Efficacy of elafibranor in patients with liver abnormalities especially non-alcoholic steatohepatitis: a systematic review and meta-analysis

Maladaptive regeneration and metabolic dysfunction associated steatotic liver disease: Common mechanisms and potential therapeutic targets

The normal liver has an extraordinary capacity of regeneration. However, this capacity is significantly impaired in steatotic livers. Emerging evidence indicates that metabolic dysfunction associated steatotic liver disease (MASLD) and liver regeneration share several key mechanisms. Some classical liver regeneration pathways, such as HGF/c-Met, EGFR, Wnt/β-catenin and Hippo/YAP-TAZ are affected in MASLD. Some recently established therapeutic targets for MASH such as the Thyroid Hormone (TH) receptors, Glucagon-like protein 1 (GLP1), Farnesoid X receptor (FXR), Peroxisome Proliferator-Activated Receptors (PPARs) as well as Fibroblast Growth Factor 21 (FGF21) are also reported to affect hepatocyte proliferation. With this review we aim to provide insight into common molecular pathways, that may ultimately enable therapeutic strategies that synergistically ameliorate steatohepatitis and improve the regenerating capacity of steatotic livers. With the recent rise of prolonged ex-vivo normothermic liver perfusion prior to organ transplantation such treatment is no longer restricted to patients undergoing major liver resection or transplantation, but may eventually include perfused (steatotic) donor livers or even liver segments, opening hitherto unexplored therapeutic avenues.

Exploring the potential of drug repurposing for liver diseases: A comprehensive study

Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.

Metabolic Dysfunction-associated Fatty Liver Disease: An Urgent Call for Global Action

There has been an exponential increase in the global prevalence of fatty liver disease in recent years in association with the obesity pandemic worldwide. 'Metabolic dysfunction-associated fatty liver disease', the new terminology adopted by an international panel of experts in 2020 to largely replace the old term 'non-alcoholic fatty liver disease', has now been accepted by most hepatologists and diabetologists across the globe. The term metabolic dysfunction-associated fatty liver disease was created to better reflect the metabolicand liver-specific manifestations and complications of fatty liver disease. It is important to disseminate our current understanding of this enigmatic disease among the global scientific fraternity. Recent publications, including articles from the latest issue of Endocrinology & Metabolism Clinics of North America, are attempting to fill this knowledge gap.

Abnormal metabolism in hepatic stellate cells: Pandora's box of MAFLD related hepatocellular carcinoma

Metabolic associated fatty liver disease (MAFLD) is a significant risk factor for the development of hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs), as key mediators in liver injury response, are believed to play a crucial role in the repair process of liver injury. However, in MAFLD patients, the normal metabolic and immunoregulatory mechanisms of HSCs become disrupted, leading to disturbances in the local microenvironment. Abnormally activated HSCs are heavily involved in the initiation and progression of HCC. The metabolic disorders and abnormal activation of HSCs not only initiate liver fibrosis but also contribute to carcinogenesis. In this review, we provide an overview of recent research progress on the relationship between the abnormal metabolism of HSCs and the local immune system in the liver, elucidating the mechanisms of immune imbalance caused by abnormally activated HSCs in MAFLD patients. Based on this understanding, we discuss the potential and challenges of metabolic-based and immunology-based mechanisms in the treatment of MAFLD-related HCC, with a specific focus on the role of HSCs in HCC progression and their potential as targets for anti-cancer therapy. This review aims to enhance researchers' understanding of the importance of HSCs in maintaining normal liver function and highlights the significance of HSCs in the progression of MAFLD-related HCC.

A model of hepatic steatosis with declined viability and function in a liver-organ-on-a-chip

Nonalcoholic fatty liver disease (NAFLD) begins with benign steatosis caused by ectopic storage of triacylglycerols in the liver. Persistent steatosis, in combination with other genetic and environmental factors, leads to nonalcoholic steatohepatitis (NASH) characterized by functional impairment, inflammation, and fibrosis. However, it remains unclear how persistent steatosis directly contributes to the progression of NAFLD, which may represent a therapeutic target. The organ-on-a-chip (OOC) has emerged as a new culture platform to recapitulate human pathological conditions under which drug candidates can be screened. Here, we developed a simple OOC steatosis model using the Mimetas OrganoPlate with a human liver cell line, HepG2. Treating the HepG2 OOCs with fatty acid overload induced steatosis within 24 h. Moreover, persistent steatosis for 6 days impaired OOC viability and hepatic function, as measured by a WST-8 assay and albumin production, respectively. Lastly, the HepG2 OOCs were exposed to drugs being tested in clinical trials for NAFLD/NASH during the 6-day period. Pioglitazone improved the OOC viability while elafibranor reduced the steatosis in association with reduced viability and albumin production. In conclusion, we show that the HepG2 steatosis OOC model is a useful tool on which the efficacy and toxicity of various therapeutic candidates can be tested.

Potential Therapeutic Strategies in the Treatment of Metabolic-Associated Fatty Liver Disease

Metabolic-associated Fatty Liver Disease is one of the outstanding challenges in gastroenterology. The increasing incidence of the disease is undoubtedly connected with the ongoing obesity pandemic. The lack of specific symptoms in the early phases and the grave complications of the disease require an active approach to prompt diagnosis and treatment. Therapeutic lifestyle changes should be introduced in a great majority of patients; but, in many cases, the adherence is not satisfactory. There is a great need for an effective pharmacological therapy for Metabolic-Associated Fatty Liver Disease, especially before the onset of steatohepatitis. Currently, there are no specific recommendations on the selection of drugs to treat liver steatosis and prevent patients from progression toward more advanced stages (steatohepatitis, cirrhosis, and cancer). Therefore, in this Review, we provide data on the clinical efficacy of therapeutic interventions that might improve the course of Metabolic-Associated Fatty Liver Disease. These include the drugs used in the treatment of obesity and hyperlipidemias, as well as affecting the gut microbiota and endocrine system, and other experimental approaches, including functional foods. Finally, we provide advice on the selection of drugs for patients with concomitant Metabolic-Associated Fatty Liver Disease.

NASH drug treatment development: challenges and lessons

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. Although NAFLD is tightly linked to obesity and type 2 diabetes, this liver disease also affects individuals who do not have obesity. NAFLD increases the risk of developing cardiovascular disease, chronic kidney disease, and certain extrahepatic cancers. There is currently no licensed pharmacotherapy for NAFLD, despite numerous clinical trials in the past two decades. Currently, the reason so few drugs have been successful in the treatment of NAFLD in a trial setting is not fully understood. As cardiovascular disease is the predominant cause of mortality in people with NAFLD, future pharmacotherapies for NAFLD must consider associated cardiometabolic risk factors. The successful use of glucose-lowering drugs in the treatment of type 2 diabetes in patients with NAFLD indicates that this strategy is important, and worth developing further. Greater public awareness of NAFLD is needed because collaboration between all stakeholders is vital to enable a holistic approach to successful treatment.

Leucine aminopeptidase 3:a promising serum biomarker candidate for nonalcoholic steatohepatitis diagnosis

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) is a highly prevalent liver disease that lacks targeted therapeutic drugs and non-invasive diagnostic methods. Increasing evidence demonstrated that aberrant expression of leucine aminopeptidase 3 (LAP3) is involved in NASH. Herein, we aimed to investigate whether LAP3 can be a promising serum biomarker for NASH diagnosis.

METHODS

Liver tissues and serum from NASH rats, serum from NASH patients, and liver biopsies from chronic hepatitis B (CHB) patients combined with NASH (CHB+NASH) were obtained to evaluate the LAP3 level. Correlation analysis was conducted to evaluate the association between LAP3 expression and clinical indexes in CHB patients and CHB+NASH patients. ROC curve analysis of LAP3 in the serum and liver was applied to assess whether LAP3 can be a promising biomarker for NASH diagnosis.

RESULTS

LAP3 was significantly upregulated in serum and hepatocytes of NASH rats and patients with NASH. Correlation analysis revealed that LAP3 in the liver of CHB patients and CHB+NASH patients showed a strong positive correlation with lipidome indicators total cholesterol (TC) and triglyceride (TG), and liver fibrosis indicator hyaluronic acid (HA), which showed a negative correlation with the international normalized ratio of prothrombin coagulation (INR) and liver injury indicator aspartate aminotransferase (AST). For NASH, the diagnostic accuracy of ALT > LAP3 > AST, the sensitivity LAP3 (0.87) > ALT (0.5957) > AST (0.2941), the specificity AST (0.975) > ALT (0.9) > LAP3 (0.5).

CONCLUSION

Our data urge that LAP3 can serve as a promising serum biomarker candidate for NASH diagnosis.

From NAFLD to MAFLD: Definition, Pathophysiological Basis and Cardiovascular Implications

Non-alcoholic fatty liver disease (NAFLD) is defined as a chronic liver disease characterized by excessive fat accumulation in the liver without another obvious cause (no excessive alcohol consumption, hepatotoxic medications, toxins, viral infections, genetic hepatic diseases), therefore it is an exclusion diagnosis. The term NAFLD literally refers to non-alcohol related hepatopathy and does not adequately correlate with metabolic dysfunction and related cardiovascular risks. Therefore, researchers and scientific societies have moved towards changing the terminology. The novel nomenclature for a metabolic-associated fatty liver disease (MAFLD) has been proposed in 2020 by a group of experts to overcome the issues related to the old terminology. The diagnosis of MAFLD is based on the presence of hepatic steatosis and at least one between these three conditions: type 2 diabetes mellitus (T2DM), obesity or metabolic dysregulation. MAFLD has been shown to be an independent risk factor for cardiovascular diseases and atherosclerosis. It is better related to the main risk factors for atherosclerosis and cardiovascular diseases than NAFLD, such as dyslipidemia, T2DM and hypertension. The aim of this review is to highlight the reasons why the term NAFLD is moving to the term MAFLD, what are the conceptual basis of this choice and its clinical implications, particularly in the cardiovascular field.

Spotlight on liver macrophages for halting injury and progression in non-alcoholic fatty liver disease

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of the metabolic syndrome and is rapidly emerging as the leading cause of liver-related morbidity and mortality. Macrophages play an essential role in the development and progression of NAFLD.

AREAS COVERED

In this review, we provide an update on recent studies of drugs, which directly or indirectly affect macrophages in NAFLD, and discuss the implication of macrophage biomarkers to monitor the disease stage and progression/regression.

EXPERT OPINION

There is an unmet need for better understanding of disease pathogenesis from hepatic fat accumulation to disease progression with inflammation and fibrosis. We expect that future research will uncover additional objects/pathways as treatment targets. We speculate that this will involve better characterization of the gut microbiome, damage-associated molecular patterns (DAMPS) or molecules and pathways involved in development of DAMPS, and advanced molecular biology studies including single-cell sequencing of macrophage subpopulations. In addition, we speculate that studies focusing on pharmaceuticals that improve insulin resistance, diminish the metabolic syndrome and reduce fibrosis will prevail.

Application of metabolomics in the diagnosis of non-alcoholic fatty liver disease and the treatment of traditional Chinese medicine

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease around the world, and it often coexists with insulin resistance-related diseases including obesity, diabetes, hyperlipidemia, and hypertension, which seriously threatens human health. Better prevention and treatment strategies are required to improve the impact of NAFLD. Although needle biopsy is an effective tool for diagnosing NAFLD, this method is invasive and difficult to perform. Therefore, it is very important to develop more efficient approaches for the early diagnosis of NAFLD. Traditional Chinese medicine (TCM) can play a certain role in improving symptoms and protecting target organs, and its mechanism of action needs to be further studied. Metabolomics, the study of all metabolites that is thought to be most closely associated with the patients’ characters, can provide useful clinically biomarkers that can be applied to NAFLD and may open up new methods for diagnosis. Metabolomics technology is consistent with the overall concept of TCM, and it can also be used as a potential mechanism to explain the effects of TCM by measuring biomarkers by metabolomics. Based on PubMed/MEDLINE and other databases, this paper retrieved relevant literature NAFLD and TCM intervention in NAFLD using metabolomics technology in the past 5 years were searched, and the specific metabolites associated with the development of NAFLD and the potential mechanism of Chinese medicine on improving symptoms were summarized.

Priming, Triggering, Adaptation and Senescence (PTAS): A Hypothesis for a Common Damage Mechanism of Steatohepatitis

Understanding the pathomechanism of steatohepatitis (SH) is hampered by the difficulty of distinguishing between causes and consequences, by the broad spectrum of aetiologies that can produce the phenotype, and by the long time-span during which SH develops, often without clinical symptoms. We propose that SH develops in four phases with transitions: (i) priming lowers stress defence; (ii) triggering leads to acute damage; (iii) adaptation, possibly associated with cellular senescence, mitigates tissue damage, leads to the phenotype, and preserves liver function at a lower level; (iv) finally, senescence prevents neoplastic transformation but favours fibrosis (cirrhosis) and inflammation and further reduction in liver function. Escape from senescence eventually leads to hepatocellular carcinoma. This hypothesis for a pathomechanism of SH is supported by clinical and experimental observations. It allows organizing the various findings to uncover remaining gaps in our knowledge and, finally, to provide possible diagnostic and intervention strategies for each stage of SH development.