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Lipopolysaccharide Enhances Wnt5a Expression through Toll-like Receptor 4, Myeloid Differentiating Factor 88, Phosphatidylinositol 3-OH Kinase/AKT and Nuclear Factor Kappa B Pathways in Human Dental Pulp Stem Cells
- Source :
- Journal of Endodontics. 40:69-75
- Publication Year :
- 2014
- Publisher :
- Elsevier BV, 2014.
-
Abstract
- Introduction Lipopolysaccharide (LPS) has been implicated in mesenchymal stem cell differentiation processes. Wnt5a, one of the “non-canonical” Wnt family members, is important in signaling stem cell differentiation and in the inflammatory responses of immune cells. Here we studied whether LPS can regulate the expression of Wnt5a in human dental pulp stem cells (hDPSCs) and investigated the intracellular signaling pathways activated by LPS. Methods Wnt5a mRNA and protein expression changes in hDPSCs were investigated by real-time polymerase chain reaction analysis and enzyme-linked immunosorbent assay. In addition, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and luciferase activity assays were used to determine whether toll-like receptor 4 (TLR4), myeloid differentiating factor 88 (MyD88), nuclear factor kappa B (NF-kB), or the phosphatidylinositol 3-OH kinase (PI3K)/AKT pathways are involved in LPS-induced Wnt5a expression. The activation of PI3K and AKT in hDPSCs was measured by Western blot analysis. Results Wnt5a mRNA and protein expression was rapidly increased in response to LPS in a time- and dose-dependent manner. LPS-induced Wnt5a expression was effectively attenuated by administration of a TLR4 neutralizing antibody, MyD88 inhibitory peptide, PI3-kinase inhibitors (LY294002 and wortmannin), an AKT inhibitor, or NF-κB inhibitor (pyrrolidine dithiocarbamate), IκBa phosphorylation inhibitor (Bay 117082), or IκB protease inhibitor (L-1-tosylamido-2-phenylethyl chloromethyl ketone). Treatment of hDPSCs with LPS activated PI3-kinase (p85) and AKT signaling in a time-dependent manner. Moreover, LPS-mediated increases in κB-luciferase activity were diminished by the overexpression of dominant negative mutants of TLR4, MyD88, p85, AKT, and IκBa. Conclusions These results demonstrated that LPS-induced Wnt5a expression was mediated through the TLR4/MyD88/PI3-kinase/AKT pathway, which then initiated NF-κB activation in hDPSCs.
- Subjects :
- Lipopolysaccharides
Pyrrolidines
Time Factors
Adolescent
Morpholines
Cellular differentiation
Cell Culture Techniques
Biology
Wnt-5a Protein
Wortmannin
Phosphatidylinositol 3-Kinases
Young Adult
chemistry.chemical_compound
NF-KappaB Inhibitor alpha
Thiocarbamates
Proto-Oncogene Proteins
Nitriles
Escherichia coli
Humans
LY294002
Sulfones
Wnt Signaling Pathway
General Dentistry
Protein kinase B
Cells, Cultured
Dental Pulp
PI3K/AKT/mTOR pathway
Phosphoinositide-3 Kinase Inhibitors
Dose-Response Relationship, Drug
Stem Cells
NF-kappa B
Wnt signaling pathway
Diazonium Compounds
Mycotoxins
Molecular biology
Androstadienes
Toll-Like Receptor 4
Wnt Proteins
chemistry
Chromones
Myeloid Differentiation Factor 88
Phosphorylation
I-kappa B Proteins
Mesenchymal stem cell differentiation
Proto-Oncogene Proteins c-akt
Signal Transduction
Subjects
Details
- ISSN :
- 00992399
- Volume :
- 40
- Database :
- OpenAIRE
- Journal :
- Journal of Endodontics
- Accession number :
- edsair.doi.dedup.....9ca6bf9029ac66abb6a0e131530f9c03