Therapies in non-alcoholic steatohepatitis (NASH)

Multiple organs involved in the pathogenesis of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) represents the leading cause of chronic liver disease worldwide and the anticipated health burden is huge. There are limited therapeutic approaches for NAFLD now. It’s imperative to get a better understanding of the disease pathogenesis if new treatments are to be discovered. As the hepatic manifestation of metabolic syndrome, this disease involves complex interactions between different organs and regulatory pathways. It’s increasingly clear that brain, gut and adipose tissue all contribute to NAFLD pathogenesis and development, in view of their roles in energy homeostasis. In the present review, we try to summarize currently available data regarding NAFLD pathogenesis and to lay a particular emphasis on the inter-organ crosstalk evidence.

Periostin antisense oligonucleotide prevents hepatic steatosis and fibrosis in a mouse model of non-alcoholic steatohepatitis

BACKGROUND AND AIM

Non-alcoholic steatohepatitis (NASH) is characterized by hepatic steatosis, inflammation, and hepatocellular injury with varying degrees of fibrosis. There are currently no established treatment approaches for NASH other than lifestyle interventions. Periostin, a matricellular protein required for tissue remodeling and fibrosis, plays an important role in hepatic steatosis and fibrosis and could be a potential target for NASH treatment. Advances in molecular biology and biochemical engineering have led to the development of antisense oligonucleotides (ASOs) that can inhibit target genes with no significant toxic effects. Herein, we investigated the therapeutic effects of periostin-targeting ASO (PNASO) in NASH.

METHODS

C57BL/6J mice were fed a choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD) to induce NASH with or without intraperitoneal injection of mouse PNASO. To explore the role of periostin in hepatocellular steatosis, Hc3716 cells, an immortalized human hepatocyte line, were treated with recombinant periostin in vitro.

RESULTS

The induced periostin expression in the liver of CDAHFD-fed mice was significantly suppressed by PNASO. The deletion of hepatic periostin by PNASO significantly ameliorated hepatic steatosis while restoring the expression levels of peroxisome proliferator-activated receptor-alpha (PPAR-α) and its target genes. PNASO also inhibited hepatic fibrosis, reflected by the reduction of alpha-smooth muscle actin, collagen type I, and other fibrotic markers. In vitro experiments demonstrated that treatment with recombinant periostin increased cellular lipid accumulation in Hc3716 cells accompanied with the downregulation of PPAR-α.

CONCLUSIONS

Periostin-targeting ASO is a potential therapeutic approach for the efficient treatment of hepatic steatosis and fibrosis in NASH.

EZH2 as a Potential Target for NAFLD Therapy

Non-alcoholic fatty liver disease (NAFLD) is a complex disease that is affected by genetic predisposition and epigenetic modification. Deregulation of epigenetic pathways is now recognized as a frequent event in NAFLD, and understanding the mechanistic roles of these epigenetic factors may lead to new strategies for NAFLD treatment. Enhancer of zeste homolog 2 (EZH2) catalyzes methylation on Lys 27 of histone H3, which leads to chromatin compaction and gene silencing. EZH2 regulates embryonic development and cell lineage determination and is related to many human diseases. Recent studies show that EZH2 has critical roles in liver development, homeostasis, and regeneration. Moreover, aberrant activation of EZH2 promotes NAFLD progression. Several EZH2 inhibitors have been developed and studied both in vitro and in clinical trials. In this review, we summarize our current understanding of the role of EZH2 in NAFLD and highlight its potential as a novel therapeutic target for NAFLD treatment.

The Gut Barrier, Intestinal Microbiota, and Liver Disease: Molecular Mechanisms and Strategies to Manage

Liver disease encompasses pathologies as non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, alcohol liver disease, hepatocellular carcinoma, viral hepatitis, and autoimmune hepatitis. Nowadays, underlying mechanisms associating gut permeability and liver disease development are not well understood, although evidence points to the involvement of intestinal microbiota and their metabolites. Animal studies have shown alterations in Toll-like receptor signaling related to the leaky gut syndrome by the action of bacterial lipopolysaccharide. In humans, modifications of the intestinal microbiota in intestinal permeability have also been related to liver disease. Some of these changes were observed in bacterial species belonging Roseburia, Streptococcus, and Rothia. Currently, numerous strategies to treat liver disease are being assessed. This review summarizes and discusses studies addressed to determine mechanisms associated with the microbiota able to alter the intestinal barrier complementing the progress and advancement of liver disease, as well as the main strategies under development to manage these pathologies. We highlight those approaches that have shown improvement in intestinal microbiota and barrier function, namely lifestyle changes (diet and physical activity) and probiotics intervention. Nevertheless, knowledge about how such modifications are beneficial is still limited and specific mechanisms involved are not clear. Thus, further in-vitro, animal, and human studies are needed.

Efficacy and safety of anti-hepatic fibrosis drugs

Recent progress in our understanding of the pathways linked to progression from hepatic insult to cirrhosis has led to numerous novel therapies being investigated as potential cures and inhibitors of hepatic fibrogenesis. Liver cirrhosis is the final result of prolonged fibrosis, which is an intimate balance between fibrogenesis and fibrinolysis. A number of these complex mechanisms are shared across the various etiologies of liver disease. Thankfully, investigation has yielded some promising results in regard to reversal of fibrosis, particularly the indirect benefits associated with antiviral therapy for the treatment of hepatitis B and C and the farnesoid receptor agonist for the treatment of primary biliary cholangitis and metabolic associated fatty liver disease. A majority of current clinical research is focused on targeting metabolic associated fatty liver disease and its progression to metabolic steatohepatitis and ultimately cirrhosis, with some hope of potential standardized therapeutics in the near future. With our ever-evolving understanding of the underlying pathophysiology, these therapeutics focus on either controlling the primary disease (the initial trigger of fibrogenesis), interrupting receptor ligand interactions and other intracellular communications, inhibiting fibrogenesis, or even promoting resolution of fibrosis. It is imperative to thoroughly test these potential therapies with the rigorous standards of clinical therapeutic trials in order to ensure the highest standards of patient safety. In this article we will briefly review the key pathophysiological pathways that lead to liver fibrosis and present current clinical and experimental evidence that has shown reversibility of liver fibrosis and cirrhosis, while commenting on therapeutic safety.

Drug discovery and treatment paradigms in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in western populations, and is closely associated with features of the metabolic syndrome. The burden of disease is set to rise exponentially, and this is further compounded by the lack of good medications. In addition, these patients tend to have multiple comorbidities that may not be adequately managed. In this article, we review the biological basis of potential therapies in nonalcoholic steatohepatitis (NASH), the current drugs being tested in clinical trials, as well some practical considerations in managing patients in the clinic.

Roles of Hepatic Innate and Innate-Like Lymphocytes in Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH), a progressive form of nonalcoholic fatty liver disease (NAFLD), is accompanied by steatosis, hepatocyte injury and liver inflammation, which has been a health problem in the world as one of the major high risk factors of cirrhosis and hepatocellular carcinoma (HCC). Complex immune responses involving T cells, B cells, Kupffer cells, monocytes, neutrophils, DCs and other innate lymphocytes account for the pathogenesis of NASH; however, the underlying mechanisms have not been clearly elucidated in detail. In the liver, innate and innate-like lymphocytes account for more than two-thirds of total lymphocytes and play an important role in maintaining the immune homeostasis. Therefore, their roles in the progression of NASH deserves investigation. In this review, we summarized murine NASH models for immunological studies, including the diet-induced NASH, chemical-induced NASH and genetic-induced NASH. The role of innate and innate-like lymphocytes including NK cells, ILCs, NKT, γδT and MAIT cells in the progression of NASH were elucidated. Further, the metabolic regulation of the innate immune response was addressed in consideration to explain the molecular mechanisms. Based on the findings of the reviewed studies, strategies of immune intervention are proposed to control the progression of NASH.

Verification of the Nutritional and Dietary Factors Associated with Skeletal Muscle Index in Japanese Patients with Nonalcoholic Fatty Liver Disease

We sought to identify the frequencies of presarcopenia, sarcopenia, and sarcopenic obesity in patients with nonalcoholic fatty liver disease (NAFLD) and to cross-sectionally determine the nutritional and dietary factors associated with loss of skeletal muscle mass in such patients. Dietary and body component changes produced by a diet intervention were longitudinally investigated. Forty-six NAFLD patients (24 males and 22 females) were enrolled. A second diet treatment was performed at 6 months after entry in 19 of the enrolled patients (6 males and 13 females). Body compositions and dietary nutrients at six months later were compared with those at entry. Three of the 24 (13%) males and four of the 22 (18%) females fulfilled the criteria for presarcopenia and one (5%) female NAFLD patient was in the criteria for sarcopenia at baseline. None of the patients were in the criteria for sarcopenic obesity. The factors associated with skeletal muscle index in the males were body mass index (BMI), insulin-like growth factor-1, total energy intake, and lipid intake, but only BMI and bone mineral density in females at baseline. The diet intervention decreased the skeletal muscle mass in the 6 males by decreasing the total energy intake via lower protein and lipid intakes and improved their liver dysfunction. In the 13 females, a decrease in total energy intake via lower carbohydrate and lipid intake did not change the skeletal muscle mass. These results suggest that loss of skeletal muscle mass is frequently observed in nonobese NAFLD patients and that the frequency of sarcopenic obesity seems to be rare in NAFLD patients. The nutritional and dietary factors that regulate loss of skeletal muscle mass were distinct between our male and female NAFLD patients. Thus, the skeletal muscle mass of such patients as well as their body weight and liver function should be monitored during diet interventions.

Transcriptional Regulation in Non-Alcoholic Fatty Liver Disease

Obesity is the primary risk factor for the pathogenesis of non-alcoholic fatty liver disease (NAFLD), the worldwide prevalence of which continues to increase dramatically. The liver plays a pivotal role in the maintenance of whole-body lipid and glucose homeostasis. This is mainly mediated by the transcriptional activation of hepatic pathways that promote glucose and lipid production or utilization in response to the nutritional state of the body. However, in the setting of chronic excessive nutrition, the dysregulation of hepatic transcriptional machinery promotes lipid accumulation, inflammation, metabolic stress, and fibrosis, which culminate in NAFLD. In this review, we provide our current understanding of the transcription factors that have been linked to the pathogenesis and progression of NAFLD. Using publicly available transcriptomic data, we outline the altered activity of transcription factors among humans with NAFLD. By expanding this analysis to common experimental mouse models of NAFLD, we outline the relevance of mouse models to the human pathophysiology at the transcriptional level.

Effects of Vitamin D Supplementation in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

CONTEXT

Vitamin D (VD) has been found to play a key role in nonalcoholic fatty liver disease (NAFLD). This meta-analysis explored the effects of VD supplementation in patients with NAFLD.

METHODS

The PubMed, EMBASE, and the Cochrane Library databases were searched to find randomized control trials (RCTs) that measured the changes between the VD supplement group and the control group until May 2019. Standard mean difference (SMD) with 95% confidence intervals (CI) was calculated when data units were different, otherwise weighted mean difference (WMD) and 95% CI was calculated. Heterogeneity was assessed using the I2 statistic.

RESULTS

Eight RCTs with 624 individuals were extracted. The main indicators, including serum alanine aminotransferase (WMD = -0.052; 95% CI: -3.740, 3.636; P = 0.978) and aspartate aminotransferase concentrations (WMD = -0.479; 95% CI: -2.791, 1.833; P = 0.685) were not significantly different between the intervention and placebo groups. In addition, no significant intergroup difference was observed in the following secondary indicators: fasting blood glucose (WMD = 0.466; 95% CI: -5.313, -10.879; P = 0.061), homeostasis model assessment (WMD = 0.380, 95% CI: -0.162, 0.923; P = 0.169), serum insulin concentration (WMD = 0.760; 95% CI: -0.532, 2.052; P = 0.249), high-density lipoprotein (WMD = -0.012; 95% CI: -0.188, 0.164; P = 0.891), and low-density lipoprotein (WMD = -0.115; 95% CI: -3.849, -3.620; P = 0.952).

CONCLUSIONS

The results indicate that VD supplementation does not improve liver enzymes, insulin resistance, glucose metabolism parameters, and lipid levels in patients with NAFLD.

Targeted Delivery of Notch Inhibitor Attenuates Obesity-Induced Glucose Intolerance and Liver Fibrosis

As the prevalence of obesity-induced type 2 diabetes mellitus (T2DM) and nonalcoholic steatohepatitis (NASH) continue to increase, the need for pharmacologic therapies becomes urgent. However, endeavors to identify and develop novel therapeutic strategies for these chronic conditions are balanced by the need for safety, impeding clinical translation. One shared pathology of these two diseases is a maladaptive reactivation of the Notch signaling pathway in liver. Notch antagonism with γ-secretase inhibitors effectively suppresses hepatic glucose production and reduces liver fibrosis in NASH, but its extrahepatic side effects, particularly goblet cell metaplasia, limit therapeutic utility. To overcome this barrier, we developed a nanoparticle-mediated delivery system to target γ-secretase inhibitor to liver (GSI NPs). GSI NP application reduced hepatic glucose production in diet-induced obese mice and reduced hepatic fibrosis and inflammation in mice fed a NASH-provoking diet, without apparent gastrointestinal toxicity. By changing the delivery method, these results provide proof-of-concept for the repurposing of a previously intolerable medication to address unmet needs in the clinical landscape for obesity-induced T2DM and NASH.

Effectiveness and safety of traditional Chinese medicines for non-alcoholic fatty liver disease: Protocol for systematic review and meta-analysis

BACKGROUND

Previous reviews indicate that the effect of Traditional Chinese medicines (TCM) on non-alcoholic fatty liver disease (NAFLD) remains uncertainty. The study results published in the past 8 years may change this situation, but there is no updated systematic review. Therefore, we designed this study to systematically evaluate the effectiveness and safety of TCM in the treatment of NAFLD.

METHODS AND ANALYSIS

We will search nine online databases from inception to October 01 2019, and the language will not be restricted on included trials. Randomized controlled trials that included patients with NAFLD receiving TCM therapy versus a control group will be included. Two researcher will perform independently the selection of studies, risk of bias assessment and data extraction. We will use the RevMan V.5.2 software with fixed effects model or random effects model according to the heterogeneity test to conduct the data synthesis. We will present the dichotomous data and the continuous data with risk ratios with 95% CIs and weighted mean differences or standardized mean differences with 95% CIs. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system will be used to evaluate the evidence quality with low risk, unclear risk, and high risk.

RESULTS

This study will demonstrate an evidence-based review of TCM for NAFLD.

CONCLUSION

The study will provide clear evidence to assess the effectiveness and side effects of TCM for NAFLD.

Treatment of Non-Alcoholic Steatosis: Preclinical Study of a New Nutraceutical Multitarget Formulation

Multifactorial pathogenesis of non-alcoholic steatohepatitis (NASH) disease, a wide-spread liver pathology associated with metabolic alterations triggered by hepatic steatosis, should be hit by multitarget therapeutics. We tested a multicomponent food supplement mixture (AP-NHm), whose components have anti-dislipidemic, antioxidant and anti-inflammatory effects, on in vitro and in vivo models of NASH. In vitro, hepatic cells cultures were treated for 24 h with 0.5 mM oleic acid (OA): in the co-treatment set cells were co-treated with AP-NH mixtures (AP-NHm, 1:3:10 ratio) and in the post-injury set AP-NHm was added for 48 h after OA damage. In vivo, C57BL/6 mice were fed with high-fat diet (HFD) for 12 weeks, inducing NASH at 7th week, and treated with AP-NHm at two dosages (1:3 ratio) in co-treatment or post-injury protocols, while a control group was fed with a standard diet. In in vitro co-treatment protocol, alterations of redox balance, proinflammatory cytokines release and glucose uptake were restored in a dose-dependent manner, at highest dosages also in post-injury regimen. In both regimens, pathologic dyslipidemias were also ameliorated by AP-NHm. In vivo, high-dose-AP-NHm-co-treated-HFD mice dose-dependently gained less body weight, were protected from dyslipidemia, and showed a lower liver weight. Dose-dependently, AP-NHm treatment lowered hepatic LDL, HDL, triglycerides levels and oxidative damage; co-treatment regimen was anti-inflammatory, reducing TNF-α and IL-8 levels. Hepatic lipidic infiltration significantly decreased in co-treated and post-injury-AP-NHm-HFD animals. The multitarget approach with AP-NHm was effective in preventing and reducing NASH-related pathologic features, warranting for the clinical development of this compound.

S-allylmercaptocysteine improves nonalcoholic steatohepatitis by enhancing AHR/NRF2-mediated drug metabolising enzymes and reducing NF-κB/IκBα and NLRP3/6-mediated inflammation

PURPOSE

To investigate the novel molecular mechanisms of the antioxidant and anti-inflammatory properties of S-allylmercaptocysteine (SAMC) based on a transcriptomic study in a nonalcoholic steatohepatitis (NASH) rat model METHODS: NASH was induced in Sprague-Dawley rats by feeding with a high fat diet (HFD) for 12 weeks. 200 mg/kg SAMC was fed by oral gavage for 4 weeks from 9 to 12 week.

RESULTS

SAMC co-administration attenuated HFD-induced liver injury, including the increased serum ALT, hepatic oxidative stress and inflammation. Transcriptomic analysis revealed that SAMC dramatically induced the XRE- and ARE-driven drug metabolising enzymes (DMEs) including Akr7a3, Akr1b8, and Nqo1. The nuclear translocation of the upstream regulator of xenobiotics metabolism, AHR, and regulator of antioxidant responses, NRF2, were significantly increased by SAMC treatment. Furthermore, SAMC counteracted the effects of HFD on NF-κB/IκB and NLRP3/6 pathways with decreasing protein levels of ASC, cleaved caspase-1, IL-18, and IL-1β. These results were further verified in another mice NASH model induced by an MCD diet with SAMC co-administration.

CONCLUSION

We propose that SAMC triggers AHR/NRF2-mediated antioxidant responses which may further suppress the NLRP3/6 inflammasome pathway and NF-κB activation, contributing to the improvement of NASH.

1,2,3,4,6 penta-O-galloyl-β-D-glucose ameliorates high-fat diet-induced nonalcoholic fatty liver disease and maintains the expression of genes involved in lipid homeostasis in mice

Non-alcoholic fatty liver disease (NAFLD) is currently the most frequently occurring liver disorder in the world. However, a specific drug for the treatment of patients with NAFLD is not available. Therefore, the discovery of novel compounds for the treatment of NAFLD and elucidation of the underlying mechanisms of therapeutic drugs that can be used to treat this disease are urgently needed. 1,2,3,4,6 penta-O-galloyl-β-d-glucose (PGG) is known to exert anti-inflammatory, antidiabetic, and hepatoprotective effects. However, little is known about the therapeutic potential of PGG in NAFLD. In this study, we investigated the effects of PGG on a high-fat diet (HFD)-induced mouse model of NAFLD. PGG was co-administered along with an HFD to C57BL/6 mice. After eight weeks of treatment, serum biochemistry, liver steatosis, and lipid metabolism-related genes were examined. The results showed that PGG treatment significantly reduced HFD-induced gain in body weight, liver steatosis, and leukocyte infiltration in a dose-dependent manner. Furthermore, PGG treatment markedly reduced serum triglyceride and glucose levels in HFD mice. Moreover, alterations in the mRNA expression of genes involved in lipid metabolism, including Hmgcr, Acc1, Abca1, Mttp, and Cd36, observed in the livers of HFD-treated mice were significantly reversed by PGG treatment. PGG significantly reduced HFD-induced protein expression of CD36, which is associated with fatty acid uptake, insulin resistance, hyperinsulinemia, and increased hepatic steatosis, in the liver of HFD mice. These results suggest that PGG inhibits HFD-induced hepatic steatosis and reverses HFD-induced alterations of gene expression in lipid metabolism. PGG has been shown to be well tolerated; therefore, it has potential uses in NAFLD treatment.

COVID-19 and Diabetes Mellitus: May Old Anti-diabetic Agents Become the New Philosopher's Stone?

Corona virus infectious disease (COVID-19) is a new pandemic. In subjects with diabetes mellitus, infection may be more frequent and severe. We discuss the potential contribution of two traditional oral antidiabetic agents, metformin and pioglitazone, to the improvement of liver injury in COVID-19. Clearly, further experience is needed to shed light on these hypotheses.

Deletion of Perilipin 5 Protects Against Hepatic Injury in Nonalcoholic Fatty Liver Disease via Missing Inflammasome Activation

Nonalcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver diseases with an increasing prevalence due to rising rates of obesity, metabolic syndrome and type II diabetes. Untreated NAFLD may progress to steatohepatitis (NASH) and ultimately liver cirrhosis. NAFLD is characterized by lipid accumulation, and when sufficient excess lipids are obtained, irreversible liver injury may follow. Perilipin 5 (PLIN5), a known lipid droplet coating protein and triglyceride metabolism regulator, is highly expressed in oxidatively modified tissues but it is still unclear how it affects NAFLD/NASH progress. We here studied how PLIN5 affects NAFLD development induced by a 30-week high-fat diet (HFD) administration in wild type and PLIN5 knock out (Plin5^−/−) mice. The disruption of PLIN5 induced differences in lipid metabolism during HFD feeding and was associated with reduced hepatic fat accumulation. Surprisingly, Plin5^−/− mice showed mitigated activation of the NLR family pyrin domain-containing 3 (NLRP3) inflammasome, leading to minor hepatic damage. We conclude that PLIN5 is a pleiotropic regulator of hepatic homeostasis in NASH development. Targeting the PLIN5 expression appears critical for protecting the liver from inflammatory activation during chronic NAFLD.

The Role of the Histone Methyltransferase EZH2 in Liver Inflammation and Fibrosis in STAM NASH Mice

Non-alcoholic fatty liver disease (NAFLD) is a leading form of chronic liver disease, with few biomarkers and treatment options currently available. Non-alcoholic steatohepatitis (NASH), a progressive disease of NAFLD, may lead to fibrosis, cirrhosis, and hepatocellular carcinoma. Epigenetic modification can contribute to the progression of NAFLD causing non-alcoholic steatohepatitis (NASH), in which the exact role of epigenetics remains poorly understood. To identify potential therapeutics for NASH, we tested small-molecule inhibitors of the epigenetic target histone methyltransferase EZH2, Tazemetostat (EPZ-6438), and UNC1999 in STAM NASH mice. The results demonstrate that treatment with EZH2 inhibitors decreased serum TNF-alpha in NASH. In this study, we investigated that inhibition of EZH2 reduced mRNA expression of inflammatory cytokines and fibrosis markers in NASH mice. In conclusion, these results suggest that EZH2 may present a promising therapeutic target in the treatment of NASH.

Loss of Hepatocyte-Specific PPARγ Expression Ameliorates Early Events of Steatohepatitis in Mice Fed the Methionine and Choline-Deficient Diet

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide. To date, there is not a specific and approved treatment for NAFLD yet, and therefore, it is important to understand the molecular mechanisms that lead to the progression of NAFLD. Methionine- and choline-deficient (MCD) diets are used to reproduce some features of NAFLD in mice. MCD diets increase the expression of hepatic peroxisome proliferator-activated receptor gamma (PPARγ, Pparg) and the fatty acid translocase (CD36, Cd36) which could increase hepatic fatty acid uptake and promote the progression of NAFLD in mice and humans. In this study, we assessed the contribution of hepatocyte-specific PPARγ and CD36 expression to the development of early events induced by the MCD diet. Specifically, mice with adult-onset, hepatocyte-specific PPARγ knockout with and without hepatocyte CD36 overexpression were fed a MCD diet for three weeks. Hepatocyte PPARγ and/or CD36 expression did not contribute to the development of steatosis induced by the MCD diet. However, the expression of inflammatory and fibrogenic genes seems to be dependent on the expression of hepatocyte PPARγ and CD36. The expression of PPARγ and CD36 in hepatocytes may be relevant in the regulation of some features of NAFLD and steatohepatitis.

Sweroside Prevents Non-Alcoholic Steatohepatitis by Suppressing Activation of the NLRP3 Inflammasome

Non-alcoholic steatohepatitis (NASH), a type of non-alcoholic fatty liver disease, is characterized as steatosis and inflammation in the liver. NLRP3 inflammasome activation is associated with NASH pathology. We hypothesized that suppressing the NLRP3 inflammasome could be effective in preventing NASH. We searched substances that could inhibit the activation of the NLRP3 inflammasome and identified sweroside as an NLRP3 inhibitor. We investigated whether sweroside can be applied to prevent the pathological symptoms associated with NASH in a methionine–choline-deficient (MCD) diet-induced NASH mouse model. The activation of the NLRP3 inflammasome was determined by detecting the production of caspase-1 and IL-1β from pro-caspase-1 and pro-IL-1β in primary mouse macrophages and mouse liver. In a NASH model, mice were fed an MCD diet for two weeks with daily intraperitoneal injections of sweroside. Sweroside effectively inhibited NLRP3 inflammasome activation in primary macrophages as shown by a decrease in IL-1β and caspase-1 production. In a MCD diet-induced NASH mouse model, intraperitoneal injection of sweroside significantly reduced serum aspartate transaminase and alanine transaminase levels, hepatic immune cell infiltration, hepatic triglyceride accumulation, and liver fibrosis. The improvement of NASH symptoms by sweroside was accompanied with its inhibitory effects on the hepatic NLRP3 inflammasome as hepatic IL-1β and caspase-1 were decreased. Furthermore, sweroside blocked de novo synthesis of mitochondrial DNA in the liver, contributing to suppression of the NLRP3 inflammasome. These results suggest that targeting the NLRP3 inflammasome with sweroside could be beneficially employed to improve NASH symptoms.

Implications of Nonalcoholic Steatohepatitis as the Cause of End-Stage Liver Disease Before and After Liver Transplant

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. Nonalcoholic steatohepatitis (NASH) is the clinically aggressive variant of NAFLD and has a propensity for fibrosis progression and cirrhosis. The prevalence of NAFLD and NASH is projected to increase rapidly in the near future and dramatically add to the already substantial health care burden. Cirrhosis and end-stage liver disease resulting from NASH is now the fastest growing indication for liver transplant (LT) in the United States. Patients with NASH cirrhosis have higher prevalence of cardiometabolic diseases. Following LT, recurrence of NAFLD and NASH is common.

Burden of Disease due to Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common liver disease in both Western populations and other parts of the world. This review discusses the prevalence and incidence of NAFLD in various regions around the world. The methodology used to identify the epidemiology and classify the stages of the disease is described. The impact of the disease on individuals, looking at both liver-related and extrahepatic consequences of the disease, is then discussed. Finally, the economic and societal impact of the disease is discussed.

Effects and therapeutic mechanism of Yinzhihuang on steatohepatitis in rats induced by a high-fat, high-cholesterol diet

OBJECTIVES

We aimed to investigate the therapeutic mechanism of Yinzhihuang (YZH) liquid, a traditional Chinese medicine mainly composed of extracts of four components, on nonalcoholic steatohepatitis (NASH) induced by a high-fat, high-cholesterol diet (HFHCD) in rats.

METHODS

Altogether 30 Sprague-Dawley rats were randomized into three groups: control, the model group (HFHCD + saline) and the treatment group (HFHCD + YZH). Liver histological features and serum biochemical parameters were assessed by the end of the 16th week. RNA sequencing and protein mass spectrometry detection were performed. The genes and proteins expressed differentially were subjected to KEGG pathway enrichment analysis and included in a network-based regulatory model.

RESULTS

The weight, liver and fat indices and serum alanine transaminase, aspartate transaminase and total cholesterol levels of the HFHCD + YZH group were all significantly lower than those of the HFHCD + saline group. Moreover, their hepatic steatosis, ballooning and lobular inflammation were relieved, and 64 hepatic genes and 73 hepatic proteins were found to be reversed in their expression patterns after YZH treatment (P < 0.05). The network-based regulatory model showed that these deregulated genes and proteins were mainly involved in oxidative phosphorylation, Toll-like receptor, nucleotide-binding oligomerization domain-like receptor, peroxisome proliferator-activated receptor signaling, nuclear factor-kappa B tumor necrosis factor signaling pathways and fatty acid metabolism.

CONCLUSION

YZH could alleviate NASH in HFHCD-fed rats by inhibiting lipogenesis, accelerating lipid β-oxidation, alleviating oxidative stress and relieving necroinflammation in the liver.

Emerging Noninvasive Biomarkers, and Medical Management Strategies for Alcoholic Hepatitis: Present Understanding and Scope

Alcohol use disorder is associated with a wide array of hepatic pathologies ranging from steatosis to alcoholic-related cirrhosis (AC), alcoholic hepatitis (AH), or hepatocellular carcinoma (HCC). Biomarkers are categorized into two main categories: biomarkers associated with alcohol consumption and biomarkers of alcoholic liver disease (ALD). No ideal biomarker has been identified to quantify the degree of hepatocyte death or severity of AH, even though numerous biomarkers have been associated with AH. This review provides information of some of the novel and latest biomarkers that are being investigated and have shown a substantial association with the degree and severity of liver injury and inflammation. Importantly, they can be measured noninvasively. In this manuscript, we consolidate the present understanding and prospects of these biomarkers; and their application in assessing the severity and progression of the alcoholic liver disease (ALD). We also review current and upcoming management options for AH.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of a Liver-Targeting Acetyl-CoA Carboxylase Inhibitor (PF-05221304): A Three-Part Randomized Phase 1 Study

PF‐05221304 is a liver‐targeted inhibitor of acetyl‐CoA carboxylase, an enzyme that catalyzes the first committed step in de novo lipogenesis (DNL). This first‐in‐human study investigated safety/tolerability and pharmacokinetics of single and multiple ascending oral PF‐05221304 doses, and fructose‐stimulated DNL inhibition with repeated oral doses. Healthy subjects (n = 96) received single (1‐240 mg) or repeated (2‐200 mg daily) doses for 14 days or single 100‐mg doses with and without food. PF‐05221304 was well tolerated at all doses. Repeated PF‐05221304 doses inhibited hepatic DNL in a dose‐dependent manner, with near‐complete inhibition seen at higher doses. With doses yielding ≥90% DNL inhibition, asymptomatic increases in fasting/postprandial serum triglyceride levels (≥40 mg/day) and declines in platelet count (≥60 mg/day) occurred; these were not observed at ≤80% DNL inhibition. Steady‐state pharmacokinetics generally increased dose‐proportionally, with a half‐life of 14‐18 hours and a minimal food effect on plasma exposure. The observed safety and tolerability, pharmacokinetics, and pharmacodynamics support the continued evaluation of PF‐05221304 for the treatment of nonalcoholic steatohepatitis.

Deficiency of glutathione peroxidase-1 and catalase attenuated diet-induced obesity and associated metabolic disorders

AIMS

Oxidative stress has been considered to contribute to the development of obesity-related metabolic disorders including insulin resistance. To the contrary, deficiency of an anti-oxidizing enzyme, glutathione peroxidase (GPx)-1, was reported to enhance insulin signaling, suggesting that oxidative stress may inhibit the development of type 2 diabetes. However, the beneficial effects of the absence of GPx-1 in metabolic homeostasis, including body weight control, have not yet been clearly manifested. To clarify the relationship between oxidative stress and obesity-related metabolic disorders, we investigated another mouse deficient with both GPx-1 and catalase (Cat).

METHODS

C57BL/6J wild-type and GPx-1^-/- × Cat^-/- mice were fed with a high-fat diet (60% fat) or a normal chow diet for 16 weeks and were investigated for metabolic and histological studies.

RESULTS

Body weight gain was significantly reduced, and glucose metabolism as well as hepatic steatosis was obviously improved in the GPx-1^-/- × Cat^-/- mice. The serum levels of insulin and total cholesterol were also significantly lowered. For the underlying mechanism, inflammation was attenuated and expression of markers for fat browning was enhanced in the visceral white adipose tissues.

CONCLUSIONS

Oxidative stress due to deficiency of GPx-1 and Cat may improve obesity-related metabolic disorders through attenuation of inflammation and fat browning.

Hypothetical treatment of patients with non-alcoholic steatohepatitis: Potential impact on important clinical outcomes

BACKGROUND & AIMS

Currently, standard of care (SOC) treatment for NASH is limited to lifestyle modifications. Drug regimens are being evaluated currently. We assessed the impact of a short-term hypothetical treatment on clinical outcomes of NASH.

METHODS

Markov models estimated differences in outcomes between SOC and 2 hypothetical NASH treatments (A and B). We modelled 10 000 50-year-old biopsy-proven NASH patients over lifetime horizon. Health states included NASH with fibrosis (F1-F3), cirrhosis, hepatocellular carcinoma, liver transplant and mortality. Fibrosis Regression Factor (FRF) variable modelled the probability of 1-3 stage fibrosis improvement with treatment. Annual probability of treatment (ATP) ranged from 10%-70%. Treatment success was defined as regression to fibrosis, whereas failure was defined as progression to stages beyond cirrhosis. In treatment-A, successful treatment was followed by a maintenance regimen which stopped disease progression. After a successful treatment-B, patients remained at risk of disease progression. Differences in outcomes were calculated between both treatments and SOC models. We conducted a probabilistic sensitivity analysis.

RESULTS

At 10% to 70% ATP, treatment-A averts 353 to 782 liver transplants and 1277 to 2381 liver-related deaths relative to SOC. Treatment-B averts 129 to 437 liver transplants and 386 to 1043 liver-related deaths. Sensitivity analysis shows our model is robust in estimating liver-related mortality and LTs averted, but is sensitive when estimating QALYs gained.

CONCLUSIONS

With a small annual probability of treatment and FRF = 1, a 2-year treatment followed by maintenance of histologic improvement for patients would be highly beneficial relative to short-term treatment alone.

Treatment of non-alcoholic fatty liver disease - Current perspectives

Therapeutics aimed at treating non-alcoholic fatty liver disease (NAFLD) target the pathogenic process from deranged metabolism leading to steatosis to cell stress and death, leading to a cascade of inflammation and fibrosis, ultimately culminating into cirrhosis. The development of drugs for management of NAFLD has bloomed over the past decade, although at present there is no approved pharmacological agent for its management. Not all patients with the disease progress to cirrhosis and decompensation; hence, treatment specifically is provided for those with a high risk of progression such as those with biopsy-proven steatohepatitis or fibrosis. Along with disease-specific management, all patients must receive therapies directed at risk factors such as dyslipidemia, insulin resistance, type 2 diabetes mellitus and obesity. Comorbidities such as cardiovascular disease, sleep apnoea and chronic kidney disease need management. A current perspective on the therapeutic options is detailed in this review.

Pirfenidone Is an Agonistic Ligand for PPARα and Improves NASH by Activation of SIRT1/LKB1/pAMPK

Nonalcoholic steatohepatitis (NASH) is recognized by hepatic lipid accumulation, inflammation, and fibrosis. No studies have evaluated the prolonged‐release pirfenidone (PR‐PFD) properties on NASH features. The aim of this study is to evaluate how PR‐PFD performs on metabolic functions, and provide insight on a mouse model of human NASH. Male C57BL/6J mice were fed with either normo diet or high‐fat/carbohydrate diet for 16 weeks and a subgroup also fed with PR‐PFD (300 mg/kg/day). An insulin tolerance test was performed at the end of treatment. Histological analysis, determination of serum hormones, adipocytokines measurement, and evaluation of proteins by western blot was performed. Molecular docking, in silico site‐directed mutagenesis, and in vitro experiments using HepG2 cultured cells were performed to validate PR‐PFD binding to peroxisome proliferator–activated receptor alpha (PPAR‐α), activation of PPAR‐α promoter, and sirtuin 1 (SIRT1) protein expression. Compared with the high‐fat group, the PR‐PFD‐treated mice displayed less weight gain, cholesterol, very low density lipoprotein and triglycerides, and showed a significant reduction of hepatic macrosteatosis, inflammation, hepatocyte ballooning, fibrosis, epididymal fat, and total adiposity. PR‐PFD restored levels of insulin, glucagon, adiponectin, and resistin along with improved insulin resistance. Noteworthy, SIRT1–liver kinase B1–phospho‐5′ adenosine monophosphate–activated protein kinase signaling and the PPAR‐α/carnitine O‐palmitoyltransferase 1/acyl‐CoA oxidase 1 pathway were clearly induced in high fat + PR‐PFD mice. In HepG2 cells incubated with palmitate, PR‐PFD induced activation and nuclear translocation of both PPARα and SIRT1, which correlated with increased SIRT1 phosphorylated in serine 47, suggesting a positive feedback loop between the two proteins. These results were confirmed with both synthetic PPAR‐α and SIRT1 activators and inhibitors. Finally, we found that PR‐PFD is a true agonist/ligand for PPAR‐α. Conclusions: PR‐PFD provided an anti‐steatogenic effect and protection for inflammation and fibrosis.

Characterization of Human Induced Pluripotent Stem Cell-Derived Hepatocytes with Mature Features and Potential for Modeling Metabolic Diseases

There is a strong anticipated future for human induced pluripotent stem cell-derived hepatocytes (hiPS-HEP), but so far, their use has been limited due to insufficient functionality. We investigated the potential of hiPS-HEP as an in vitro model for metabolic diseases by combining transcriptomics with multiple functional assays. The transcriptomics analysis revealed that 86% of the genes were expressed at similar levels in hiPS-HEP as in human primary hepatocytes (hphep). Adult characteristics of the hiPS-HEP were confirmed by the presence of important hepatocyte features, e.g., Albumin secretion and expression of major drug metabolizing genes. Normal energy metabolism is crucial for modeling metabolic diseases, and both transcriptomics data and functional assays showed that hiPS-HEP were similar to hphep regarding uptake of glucose, low-density lipoproteins (LDL), and fatty acids. Importantly, the inflammatory state of the hiPS-HEP was low under standard conditions, but in response to lipid accumulation and ER stress the inflammation marker tumor necrosis factor α (TNFα) was upregulated. Furthermore, hiPS-HEP could be co-cultured with primary hepatic stellate cells both in 2D and in 3D spheroids, paving the way for using these co-cultures for modeling non-alcoholic steatohepatitis (NASH). Taken together, hiPS-HEP have the potential to serve as an in vitro model for metabolic diseases. Furthermore, differently expressed genes identified in this study can serve as targets for future improvements of the hiPS-HEP.

Dual Farnesoid X Receptor/Soluble Epoxide Hydrolase Modulators Derived from Zafirlukast

The nuclear farnesoid X receptor (FXR) and the enzyme soluble epoxide hydrolase (sEH) are validated molecular targets to treat metabolic disorders such as non-alcoholic steatohepatitis (NASH). Their simultaneous modulation in vivo has demonstrated a triad of anti-NASH effects and thus may generate synergistic efficacy. Here we report dual FXR activators/sEH inhibitors derived from the anti-asthma drug Zafirlukast. Systematic structural optimization of the scaffold has produced favorable dual potency on FXR and sEH while depleting the original cysteinyl leukotriene receptor antagonism of the lead drug. The resulting polypharmacological activity profile holds promise in the treatment of liver-related metabolic diseases.

Carbon monoxide releasing molecule-A1 improves nonalcoholic steatohepatitis via Nrf2 activation mediated improvement in oxidative stress and mitochondrial function

Nuclear factor-erythroid 2 related factor 2 (Nrf2)-mediated signaling plays a central role in maintaining cellular redox homeostasis of hepatic cells. Carbon monoxide releasing molecule-A1 (CORM-A1) has been reported to stimulate up-regulation and nuclear translocation of Nrf2 in hepatocytes. However, the role of CORM-A1 in improving lipid metabolism, antioxidant signaling and mitochondrial functions in nonalcoholic steatohepatitis (NASH) is unknown. In this study, we report that CORM-A1 prevents hepatic steatosis in high fat high fructose (HFHF) diet fed C57BL/6J mice, used as model of NASH. The beneficial effects of CORM-A1 in HFHF fed mice was associated with improved lipid homeostasis, Nrf2 activation, upregulation of antioxidant responsive (ARE) genes and increased ATP production. As, mitochondria are intracellular source of reactive oxygen species (ROS) and important sites of lipid metabolism, we further investigated the mechanisms of action of CORM-A1-mediated improvement in mitochondrial function in palmitic acid (PA) treated HepG2 cells. Cellular oxidative stress and cell viability were found to be improved in PA + CORM-A1 treated cells via Nrf2 translocation and activation of cytoprotective genes. Furthermore, in PA treated cells, CORM-A1 improved mitochondrial oxidative stress, membrane potential and rescued mitochondrial biogenesis thru upregulation of Drp1, TFAM, PGC-1α and NRF-1 genes. CORM-A1 treatment improved cellular status by lowering glycolytic respiration and maximizing OCR. Improvement in mitochondrial respiration and increment in ATP production in PA + CORM-A1 treated cells further corroborate our findings. In summary, our data demonstrate for the first time that CORM-A1 ameliorates tissue damage in steatotic liver via Nrf2 activation and improved mitochondrial function, thus, suggesting the anti-NASH potential of CORM-A1.

Herbal drug discovery for the treatment of nonalcoholic fatty liver disease

Few medications are available for meeting the increasing disease burden of nonalcoholic fatty liver disease (NAFLD) and its progressive stage, nonalcoholic steatohepatitis (NASH). Traditional herbal medicines (THM) have been used for centuries to treat indigenous people with various symptoms but without clarified modern-defined disease types and mechanisms. In modern times, NAFLD was defined as a common chronic disease leading to more studies to understand NAFLD/NASH pathology and progression. THM have garnered increased attention for providing therapeutic candidates for treating NAFLD. In this review, a new model called “multiple organs-multiple hits” is proposed to explain mechanisms of NASH progression. Against this proposed model, the effects and mechanisms of the frequently-studied THM-yielded single anti-NAFLD drug candidates and multiple herb medicines are reviewed, among which silymarin and berberine are already under U.S. FDA-sanctioned phase 4 clinical studies. Furthermore, experimental designs for anti-NAFLD drug discovery from THM in treating NAFLD are discussed. The opportunities and challenges of reverse pharmacology and reverse pharmacokinetic concepts-guided strategies for THM modernization and its global recognition to treat NAFLD are highlighted. Increasing mechanistic evidence is being generated to support the beneficial role of THM in treating NAFLD and anti-NAFLD drug discovery.

Anti-NASH Drug Development Hitches a Lift on PPAR Agonism

Non-alcoholic fatty liver disease (NAFLD) affects one-third of the population worldwide, of which a substantial number of patients suffer from non-alcoholic steatohepatitis (NASH). NASH is a severe condition characterized by steatosis and concomitant liver inflammation and fibrosis, for which no drug is yet available. NAFLD is also generally conceived as the hepatic manifestation of the metabolic syndrome. Consequently, well-established drugs that are indicated for the treatment of type 2 diabetes and hyperlipidemia are thought to exert effects that alleviate the pathological features of NASH. One class of these drugs targets peroxisome proliferator-activated receptors (PPARs), which are nuclear receptors that play a regulatory role in lipid metabolism and inflammation. Therefore, PPARs are now also being investigated as potential anti-NASH druggable targets. In this paper, we review the mechanisms of action and physiological functions of PPARs and discuss the position of the different PPAR agonists in the therapeutic landscape of NASH. We particularly focus on the PPAR agonists currently under evaluation in clinical phase II and III trials. Preclinical strategies and how refinement and optimization may improve PPAR-targeted anti-NASH drug testing are also discussed. Finally, potential caveats related to PPAR agonism in anti-NASH therapy are stipulated.

Saroglitazar Deactivates the Hepatic LPS/TLR4 Signaling Pathway and Ameliorates Adipocyte Dysfunction in Rats with High-Fat Emulsion/LPS Model-Induced Non-alcoholic Steatohepatitis

The most epidemic liver disorder non-alcoholic steatohepatitis (NASH) is characterized by hepatic steatosis and inflammation with hepatocellular damage. Recently, it is predictable to be the extensive cause for liver transplantation. The absence of an approved therapeutic agent for NASH is the reason for investigating saroglitazar (SAR) which showed promising effects as a dual PPAR-α/γ agonist in recent studies on NASH. Here, we aimed to investigate the effect of SAR on NASH induced in rats by the administration of high-fat emulsion (HFE) and small doses of lipopolysaccharides (LPS) for 5 weeks. Rats were divided into three groups: negative control group (saline and standard rodent chow), model group (HFE(10 ml/kg/day, oral gavage) + LPS(0.5 mg/kg/week, i.p)), and SAR-treated group (HFE(10 ml/kg/day, oral gavage) + LPS(0.5 mg/kg/week, i.p.) + SAR(4 mg/kg/day, oral gavage) starting at week 3.Treatment with SAR successfully ameliorated the damaging effects of HFE with LPS, by counteracting body weight gain and biochemically by normalization of liver function parameters activity, glucose, insulin, homeostasis model of assessment (HOMA-IR) score, lipid profile levels, and histopathological examination. Significant changes in adipokine levels were perceived, resulting in a significant decline in serum leptin and tumor necrosis factor-α (TNF-α) level concurrent with adiponectin normalization. The positive effects observed for SAR on NASH are due to the downregulation of the LPS/TLR4 pathway, as indicated by the suppression of hepatic Toll-like receptor 4 (TLR4), NF-κB, TNF-α, and transforming growth factor-β1 (TGF-β1) expression. In conclusion, this work verified that SAR ameliorates NASH through deactivation of the hepatic LPS/TLR4 pathway and inhibition of adipocyte dysfunction.

Deep learning enables pathologist-like scoring of NASH models

Non-alcoholic fatty liver disease (NAFLD) and the progressive form of non-alcoholic steatohepatitis (NASH) are diseases of major importance with a high unmet medical need. Efficacy studies on novel compounds to treat NAFLD/NASH using disease models are frequently evaluated using established histological feature scores on ballooning, inflammation, steatosis and fibrosis. These features are assessed by a trained pathologist using microscopy and assigned discrete scores. We demonstrate how to automate these scores with convolutional neural networks (CNNs). Whole slide images of stained liver sections are analyzed using two different scales with four CNNs, each specialized for one of four histopathological features. A continuous value is obtained to quantify the extent of each feature, which can be used directly to provide a high resolution readout. In addition, the continuous values can be mapped to obtain the established discrete pathologist-like scores. The automated deep learning-based scores show good agreement with the trainer - a human pathologist.

Survey of Nonalcoholic Fatty Liver Disease Knowledge, Nutrition, and Physical Activity Patterns Among the General Public in Beijing, China

BACKGROUND

Despite high prevalence of nonalcoholic fatty liver disease in China, understanding of the disease appears to be low.

AIMS

We assessed the knowledge of NAFLD among the public in Beijing, China, as well as diet and physical activity patterns, which may provide information useful for NAFLD prevention and management.

METHODS

We surveyed adult patients and family members in the Peking University Health Science Center (PUHSC) ultrasound clinic and office staff in Beijing, China. Participants provided demographic and medical history data. NAFLD-related knowledge and diet and physical activity were assessed.

RESULTS

A total of 1296 participants at the PUHSC clinic (51% female, median age 35, 61% college-educated) and 494 participants in offices (61% female, median age 43, 74% college-educated) completed the survey. Response rate was 68.4% and 96.7%, respectively. In clinic and offices, 44% versus 48% were overweight/obese, 5% had a history of diabetes in both groups, and 14% versus 23% had a personal history of NAFLD. Median knowledge score was 15 out of 25 in clinic versus 16 in offices. 44.9% reported minimal physical activity. Factors associated with higher NAFLD knowledge scores (> 16) on multivariate analysis included college education or higher (OR 1.7, p = 0.01), family history of hyperlipidemia (OR 1.96, p < 0.001), and number of sugary drinks per week (OR 0.74, p = 0.006). No factors were significantly associated with physical activity levels.

CONCLUSIONS

Adults in Beijing had low knowledge about NAFLD, and most were not physically active. Programs to increase public awareness of NAFLD and promote physical activity are critical to curb this growing epidemic.

Potential clinical variants detected in mitochondrial DNA D-loop hypervariable region I of patients with non-alcoholic steatohepatitis

PURPOSE

Non-alcoholic steatohepatitis (NASH) is a mitochondrial disease. However, the underlying role of mitochondrial genetics has not yet been completely elucidated. Evaluation of D-loop nucleotide variations with respect to statistical significance and clinical data distribution.

METHODS

Genomic DNAs were extracted from the peripheral blood samples of patients with biopsy-proven 150 NASH as well as from 150 healthy individuals to explore the functional D-loop region responsible for the replication and transcription of the mitochondrial genome. DNA sequencing by capillary electrophoresis analysis was performed for the D-loop region of mitochondrial DNA containing the hypervariable region I, and restriction fragment length polymorphism with MnlI analysis was performed for the m.16189 T/C D-loop variant.

RESULTS

The m.A16318C variant was detected only in patients with NASH and approached significance level. Based on clinical data, six variants associated with histological subgroups of NASH and NASH-complicated diseases were identified. In patients with NASH, the m.16129 AA genotype was associated with advanced-stage fibrosis; the m.16249 CC genotype was associated with advanced lobular inflammation and advanced-stage histological steatosis; the m.16296 TT genotype was associated with hypothyroidism; the m.16163 GG and m.16294 TT genotypes were associated with metabolic syndrome; and the m.16256 TT+CT genotypes were associated with type II diabetes. In patients with NASH, microRNAs were estimated by targeting the significant variants identified in this study.

CONCLUSION

These findings suggest that NASH may be associated with D-loop nucleotide variations and that microRNA-based in vitro and/or in vivo studies may be developed by targeting the D-loop variants.

A Newly Established Murine Cell Line as a Model for Hepatocellular Cancer in Non-Alcoholic Steatohepatitis

Non-alcoholic steatohepatitis (NASH) has become a major risk factor for hepatocellular cancer (HCC) due to the worldwide increasing prevalence of obesity. However, the pathophysiology of NASH and its progression to HCC is incompletely understood. Thus, the aim of this study was to generate a model specific NASH-derived HCC cell line. A murine NASH-HCC model was conducted and the obtained cancer cells (N-HCC25) were investigated towards chromosomal aberrations, the expression of cell type-specific markers, dependency on nutrients, and functional importance of mTOR. N-HCC25 exhibited several chromosomal aberrations as compared to healthy hepatocytes. Hepatocytic (HNF4), EMT (Twist, Snail), and cancer stem cell markers (CD44, EpCAM, CK19, Sox9) were simultaneously expressed in these cells. Proliferation highly depended on the supply of glucose and FBS, but not glutamine. Treatment with a second generation mTOR inhibitor (KU-0063794) resulted in a strong decrease of cell growth in a dose-dependent manner. In contrast, a first generation mTOR inhibitor (Everolimus) only slightly reduced cell proliferation. Cell cycle analyses revealed that the observed growth reduction was most likely due to G₁/G₀ cell cycle arrest. These results indicate that N-HCC25 is a highly proliferative HCC cell line from a NASH background, which might serve as a suitable in vitro model for future investigations of NASH-derived HCC.

Agaricus brasiliensis KA21 May Prevent Diet-Induced Nash Through Its Antioxidant, Anti-Inflammatory, and Anti-Fibrotic Activities in the Liver

Non-alcoholic steatohepatitis (NASH) is a progressive disease that occurs in the liver. As the number of people with NASH has increased, effective prevention and treatment strategies are needed. Agaricus brasiliensis KA21 (AGA) is a mushroom native to Brazil and is considered a healthy food because of its purported health benefits, including its antioxidant properties. In this study, we focused on the oxidative stress that accompanies the onset of NASH and examined whether AGA can prevent NASH development through its antioxidant activity. We used a mouse model of NASH in which pathogenesis was promoted by dietary induction. Supplementation with AGA attenuated the development of hepatic fibrosis, which is a characteristic feature of late-stage NASH. This effect appeared to be mechanistically linked to an AGA-promoted reduction in hepatic oxidative stress. These results demonstrate a novel role for AGA in NASH prevention.

Withaferin A Improves Nonalcoholic Steatohepatitis in Mice

Nonalcoholic steatohepatitis (NASH) is the progressive stage of nonalcoholic fatty liver disease that highly increases the risk of cirrhosis and liver cancer, and there are few therapeutic options available in the clinic. Withaferin A (WA), extracted from the ayurvedic medicine Withania somnifera, has a wide range of pharmacological activities; however, little is known about its effects on NASH. To explore the role of WA in treating NASH, two well defined NASH models were used, the methionine-choline-deficient diet and the 40 kcal% high-fat diet (HFD). In both NASH models, WA treatment or control vehicle was administered to evaluate its hepatoprotective effects. As assessed by biochemical and histologic analyses, WA prevented and therapeutically improved liver injury in both models, as revealed by lower serum aminotransaminases, hepatic steatosis, liver inflammation, and fibrosis. In the HFD-induced NASH model, both elevated serum ceramides and increased hepatic oxidative stress were decreased in the WA-treated group compared with the control vehicle-treated group. To further explore whether WA has an anti-NASH effect independent of its known action in leptin signaling associated with obesity, leptin signaling-deficient ob/ob mice maintained on an HFD were used to induce NASH. WA therapeutically reduced NASH in HFD-treated leptin-deficient ob/ob mice, thus demonstrating a leptin-independent hepatoprotective effect. This study revealed that WA treatment could be an option for NASH treatment.

Cigarette smoking differentially regulates inflammatory responses in a mouse model of nonalcoholic steatohepatitis depending on exposure time point

Cigarette smoke (CS) is a risk factor for the development of nonalcoholic fatty liver disease. However, the role of mainstream CS (MSCS) in the pathogenesis of nonalcoholic steatohepatitis (NASH) remains unclear. During the first (early exposure) or last (late exposure) three weeks of methionine-choline deficient with high fat diet feeding (6 weeks), each diet group was exposed to MSCS (300 or 600 μg/L). Hepatic or serum biochemical analysis showed that MSCS differentially modulated hepatic injury in NASH milieu, depending on exposure time points. Consistently, NASH-related hepatocellular apoptosis and fibrosis were increased in the early exposure group, but decreased in the late exposure group, except for steatosis. Ex vivo experiments showed that CS extract differentially regulated inflammatory responses in co-cultured hepatocytes and macrophages isolated from steatohepatitic livers after 10 days or 3 weeks of diet feeding. Furthermore, CS differentially up- and down-regulated the expression levels of M1/M2 polarization markers and peroxisome proliferator-activated receptor-gamma (PPARγ) in livers (29% and 38%, respectively) or co-cultured macrophages (2 and 2.5 fold, respectively). Collectively, our findings indicate that opposite effects of MSCS on NASH progression are mediated by differential modulation of PPARγ and its-associated M1/M2 polarization in hepatic macrophages, depending on exposure time points.

Non-alcoholic fatty liver disease in lean individuals

Non-alcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease, encompassing a spectrum from non-alcoholic fatty liver to non-alcoholic steatohepatitis, which can progress to cirrhosis. It has recently been recognised that NAFLD also occurs in individuals who are not obese, especially in Asian populations. In these patients, NAFLD manifests at lower overall body mass index thresholds in the presence of increased visceral adipose tissue. Currently, the principles of clinical management are similar to those in obese individuals, although, in specific regions and clinical situations, unique aetiologies of NAFLD must be treated specifically.

Importance of fatigue and its measurement in chronic liver disease

The mechanisms of fatigue in the group of people with non-alcoholic fatty liver disease and non-alcoholic steatohepatitis are protean. The liver is central in the pathogenesis of fatigue because it uniquely regulates much of the storage, release and production of substrate for energy generation. It is exquisitely sensitive to the feedback controlling the uptake and release of these energy generation substrates. Metabolic contributors to fatigue, beginning with the uptake of substrate from the gut, the passage through the portal system to hepatic storage and release of energy to target organs (muscle and brain) are central to understanding fatigue in patients with chronic liver disease. Inflammation either causing or resulting from chronic liver disease contributes to fatigue, although inflammation has not been demonstrated to be causal. It is this unique combination of factors, the nexus of metabolic abnormality and the inflammatory burden of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis that creates pathways to different types of fatigue. Many use the terms central and peripheral fatigue. Central fatigue is characterized by a lack of self-motivation and can manifest both in physical and mental activities. Peripheral fatigue is classically manifested by neuromuscular dysfunction and muscle weakness. Therefore, the distinction is often seen as a difference between intention (central fatigue) versus ability (peripheral fatigue). New approaches to measuring fatigue include the use of objective measures as well as patient reported outcomes. These measures have improved the precision with which we are able to describe fatigue. The measures of fatigue severity and its impact on usual daily routines in this population have also been improved, and they are more generally accepted as reliable and sensitive. Several approaches to evaluating fatigue and developing endpoints for treatment have relied of biosignatures associated with fatigue. These have been used singly or in combination and include: physical performance measures, cognitive performance measures, mood/behavioral measures, brain imaging and serological measures. Treatment with non-pharmacological agents have been shown to be effective in symptom reduction, whereas pharmacological agents have not been shown effective.

Serum Vitamin E Levels of Adults with Nonalcoholic Fatty Liver Disease: An Inverse Relationship with All-Cause Mortality in Non-Diabetic but Not in Pre-Diabetic or Diabetic Subjects

Nonalcoholic fatty liver disease (NAFLD) is a growing health threat worldwide. Vitamin E supplementation is recommended for nonalcoholic steatohepatitis (NASH) patients, but only for non-diabetic subjects. We aimed to investigate whether serum vitamin E levels differently impact long-term prognosis in diabetic versus non-diabetic NAFLD individuals. A total of 2404 ultrasonographically defined NAFLD individuals from National Health and Nutrition Examination Survey (NHANES) III were stratified by their glycemic statuses into diabetic (N = 662), pre-diabetic (N = 836) and non-diabetic (N = 906), and the relationship between serum vitamin E levels and all-cause mortality was analyzed. The serum vitamin E concentrations were 31.1 ± 14.1, 26.7 ± 9.6, and 24.7 ± 9.8 µmol/L and vitamin E: total cholesterol ratios were 5.16 ± 1.70, 4.81 ± 1.46, and 4.80 ± 1.34 µmol/mmol in in diabetic, pre-diabetic, and non-diabetic groups, respectively. Of 2404 NAFLD subjects, 2403 have mortality information and 152 non-diabetic, 244 pre-diabetic, and 342 diabetic participants died over a median follow-up period of 18.8 years. Both serum vitamin E levels and vitamin E: total cholesterol ratios were negatively associated with all-cause mortality after adjusting for possible confounders in non-diabetic subjects (HR = 0.483, and 0.451, respectively, p < 0.005), but not in either diabetic or pre-diabetic subjects. In NAFLD individuals, both serum vitamin E and lipid-corrected vitamin E were (1) higher in the diabetic group; and (2) negatively associated with all-cause mortality only in the non-diabetic group. Further investigations are warranted to elucidate the underlying mechanism of this inverse association of serum vitamin E concentration with all-cause mortality in non-diabetic but not pre-diabetic or diabetic subjects.

Twitter As a Noninvasive Bio-Marker for Trends in Liver Disease

With the success of hepatitis C virus (HCV) direct-acting antiviral therapies, there has been a shift in research focus to the other major chronic liver diseases (CLDs). The use of social media, specifically Twitter, has become a popular platform for understanding public health trends and for performing health care research. To evaluate this, we studied the areas of public interest and social media trends of the following three major CLDs: hepatitis B virus (HBV), HCV, and nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). Twitter activity data from January 1, 2013, through January 1, 2019, for HBV, HCV, and NAFLD/NASH were collected using the social media analytic tool Symplur Signals (Symplur LLC) software. Content and regression analyses were performed to understand and predict Twitter activity for each of the CLDs. Over the study period, there were 810,980 tweets generating 4,452,939,516 impressions. HCV tweet activity peaked in 2015 at 243,261 tweets, followed by a decline of 52.4% from 2015 to 2016 with a subsequent plateau through 2018. Meanwhile, NAFLD/NASH and HBV tweet activity has continued to increase, with projections that these two CLDs will surpass HCV by the second half of 2023 and 2024, respectively. Treatment and Management was the most popular content category for HCV and NAFLD/NASH, while Prevention was the most popular content category for HBV. Conclusion: Twitter is a useful social media tool to gauge public interest in liver disease over time. The information provided by Twitter can be used to identify gaps in public knowledge or highlight areas of interest that may need further research. Future studies on the use of Twitter in liver disease are warranted.

A Structured Literature Review of the Epidemiology and Disease Burden of Non-Alcoholic Steatohepatitis (NASH)

INTRODUCTION

Non-Alcoholic Steatohepatitis (NASH) is a chronic, progressive disease characterized by fatty liver and liver cell injury, advancing to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Diagnosis involves liver biopsy; however, as a result of its high cost and invasiveness, NASH remains underdiagnosed, and accurate burden of disease (BoD) data are lacking. Our aim was to understand the epidemiological and BoD landscape in NASH and identify knowledge gaps.

METHODS

The Ovid search engine was used to conduct a structured review, following quality systematic principles. It included publications that reported on epidemiology, quality of life (QoL) and BoD outcomes in NASH adults. Searches were limited to English language studies published between January 2007 and September 2017. Additional grey literature searches were conducted. A total of 53 references were selected; 38 were peer-reviewed and 15 were grey literature sources.

RESULTS

NASH is estimated to affect 3-5% of the global population, most suffering from several comorbidities. Advancing fibrosis drives clinical outcomes, with approximately 20% of patients developing cirrhosis and/or HCC, the latter being a leading cause of death in NASH. A recent model predicted the 15-year survival of advanced fibrosis patients at F3 and F4 as 51.0% and 28.4%, respectively. The limited data consistently show that NASH patients experience significantly poorer QoL and higher costs compared to non-NASH patients.

CONCLUSION

This first broad-ranging examination of NASH literature revealed a paucity of evidence, with poor-quality, small studies found. The overwhelming impact of NASH and its patient and healthcare burden is evident. Further evidence is needed to improve our understanding of NASH, especially as fibrosis stages advance.

FUNDING

Gilead Science Inc.

A dual farnesoid X receptor/soluble epoxide hydrolase modulator treats non-alcoholic steatohepatitis in mice

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are the most prevalent metabolic liver disorders and a serious global health burden. NAFLD/NASH pathogenesis and progression are highly multi-factorial and likely demand a combination of multiple mechanisms to provide a more effective treatment. We have developed a dual farnesoid X receptor agonist (FXRA)/soluble epoxide hydrolase inhibitor (sEHi) to simultaneously address two validated and complementary modes of action in NASH treatment. Here we report the in vivo profiling for this FXRA/sEHi in toxin- and diet-induced rodent NASH models. In streptozotocin-induced NASH as a proof-of-concept study, the experimental FXRA/sEHi drug robustly prevented hepatic steatosis and fibrosis, and improved lipid homeostasis as well as biochemical markers of liver health. In methionine-choline-deficient high-fat diet-induced NASH, FXRA/sEHi treatment reduced hepatic steatosis and fibrosis to levels similar to healthy animals and demonstrated anti-inflammatory activity confirming that dual FXRA/sEHi modulation produces a triad of complementary anti-NASH effects. Our results validate dual FXRA/sEHi modulation as an effective therapeutic strategy to treat NASH and advocates for a combinational drug therapeutic approach for multifactorial liver diseases.