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Background & Aims: Development of liver fibrosis is associated with activation of quiescent hepatic stellate cells (HSCs) into collagen type I-producing myofibroblasts (activated HSCs). Cessation of liver injury often results in fibrosis resolution and inactivation of activated HSCs/myofibroblasts into a quiescent-like state (inactivated HSCs). We aimed to identify molecular features of phenotypes of HSCs from mice and humans., Methods: We performed studies with Lrat Cre , Ets1-floxed, Nf1-floxed, Pparγ-floxed, Gata6-floxed, Rag2 -/- γc -/- , and C57/Bl6 (control) mice. Some mice were given carbon tetrachloride (CCl 4 ) to induce liver fibrosis, with or without a peroxisome proliferator-activated receptor-γ (PPARγ) agonist. Livers from mice were analyzed by immunohistochemistry. Quiescent, activated, and inactivated HSCs were isolated from livers of Col1α1 YFP mice and analyzed by chromatin immunoprecipitation and sequencing. Human HSCs were isolated from livers denied for transplantation. We compared changes in gene expression patterns and epigenetic modifications (histone H3 lysine 4 dimethylation and histone H3 lysine 27 acetylation) in primary mouse and human HSCs. Transcription factors were knocked down with small hairpin RNAs in mouse HSCs., Results: Motif enrichment identified E26 transcription-specific transcription factors (ETS) 1, ETS2, GATA4, GATA6, interferon regulatory factor (IRF) 1, and IRF2 transcription factors as regulators of the mouse and human HSC lineage. Small hairpin RNA-knockdown of these transcription factors resulted in increased expression of genes that promote fibrogenesis and inflammation, and loss of HSC phenotype. Disruption of Gata6 or Ets1, or Nf1 or Pparγ (which are regulated by ETS1), increased the severity of CCl 4 -induced liver fibrosis in mice compared to control mice. Only mice with disruption of Gata6 or Pparγ had defects in fibrosis resolution after CCl 4 administration was stopped, associated with persistent activation of HSCs. Administration of a PPARγ agonist accelerated regression of liver fibrosis after CCl 4 administration in control mice but not in mice with disruption of Pparγ., Conclusions: Phenotypes of HSCs from humans and mice are regulated by transcription factors, including ETS1, ETS2, GATA4, GATA6, IRF1, and IRF2. Activated mouse and human HSCs can revert to a quiescent-like, inactivated phenotype. We found GATA6 and PPARγ to be required for inactivation of human HSCs and regression of liver fibrosis in mice., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Chronic alcohol abuse has a detrimental effect on the brain and liver. There is no effective treatment for these patients, and the mechanism underlying alcohol addiction and consequent alcohol-induced damage of the liver/brain axis remains unresolved. We compared experimental models of alcoholic liver disease (ALD) and alcohol dependence in mice and demonstrated that genetic ablation of IL-17 receptor A (IL-17ra-/-) or pharmacological blockade of IL-17 signaling effectively suppressed the increased voluntary alcohol drinking in alcohol-dependent mice and blocked alcohol-induced hepatocellular and neurological damage. The level of circulating IL-17A positively correlated with the alcohol use in excessive drinkers and was further increased in patients with ALD as compared with healthy individuals. Our data suggest that IL-17A is a common mediator of excessive alcohol consumption and alcohol-induced liver/brain injury, and targeting IL-17A may provide a novel strategy for treatment of alcohol-induced pathology.

Background & Aims: Although there are associations among oxidative stress, reduced nicotinamide adenine dinucleotide phosphate oxidase (NOX) activation, and hepatocellular carcinoma (HCC) development, it is not clear how NOX contributes to hepatocarcinogenesis. We studied the functions of different NOX proteins in mice after administration of a liver carcinogen., Methods: Fourteen-day-old Nox1 -/- mice, Nox4 -/- mice, Nox1 -/- Nox4 -/- (double-knockout) mice, and wild-type (WT) C57BL/6 mice were given a single intraperitoneal injection of diethylnitrosamine (DEN) and liver tumors were examined at 9 months. We also studied the effects of DEN in mice with disruption of Nox1 specifically in hepatocytes (Nox1 ΔHep ), hepatic stellate cells (Nox1 ΔHep ), or macrophages (Nox1 ΔMac ). Some mice were also given injections of the NOX1-specific inhibitor ML171. To study the acute effects of DEN, 8-12-week-old mice were given a single intraperitoneal injection, and liver and serum were collected at 72 hours. Liver tissues were analyzed by histologic examination, quantitative polymerase chain reaction, and immunoblots. Hepatocytes and macrophages were isolated from WT and knockout mice and analyzed by immunoblots., Results: Nox4 -/- mice and WT mice developed liver tumors within 9 months after administration of DEN, whereas Nox1 -/- mice developed 80% fewer tumors, which were 50% smaller than those of WT mice. Nox1 ΔHep and Nox1 ΔHSC mice developed liver tumors of the same number and size as WT mice, whereas Nox1 ΔMac developed fewer and smaller tumors, similar to Nox1 -/- mice. After DEN injection, levels of tumor necrosis factor, interleukin 6 (IL6), and phosphorylated signal transducer and activator of transcription 3 were increased in livers from WT, but not Nox1 -/- or Nox1 ΔMac , mice. Conditioned medium from necrotic hepatocytes induced expression of NOX1 in cultured macrophages, followed by expression of tumor necrosis factor, IL6, and other inflammatory cytokines; this medium did not induce expression of IL6 or cytokines in Nox1 ΔMac macrophages. WT mice given DEN followed by ML171 developed fewer and smaller liver tumors than mice given DEN followed by vehicle., Conclusions: In mice given injections of a liver carcinogen (DEN), expression of NOX1 by macrophages promotes hepatic tumorigenesis by inducing the production of inflammatory cytokines. We propose that upon liver injury, damage-associated molecular patterns released from dying hepatocytes activate liver macrophages to produce cytokines that promote tumor development. Strategies to block NOX1 or these cytokines might be developed to slow hepatocellular carcinoma progression., (Copyright © 2019 AGA Institute. Published by Elsevier Inc. All rights reserved.)

A new measure assessing respondents' perceptions of the threat posed by their own emotions (the Perception of Threat from Emotion Questionnaire; the PTEQ) is presented. A range of data relating to the psychometric properties of the PTEQ indicates that it is a reliable measure of people's stable beliefs about their emotions, and is not highly correlated with either mood or measures of responsibility and thought-action fusion. In a student sample, regression analyses indicate that responses to the PTEQ significantly predict responses to a general measure of obsessionality (the Padua Inventory), even when levels of depression and anxiety are controlled for. Moreover, when compared with measures of responsibility and thought-action fusion, the PTEQ emerges as the strongest independent predictor of obsessionality. Of the seven different emotions to which the PTEQ relates, it is found that beliefs about 'anger' are the strongest predictor of obsessionality. Implications of these findings are discussed.