Effects of Porphyromonas gingivalis and Fusobacterium nucleatum on inflammasomes and their regulators in H400 cells

Research output: Contribution to journalArticlepeer-review

Colleges, School and Institutes

External organisations

  • Health Education West Midlands and honorary research fellow, Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK.
  • Republic of Turkey Ministry of Health
  • Ankara University, Ankara, Turkey
  • University of Otago
  • Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand; School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand.

Abstract

INTRODUCTION: Inflammasomes are multiprotein complexes that regulate immune processes in response to infections and tissue damage. They modulate Interleukin-1beta (IL-1β) expression, a major proinflammatory cytokine. The inflammasome/IL-1β pathway is involved in head and neck squamous cell carcinoma (HNSCC) progression and the periodontal pathogens Fusobacterium nucleatum (Fn) and Porphyromonas gingivalis (Pg) have been reported to cause chronic inflammation in HNSCC. The aim of this study was to characterise the role of these pathogens in regulating inflammasome activity and the IL-1β response in HNSCC in vitro.

METHODS: An HNSCC cell line (H400) was exposed to Fn and Pg individually or in combination for 24h, ± incubation for 30 min with 5 mM adenosine triphosphate (ATP). Transcript levels of inflammasomes, NLRP3 and AIM2; inflammasome-regulatory proteins, POP1, CARD16 and TRIM16; and inflammasome-component, ASC and caspase 1 and IL-1β, were assayed by RT-PCR. Expression of IL-1β was by immunocytochemistry and ELISA.

RESULTS: NLRP3 expression was significantly upregulated in response to Pg, Fn + Pg, Pg + ATP and Fn + Pg + ATP. AIM2 was significantly upregulated by Fn, Pg and Fn + Pg + ATP exposure. All conditions significantly upregulated IL-1β gene expression. POP1 expression was significantly downregulated by Pg or Fn exposure but not by Fn + Pg. Intracellular pro- and mature IL-1β were significantly higher following Fn and Pg + ATP exposure.

CONCLUSION: Pg alone increased IL-1β by upregulating AIM2, NLRP3 and downregulating POP1. Fn promoted IL-1β by increasing AIM2 and downregulating POP1. Pg + ATP with or without Fn upregulated NLRP3, IL-1β by downregulating POP1. Periodontal pathogens may contribute to HNSCC pathogenesis by increasing the IL-1β response due to inflammasome dysregulation.

Bibliographic note

© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Details

Original languageEnglish
Pages (from-to)158-167
Number of pages10
JournalMolecular Oral Microbiology
Volume35
Issue number4
Publication statusPublished - 9 Jun 2020