D048031:JNK Mitogen-Activated Protein Kinases; D056564:Sirtuin 1
keywords: angiogenesis; human dental pulp cells; lipopolysaccharide; silent information regulator protein 1; tumour necrosis factor-α; vascular endothelial growth factor