IRE1α regulates macrophage polarization in type 2 diabetic periodontitis through promoting endoplasmic reticulum stress

Int Immunopharmacol. 2024 May 30:133:112056. doi: 10.1016/j.intimp.2024.112056. Epub 2024 Apr 15.

Abstract

Objectives: The aim of this study was to investigate the effect of 4μ8c, an inhibitor targeting the endoplasmic reticulum stress-associated factor IRE1α, on macrophage polarization in an experimental model of diabetic periodontitis through ex vivo experiments.

Materials and methods: Local alveolar bone parameters were evaluated using Micro-CT following intraperitoneal administration of 4μ8c in mice with experimental diabetic periodontitis. Surface markers indicating macrophage polarization were identified using immunofluorescence. In vitro experiments were performed employing bone marrow-derived macrophages and gingival fibroblasts. Macrophage polarization was determined using flow cytometry. Principal impacted signaling pathways were identified through Western blot analysis.

Results: Results from both in vitro and in vivo experiments demonstrated that 4μ8c mitigated alveolar bone resorption and inflammation in mice with diabetic periodontitis. Furthermore, it modulated macrophage polarization towards the M2 phenotype and augmented M2 macrophage polarization through the MAPK signaling pathway.

Conclusions: These findings suggest that inhibiting IRE1α can modulate macrophage polarization and alleviate ligature-induced diabetic periodontitis via the MAPK signaling pathway. This unveils a novel mechanism, offering a scientific foundation for the treatment of experimental diabetic periodontitis.

Keywords: Diabetes mellitus; Endoplasmic reticulum stress; IRE1α; Macrophages; Periodontitis.

MeSH terms

  • Alveolar Bone Loss / immunology
  • Animals
  • Cells, Cultured
  • Diabetes Mellitus, Experimental / immunology
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Type 2* / immunology
  • Diabetes Mellitus, Type 2* / metabolism
  • Endoplasmic Reticulum Stress* / drug effects
  • Endoplasmic Reticulum Stress* / immunology
  • Endoribonucleases* / metabolism
  • Humans
  • MAP Kinase Signaling System / drug effects
  • Macrophages* / drug effects
  • Macrophages* / immunology
  • Macrophages* / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL*
  • Periodontitis* / immunology
  • Periodontitis* / metabolism
  • Protein Serine-Threonine Kinases* / metabolism

Substances

  • Protein Serine-Threonine Kinases
  • Endoribonucleases
  • Ern1 protein, mouse