Project description:Non-alcoholic fatty liver disease (NAFLD) is a leading form of chronic liver disease with large unmet need. Non-alcoholic steatohepatitis (NASH), a progressive variant of NAFLD, can lead to fibrosis, cirrhosis, and hepatocellular carcinoma. To identify potential new therapeutics for NASH, we used a computational approach based on Connectivity Map (CMAP) analysis, which pointed us to a potential application of bromodomain and extra-terminal motif (BET) inhibitors for treating NASH. To experimentally validate this hypothesis, we tested a small-molecule inhibitor of the BET family of proteins, GSK1210151A (I-BET151), in the STAM mouse NASH model at two different dosing timepoints (onset of NASH and onset of fibrosis) to assess its potential effectiveness for the treatment of NASH and liver fibrosis. I-BET151 decreased the non-alcoholic fatty liver disease activity score (NAS), a clinical endpoint for assessing the severity of NASH, as well as progression of liver fibrosis and interferon-γ expression. Transcriptional characterization through RNA-sequencing pointed to alterations in molecular mechanisms related to interferon signaling and cholesterol biosynthesis following treatment, as well as reversal of gene expression patterns linked to fibrotic markers. Altogether, these results suggest that inhibition of BET proteins may present a novel therapeutic opportunity in the treatment of NASH and liver fibrosis.
Project description:Non-alcoholic fatty liver disease (NAFLD) is a leading form of chronic liver disease with large unmet need. Non-alcoholic steatohepatitis (NASH), a progressive variant of NAFLD, can lead to fibrosis, cirrhosis, and hepatocellular carcinoma. To identify potential new therapeutics for NASH, we used a computational approach based on Connectivity Map (CMAP) analysis, which pointed us to bromodomain and extra-terminal motif (BET) inhibitors for treating NASH. To experimentally validate this hypothesis, we tested a small-molecule inhibitor of the BET family of proteins, GSK1210151A (I-BET151), in the STAM mouse NASH model at two different dosing timepoints (onset of NASH and progression to fibrosis). I-BET151 decreased the non-alcoholic fatty liver disease activity score (NAS), a clinical endpoint for assessing the severity of NASH, as well as progression of liver fibrosis and interferon-? expression. Transcriptional characterization of these mice through RNA-sequencing was consistent with predictions from the CMAP analysis of a human NASH signature and pointed to alterations in molecular mechanisms related to interferon signaling and cholesterol biosynthesis, as well as reversal of gene expression patterns linked to fibrotic markers. Altogether, these results suggest that inhibition of BET proteins may present a novel therapeutic opportunity in the treatment of NASH and liver fibrosis.
Project description:Increased liver de novo lipogenesis (DNL) is a hallmark of nonalcoholic steatohepatitis (NASH). A key enzyme controlling DNL upregulated in NASH is ATP citrate lyase (ACLY). In mice, inhibition of ACLY reduces liver steatosis, ballooning and fibrosis and inhibits activation of hepatic stellate cells. Glucagon like peptide-1 receptor (GLP-1R) agonists lower body mass, insulin resistance and steatosis without improving fibrosis. Here, we find that combining an inhibitor of liver ACLY, bempedoic acid, and the GLP-1R agonist liraglutide reduces liver steatosis, hepatocellular ballooning, and hepatic fibrosis in a mouse model of NASH. Liver RNA analyses revealed additive downregulation of pathways that are predictive of NASH resolution, reductions in the expression of prognostically significant genes compared to clinical NASH samples, and a predicted gene signature profile that supports fibrosis resolution. These findings support further investigation of this combinatorial therapy to treat obesity, insulin resistance, hypercholesterolemia, steatohepatitis, and fibrosis in people with NASH.
Project description:Increased liver de novo lipogenesis (DNL) is a hallmark of nonalcoholic steatohepatitis (NASH). A key enzyme controlling DNL upregulated in NASH is ATP citrate lyase (ACLY). In mice, inhibition of ACLY reduces liver steatosis, ballooning and fibrosis and inhibits activation of hepatic stellate cells. Glucagon like peptide-1 receptor (GLP-1R) agonists lower body mass, insulin resistance and steatosis without improving fibrosis. Here, we find that combining an inhibitor of liver ACLY, bempedoic acid, and the GLP-1R agonist liraglutide reduces liver steatosis, hepatocellular ballooning, and hepatic fibrosis in a mouse model of NASH. Liver RNA analyses revealed additive downregulation of pathways that are predictive of NASH resolution, reductions in the expression of prognostically significant genes compared to clinical NASH samples, and a predicted gene signature profile that supports fibrosis resolution. These findings support further investigation of this combinatorial therapy to treat obesity, insulin resistance, hypercholesterolemia, steatohepatitis, and fibrosis in people with NASH.
Project description:Obesity is increasing worldwide and leads to a multitude of metabolic diseases including non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatosis (NASH). Here we examine the role of CYR61 in liver fibrosis and inflammation and its potential as a therapeutic target. Loss of CYR61 during NASH injury improves glucose tolerance, decreases liver inflammation and reduces fibrosis. CYR61 activates signaling in monocytes and monocyte-derived macrophages promoting a pro-inflammatory/pro-fibrotic phenotype through a CYR61/SYK/NFKB signaling cascade. In vitro, CYR61 activates Pdgfa and Pdgfb expression in macrophages in a NFκB-dependent manner. Ultimately, we identify a potential therapeutic for NASH: a CYR61-blocking antibody that reduces fibrotic injury and CYR61-driven signaling in macrophages in vitro and in vivo. This study demonstrates that CYR61 is a key driver of liver inflammation and fibrosis and a strong therapeutic target for treatment of NAFLD/NASH.
Project description:Non-alcoholic steatohepatitis (NASH) is a serious health challenge affecting millions worldwide, and research advances are restricted by the limited availability of preclinical models recapitulating the complex disease etiology and hepatic histopathology. Uniquely, the diet induced guinea pig model develops NASH with fibrosis resembling human histopathology however, no data is available depicting the guinea pig NASH transcriptome. We provide the first high throughput sequencing results on guinea pig NASH with advanced fibrosis. Transcriptomic profiles in guinea pig NASH clearly separated from controls, and pathways involved in fibrosis, inflammation and lipid metabolism were all highly regulated.
Project description:Obesity is increasing worldwide and leads to a multitude of metabolic diseases including non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatosis (NASH). Here we examine the role of CYR61 in liver fibrosis and inflammation and its potential as a therapeutic target. Loss of CYR61 during NASH injury improves glucose tolerance, decreases liver inflammation and reduces fibrosis. CYR61 activates signaling in monocytes and monocyte-derived macrophages promoting a pro-inflammatory/pro-fibrotic phenotype through a CYR61/SYK/NFKB signaling cascade. In vitro, CYR61 activates Pdgfa and Pdgfb expression in macrophages in a NFκB-dependent manner. Ultimately, we identify a potential therapeutic for NASH: a CYR61-blocking antibody that reduces fibrotic injury and CYR61-driven signaling in macrophages in vitro and in vivo. This study demonstrates that CYR61 is a key driver of liver inflammation and fibrosis and a strong therapeutic target for treatment of NAFLD/NASH.
Project description:Obesity is increasing worldwide and leads to a multitude of metabolic diseases including non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatosis (NASH). Here we examine the role of CYR61 in liver fibrosis and inflammation and its potential as a therapeutic target. Loss of CYR61 during NASH injury improves glucose tolerance, decreases liver inflammation and reduces fibrosis. CYR61 activates signaling in monocytes and monocyte-derived macrophages promoting a pro-inflammatory/pro-fibrotic phenotype through a CYR61/SYK/NFKB signaling cascade. In vitro, CYR61 activates Pdgfa and Pdgfb expression in macrophages in a NFκB-dependent manner. Ultimately, we identify a potential therapeutic for NASH: a CYR61-blocking antibody that reduces fibrotic injury and CYR61-driven signaling in macrophages in vitro and in vivo. This study demonstrates that CYR61 is a key driver of liver inflammation and fibrosis and a strong therapeutic target for treatment of NAFLD/NASH.
Project description:SUMMARY: This article presents a predictive molecular signature that marks the early onset of fibrosis in a translational nonalcoholic steatohepatitis mouse model. Overlap of genes and processes with human nonalcoholic steatohepatitis and a list of top candidate biomarkers for early fibrosis are described. BACKGROUND & AIMS: The incidence of nonalcoholic steatohepatitis (NASH) is increasing. The pathophysiological mechanisms of NASH and the sequence of events leading to hepatic fibrosis are incompletely understood. The aim of this study was to gain insight into the dynamics of key molecular processes involved in NASH and to rank early markers for hepatic fibrosis. METHODS: A time-course study in low-density lipoprotein–receptor knockout. Leiden mice on a high-fat diet was performed to identify the temporal dynamics of key processes contributing to NASH and fibrosis. An integrative systems biology approach was used to elucidate candidate markers linked to the active fibrosis process by combining transcriptomics, dynamic proteomics, and histopathology. The translational value of these findings were confirmed using human NASH data sets. RESULTS: High-fat-diet feeding resulted in obesity, hyperlipidemia, insulin resistance, and NASH with fibrosis in a time-dependent manner. Temporal dynamics of key molecular processes involved in the development of NASH were identified, including lipid metabolism, inflammation, oxidative stress, and fibrosis. A data-integrative approach enabled identification of the active fibrotic process preceding histopathologic detection using a novel molecular fibrosis signature. Human studies were used to identify overlap of genes and processes and to perform a network biology-based prioritization to rank top candidate markers representing the early manifestation of fibrosis. CONCLUSIONS: An early predictive molecular signature was identified that marked the active profibrotic process before histopathologic fibrosis becomes manifest. Early detection of the onset of NASH and fibrosis enables identification of novel blood-based biomarkers to stratify patients at risk, development of new therapeutics, and help shorten (pre)clinical experimental time frames. Keywords: Systems Biology; Metabolic Syndrome; Liver Disease; Diagnosis.