An important role for PPARβ/δ in the regulation of the inflammatory profile of tissue macrophages has been recently discovered [86, 87]. Odegaard and coworkers showed that PPARβ / δ is required for alternative activation of Kupffer cells, and alternatively activated macrophages suppress inflammation and promote tissue repair [87, 88]. Moreover, alternatively activated Kupffer cells promote the β-oxidative pathways and suppress lipogenesis in hepatocytes via a paracrine cross-talk [87]. The mouse model used by Odeggard and coworkers was developed to study obesity-induced insulin resistance and type-2 diabetes; however since several parallelisms exist between alcoholic and nonalcoholic liver injury [23], it would be of great interest to test the hypothesis that macrophage specific inhibition of PPARβ/δ would play an important role in alcohol-induced steatohepatitis.
