Amelogenin induces M2 macrophage polarisation via PGE2/cAMP signalling pathway

Kensuke Yamamichi; Takao Fukuda; Terukazu Sanui; Kyosuke Toyoda; Urara Tanaka; Yuki Nakao; Karen Yotsumoto; Hiroaki Yamato; Takaharu Taketomi; Takeshi Uchiumi; Fusanori Nishimura

doi:10.1016/j.archoralbio.2017.08.005

Amelogenin induces M2 macrophage polarisation via PGE2/cAMP signalling pathway

Arch Oral Biol. 2017 Nov:83:241-251. doi: 10.1016/j.archoralbio.2017.08.005. Epub 2017 Aug 12.

Affiliations

¹ Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
² Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan. Electronic address: tfukuda@dent.kyushu-u.ac.jp.
³ Department of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan. Electronic address: sanuteru@dent.kyushu-u.ac.jp.
⁴ Dental and Oral Medical Center, Kurume University School of Medicine, Kurume, Fukuoka, Japan.
⁵ Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

PMID: 28822800
DOI: 10.1016/j.archoralbio.2017.08.005

Abstract

Objectives: Amelogenin, the major component of the enamel matrix derivative (EMD), has been suggested as a bioactive candidate for periodontal regeneration. Apart from producing a regenerative effect on periodontal tissues, amelogenin has also been reported to have an anti-inflammatory effect. However, the precise molecular mechanisms underlying these effects remain unclear. In the present study, we examined the immunomodulatory effects of amelogenin on macrophages.

Design: Human phorbol 12-myristate 13-acetate (PMA)-differentiated U937 macrophages and CD14+ peripheral blood-derived monocytes (PBMC)-derived macrophages were stimulated with recombinant amelogenin (rM180). After performing a detailed microarray analysis, the effects of rM180 on macrophage phenotype and signal transduction pathways were evaluated by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, confocal microscopy and flow cytometry.

Results: The microarray analysis demonstrated that rM180 increased the expression of anti-inflammatory genes in lipopolysaccharide (LPS)-challenged macrophages after 24h, while it temporarily up-regulated inflammatory responses at 4h. rM180 significantly enhanced the expression of M2 macrophage markers (CD163 and CD206). rM180-induced M2 macrophage polarisation was associated with morphological changes as well as vascular endothelial growth factor (VEGF) production. rM180 enhanced prostaglandin E2 (PGE2) expression, and the activation of the cAMP/cAMP-responsive element binding (CREB) signaling pathway was involved in amelogenin-induced M2 macrophage polarisation. Blocking of PGE2 signaling by indomethacin specifically abrogated rM180 with or without LPS-induced M2 shift in PBMC-derived macrophages.

Conclusion: Amelogenin could reprogram macrophages into the anti-inflammatory M2 phenotype. It could therefore contribute to the early resolution of inflammation in periodontal lesions and provide a suitable environment for remodeling-periodontal tissues.

Keywords: Amelogenin; Enamel matrix derivative; Macrophage; Microarray; Prostaglandin E2.

MeSH terms

Amelogenin / pharmacology*
Cyclic AMP-Dependent Protein Kinases / physiology*
Dinoprostone / physiology*
Enzyme-Linked Immunosorbent Assay
Flow Cytometry
Humans
Lipopolysaccharides
Macrophages / drug effects*
Microarray Analysis
Microscopy, Confocal
Phenotype
Polymerase Chain Reaction
Signal Transduction / physiology*
Up-Regulation
Vascular Endothelial Growth Factor A / metabolism

Substances

Amelogenin
Lipopolysaccharides
Vascular Endothelial Growth Factor A
Cyclic AMP-Dependent Protein Kinases
Dinoprostone