The VDR/FFAR2 axis mitigates sepsis-induced lung injury by suppressing macrophage lipid peroxidation

Int Immunopharmacol. 2024 Dec 25;143(Pt 2):113328. doi: 10.1016/j.intimp.2024.113328. Epub 2024 Oct 17.

Abstract

Sepsis-induced lung injury is a common critical condition in clinical practice, characterized by the accumulation of peroxides and inflammatory damage caused by excessive macrophage activation. Currently, effective treatments for sepsis-induced lung injury are lacking. Short-chain fatty acid receptor FFAR2 serves as an anti-inflammatory biomarker, but its role and mechanism in sepsis-induced lung injury remain unclear. To elucidate the influence and mechanism of FFAR2 on macrophage lipid peroxidation levels in sepsis-induced lung injury, this study conducted bioinformatics analysis and cellular experiments using the THP-1 macrophage cell line. By dual luciferase reporter and chromatin immunoprecipitation-quantitative PCR assays, it is confirmed that the transcription factor VDR upregulates FFAR2 expression in macrophages by binding to the promoter region -1695 ∼ 1525, thereby increasing the expression of iron death negative regulatory molecules and lowering macrophage lipid peroxidation levels. Moreover, both in vitro using THP-1 cells and bone marrow-derived macrophages (BMDMs) and in vivo using an LPS-induced septic mice model experiments revealed that activating the VDR/FFAR2 axis could reduce inflammation-induced macrophage lipid peroxide accumulation and alleviate lung injury in septic mice. This finding highlights the potential of FFAR2 as an immunotherapeutic target for mitigating sepsis-related lung injury.

Keywords: Acute lung injury; Lipid peroxidation; Macrophage; Sepsis.

MeSH terms

  • Animals
  • Disease Models, Animal
  • Humans
  • Lipid Peroxidation*
  • Lipopolysaccharides
  • Lung Injury / immunology
  • Lung Injury / metabolism
  • Macrophages* / immunology
  • Macrophages* / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL*
  • Receptors, Calcitriol* / metabolism
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism
  • Sepsis* / complications
  • Sepsis* / immunology
  • Sepsis* / metabolism
  • Signal Transduction
  • THP-1 Cells

Substances

  • Receptors, Calcitriol
  • Receptors, G-Protein-Coupled
  • Lipopolysaccharides
  • VDR protein, human
  • Vdr protein, mouse