Project description:Non-alcoholic fatty liver disease (NAFLD) influence one of third population around the world. Until now, no effective treatments have been established due to the improper in vitro assays and experimental animal models. By co-culturing human gut and liver cell lines (CaCO2 and HepG2 cells, respectively) interconnected via the microfluidic closed medium circulation loop, we created a gut-liver-on-a-chip (iGLC) platform as an in vitro human model of the gut-liver axis (GLA) in initiation and progression of NAFLD.
Project description:Non-alcoholic fatty liver disease (NAFLD) influence one of third population around the world. Until now, no effective treatments have been established due to the improper in vitro assays and experimental animal models. By co-culturing human gut and liver cell lines (CaCO2 and HepG2 cells, respectively) interconnected via the microfluidic closed medium circulation loop, we created a gut-liver-on-a-chip (iGLC) platform as an in vitro human model of the gut-liver axis (GLA) in initiation and progression of NAFLD.
Project description:BACKGROUND & AIMS: There is mounting evidence that microbes resident in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcoholic hepatitis (AH). However, mechanisms by which gut microbiota synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. METHODS: We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, and identified the metabolite trimethylamine (TMA) as a gut microbe-derived biomarker of AH. In subsequent studies, we treated mice with non-lethal mechanism-based bacterial choline TMA lyase inhibitors to blunt gut microbe-dependent production of TMA in the context of chronic ethanol administration. Indices of liver injury were quantified by complementary RNA sequencing, biochemical, and histological approaches. In addition, we examined the impact of ethanol consumption and TMA lyase inhibition on gut microbiome structure via 16S rRNA sequencing. RESULTS: We show the gut microbial choline metabolite trimethylamine (TMA) is elevated in AH patients, which is correlated with reduced hepatic expression of the TMA oxygenase flavin-containing monooxygenase 3 (FMO3). Provocatively, we find that small molecule inhibition of gut microbial choline TMA lyase activity protects mice from ethanol-induced liver injury. TMA lyase inhibitor-driven improvement in ethanol-induced liver injury is associated with distinct reorganization of the gut microbiome community and host liver transcriptome. CONCLUSIONS: The microbial metabolite TMA is a biomarker of AH, and blocking TMA production from gut microbes can blunt ALD in mice.
Project description:In this study we tested the ability to predict liver injury from in vitro human pooled hepatocyte data after exposure to thioacetamide (24 hour). We selected thioacetamide, a compound extensively used in various studies for its ability to cause liver injury.
Project description:There is an evident, unmet need to develop a commercially available in vitro system that can model inflammatory states of the liver and predict immune-mediated hepatotoxicity of drugs and xenobiotics taken under inflamed conditions. Hepatocyte-Kupffer cell co-cultures can model inflammation-mediated hepatotoxicity; however, Kupffer cell (KC) source remains an important bottleneck for the development of such models. Primary human Kupffer cells (PHKCs) are costly, limited in availability and exhibit donor variability. An alternative cell source for KCs has not been reported. Important paradigm shift from the classical dogma of adult blood-circulating monocyte-derived macrophages to intrahepatic precursor/fetal monocyte-derived macrophages has shed new light into the origin of KCs in vivo. Based on these recent findings, we report here, a novel method to generate human KCs in vitro from stem cells (hPSC-KCs) via fetal monocytes. hPSC-KCs expressed macrophage markers, CD11, CD14, CD68, CD163 and CD32 at gene and protein level and exhibited functional properties such as phagocytosis and Interleukin-6 and Tumor Necrosis Factor-4alpha production upon activation. Importantly, molecular signature, liver-macrophage specific CLEC-4F expression and cytokines production levels of hPSC-KCs were similar to PHKCs but different from non-liver macrophages. We used an inflammatory liver co-culture model to demonstrate that activated hPSC-KCs, but not non-liver macrophages, were able to recapitulate effects of PHKCs when stimulated with paradigm hepatotoxicants. hPSC-KCs developed in this study offer a renewable human cell source for liver-specific macrophages which can be used to develop in vitro systems for modelling the inflammatory state of the liver. Gene expression profiles of 9 samples were determined using Human Gene 2.0 ST Array. These 9 samples included three replicates each of PHKCs (primary human Kupffer cells), human pluripotent stem cell-dervied Kupffer cells (hPSC-KCs) and non-liver macrophages (NL-Mφ).
Project description:To investigate the alterlation of liver gene expression by linoleic acid (LA) metabolite HYA (10-hydroxy-cis-12-octadecenoic acid) in a diet-induced NAFLD/NASH model, we evaluated liver of male C57BL/6J mice fed a nomal diet (ND), a high fat diet (HFD, Control(CT)), HFD supplemented with 1% HYA (HYA), or HFD supplemented with 1% LA (LA) for 26 weeks from 5-week-old. We then performed gene expression profiling analysis using data obtained from RNA-seq of these 4 groups.