Figure 7.

Model highlighting the metabolic functions of alternatively activated macrophages. PPARγ transcriptional signaling is required for maturation of these cells in adipose tissue, whereas PPARδ controls the expression of alternative phenotype in Kupffer cells of obese mice. Two potential mechanisms by which alternatively activated macrophages improve insulin action in obese mice are: paracrine inhibition of inflammation and secretion of trophic factors that can directly modulate oxidative metabolism in parenchymal cells (small arrows).