Glucagon-like peptide 1 improves insulin resistance in vitro through anti-inflammation of macrophages

Braz J Med Biol Res. 2016 Nov 21;49(12):e5826. doi: 10.1590/1414-431X20165826.

Abstract

Glucagon-like peptide 1 (GLP-1), a kind of gut hormone, is used in the treatment of type 2 diabetes (T2D). Emerging evidence indicates that GLP-1 has anti-inflammatory activity. Chronic inflammation in the adipose tissue of obese individuals is a cause of insulin resistance and T2D. We hypothesized that GLP-1 analogue therapy in patients with T2D could suppress the inflammatory response of macrophages, and therefore inhibit insulin resistance. Our results showed that GLP-1 agonist (exendin-4) not only attenuated macrophage infiltration, but also inhibited the macrophage secretion of inflammatory cytokines including TNF-β, IL-6, and IL-1β. Furthermore, we observed that lipopolysaccharide (LPS)-induced macrophage conditioned media could impair insulin-stimulated glucose uptake. This effect was compensated by treatment with the conditioned media from macrophages treated with the combination of LPS and exendin-4. It was also observed that exendin-4 directly inhibited the activation of NF-κB in macrophages. In conclusion, our results indicated that GLP-1 improved inflammatory macrophage-derived insulin resistance by inhibiting NF-κB pathway and secretion of inflammatory cytokines in macrophages. Furthermore, our observations suggested that the anti-inflammatory effect of GLP-1 on macrophages can contribute to GLP-1 analogue therapy of T2D.

MeSH terms

  • Adipose Tissue / metabolism
  • Animals
  • Cell Migration Assays
  • Exenatide
  • Glucagon-Like Peptide 1 / pharmacology*
  • Humans
  • Inflammation / drug therapy*
  • Inflammation / metabolism
  • Inflammation Mediators / pharmacology*
  • Insulin Resistance*
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Mice
  • Peptides / pharmacology*
  • Venoms / pharmacology*

Substances

  • Inflammation Mediators
  • Peptides
  • Venoms
  • Glucagon-Like Peptide 1
  • Exenatide