Adiponectin and Liver Figure 2. Acute treatment with adiponectin elevates UCP2 expression in NPCs. PBS or 50 mg of murine adiponectin protein was injected into the portal vein of AKO mice livers. Liver tissues were collected for evaluation of UCP2 expression. The protein abundance in mitochondria (A), mRNA expression in total tissue lysates (B), and the protein content in PC and NPC fractions (C) were analyzed as in Figure 1. *, P,0.05 vs vehicle treated samples, n = 3. doi:10.1371/journal.pone.0032349.g002 Figure 3. Adiponectin promotes UCP2 expression in hepatic endothelial cells. AKO mice were treated as in Figure 1B. The NPCs were used for further fractionation to collect those enriched with Kupffer (K)- and sinusoidal endothelial (E) cells. The enrichment of the two cell types were confirmed by Western blotting using macrophage marker F4/80 and sinusoidal endothelial marker SE-1, respectively (A). UCP2 expression was monitored as in Figure 1. After densitometry analysis, the protein ratio of UCP2/b-actin was calculated and presented as fold changes against Luci Kupffer samples (B). UCP2 gene expression was also quantified in four types of cells treated with or without adiponectin (10 mg/ml) (C). *, P,0.05 and **, P,0.01 vs corresponding controls, n = 3. doi:10.1371/journal.pone.0032349.g003 PLoS ONE | www.plosone.org 3 February 2012 | Volume 7 | Issue 2 | e32349