Figure 6. Schematic diagram of proposed role of GHS-R in adipose tissues during aging. Our data demonstrate that GHS-R is an important regulator of macrophage polarization, and GHS-R has a pivotal role in adipose tissue inflammation in aging. GHS-R ablation shifts macrophage phenotype toward anti-inflammatory state and releases more norepinephrine. Alternatively-activated macrophages induced by GHS-R deletion infiltrate into adipose tissues, increasing lipid mobilization in WAT and activating thermogenesis in BAT, ultimately promoting a lean and insulin-sensitive metabolic state.