scholarly journals Investigating fibrosis and inflammation in an ex vivo NASH murine model

2020 ◽  
Vol 318 (2) ◽  
pp. G336-G351
Author(s):  
Emilia Gore ◽  
Emilia Bigaeva ◽  
Anouk Oldenburger ◽  
Yvette J. M. Jansen ◽  
Detlef Schuppan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lipid Metabolism ◽  
Liver Disease ◽  
Nonalcoholic Steatohepatitis ◽  
Ex Vivo ◽  
Ex Vivo Model ◽  
Nonalcoholic Fatty Liver ◽  
Liver Slices ◽  
Expression Of Genes

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease, characterized by excess fat accumulation (steatosis). Nonalcoholic steatohepatitis (NASH) develops in 15–20% of NAFLD patients and frequently progresses to liver fibrosis and cirrhosis. We aimed to develop an ex vivo model of inflammation and fibrosis in steatotic murine precision-cut liver slices (PCLS). NASH was induced in C57Bl/6 mice on an amylin and choline-deficient l-amino acid-defined (CDAA) diet. PCLS were prepared from steatohepatitic (sPCLS) and control (cPCLS) livers and cultured for 48 h with LPS, TGFβ1, or elafibranor. Additionally, C57Bl/6 mice were placed on CDAA diet for 12 wk to receive elafibranor or vehicle from weeks 7 to 12. Effects were assessed by transcriptome analysis and procollagen Iα1 protein production. The diets induced features of human NASH. Upon culture, all PCLS showed an increased gene expression of fibrosis- and inflammation-related markers but decreased lipid metabolism markers. LPS and TGFβ1 affected sPCLS more pronouncedly than cPCLS. TGFβ1 increased procollagen Iα1 solely in cPCLS. Elafibranor ameliorated fibrosis and inflammation in vivo but not ex vivo, where it only increased the expression of genes modulated by PPARα. sPCLS culture induced inflammation-, fibrosis-, and lipid metabolism-related transcripts, explained by spontaneous activation. sPCLS remained responsive to proinflammatory and profibrotic stimuli on gene expression. We consider that PCLS represent a useful tool to reproducibly study NASH progression. sPCLS can be used to evaluate potential treatments for NASH, as demonstrated in our elafibranor study, and serves as a model to bridge results from rodent studies to the human system. NEW & NOTEWORTHY This study showed that nonalcoholic steatohepatitis can be studied ex vivo in precision-cut liver slices obtained from murine diet-induced fatty livers. Liver slices develop a spontaneous inflammatory and fibrogenic response during culture that can be augmented with specific modulators. Additionally, the model can be used to test the efficacy of pharmaceutical compounds (as shown in this investigation with elafibranor) and could be a tool for preclinical assessment of potential therapies.

scholarly journals Liraglutide Attenuates Nonalcoholic Fatty Liver Disease through Adjusting Lipid Metabolism via SHP1/AMPK Signaling Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Peng Yu ◽  
Xi Xu ◽  
Jing Zhang ◽  
Xuan Xia ◽  
Fen Xu ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Hepg2 Cells ◽  
Fatty Liver Disease ◽  
Nonalcoholic Fatty Liver ◽  
Ampk Signaling

A glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide (LR) had been experimentally and clinically shown to ameliorate nonalcoholic fatty liver disease (NAFLD). This study aimed to investigate the beneficial effect of LR on NAFLD in vivo and in vitro and its underlying molecular mechanism. The effects of LR were examined on the high-fat diet-induced in vivo model in mice and in vitro model of NAFLD in human HepG2 cells. Liver tissues and HepG2 cells were procured for measuring lipid metabolism, histological examination, and western blot analysis. LR administration significantly lowered the serum lipid profile and lipid disposition in vitro and in vivo because of the altered expression of enzymes on hepatic gluconeogenesis and lipid metabolism. Moreover, LR significantly decreased Src homology region 2 domain-containing phosphatase-1 (SHP1) and then increased the expression of phosphorylated-AMP-activated protein kinase (p-AMPK). However, the overexpression of SHP1 mediated by lentivirus vector reversed LR-induced improvement in lipid deposition. Moreover, SHP1 silencing could further increase the expression of p-AMPK to ameliorate lipid metabolism and relative lipogenic gene induced by LR. In addition, abrogation of AMPK by Compound C eliminated the protective effects of LR on lipid metabolism without changing the expression of SHP1. LR markedly prevented NAFLD through adjusting lipid metabolism via SHP1/AMPK signaling pathway.

scholarly journals Thrombin Generation Assay and Its Application in the Clinical Laboratory

2016 ◽  
Vol 62 (5) ◽  
pp. 699-707 ◽  
Author(s):  
Armando Tripodi
Keyword(s):  
Liver Disease ◽  
Thrombin Generation ◽  
Clinical Laboratory ◽  
Ex Vivo ◽  
Myeloproliferative Neoplasms ◽  
Oral Anticoagulants ◽  
Relative Strength ◽  
Nonalcoholic Fatty Liver ◽  
Thrombin Generation Assay

Abstract BACKGROUND A gap exists between in vivo and ex vivo coagulation when investigated by use of the coagulation tests prothrombin time (PT) and activated partial thromboplastin time (APTT). The thrombin generation assay (TGA) has been developed to fill this gap. CONTENT TGA evaluates thrombin generation (resulting from the action of the procoagulant driver) and decay (resulting from the action of the anticoagulant driver), thus assessing the balance between the two. Coagulation of the test plasma (platelet poor or platelet rich) is activated by small amounts of tissue factor and phospholipids, and the reaction of thrombin generation is continuously monitored by means of a thrombin-specific fluorogenic substrate. Among the parameters derived from the thrombin-generation curve, the most important is the endogenous thrombin potential, defined as the net amount of thrombin that test plasmas can generate on the basis of the relative strength of the pro- and anticoagulant drivers. TGA is therefore the candidate assay to investigate hypo- or hypercoagulability. SUMMARY From my analysis of the literature, I draw the following conclusions. There is strong evidence that TGA is helpful to elucidate coagulation mechanisms in various clinical conditions that until recently were poorly understood (chronic liver disease; diabetes; inflammatory bowel disease, myeloproliferative neoplasms, nonalcoholic fatty liver disease). TGA is a promising laboratory tool for investigating hemorrhagic coagulopathies and monitoring replacement therapy in hemophiliacs, predicting the risk of recurrent venous thromboembolism after a first event, and monitoring patients on parenteral or oral anticoagulants. These applications require clinical trials in which TGA results are combined with specific clinical end points.

scholarly journals Altered Hepatic Lipid Metabolism Contributes to Nonalcoholic Fatty Liver Disease in Leptin-Deficient Ob/Ob Mice

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
James W. Perfield ◽  
Laura C. Ortinau ◽  
R. Taylor Pickering ◽  
Meghan L. Ruebel ◽  
Grace M. Meers ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lipid Metabolism ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
De Novo ◽  
Hepatic Lipid Metabolism ◽  
Nonalcoholic Fatty Liver ◽  
Hepatic Lipid

Nonalcoholic fatty liver disease (NAFLD) is strongly linked to obesity, insulin resistance, and abnormal hepatic lipid metabolism; however, the precise regulation of these processes remains poorly understood. Here we examined genes and proteins involved in hepatic oxidation and lipogenesis in 14-week-old leptin-deficient Ob/Ob mice, a commonly studied model of obesity and hepatic steatosis. Obese Ob/Ob mice had increased fasting glucose, insulin, and calculated HOMA-IR as compared with lean wild-type (WT) mice. Ob/Ob mice also had greater liver weights, hepatic triglyceride (TG) content, and markers ofde novolipogenesis, including increased hepatic gene expression and protein content of acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and stearoyl-CoA desaturase-1 (SCD-1), as well as elevated gene expression of PPARγand SREBP-1c compared with WT mice. While hepatic mRNA levels for PGC-1α, PPARα, and TFAM were elevated in Ob/Ob mice, measures of mitochondrial function (β-HAD activity and complete (to CO2) and total mitochondrial palmitate oxidation) and mitochondrial OXPHOS protein subunits I, III, and V content were significantly reduced compared with WT animals. In summary, reduced hepatic mitochondrial content and function and an upregulation inde novolipogenesis contribute to obesity-associated NAFLD in the leptin-deficient Ob/Ob mouse.

Fetuin A in nonalcoholic fatty liver disease: in vivo and in vitro studies

2012 ◽  
Vol 166 (3) ◽  
pp. 503-510 ◽  
Author(s):  
John Willy Haukeland ◽  
Tuva B Dahl ◽  
Arne Yndestad ◽  
Ivar P Gladhaug ◽  
Else Marit Løberg ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Liver Disease ◽  
Fatty Liver Disease ◽  
Mrna Levels ◽  
Fetuin A ◽  
Nonalcoholic Fatty Liver ◽  
Key Enzymes ◽  
Glucose And Lipid Metabolism

ObjectiveFetuin A has been associated with insulin resistance and the metabolic syndrome. We therefore explored the role of fetuin A in nonalcoholic fatty liver disease (NAFLD).DesignCross-sectional and intervention studies.MethodsWe included 111 subjects with histologically proven NAFLD of whom 44 participated in a randomized, controlled trial with metformin. One hundred and thirty-one healthy subjects and 13 subjects undergoing hepatic surgery for metastatic cancer served as controls. Main outcome variables were circulating levels of fetuin A according to the presence of NAFLD, hepatic gene expression of fetuin A and key enzymes in glucose and lipid metabolism, and the effect of metformin on fetuin A levels in vivo and in vitro (HepG2 cells).ResultsFetuin A levels were significantly higher in NAFLD patients compared with controls (324±98 vs 225±75 mg/l, P<0.001). NAFLD was a significant predictor of elevated fetuin A levels (β=174 (95% confidence interval: 110–234)) independent of body mass index, age, sex, fasting glucose, and triglycerides. Hepatic fetuin A mRNA levels correlated significantly with hepatic mRNA levels of key enzymes in lipid (sterol regulatory element-binding protein 1c, carnitine palmitoyltransferase 1) and glucose (phosphoenol pyruvate kinase 1, glucose-6-phosphatase) metabolism. Plasma fetuin A levels decreased significantly after metformin treatment compared with placebo (−40±47 vs 15±82 mg/l, P=0.008). Metformin induced a dose-dependent decrease in fetuin A secretion in vitro.ConclusionsFetuin A levels were elevated in NAFLD. Hepatic expression of fetuin A correlated with key enzymes in glucose and lipid metabolism. Metformin decreased fetuin A levels in vitro.

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