Exosomes derived from periodontitis induce hepatic steatosis through the SCD-1/AMPK signaling pathway

Biochim Biophys Acta Mol Basis Dis. 2024 Oct;1870(7):167343. doi: 10.1016/j.bbadis.2024.167343. Epub 2024 Jul 8.

Abstract

Aim: To investigate the impact of exosomes released by Porphyromonas gingivalis-Lipopolysaccharide activated THP-1 macrophages and human periodontal ligament fibroblasts on hepatocyte fat metabolism.

Results: The liver of rats with experimental periodontitis showed obvious steatosis and inflammation compared with control rats. The culture supernatant of macrophages and human periodontal ligament fibroblasts (hPDLFs), when stimulated with Pg-LPS, induced lipogenesis in HepG2 cells. Furthermore, the lipid-promoting effect was effectively inhibited by the addition of the exosome inhibitor GW4869. Subsequently, we isolated exosomes from cells associated with periodontitis. Exosomes released by Pg-LPS-stimulated macrophages and hPDLFs are taken up by hepatocytes, causing mRNA expression related to fat synthesis, promoting triglyceride synthesis, and aggravating NAFLD progression. Finally, two sets of exosomes were injected into mice through the tail vein. In vivo experiments have also demonstrated that periodontitis-associated exosomes promote the development of hepatic injury and steatosis, upregulate SCD-1 expression and inhibit the AMPK signaling pathway.

Conclusions: In conclusion, we found that exosomes associated with periodontitis promote hepatocyte adipogenesis by increasing the expression of SCD-1 and suppressing the AMPK pathway, which indicates that close monitoring of the progression of stomatopathy associated extra-oral disorders is important and establishes a theoretical foundation for the prevention and management of fatty liver disease linked to periodontitis.

Keywords: Exosomes; Liver steatosis; NAFLD; Periodontitis; SCD-1/AMPK signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases* / metabolism
  • Animals
  • Exosomes* / metabolism
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Hep G2 Cells
  • Hepatocytes / metabolism
  • Hepatocytes / pathology
  • Humans
  • Lipogenesis
  • Lipopolysaccharides / toxicity
  • Macrophages / metabolism
  • Macrophages / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Non-alcoholic Fatty Liver Disease / etiology
  • Non-alcoholic Fatty Liver Disease / metabolism
  • Non-alcoholic Fatty Liver Disease / pathology
  • Periodontal Ligament / metabolism
  • Periodontal Ligament / pathology
  • Periodontitis* / metabolism
  • Periodontitis* / pathology
  • Porphyromonas gingivalis
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction*
  • Stearoyl-CoA Desaturase* / genetics
  • Stearoyl-CoA Desaturase* / metabolism
  • THP-1 Cells

Substances

  • AMP-Activated Protein Kinases
  • Stearoyl-CoA Desaturase
  • SCD1 protein, human
  • Lipopolysaccharides