Hydrogen peroxide-induced oxidative stress promotes expression of CXCL15/Lungkine mRNA in a MEK/ERK-dependent manner in fibroblast-like synoviocytes derived from mouse temporomandibular joint

J Oral Biosci. 2023 Mar;65(1):97-103. doi: 10.1016/j.job.2022.12.002. Epub 2022 Dec 28.

Abstract

Objectives: Temporomandibular joint osteoarthritis (TMJ-OA) is a multifactorial disease caused by inflammation and oxidative stress. It has been hypothesized that mechanical stress-induced injury of TMJ tissues induces the generation of reactive oxygen species (ROS), such as hydroxyl radical (OH∙), in the synovial fluid (SF). In general, the overproduction of ROS contributes to synovial inflammation and dysfunction of the subchondral bone in OA. However, the mechanism by which ROS-injured synoviocytes recruit inflammatory cells to TMJ-OA lesions remains unclear.

Methods: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to evaluate the mRNA expression of chemoattractant molecules. The phosphorylation levels of intracellular signaling molecules were evaluated using western blot analysis.

Results: Hydrogen peroxide (H2O2) treatment significantly promoted mRNA expression of neutrophil chemoattractant CXCL15/Lungkine in a dose-dependent manner (100-500 μM) in fibroblast-like synoviocytes (FLSs) derived from mouse TMJ. H2O2 (500 μM) significantly upregulated the phosphorylation of extracellular signal-regulated kinase (ERK)1 and ERK2 in FLSs. Intriguingly, the mitogen-activated protein (MAP)/ERK kinase (MEK) inhibitor U0126 (10 μM) nullified H2O2-induced increase in CXCL15/Lungkine mRNA expression. Additionally, H2O2 (500 μM) administration significantly upregulated OH∙ production in FLSs, as assessed by live-cell permeant fluorescent probe targeted against OH∙ under fluorescence microscopy. Furthermore, the ROS inhibitor N-acetyl-l-cysteine (5 mM) partially but significantly reversed H2O2-mediated phosphorylation of ERK1/2.

Conclusions: H2O2-induced oxidative stress promoted the expression of CXCL15/Lungkine mRNA in a MEK/ERK-dependent manner in mouse TMJ-derived FLSs, suggesting that FLSs recruit neutrophils to TMJ-OA lesions through the production of CXCL15/Lungkine and exacerbate the local inflammatory response.

Keywords: CXCL15; Fibroblast-like synoviocytes; MEK/ERK; Oxidative stress; Temporomandibular joint.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chemotactic Factors / metabolism
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Hydrogen Peroxide / adverse effects
  • Hydrogen Peroxide / metabolism
  • Inflammation / chemically induced
  • Inflammation / metabolism
  • Inflammation / pathology
  • Mice
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Osteoarthritis* / metabolism
  • Osteoarthritis* / pathology
  • Oxidative Stress
  • RNA, Messenger / metabolism
  • Reactive Oxygen Species / adverse effects
  • Reactive Oxygen Species / metabolism
  • Synoviocytes* / metabolism
  • Synoviocytes* / pathology
  • Temporomandibular Joint / metabolism
  • Temporomandibular Joint / pathology

Substances

  • Chemotactic Factors
  • Cxcl15 protein, mouse
  • Hydrogen Peroxide
  • Mitogen-Activated Protein Kinase Kinases
  • Reactive Oxygen Species
  • RNA, Messenger