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Approaches to manage nonalcoholic fatty liver disease (NAFLD) are limited by an incomplete understanding of disease pathogenesis. The aim of this study was to identify hepatic gene-expression patterns associated with different patterns of liver injury in a high-risk cohort of adults with obesity. Using the NanoString Technologies (Seattle, WA) nCounter assay, we quantified expression of 795 genes, hypothesized to be involved in hepatic fibrosis, inflammation, and steatosis, in liver tissue from 318 adults with obesity. Liver specimens were categorized into four distinct NAFLD phenotypes: normal liver histology (NLH), steatosis only (steatosis), nonalcoholic steatohepatitis without fibrosis (NASH F0), and NASH with fibrosis stage 1-4 (NASH F1-F4). One hundred twenty-five genes were significantly increasing or decreasing as NAFLD pathology progressed. Compared with NLH, NASH F0 was characterized by increased inflammatory gene expression, such as gamma-interferon-inducible lysosomal thiol reductase (IFI30) and chemokine (C-X-C motif) ligand 9 (CXCL9), while complement and coagulation related genes, such as C9 and complement component 4 binding protein beta (C4BPB), were reduced. In the presence of NASH F1-F4, extracellular matrix degrading proteinases and profibrotic/scar deposition genes, such as collagens and transforming growth factor beta 1 (TGFB1), were simultaneously increased, suggesting a dynamic state of tissue remodeling. Conclusion: In adults with obesity, distinct states of NAFLD are associated with intrahepatic perturbations in genes related to inflammation, complement and coagulation pathways, and tissue remodeling. These data provide insights into the dynamic pathogenesis of NAFLD in high-risk individuals.

T cell exhaustion is associated with failure to clear chronic infections and malignant cells. Defining the molecular mechanisms of T cell exhaustion and reinvigoration is essential to improving immunotherapeutic modalities. Here we confirmed pervasive phenotypic, functional and transcriptional differences between memory and exhausted antigen-specific CD8+ T cells in human hepatitis C virus (HCV) infection before and after treatment. After viral cure, phenotypic changes in clonally stable exhausted T cell populations suggested differentiation toward a memory-like profile. However, functionally, the cells showed little improvement, and critical transcriptional regulators remained in the exhaustion state. Notably, T cells from chronic HCV infection that were exposed to antigen for less time because of viral escape mutations were functionally and transcriptionally more similar to memory T cells from spontaneously resolved HCV infection. Thus, the duration of T cell stimulation impacts exhaustion recovery, with antigen removal after long-term exhaustion being insufficient for the development of functional T cell memory. Lauer and colleagues examine CD8+ T cells following cure of human hepatitis C virus (HCV) infection. CD8+ T cells exposed to chronic HCV-specific activation show durable functional, phenotypic and transcriptional exhaustion that is maintained even after antigen stimulus is removed.

A variety of dietary nonalcoholic steatohepatitis (NASH) mouse models are available, and choosing the appropriate mouse model is one of the most important steps in the design of NASH studies. In addition to the histopathological and metabolic findings of NASH, a sufficient mouse model should guarantee a robust clinical status and good animal welfare. Three different NASH diets, a high-fat diet (HFD60), a western diet (WD), and a cafeteria diet (CAFD), were fed for 12 or 16 weeks. Metabolic assessment was conducted at baseline and before scheduled sacrifice, and liver inflammation was analyzed via fluorescence-associated cell sorting and histopathological examination. Clinical health conditions were scored weekly to assess the impact on animal welfare. The HFD60 and WD were identified as suitable NASH mouse models without a significant strain on animal welfare. Furthermore, the progression of inflammation and liver fibrosis was associated with a decreased proportion of CD3+ NK1.1+ cells. The WD represents a model of advanced-stage NASH, and the HFD60 is a strong model of nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome. However, the CAFD should not be considered a NASH model.

The GH and IGF-1 axis is a candidate disease-modifying target in nonalcoholic fatty liver disease (NAFLD) given its lipolytic, anti-inflammatory and anti-fibrotic properties. IGF-1 receptor (IGF-1R) and GH receptor (GHR) expression in adult, human hepatic tissue is not well understood across the spectrum of NAFLD severity. Therefore, we sought to investigate hepatic IGF-1R and GHR expression in subjects with NAFLD utilizing gene expression analysis (GEA) and immunohistochemistry (IHC).GEA (n = 318) and IHC (n = 30) cohorts were identified from the Massachusetts General Hospital NAFLD Tissue Repository. GEA subjects were categorized based on histopathology as normal liver histology (NLH), steatosis only (Steatosis), nonalcoholic steatohepatitis (NASH) without fibrosis (NASH F0), and NASH with fibrosis (NASH F1-4) with GEA by the Nanostring nCounter assay. IHC subjects were matched for age, body mass index (BMI), sex, and diabetic status across three groups (n = 10 each): NLH, Steatosis, and NASH with fibrosis (NASH F1-3). IHC for IGF-1R, IGF-1 and GHR was performed on formalin-fixed, paraffin-embedded hepatic tissue samples.IGF-1R gene expression did not differ across NAFLD severity while IGF-1 gene expression decreased with increasing NAFLD severity, including when controlled for BMI and age. GHR expression did not differ by severity of NAFLD based on GEA or IHC.IGF-1R and GHR expression levels were not significantly different across NAFLD disease severity. However, expression of IGF-1 was lower with increasing severity of NAFLD. Additional research is needed regarding the contribution of the GH/IGF-1 axis to the pathophysiology of NAFLD and NASH.

Background & Aims: With or without antiviral treatment, few individuals achieve sustained functional cure of chronic hepatitis B virus (HBV) infection. A better definition of what mediates functional cure is essential for improving immunotherapeutic strategies. We aimed to compare HBV-specific T cell responses in patients with different degrees of viral control. Methods: We obtained blood from 124 HBV-infected individuals, including those with acute self-limiting HBV infection, chronic infection, and chronic infection with functional cure. We screened for HBV-specific T cell specificities by ELISpot, assessed the function of HBV-specific T cells using intracellular cytokine staining, and characterized HBV-specific CD4 T cells using human leukocyte antigen (HLA) class II tetramer staining, all directly ex vivo. Results: ELISpot screening readily identified HBV-specific CD4 and CD8 T cell responses in acute resolving infection compared with more limited reactivity in chronic infection. Applying more sensitive assays revealed higher frequencies of functional HBV-specific CD4 T cells, but not CD8 T cells, in functional cure compared to chronic infection. Function independent analysis using HLA multimers also identified more HBV-specific CD4 T cell responses in functional cure compared to chronic infection, with the emergence of CD4 T cell memory both after acute and chronic infection. Conclusions: Functional cure is associated with higher frequencies of functional HBV-specific CD4 memory T cell responses. Thus, immunotherapeutic approaches designed to induce HBV functional cure should also aim to improve CD4 T cell responses. Lay summary: Immunotherapy is a form of treatment that relies on harnessing the power of an individual's immune system to target a specific disease or pathogen. Such approaches are being developed for patients with chronic HBV infection, in an attempt to mimic the immune response in patients who control HBV infection spontaneously, achieving a so-called functional cure. However, what exactly defines protective immune responses remains unclear. Herein, we show that functional cure is associated with robust responses by HBV-specific CD4 T cells (a type of immune cell).

International journal of molecular sciences 22(14), 7314 (2021). doi:10.3390/ijms22147314 special issue: "Molecular Endocrinology and Metabolism / José L. Quiles, Section Editor-in-Chief", Published by Molecular Diversity Preservation International, Basel

Non-alcoholic fatty liver disease ranges from steatosis to non-alcoholic steatohepatitis (NASH), potentially progressing to cirrhosis and hepatocellular carcinoma (HCC). Here, we show that platelet number, platelet activation and platelet aggregation are increased in NASH but not in steatosis or insulin resistance. Antiplatelet therapy (APT; aspirin/clopidogrel, ticagrelor) but not nonsteroidal anti-inflammatory drug (NSAID) treatment with sulindac prevented NASH and subsequent HCC development. Intravital microscopy showed that liver colonization by platelets depended primarily on Kupffer cells at early and late stages of NASH, involving hyaluronan-CD44 binding. APT reduced intrahepatic platelet accumulation and the frequency of platelet-immune cell interaction, thereby limiting hepatic immune cell trafficking. Consequently, intrahepatic cytokine and chemokine release, macrovesicular steatosis and liver damage were attenuated. Platelet cargo, platelet adhesion and platelet activation but not platelet aggregation were identified as pivotal for NASH and subsequent hepatocarcinogenesis. In particular, platelet-derived GPIbα proved critical for development of NASH and subsequent HCC, independent of its reported cognate ligands vWF, P-selectin or Mac-1, offering a potential target against NASH.

Biomedicines : open access journal 9(11), 1613 (2021). doi:10.3390/biomedicines9111613 special issue: "Clinical, Translational and Basic Research on Liver Diseases / Topic Editors: Prof. Dr. Neuman Manuela, Prof. Dr. Stephen Malnick", Published by MDPI, Basel

Both acute and chronic hepatic inflammation likely result from an imbalance in the TH1/TH2 cell response and can lead to liver fibrosis and end-stage liver disease. More recently, a novel CD4+ T helper cell subset was described, characterized by the production of IL-17 and IL-22. These TH17 cells 50were predominantly implicated in host defense against infections and in autoimmune diseases. Interestingly, studies over the last 10 years revealed that the development of TH17 cells favors pro-inflammatory responses in almost all tissues and there is a reciprocal relationship between TH17 and TReg cells. The balance between TH17and TReg cells is critical for immune reactions, especially in injured liver tissue and the return to immune homeostasis. The pathogenic contribution of TH17 and TReg cells in autoimmunity, acute infection, and chronic liver injury is diverse and varies among disease etiologies. Understanding the mechanisms underlying TH17 cell development, recruitment, and maintenance, along with the suppression of TReg cells, will inform the development of new therapeutic strategies in liver diseases. Active manipulation of the balance between pathogenic and regulatory processes in the liver may assist in the restoration of homeostasis, especially in hepatic inflammation.

T cell exhaustion is associated with failure to clear chronic infections and malignant cells. Defining the molecular mechanisms of T cell exhaustion and reinvigoration is essential to improving immunotherapeutic modalities. Here we confirmed pervasive phenotypic, functional, and transcriptional differences between memory and exhausted antigen-specific CD8+ T cells in human hepatitis C virus (HCV) infection before and after treatment. After viral cure, phenotypic changes in clonally stable exhausted T cell populations suggested differentiation towards a memory-like profile. However, functionally, the cells showed little improvement and critical transcriptional regulators remained in the exhaustion state. Notably, T cells from chronic HCV infection that were exposed to antigen for less time because of viral escape mutations were functionally and transcriptionally more similar to memory T cells from spontaneously resolved HCV infection. Thus, T cell stimulation duration impacts exhaustion recovery, with antigen removal after long-term exhaustion being insufficient for development of functional T cell memory.

Tumor necrosis factor (TNF) is a well-known mediator of sepsis. In many cases, sepsis results in multiple organ injury including the lung with acute respiratory distress syndrome (ARDS). More than 20-year-old studies have suggested that TNF may be directly responsible for organ injury during sepsis. However, these old studies are inconclusive, because they relied on human rather than conspecific TNF, which was contaminated with endotoxin in most studies. In this study, we characterized the direct effects of intravenous murine endotoxin-free TNF on cardiovascular functions and organ injury in mice with a particular focus on the lungs. Because of the relevance of the acid sphingomyelinase in sepsis, ARDS, and caspase-independent cell death, we also included acid sphingomyelinase-deficient (ASM-/-) mice. ASM-/- and wild-type (WT) mice received 50 μg endotoxin-free murine TNF intravenously alone or in combination with the pan-caspase inhibitor carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoromethylketone (zVAD) and were ventilated at low tidal volume while lung mechanics were followed. Blood pressure was stabilized by intra-arterial fluid support, and body temperature was kept at 37°C to delay lethal shock and to allow investigation of blood gases, lung histopathology, proinflammatory mediators, and microvascular permeability 6 hours after TNF application. Besides the lungs, also the kidneys and liver were examined. TNF elicited the release of inflammatory mediators and a high mortality rate, but failed to injure the lungs, kidneys, or liver of healthy mice significantly within 6 hours. Mortality in WT mice was most likely due to sepsis-like shock, as indicated by metabolic acidosis, high procalcitonin levels, and cardiovascular failure. ASM-/- mice were protected from TNF-induced hypotension and reflex tachycardia and also from mortality. In WT mice, intravenous exogenous TNF does not cause organ injury but induces a systemic inflammatory response with cardiovascular failure, in which the ASM plays a role.

Background: Obesity is a state of relative growth hormone (GH) and insulin-like growth factor-1 (IGF-1) deficiency, and the GH/IGF-1 axis has been implicated in the pathophysiology of nonalcoholic fatty liver disease (NAFLD) and the progression to steatohepatitis (NASH) in preclinical models and human studies. GH has both lipolytic and anti-inflammatory properties while IGF-1 has been implicated in reducing hepatic fibrosis and promoting hepatic regeneration. The GH/IGF-1 axis may be a therapeutic target in NAFLD/NASH, however, IGF-1, IGF-1 receptor (IGF-1R) and GH receptor (GHR) expression in adult human hepatic tissue has not been studied across the spectrum of disease severity. Methods: We quantified IGF-1, IGF-1R, and GHR gene expression in hepatic tissue from 318 adults with obesity using the Nanostring nCounter assay. Subjects were classified into four categories of disease severity based on histopathology: normal liver histology (NLH) (n=76, 24%), steatosis only (Steatosis) (n=88, 28%), NASH without fibrosis (NASH F0) (n=72, 23%), and NASH with fibrosis (NASH F1-F4) (n=82, 26%). Gene expression analysis is presented as normalized gene counts by group with p-value of the generalized linear model controlled for age, sex and BMI. Results: Mean (±SD) age (whole cohort 44.0±12 years) and BMI (whole cohort 46.8±7.2 kg/m2) did not differ across groups (p=0.2 for both). ALT was higher with increasing disease severity (NLH 30.1±26.7, Steatosis 31.9±15.7, NASH F0 35.7±16.5, NASH F1-4 48.4±34.9, p0.05 between any disease state; GHR NLH 6382±2366, Steatosis 6544±2699, NASH F0 7220±2542 and NASH F1-4 5997±2352, p>0.05 between any disease state). Conclusion: We demonstrated that IGF-1 gene expression was lower in liver tissue from patients with NAFLD and NASH than healthy controls. This is consistent with our prior finding that histologic NASH and fibrosis are associated with lower serum IGF-1 levels. Moreover, we demonstrated that hepatic IGF-1R and GHR gene expression is not lower in liver tissue from patients with NAFLD and does not decline across disease severity. This reinforces our prior finding that GHR staining intensity and zonality by immunohistochemistry does not change with increasing disease severity in NAFLD/NASH. These data demonstrate that the GH axis is relatively suppressed but that expression of GHR and IGF-1R receptors is stable with worsening disease severity in NAFLD/NASH, suggesting that GH augmentation may be a viable therapeutic target in NAFLD.

Background & Aims Non-alcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease in Western countries. It is unclear how infiltrating leukocytes affect NASH-development. Our study aims to investigate the role of the homing/receptor, pair mucosal addressin cell adhesion molecule-1 (MAdCAM-1)/β 7 -Integrin, on immune cell recruitment and disease progression in a steatohepatitis model. Methods Constitutive β 7 -Integrin deficient ( β 7 −/− ) and MAdCAM-1 deficient ( MAdCAM-1 −/− ) mice were fed a high fat diet (HFD) for 26weeks or methionine-choline-deficient-diet (MCD) for 4weeks. Results β 7 −/− mice displayed earlier and more progressive steatohepatitis during HFD- and MCD-treatment, while MAdCAM-1 −/− mice showed less histomorphological changes. The anti-oxidative stress response was significantly weaker in β 7 −/− mice as reflected by a significant downregulation of the transcription factors nuclear-factor(erythroid-derived 2)-like 2 (Nrf2) and heme-oxigenase-1 (HO-1). Additionally, stronger dihydroethidium-staining revealed an increased oxidative stress response in β 7 −/− animals. In contrast, MAdCAM-1 −/− mice showed an upregulation of the anti-oxidative stress response. β 7 −/− animals exhibited stronger hepatic infiltration of inflammatory cells, especially neutrophils, reflecting earlier steatohepatitis initiation. Expression of regulatory T cell (T Reg ) markers as well as numbers of anti-inflammatory macrophages was significantly enhanced in MAdCAM-1 −/− mice. Those changes finally resulted in earlier and stronger collagen accumulation in β 7 −/− mice, whereas MAdCAM-1 −/− mice were protected from fibrosis initiation. Conclusions Adhesion molecule mediated effector cell migration contributes to the outcome of steatohepatitis in the HFD- and the MCD model. While MAdCAM-1 promotes steatohepatitis, β 7 -Integrin unexpectedly exerts protective effects. β 7 −/− mice show earlier steatohepatitis initiation and significantly stronger fibrosis progression. Accordingly, the interaction of β 7 -Integrins and their receptor MAdCAM-1 provide novel targets for therapeutic interventions in steatohepatitis. Lay summary The mucosal addressin cell adhesion molecule 1 (MAdCAM-1) is expressed in livers upon diet-induced non-alcoholic steatohepatitis (NASH). Loss of MAdCAM-1 has beneficial effects regarding the development of NASH - manifested by reduced hepatic oxidative stress and decreased inflammation. In contrast, β 7 -Integrin-deficiency results in increased steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western countries with almost 25% affected adults worldwide. The growing public health burden is getting evident when considering that NAFLD-related liver transplantations are predicted to almost double within the next 20 years. Typically, hepatic alterations start with simple steatosis, which easily progresses to more advanced stages such as nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis. This course of disease finally leads to end-stage liver disease such as hepatocellular carcinoma, which is associated with increased morbidity and mortality. Although clinical trials show promising results, there is actually no pharmacological agent approved to treat NASH. Another important problem associated with NASH is that presently the liver biopsy is still the gold standard in diagnosis and for disease staging and grading. Because of its invasiveness, this technique is not well accepted by patients and the method is prone to sampling error. Therefore, an urgent need exists to find reliable, accurate and noninvasive biomarkers discriminating between different disease stages or to develop innovative imaging techniques to quantify steatosis.

Frontiers in physiology 10, 326 (2019). doi:10.3389/fphys.2019.00326, Published by Frontiers Research Foundation, Lausanne

Generation of reactive oxygen species (ROS) in response to fatty acids accumulation has been classically proposed as a possible "second hit" triggering progression from simple steatosis to non-alcoholic steatohepatitis (NASH). In this study we challenged hepatocyte-specific Keap1 knockout mice (Keap1(Δhepa)) and littermate Cre- controls (Keap1(fx/fx)) with two different diet models of NASH in order to evaluate the effects of the anti-oxidant transcription factor Nrf2 over-activation on hepatic metabolism and disease progression. After 4 weeks of MCD diet the liver/body weight ratio of Keap1(Δhepa) mice was significantly higher compared to littermate controls with no differences in total body weight. Strikingly, liver histology revealed a dramatic reduction of lipid droplets confirmed by a decreased content of intra-hepatic triglycerides in Keap1(Δhepa) compared to controls. In parallel to reduced expression of genes involved in lipid droplet formation, protein expression of Liver X Receptor (LXRα/β) and Peroxisome proliferator-activated receptor α (PPARα) was significantly decreased. In contrast, genes involved in mitochondrial lipid catabolism were markedly up-regulated in Keap1(Δhepa) livers. A similar phenotype characterized by inhibition of lipogenesis in favor of increased mitochondrial catabolic activity was also observed after 13 weeks of western diet administration. MCD-induced apoptosis was significantly dampened in Keap1(Δhepa) compared to Keap1(fx/fx) as detected by TUNEL, cleaved caspase-3 and Bcl-2 protein expression analyses. However, no differences in inflammatory F4/80- and CD11b-positive cells and pro-fibrogenic genes were detected between the two groups. Although hepatic lack of Keap1 did not ameliorate inflammation, the resulting constitutive Nrf2 over-activation in hepatocytes strongly reduced hepatic steatosis via enhanced lipid catabolism and repressed de novo lipogenesis during murine NASH development.

Oxidative medicine and cellular longevity 2018, 6957497 (2018). doi:10.1155/2018/6957497, Published by Landes Bioscience, Austin, Tex.

Background: Antimicrobial peptides (AMP) are an important defense mechanism of the innate immune system and can modulate the course of various diseases. However, their significance during liver pathogenesis is currently not well defined. Methods: Patients with liver diseases were analyzed for LL-37/CRAMP, human beta-defensin-2 (hBD2), and complement 5a (C5a) serum levels. Mice deficient in CRAMP (Cathelicidin-related Antimicrobial Peptide), the mouse homolog for human LL-37, were fed with a methionine- and choline-deficient diet (MCD) and underwent bile-duct ligation (BDL). Results: First, serum samples from patients with chronic liver diseases were investigated. Therefore, significantly enhanced levels for LL-37, hBD2, and complement C5a were detected, all of which comprise antimicrobial properties. Next, CRAMP-knockout (CRAMP-KO) mice were investigated, to better define a functional role of LL-37/CRAMP in animal models of liver diseases. MCD feeding and bile-duct ligation of CRAMP-KO mice resulted in an enhanced degree of liver injury during the early treatment phase. MCD feeding in CRAMP-KO mice led to stronger intrahepatic fat accumulation and significantly enhanced matrix remodeling, whereas BDL caused more extensive liver necrosis. At the late 28 days time point, MCD-fed CRAMP-KO mice displayed a higher intrahepatic fat load. Long-term changes in bile-duct-ligated mice included higher collagen content as a sign of enhanced fibrosis progression if CRAMP was absent. Conclusion: The study shows a clear correlation of antimicrobial peptide serum levels in patients with chronic liver diseases. Furthermore, we were able to demonstrate protective functions of LL-37/CRAMP in two independent mouse models of chronic liver injury.

Non-alcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease in Western countries. It is unclear how infiltrating leukocytes affect NASH-development. Our study aims to investigate the role of the homing/receptor, pair mucosal addressin cell adhesion molecule-1 (MAdCAM-1)/βConstitutive ββAdhesion molecule mediated effector cell migration contributes to the outcome of steatohepatitis in the HFD- and the MCD model. While MAdCAM-1 promotes steatohepatitis, βThe mucosal addressin cell adhesion molecule 1 (MAdCAM-1) is expressed in livers upon diet-induced non-alcoholic steatohepatitis (NASH). Loss of MAdCAM-1 has beneficial effects regarding the development of NASH - manifested by reduced hepatic oxidative stress and decreased inflammation. In contrast, β

Introduction: Non-alcoholic steatohepatitis (NASH), the hepatic correlate of the metabolic syndrome, is the third most common cause of chronic liver disease in western countries. Its global incidence is on the rise and reflects one of the fastest growing medical problems. Aim: The significance of leukocyte infiltration during the development of NASH remains unclear until now. We therefore investigated the role of β7-Integrin and one of its receptors MAdCAM-1 in a mouse model of NASH development. Methods: Constitutive MAdCAM-1 and β7-Integrin knockout (KO) mice were fed a MCD diet (methionine and choline deficient) for 4 weeks. Results: Interestingly β7-deficient mice displayed an earlier and faster progressing steatohepatitis during MCD treatment, while MAdCAM-1 KO showed less histomorphological changes in contrast to wildtype mice. Oxidative stress analysis in β7 KO mice showed a stronger response as indicated by DHE (dihydroethidium) staining and a down regulation of transcription factors involved in anti-oxidative stress and fatty acid metabolism (e.g. FAS and SREBP). MAdCAM-1 KO mice on the other hand had an upregulation of the anti-oxidative stress response. Moreover, we detected a stronger hepatic infiltration of inflammatory cells (CD4+ and CD11b+) in the β7 KO group, reflecting an earlier onset of NASH. Those changes finally resulted in an earlier and stronger collagen accumulation (Sirius red) in the β7-Integrin deficient group, while MAdCAM-1 KO mice were protected. Conclusion: MAdCAM-1 and β7 Integrins mediate opposing effects in the MCD model, with protection in MAdCAM-1 KO animals and a more severe phenotype and significantly stronger fibrosis progression in β7-Integrin KO mice. Therefore, the interaction of β7 Integrins and their receptor MAdCAM-1 provide a novel interesting target for therapeutic interventions during NASH development.

euglycemic insulin clamp combined with (3-H)-glucose, and suppression of hepatic glucose production (HGP), in 117 subjects. Results: PNPLA3 relative to b-actin expression was 2.0 (1.6–2.8)-fold higher (p < 0.001) in AT than the liver. When related to total adipose and liver tissue masses, PNPLA3 expression was 5.9 (5.1–8.9)-fold higher in AT than the liver (p < 0.001). In the in vivo study, for a given LFAT, insulin sensitivity of AT lipolysis (p < 0.05) and of HGP (p < 0.05) were significantly higher in I148M carriers than noncarriers.