m6 A demethylase Fto regulates the TNF-α-induced inflammatory response in cementoblasts

Oral Dis. 2023 Oct;29(7):2806-2815. doi: 10.1111/odi.14396. Epub 2022 Nov 13.

Abstract

Objective: Apical periodontitis is the most frequently occurring pathological lesion. Fat mass and obesity-associated protein (Fto) is the first identified RNA N6-methyladenosine demethylase. However, whether Fto regulates apical periodontitis remains unclear. This study aimed to explore the mechanisms of Fto in the tumor necrosis factor-α (TNF-α)-induced inflammatory response.

Materials and methods: We established an apical periodontitis model. An immortalized cementoblast cell line (OCCM-30) cells were exposed to TNF-α. Fto, Il6, Mcp1, and Mmp9 expressions were assessed by qRT-PCR. We knocked down Fto using lentiviruses and detected TNF-α-induced inflammation-related gene expressions and mRNA stability.

Results: Mice with apical periodontitis showed downregulation of Fto expression. OCCM-30 cells exposed to TNF-α showed an upregulation of inflammation-related genes with a decrease in Fto. Furthermore, knockdown of Fto promoted the expressions of Il6, Mcp1, and Mmp9 in TNF-α-treated OCCM-30 cells as compared with negative control cells, whereas it did not affect the mRNA stability. Interestingly, Fto knockdown activated the p65, p38, and ERK1/2 pathways, and it slightly activated the JNK signaling pathway after TNF-α administration in OCCM-30 cells.

Conclusion: A TNF-α-induced decrease in the expression of Fto might play a critical role in the inflammatory response in cementoblasts, and knockdown of Fto might upregulate the inflammatory response.

Keywords: Fto; MAPK; NF-κB; inflammatory response; mRNA stability.

MeSH terms

  • Animals
  • Dental Cementum*
  • Inflammation / metabolism
  • Interleukin-6 / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • Mice
  • NF-kappa B / metabolism
  • Periapical Periodontitis* / metabolism
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Tumor Necrosis Factor-alpha
  • NF-kappa B
  • Matrix Metalloproteinase 9
  • Interleukin-6