Adipose mRNA levels for Tnfα, Mcp1 (macrophage chemokine), Cd68 (macrophages), and Cd11c (dendritic cells) were significantly lower in Tlr9-/- and MyD88-/-

mice fed Ath diet, and macrophage recruitment into adipose tissue (F4/80 IHC staining) (Fig C) was correspondingly less. Conclusions: Our observation that Tlr9-/- signalling is important for macrophage infiltration and inflammatory recruitment in adipose tissue is entirely novel. Correspondingly, liver inflammation was much less in Tlr9-/- and MyD88-/- mice though ALT levels were paradoxically higher. Thus, Tlr9 (and MyD88) is important for adipose and hepatic inflammation in obese mice. However, MyD88 (and or Tlr9) has hepatoprotective signalling against steatosis-associated liver injury and also combats development of insulin resistance. LT GAN,1 DM VAN ROOYEN,1 M KOINA,2 RS MCCUSKEY,3 N TEOH,1 G FARRELL1 1Liver Research Group, selleck chemicals ANU Navitoclax molecular weight Medical School at The Canberra Hospital, Garran, ACT, Australia, 2Department of Anatomical Pathology, ACT Pathology, The Canberra Hospital, ACT, Australia, 3Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, USA Introduction: Indirect evidence implicates hepatic free cholesterol (FC) accumulation in non-alcoholic steatohepatitis (NASH)pathogenesis in humans and mouse models that exhibit similar metabolic dysregulation (obesity, insulin resistance, diabetes, artherogenic

dyslipidemia). Cholesterol-loaded livers are sensitized to cytokine-mediated mitochondrial injury, but there is no direct evidence linking FC lipotoxicity to

hepatocellular injury and inflammatory recruitment. Last year we reported a system to load primary murine hepatocytes with FC by incubation with human low density lipoprotein (LDL). We now characterize the signaling and subcellular mechanisms of apoptosis and necrosis and test the hypothesis that c-Jun N-terminal kinase (JNK) activation and mitochondrial oxidative stress are essential steps in cholesterol lipotoxicity. We also explore how FC-induced hepatocyte injury/necrosis might promote Kupffer cell (KC) activation via effects on damage-associated molecular Org 27569 patterns (DAMPs) released from injured primary hepatocytes and/or microparticles (MPs) liberated by the cytoskeletal injury that leads to blebbing of cholesterol-loaded hepatocyte plasma membranes. Materials and methods: We used frozen liver sections from earlier experiments1,2 to establish the subcellular site of hepatocyte FC in NASH by determining co-localisation of filipin fluorescence with organelle markers. Primary murine hepatocytes (C57B6/J wild type [WT] or JNK1-/-) were incubated with LDL (20–40 μM) to load with FC. Pathways and patterns of FC-mediated cell death were determined by western blot, immunofluorescence and use of pathway-specific inhibitors. Separately, supernatants and MP fractions (100,000 g sedimentation) from FC-injured hepatocytes were added to murine KC cultures.