Serum Amyloid A Contributes to Chronic Apical Periodontitis via TLR2 and TLR4

K. Hirai, H. Furusho, N. Kawashima, S. Xu, M. C. de Beer, R. Battaglino, T. Van Dyke, P. Stashenko, H. Sasaki

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

In the current concept of bacterial infections, pathogen-associated molecular patterns (PAMPs) derived from pathogens and damage-associated molecular patterns (DAMPs) released from damaged/necrotic host cells are crucial factors in induction of innate immune responses. However, the implication of DAMPs in apical and marginal periodontitis is unknown. Serum amyloid A (SAA) is a DAMP that is involved in the development of various chronic inflammatory diseases, such as rheumatoid arthritis. In the present study, we tested whether SAA is involved in the pathogenesis of periapical lesions, using human periapical surgical specimens and mice deficient in SAA and Toll-like receptors (TLR). SAA1/2 was locally expressed in human periapical lesions at the mRNA and protein levels. The level of SAA protein appeared to be positively associated with the inflammatory status of the lesions. In the development of mouse periapical inflammation, SAA1.1/2.1 was elevated locally and systemically in wild-type (WT) mice. Although SAA1.1/2.1 double-knockout and SAA3 knockout mice had redundant attenuation of the extent of periapical lesions, these animals showed strikingly improved inflammatory cell infiltration versus WT. Recombinant human SAA1 (rhSAA1) directly induced chemotaxis of WT neutrophils in a dose-dependent manner in vitro. In addition, rhSAA1 stimulation significantly prolonged the survival of WT neutrophils as compared with nonstimulated neutrophils. Furthermore, rhSAA1 activated the NF-κB pathway and subsequent IL-1α production in macrophages in a dose-dependent manner. However, TLR2/TLR4 double deficiency substantially diminished these SAA-mediated proinflammatory responses. Taken together, the SAA-TLR axis plays an important role in the chronicity of periapical inflammation via induction of inflammatory cell infiltration and prolonged cell survival. The interactions of PAMPs and DAMPs require further investigation in dental/oral inflammation.

Original languageEnglish (US)
Pages (from-to)117-125
Number of pages9
JournalJournal of dental research
Volume98
Issue number1
DOIs
StatePublished - Jan 1 2019
Externally publishedYes

Fingerprint

Periapical Periodontitis
Serum Amyloid A Protein
Chronic Periodontitis
Neutrophils
Toll-Like Receptors
Inflammation
Chemotaxis
Interleukin-1
Bacterial Infections
Innate Immunity
Knockout Mice
Rheumatoid Arthritis
Cell Survival
Tooth
Chronic Disease
Macrophages
Messenger RNA

Keywords

  • alarmins
  • chemotaxis
  • endodontics
  • inflammation
  • innate immunity
  • pattern recognition receptors

PubMed: MeSH publication types

  • Journal Article

Cite this

Hirai, K., Furusho, H., Kawashima, N., Xu, S., de Beer, M. C., Battaglino, R., ... Sasaki, H. (2019). Serum Amyloid A Contributes to Chronic Apical Periodontitis via TLR2 and TLR4. Journal of dental research, 98(1), 117-125. https://doi.org/10.1177/0022034518796456

Serum Amyloid A Contributes to Chronic Apical Periodontitis via TLR2 and TLR4. / Hirai, K.; Furusho, H.; Kawashima, N.; Xu, S.; de Beer, M. C.; Battaglino, R.; Van Dyke, T.; Stashenko, P.; Sasaki, H.

In: Journal of dental research, Vol. 98, No. 1, 01.01.2019, p. 117-125.

Research output: Contribution to journalArticle

Hirai, K, Furusho, H, Kawashima, N, Xu, S, de Beer, MC, Battaglino, R, Van Dyke, T, Stashenko, P & Sasaki, H 2019, 'Serum Amyloid A Contributes to Chronic Apical Periodontitis via TLR2 and TLR4', Journal of dental research, vol. 98, no. 1, pp. 117-125. https://doi.org/10.1177/0022034518796456
Hirai, K. ; Furusho, H. ; Kawashima, N. ; Xu, S. ; de Beer, M. C. ; Battaglino, R. ; Van Dyke, T. ; Stashenko, P. ; Sasaki, H. / Serum Amyloid A Contributes to Chronic Apical Periodontitis via TLR2 and TLR4. In: Journal of dental research. 2019 ; Vol. 98, No. 1. pp. 117-125.
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