Irisin acts as a regulator of macrophages host defense.

AIM: Irisin, the adipomyokine, released mainly by exercised muscles, participate in the browning of adipose tissue and contribute to the restriction of insulin resistance and diabetes mellitus 2 development. Because of the limited reports describing the effect of irisin on inflammation and immunocompetent cells activation, the present study attempted to assess the influence of various irisin concentrations on basic macrophage activity.

MAIN METHODS: Studies were carried out on murine RAW 264.7 macrophages cultured in medium enriched with irisin (0nM, 10nM, 50nM, or 100nM). General cell activity, viability, and proliferation were assessed along with phagocytosis process, and respiratory burst generation.

KEY FINDING: Irisin level positively correlates with general cell activity and cell cycle progression as well as with phagocytosis intensity, but negatively correlates with the intensity of respiratory burst generation. No influence of irisin on quiescent cell viability, including apoptosis or necrosis, was observed.

SIGNIFICANCE: This research is the first to show that irisin modulates macrophage activity by reducing reactive oxygen species (ROS) overproduction, which could suggest its potential anti-inflammatory properties. Therefore, further studies are needed for the evaluation of influence of irisin on immunocompetent cell function.