Transcriptional regulation of bone sialoprotein gene by Porphyromonas gingivalis lipopolysaccharide.
Lipopolysaccharide (LPS) is a major mediator of inflammatory response. Periodontopathic bacterium Porphyromonas gingivalis LPS has quite different character from Escherichia coli LPS. E. coli LPS is agonist for Toll-like receptor 4 (TLR4), whereas P. gingivalis LPS worked as antagonist for TLR4. Bone sialoprotein (BSP) is an early marker of osteoblast differentiation. To investigate the effects of P. gingivalis LPS on BSP transcription, we used rat osteoblast-like ROS17/2.8 cells. BSP mRNA levels were decreased by 0.1 microg/ml and increased by 0.01 microg/ml P. gingivalis LPS at 12 h. Results of luciferase assays showed that 0.1 microg/ml decreased and 0.01 microg/ml P. gingivalis LPS increased BSP transcription in -116 to +60 BSP construct. The effects of P. gingivalis LPS were abrogated by double mutations in cAMP response element (CRE) and FGF2 response element (FRE). Tyrosine kinase inhibitor herbimycin A, ERK1/2 inhibitor and antioxidant N-acetylcystein inhibited effects of P. gingivalis LPS. Protein kinase A inhibitor and PI3-kinase/Akt inhibitor only abolished the effect of 0.01 microg/ml P. gingivalis LPS. Furthermore, 0.1 microg/ml LPS decreased the CRE- and FRE-protein complexes formation, whereas 0.01 microg/ml P. gingivalis LPS increased the nuclear protein binding to CRE and FRE. ChIP assays revealed increased binding of CREB1, JunD, Fra2, Runx2, Dlx5, and Smad1 to a chromatin fragment containing the CRE and FRE by 0.01 microg/ml P. gingivalis LPS. These studies therefore indicated that 0.1 microg/ml suppressed, and 0.01 microg/ml P. gingivalis LPS increased BSP gene transcription mediated through CRE and FRE elements in the rat BSP gene promoter.
Li
Xinyue
X
Department of Periodontology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan.
Kato
Naoko
N
Mezawa
Masaru
M
Li
Zhengyang
Z
Wang
Zhitao
Z
Yang
Li
L
Sasaki
Yoko
Y
Kaneko
Takashi
T
Takai
Hideki
H
Yoshimura
Atsutoshi
A
Ogata
Yorimasa
Y
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects*; D058574:Integrin-Binding Sialoprotein; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D012795:Sialoglycoproteins / Q000235:genetics*; D014158:Transcription, Genetic
D017931:DNA Primers; C546873:Ibsp protein, rat; D058574:Integrin-Binding Sialoprotein; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D012795:Sialoglycoproteins