IADR Abstract Archives

DNA Released by Dying Cells Induces CGAS-STING Mediated Pulp Inflammation

Objectives: DNA released by dying cells is a danger-associated molecular pattern (DAMP) that has been implicated in many inflammatory diseases, but its role in pulp inflammation and the subsequent reparative process is unknown. This study aimed to investigate if dental pulp cells (DPCs) were capable of sensing dsDNA and determine the inflammatory response mounted by DPCs upon exposure to dsDNA and its effect on DPCs proliferation, migration, and differentiation.
Methods: dsDNA [poly(dA:dT)] was transfected into DPCs using Lyovec transfection reagent. Lactate Dehydrogenase (LDH) cytotoxic assay was used to determine the potential cytotoxicity of dsDNA on DPCs. MTT assay was used to determine DPCs proliferation upon exposure to dsDNA. Supernatants were collected from DPCs at 24, 72 hours, or 7 days following transfection, and ELISA was carried out to measure IL-6 and IL-8 levels. RT-qPCR was used to determine the expression of the DNA sensors, AIM2, cGAS, and STING in DPCs and the odontogenic genes DSPP, RUNX2, ALP, COLA1, and SPP-1 following transfection. Wound healing assays were used to assess the migratory properties of the DPCs exposed to dsDNA. The STING inhibitor, H-151, and the cGAS inhibitor, G140, were used to determine the key dsDNA sensor at play.
Results: No cytotoxicity was induced upon transfecting dsDNA into DPCs. dsDNA induced an acute inflammatory response that was diminished at day 7. AIM2 was significantly expressed in DPCs upon exposure to dsDNA. cGAS and STING were expressed significantly although at a lower level. H1-51 STING inhibitor significantly reduced IL-6 and IL-8 levels. DPCs proliferative and migratory abilities were diminished upon exposure to dsDNA, but the expression of odontogenic genes SPP-1 and DSPP were increased.
Conclusions: DPCs express the DNA sensors AIM2, STING, and cGAS which enabled the initiation of acute inflammatory responses via the STING pathway suggesting an important role in pulp inflammation.

2021 Irish Division Meeting (Virtual)

2021

  • Al-natour, Banan  ( Queen's university of belfast , Belfast , United Kingdom )
  • Lundy, Fionnuala  ( Queen's University Belfast , Belfast , Ireland )
  • Dombrowski, Yvonne  ( School of Medicine Dentistry and Biomedical Sciences Queen's University of Belfast , Belfast , Ireland )
  • About, Imad  ( Faculté d'Odontologie , Marseille , France )
  • El Karim, Ikhlas  ( School of Medicine Dentistry and Biomedical Sciences Queen's University of Belfast , Belfast , Ireland )
  • none
    Oral Session
    Senior Hatton