Adiponectin primes human monocytes into alternative anti-inflammatory M2 macrophages

Am J Physiol Heart Circ Physiol. 2010 Sep;299(3):H656-63. doi: 10.1152/ajpheart.00115.2010. Epub 2010 Jul 9.

Abstract

Altered macrophage kinetics is a pivotal mechanism of visceral obesity-induced inflammation and cardiometabolic risk. Because monocytes can differentiate into either proatherogenic M1 macrophages or anti-inflammatory M2 macrophages, approaches that limit M1 while promoting M2 differentiation represent a unique therapeutic strategy. We hypothesized that adiponectin may prime human monocytes toward the M2 phenotype. Adiponectin promoted the alternative activation of human monocytes into anti-inflammatory M2 macrophages as opposed to the classically activated M1 phenotype. Adiponectin-treated cells displayed increased M2 markers, including the mannose receptor (MR) and alternative macrophage activation-associated CC chemokine-1. Incubation of M1 macrophages with adiponectin-treated M2-derived culture supernatant resulted in a pronounced inhibition of tumor necrosis factor-alpha and monocyte chemotactic protein-1 secretion. Activation of human monocytes into M2 macrophages by adiponectin was mediated, in addition to AMP-activated protein kinase and peroxisome proliferator-activated receptor (PPAR)-gamma, via PPAR-alpha. Furthermore, macrophages isolated from adiponectin knockout mice demonstrated diminished levels of M2 markers such as MR, which were restored with adiponectin treatment. We report a novel immunoregulatory mechanism through which adiponectin primes human monocyte differentiation into anti-inflammatory M2 macrophages. Conditions associated with low adiponectin levels, such as visceral obesity and insulin resistance, may promote atherosclerosis, in part through aberrant macrophage kinetics.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / metabolism
  • Adiponectin / genetics
  • Adiponectin / metabolism*
  • Adiponectin / pharmacology
  • Analysis of Variance
  • Animals
  • Cell Differentiation / physiology*
  • Cells, Cultured
  • Enzyme-Linked Immunosorbent Assay
  • Flow Cytometry
  • Humans
  • Inflammation / metabolism
  • Macrophage Activation*
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Mice
  • Mice, Knockout
  • Monocytes / drug effects
  • Monocytes / metabolism*
  • PPAR gamma / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Adiponectin
  • PPAR gamma
  • AMP-Activated Protein Kinases