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TNF‐α and LPS activate angiogenesis via VEGF and SIRT1 signalling in human dental pulp cells
Author(s) -
Shin M. R.,
Kang S. K.,
Kim Y. S.,
Lee S. Y.,
Hong S. C.,
Kim E.C.
Publication year - 2015
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/iej.12396
Subject(s) - angiogenesis , p38 mitogen activated protein kinases , mapk/erk pathway , umbilical vein , downregulation and upregulation , tumor necrosis factor alpha , vascular endothelial growth factor , pi3k/akt/mtor pathway , kinase , chemistry , protein kinase b , microbiology and biotechnology , phosphorylation , cancer research , signal transduction , biology , immunology , biochemistry , in vitro , vegf receptors , gene
Aim To assess whether SIRT 1 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 ( HDPC s). Methodology 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 SIRT 1, and subsequent upregulation of MMP ‐2 and MMP ‐9 production, and promote angiogenesis via pathways involving PI 3K, p38, ERK , JNK and NF ‐κB. The results suggest that inhibition of SIRT 1 and VEGF might attenuate pro‐inflammatory mediator‐induced pulpal disease.