Increased expression levels of inflammatory cytokines and adhesion molecules in lipopolysaccharide‑induced acute inflammatory apoM‑/‑ mice

Mol Med Rep. 2020 Oct;22(4):3117-3126. doi: 10.3892/mmr.2020.11426. Epub 2020 Aug 11.

Abstract

Apolipoprotein M (apoM) may serve a protective role in the development of inflammation. Nuclear factor‑κB (NF‑κB) and its downstream factors (including a number of inflammatory cytokines and adhesion molecules) are essential for the regulation of inflammatory processes. In the present study, the importance of apoM in lipopolysaccharide (LPS)‑induced acute inflammation and its potential underlying mechanisms, were investigated using an apoM‑knockout mouse model. The levels of inducible nitric oxide synthase (iNOS), NF‑κB, interleukin (IL)‑1β, intercellular adhesion molecule 1 (ICAM‑1) and vascular cell adhesion protein 1 (VCAM‑1) were detected using reverse transcription‑quantitative PCR and western blotting. The serum levels of IL‑6 and IL‑10 were detected using Luminex technology. The results demonstrated that the protein levels of iNOS, NF‑κB, IL‑1β, ICAM‑1 and VCAM‑1 were significantly increased in apoM‑/‑ mice compared with those in apoM+/+ mice. In addition, two‑way ANOVA revealed that the interaction between apoM and LPS had a statistically significant effect on a number of factors, including the mRNA expression levels of hepatic iNOS, NF‑κB, IL‑1β, ICAM‑1 and VCAM‑1. Notably, the effects of apoM and 10 mg/kg LPS on the levels of IL‑6 and IL‑10 were the opposite of those induced by 5 mg/kg LPS, which could be associated with the dual anti‑ and pro‑inflammatory effects of IL‑6 and IL‑10. Collectively, the results of the present study revealed that apoM is an important regulator of inflammatory cytokine and adhesion molecule production in LPS‑induced inflammation, which may consequently be associated with the severity of inflammation. These findings indicated that the anti‑inflammatory effects of apoM may partly result from the inhibition of the NF‑κB pathway.

MeSH terms

  • Animals
  • Apolipoproteins M / genetics*
  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism*
  • Cytokines / blood*
  • Cytokines / genetics
  • Cytokines / metabolism
  • Gene Knockout Techniques
  • Inflammation / chemically induced
  • Inflammation / genetics
  • Inflammation / immunology*
  • Intercellular Adhesion Molecule-1 / genetics
  • Intercellular Adhesion Molecule-1 / metabolism
  • Interleukin-10 / blood
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Interleukin-6 / blood
  • Lipopolysaccharides / adverse effects*
  • Male
  • Mice
  • Nitric Oxide Synthase Type II / genetics
  • Nitric Oxide Synthase Type II / metabolism
  • Up-Regulation*
  • Vascular Cell Adhesion Molecule-1 / genetics
  • Vascular Cell Adhesion Molecule-1 / metabolism

Substances

  • ApoM protein, mouse
  • Apolipoproteins M
  • Cell Adhesion Molecules
  • Cytokines
  • IL10 protein, mouse
  • IL1B protein, mouse
  • Icam1 protein, mouse
  • Interleukin-1beta
  • Interleukin-6
  • Lipopolysaccharides
  • Vascular Cell Adhesion Molecule-1
  • interleukin-6, mouse
  • Intercellular Adhesion Molecule-1
  • Interleukin-10
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse