Nonalcoholic Steatohepatitis Fibrosis Research Articles

Effect of pegbelfermin on NASH and fibrosis-related biomarkers and correlation with histological response in the FALCON 1 trial

FALCON 1 was a phase IIb study of pegbelfermin in patients with non-alcoholic steatohepatitis (NASH) and stage 3 fibrosis. This FALCON 1 post hoc analysis aimed to further assess the effect of pegbelfermin on NASH-related biomarkers, correlations between histological assessments and non-invasive biomarkers, and concordance between the week 24 histologically assessed primary endpoint response and biomarkers. Blood-based composite fibrosis scores, blood-based biomarkers, and imaging biomarkers were evaluated for patients with available data from FALCON 1at baseline through week 24. SomaSignal tests assessed protein signatures of NASH steatosis, inflammation, ballooning, and fibrosis in blood. Linear mixed-effect models were fit for each biomarker. Correlations and concordance were assessed between blood-based biomarkers, imaging, and histological metrics. At week 24, pegbelfermin significantly improved blood-based composite fibrosis scores (ELF, FIB-4, APRI), fibrogenesis biomarkers (PRO-C3 and PC3X), adiponectin, CK-18, hepatic fat fraction measured by MRI-proton density fat fraction, and all four SomaSignal NASH component tests. Correlation analyses between histological and non-invasive measures identified four main categories: steatosis/metabolism, tissue injury, fibrosis, and biopsy-based metrics. Concordant and discordant effects of pegbelfermin on the primary endpoint vs. biomarker responses were observed; the most clear and concordant effects were on measures of liver steatosis and metabolism. A significant association between hepatic fat measured histologically and by imaging was observed in pegbelfermin arms. Pegbelfermin improved NASH-related biomarkers most consistently through improvement of liver steatosis, though biomarkers of tissue injury/inflammation and fibrosis were also improved. Concordance analysis shows that non-invasive assessments of NASH support and exceed the improvements detected by liver biopsy, suggesting that greater consideration should be given to the totality of available data when evaluating the efficacy of NASH therapeutics. Post hoc analysis of NCT03486899. FALCON 1 was a study of pegbelfermin vs. placebo in patients with non-alcoholic steatohepatitis (NASH) without cirrhosis; in this study, patients who responded to pegbelfermin treatment were identified through examination of liver fibrosis in tissue samples collected through biopsy. In the current analysis, non-invasive blood- and imaging-based measures of fibrosis, liver fat, and liver injury were used to determine pegbelfermin treatment response to see how they compared with the biopsy-based results. We found that many of the non-invasive tests, particularly those that measured liver fat, identified patients who responded to pegbelfermin treatment, consistent with the liver biopsy findings. These results suggest that there may be additional value in using data from non-invasive tests, along with liver biopsy, to evaluate how well patients with NASH respond to treatment.

Developing Technical Specifications for Submitting Clinical Trial Data Sets for Treatment of Noncirrhotic Nonalcoholic Steatohepatitis (NASH) Liver Fibrosis

Nonalcoholic steatohepatitis (NASH) can progress to cirrhosis and liver failure and is associated with an increase incidence of liver cancer. Currently, there are no approved therapies for treatment of NASH fibrosis.  During evaluation of a new drug application, it can be challenging to differentiate between progression of liver disease and potential drug-induced liver injury (DILI) in subjects with NASH fibrosis and DILI.  Therefore, clinical trials for treatment of NASH fibrosis require standardized disease-specific metadata to adequately support evaluation of efficacy and safety, including potentially DILI assessment. To improve reviewability and quality of data submission, it is helpful for all stakeholders to understand specifications needed for subject level data submission to the FDA. Development of technical specifications requires a multidisciplinary approach. This report describes the rationale, process and methods used in developing Technical Specifications for Submitting Clinical Trial Data Sets for Treatment of Noncirrhotic Nonalcoholic Steatohepatitis (NASH). The recommendations outlined in the NASH technical specifications pertain to submission of the sponsor’s tabulated and analysis data sets in a standardized manner based on CDISC standards to improve reviewability. These specifications also provide an opportunity for dialogue between the sponsor and regulatory agency to discuss issues related to trial design or conduct that may affect the content of these data sets. These specifications are intended to support the draft guidance for industry Noncirrhotic Nonalcoholic Steatohepatitis with Liver Fibrosis: Developing Drugs for Treatment (NASH Guidance) and reflect the data standards and processes described in the FDA Study Data Technical Conformance Guide and the FDA Data Standards Catalog.

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in non-alcoholic steatohepatitis

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in non-alcoholic steatohepatitis

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in nonalcoholic steatohepatitis.

Advanced hepatic fibrosis, driven by the activation of hepatic stellate cells (HSCs), affects millions worldwide and is the strongest predictor of mortality in nonalcoholic steatohepatitis (NASH); however, there are no approved antifibrotic therapies. To identify antifibrotic drug targets, we integrated progressive transcriptomic and morphological responses that accompany HSC activation in advanced disease using single-nucleus RNA sequencing and tissue clearing in a robust murine NASH model. In advanced fibrosis, we found that an autocrine HSC signaling circuit emerged that was composed of 68 receptor-ligand interactions conserved between murine and human NASH. These predicted interactions were supported by the parallel appearance of markedly increased direct stellate cell-cell contacts in murine NASH. As proof of principle, pharmacological inhibition of one such autocrine interaction, neurotrophic receptor tyrosine kinase 3-neurotrophin 3, inhibited human HSC activation in culture and reversed advanced murine NASH fibrosis. In summary, we uncovered a repertoire of antifibrotic drug targets underlying advanced fibrosis in vivo. The findings suggest a therapeutic paradigm in which stage-specific therapies could yield enhanced antifibrotic efficacy in patients with advanced hepatic fibrosis.

Prevalence and risk factors of nonalcoholic fatty liver disease, high-risk nonalcoholic steatohepatitis, and fibrosis among lean United States adults: NHANES 2017-2020.

Nonalcoholic fatty liver disease (NAFLD) is a growing public health concern worldwide. Early detection and management of modifiable risk factors are critical to mitigating its impact. This study aimed to investigate the prevalence and risk factors of NAFLD, nonalcoholic steatohepatitis (NASH), and fibrosis among lean adults in the United States (US), using the latest National Health and Nutrition Examination Survey (NHANES) dataset from 2017-2020. Using controlled attenuation parameter scores of ≥285 dB/m, we assessed the age-adjusted prevalence of lean NAFLD. To determine the age-adjusted prevalence of high-risk NASH and significant fibrosis, we used the FibroScan-aspartate aminotransferase (FAST) score (cutoffs 0.35 and 0.67) and vibration-controlled transient elastography (liver stiffness measurement ≥8 kPa). Multivariate logistic regression was used to identify potential risk factors. We found the age-adjusted prevalence of lean NAFLD to be 6.30%. Among lean US adults, the age-adjusted prevalence of high-risk NASH and significant fibrosis was 1.29% and 4.35%, respectively. Older age and metabolic comorbidities, such as hypertension, diabetes, and dyslipidemia were associated with NAFLD and its complications. These findings suggest that the prevalence of NAFLD is of concern among lean individuals, particularly those aged 40 and older with metabolic comorbidities, while a targeted approach to screening and risk stratification for hepatic fibrosis upon lean NAFLD diagnosis is warranted.

Low-Dose Administration of Cannabigerol Attenuates Inflammation and Fibrosis Associated with Methionine/Choline Deficient Diet-Induced NASH Model via Modulation of Cannabinoid Receptor

8-week-old C57BL/6 male mice were fed with methionine/choline deficient (MCD) diet or control (CTR) diets for five weeks. At the beginning of week 4, mice were divided into three sub-groups and injected with either a vehicle, a low or high dose of CBG for two weeks. Overall health of the mice, Hepatic steatosis, fibrosis, and inflammation were evaluated. Increased liver-to-body weight ratio was observed in mice fed with MCD diet, while a low dose of CBG treatment rescued the liver-to-body weight ratio. Hepatic ballooning and leukocyte infiltration were decreased in MCD mice with a low dose of CBG treatment, whereas the CBG treatment did not change the hepatic steatosis. The high dose CBG administration increased inflammation and fibrosis. Similarly, the expression of cannabinoid receptor (CB)1 and CB2 showed decreased expression with the low CBG dose but not with the high CBG dose intervention in the MCD group and were co-localized with mast cells. Additionally, the decreased mast cells were accompanied by decreased expression of transforming growth factor (TGF)-β1. Collectively, the low dose of CBG alleviated hepatic fibrosis and inflammation in MCD-induced NASH, however, the high dose of CBG treatment showed enhanced liver damage when compared to MCD only group. These results will provide pre-clinical data to guide future intervention studies in humans addressing the potential uses of CBG for inflammatory liver pathologies, as well as open the door for further investigation into systemic inflammatory pathologies.

Enzymatically-epoxidized docosahexaenoic acid, 19,20-EpDPE, suppresses hepatic crown-like structure formation and nonalcoholic steatohepatitis fibrosis through GPR120

A hepatic crown-like structure (hCLS) formed by macrophages accumulating around lipid droplets and dead cells in the liver is a unique feature of nonalcoholic steatohepatitis (NASH) that triggers progression of liver fibrosis. As hCLS plays a key role in the progression of NASH fibrosis, hCLS formation has emerged as a potential therapeutic target. n-3 polyunsaturated fatty acids (n-3 PUFAs) have potential suppressive effects on NASH fibrosis; however, the mechanisms underlying this effect are poorly understood. Here, we report that n-3 PUFA-enriched Fat-1 transgenic mice are resistant to hCLS formation and liver fibrosis in a NASH model induced by a combination of high-fat diet, CCl4 and a Liver X receptor (LXR) agonist. Liquid chromatography–tandem mass spectrometry-based mediator lipidomics revealed that the amount of endogenous n-3 PUFA-derived metabolites, such as 17,18-dihydroxyeicosatetraenoic acid (17,18-diHETE), and 19,20-epoxy docosapentaenoic acid (19,20-EpDPE), was significantly elevated in Fat-1 mice, along with hCLS formation. In particular, DHA-derived 19,20-EpDPE produced by Cyp4f18 attenuated the hCLS formation and liver fibrosis in a G protein-coupled receptor 120 (GPR120)-dependent manner. These results indicated that 19,20-EpDPE is an endogenous active metabolite that mediates the preventive effect of n-3 PUFAs against NASH fibrosis.

Fibro-Scope V1.0.1: an artificial intelligence/neural network system for staging of nonalcoholic steatohepatitis.

Fibro-Scope is an artificial intelligence/neural network system to determine the fibrosis stage in nonalcoholic steatohepatitis (NASH) using 12 parameters of the patient: age, sex, height, weight, waist circumference (WC), platelet count, and the levels of aspartate and alanine aminotransferase, gamma-glutamyltransferase, cholesterol, triglycerides, and type IV collagen 7S. However, measurement of WC is unstable and often missing from patient databases. Herein, we created Fibro-Scope V1.0.1 that has the same detection power as its predecessor, without the need to consider WC. To build a new AI diagnostic system available for the global needs, data from 764 patients with NASH and bridging fibrosis (STELLAR-3) or compensated cirrhosis (STELLAR-4) that participated in two phase III trials were added to the Japanese data. Finally, the data of a total of 898 patients in the training and of 300 patients in the validation studies were analyzed, respectively. The discrimination of F0-2 from F3,4 through Fibro-Scope V1.0.1 was characterized by a 99.8% sensitivity, a 99.6% specificity, a 99.8% positive predictive value, and a 99.6% negative predictive value in a training study with gray zone analysis; similar effectiveness was also revealed in the analysis without a gray zone. In the validation studies with and without gray zone analysis, high sensitivity and specificity were also identified. Fibro-Scope V1.0.1 exerted a diagnostic accuracy for F3,4 advanced fibrosis that was comparable to that of the original Fibro-Scope and delivered high (> 92%) sensitivity and specificity. Fibro-Scope V1.0.1 can accurately diagnose F3,4 fibrosis without the need of WC.

Pharmacological advances in the treatment of nonalcoholic fatty liver diseases : focused on global results of randomized controlled trials.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease globally, and its prevalence is rapidly increasing. Nonalcoholic steatohepatitis (NASH), a progressive form of NAFLD, is characterized by hepatocellular injury, inflammation, and fibrosis. Patients with NASH or severe fibrosis should be treated according to international NAFLD guidelines. Currently, regulatory agencies have not approved any pharmaceutical treatment for NAFLD. Vitamin E and pioglitazone are efficacious for NASH resolution; however, their benefits must be weighed against the reported risks. In a phase 2 trial, a glucagon-like peptide-1 agonist commonly used for diabetes and obesity was found to improve liver histology in patients with NASH. Furthermore, therapeutic agents targeting NASH pathogenesis, including bile acid signaling, insulin resistance, and lipid metabolism, are in various phases of clinical development. In this article, we review the benefits and drawbacks of current pharmacotherapy and the efficacy of upcoming treatments for NASH.

Selective disruption of NRF2-KEAP1 interaction leads to NASH resolution and reduction of liver fibrosis in mice

Oxidative stress is recognized as a major driver of non-alcoholic steatohepatitis (NASH) progression. The transcription factor NRF2 and its negative regulator KEAP1 are master regulators of redox, metabolic and protein homeostasis, as well as detoxification, and thus appear to be attractive targets for the treatment of NASH. Molecular modeling and X-ray crystallography were used to design S217879 - a small molecule that could disrupt the KEAP1-NRF2 interaction. S217879 was highly characterized using various molecular and cellular assays. It was then evaluated in two different NASH-relevant preclinical models, namely the methionine and choline-deficient diet (MCDD) and diet-induced obesity NASH (DIO NASH) models. Molecular and cell-based assays confirmed that S217879 is a highly potent and selective NRF2 activator with marked anti-inflammatory properties, as shown in primary human peripheral blood mononuclear cells. In MCDD mice, S217879 treatment for 2 weeks led to a dose-dependent reduction in NAFLD activity score while significantly increasing liver Nqo1 mRNA levels, a specific NRF2 target engagement biomarker. In DIO NASH mice, S217879 treatment resulted in a significant improvement of established liver injury, with a clear reduction in both NAS and liver fibrosis. αSMA and Col1A1 staining, as well as quantification of liver hydroxyproline levels, confirmed the reduction in liver fibrosis in response to S217879. RNA-sequencing analyses revealed major alterations in the liver transcriptome in response to S217879, with activation of NRF2-dependent gene transcription and marked inhibition of key signaling pathways that drive disease progression. These results highlight the potential of selective disruption of the NRF2-KEAP1 interaction for the treatment of NASH and liver fibrosis. We report the discovery of S217879 - a potent and selective NRF2 activator with good pharmacokinetic properties. By disrupting the KEAP1-NRF2 interaction, S217879 triggers the upregulation of the antioxidant response and the coordinated regulation of a wide spectrum of genes involved in NASH disease progression, leading ultimately to the reduction of both NASH and liver fibrosis progression in mice.

Increased CHCHD2 expression promotes liver fibrosis in nonalcoholic steatohepatitis via Notch/osteopontin signaling.

Nonalcoholic steatohepatitis (NASH) is closely related to liver fibrosis. The role of coiled-coil-helix-coiled-coil-helix domain-containing 2 (CHCHD2) in NASH remains unknown. CHCHD2's functions as a transcription factor have received much less attention than those in mitochondria. Herein, we systematically characterized the role of CHCHD2 as a transcription factor by chromatin immunoprecipitation sequencing and found its target genes were enriched in nonalcoholic fatty liver disease (NAFLD). Overall, CHCHD2 expression was found to be increased in the livers of patients with NAFLD and those of NASH mice. In line with these findings, CHCHD2 deficiency ameliorated NASH- and thioacetamide-induced liver fibrosis, whereas hepatocyte-specific CHCHD2 overexpression promoted liver fibrosis in NASH mice via Notch signaling. Specifically, CHCHD2-overexpressing hepatocytes activated hepatic stellate cells by upregulating osteopontin levels, a downstream mediator of Notch signals. Moreover, Notch inhibition attenuated CHCHD2 overexpression-induced liver fibrosis in vivo and in vitro. Then we found lipopolysaccharide-induced CHCHD2 expression in hepatocytes was reverted by verteporfin, an inhibitor that disrupts the interaction between Yes-associated protein (YAP) and transcriptional enhanced associate domains (TEADs). In addition, CHCHD2 levels were positively correlated with those of TEAD1 in human samples. In conclusion, CHCHD2 is upregulated via YAP/TAZ-TEAD in NASH livers and consequently promotes liver fibrosis by activating the Notch pathway and enhancing osteopontin production.

Artificial Intelligence for Detecting and Quantifying Fatty Liver in Ultrasound Images: A Systematic Review.

Non-alcoholic Fatty Liver Disease (NAFLD) is growing more prevalent worldwide. Although non-invasive diagnostic approaches such as conventional ultrasonography and clinical scoring systems have been proposed as alternatives to liver biopsy, their efficacy has been called into doubt. Artificial Intelligence (AI) is now combined with traditional diagnostic processes to improve the performance of non-invasive approaches. This study explores how well various AI methods function and perform on ultrasound (US) images to diagnose and quantify non-alcoholic fatty liver disease. A systematic review was conducted to achieve this objective. Five science bibliographic databases were searched, including PubMed, Association for Computing Machinery ACM Digital Library, Institute of Electrical and Electronics Engineers IEEE Xplore, Scopus, and Google Scholar. Only peer-reviewed English articles, conferences, theses, and book chapters were included. Data from studies were synthesized using narrative methodologies per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Forty-nine studies were included in the systematic review. According to the qualitative analysis, AI significantly enhanced the diagnosis of NAFLD, Non-Alcoholic Steatohepatitis (NASH), and liver fibrosis. In addition, modalities, image acquisition, feature extraction and selection, data management, and classifiers were assessed and compared in terms of performance measures (i.e., accuracy, sensitivity, and specificity). AI-supported systems show potential performance increases in detecting and quantifying steatosis, NASH, and liver fibrosis in NAFLD patients. Before real-world implementation, prospective studies with direct comparisons of AI-assisted modalities and conventional techniques are necessary.

Associations between subcutaneous adipocyte hypertrophy and nonalcoholic fatty liver disease

Adipocyte hypertrophy and expression of adipokines in subcutaneous adipose tissue (SAT) have been linked to steatosis, nonalcoholic steatohepatitis (NASH) and fibrosis in morbidly obese (BMI ≥ 40 kg/m2) subjects. It is unknown if this is also true for subjects with NAFLD with lesser degrees of obesity (BMI < 35 kg/m2). Thirty-two subjects with biopsy-proven NAFLD and 15 non-diabetic controls matched for BMI underwent fine-needle biopsies of SAT. Adipocyte volume was calculated. RNA-sequencing of SAT was performed in a subset of 20 NAFLD patients. Adipocyte volume and gene expression levels were correlated to the presence of NASH or significant fibrosis. Subjects with NAFLD had larger adipocyte volume compared with controls, (1939 pL, 95% CI 1130–1662 vs. 854 pL, 95% CI 781–926, p < 0.001). There was no association between adipocyte volume and the presence of NASH. Gene expression of adipokines previously described to correlate with NASH in morbid obesity, was not associated with NASH or fibrosis. Our results suggest that persons with NAFLD have larger SAT adipocytes compared with controls and that adipocytes are involved in the pathophysiology of hepatic steatosis in NAFLD. However, adipocyte volume was not associated with NASH or fibrosis in NAFLD subjects with varying degrees of obesity.

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in non-alcoholic steatohepatitis

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in non-alcoholic steatohepatitis

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in non-alcoholic steatohepatitis

An autocrine signaling circuit in hepatic stellate cells underlies advanced fibrosis in non-alcoholic steatohepatitis

Spatial molecular and cellular determinants of STAT3 activation in liver fibrosis progression in non-alcoholic fatty liver disease

The prevalence of non-alcoholic fatty liver disease (NAFLD) and its severe form, non-alcoholic steatohepatitis (NASH), is increasing. Individuals with NASH often develop liver fibrosis and advanced liver fibrosis is the main determinant of mortality in individuals with NASH. We and others have reported that STAT3 contributes to liver fibrosis and hepatocellular carcinoma in mice. Here, we explored whether STAT3 activation in hepatocyte and non-hepatocyte areas, measured by phospho-STAT3 (pSTAT3), is associated with liver fibrosis progression in 133 patients with NAFLD. We further characterized the molecular and cellular determinants of STAT3 activation by integrating spatial distribution and transcriptomic changes in fibrotic NAFLD livers.Results: pSTAT3 scores in non-hepatocyte areas progressively increased with fibrosis severity (r= 0.53, p <0.001). Correlation analyses between pSTAT3 scores and expression of 1,540 immune- and cancer-associated genes revealed a large effect of STAT3 activation on gene expression changes in non-hepatocyte areas and confirmed a major role for STAT3 activation in fibrogenesis. Digital spatial transcriptomic profiling was also performed on 13 regions selected in hepatocyte and non-hepatocyte areas from four NAFLD liver biopsies with advanced fibrosis, using a customized panel of markers including pSTAT3, PanCK+CK8/18, and CD45. The regions were further segmented based on positive or negative pSTAT3 staining. Cell deconvolution analysis revealed that activated STAT3 was enriched in hepatic progenitor cells (HPCs) and sinusoidal endothelial cells. Regression of liver fibrosis upon STAT3 inhibition in mice with NASH resulted in a reduction of HPCs, demonstrating a direct role for STAT3 in HPC expansion. Increased understanding of the spatial dependence of STAT3 signaling in NASH and liver fibrosis progression could lead to novel targeted treatment approaches. Advanced liver fibrosis is the main determinant of mortality in patients with NASH. This study showed using liver biopsies from 133 patients with NAFLD, that STAT3 activation in non-hepatocyte areas is strongly associated with fibrosis severity, inflammation, and progression to NASH. STAT3 activation was enriched in hepatic progenitor cells (HPCs) and sinusoidal endothelial cells (SECs), as determined by innovative technologies interrogating the spatial distribution of pSTAT3. Finally, STAT3 inhibition in mice resulted in reduced liver fibrosis and depletion of HPCs, suggesting that STAT3 activation in HPCs contributes to their expansion and fibrogenesis in NAFLD.

Single-cell phenotypes of peripheral blood immune cells in early and late stages of non-alcoholic fatty liver disease.

Immune and inflammatory cells respond to multiple pathological hits in the development of nonalcoholic steatohepatitis (NASH) and fibrosis. Relatively little is known about how their type and function change through the non-alcoholic fatty liver disease (NAFLD) spectrum. Here we used multi-dimensional mass cytometry and a tailored bioinformatic approach to study circulating immune cells sampled from healthy individuals and people with NAFLD. Cytometry by time of flight using 36 metal-conjugated antibodies was applied to peripheral blood mononuclear cells (PBMCs) from biopsy-proven NASH fibrosis (late disease), steatosis (early disease), and healthy patients. Supervised and unsupervised analyses were used, findings confirmed, and mechanisms assessed using independent healthy and disease PBMC samples. Of 36 PBMC clusters, 21 changed between controls and disease samples. Significant differences were observed between diseases stages with changes in T cells and myeloid cells throughout disease and B cell changes in late stages. Semi-supervised gating and re-clustering showed that disease stages were associated with fewer monocytes with active signalling and more inactive NK cells; B and T cells bearing activation markers were reduced in late stages, while B cells bearing co-stimulatory molecules were increased. Functionally, disease states were associated with fewer activated mucosal-associated invariant T cells and reduced toll-like receptor-mediated cytokine production in late disease. A range of innate and adaptive immune changes begin early in NAFLD, and disease stages are associated with a functionally less active phenotype compared to controls. Further study of the immune response in NAFLD spectrum may give insight into mechanisms of disease with potential clinical application.

Effects of apical sodium-bile acid transporter inhibitor and obeticholic acid co-treatment in experimental non-alcoholic steatohepatitis

Background and aimsSeveral bile acids-based monotherapies have been developed for non-alcoholic steatohepatitis (NASH) treatment but clinical trial findings suggest that they do not satisfactorily improve NASH and liver fibrosis in many patients. Recently, we have shown that combining a gut-restricted apical sodium-bile acid transporter (ASBT) inhibitor GSK2330672 (GSK) with adeno-associated virus (AAV)-mediated liver fibroblast growth factor 15 (FGF15) overexpression provides significantly improved efficacy than either single treatment against NASH and liver fibrosis in a high fat, cholesterol, and fructose (HFCFr) diet-induced NASH mouse model. The beneficial effects of the combined treatment can be attributed to the markedly reduced bile acid pool that reduces liver bile acid burden and intestinal lipid absorption. The aim of this study is to further investigate if combining GSK treatment with the orally bioavailable obeticholic acid (OCA), which induces endogenous FGF15 and inhibits hepatic bile acid synthesis, can achieve similar anti-NASH effect as the GSK + AAV-FGF15 co-treatment in HFCFr-diet-fed mice. Materials and methodsMale C57BL/6J mice were fed HFCFr diet to induce NASH and liver fibrosis. The effect of GSK, OCA, and GSK + OCA treatments on NASH development was compared and contrasted among all groups. ResultsFindings from this study showed that the GSK + OCA co-treatment did not cause persistent reduction of obesity over a 12-week treatment period. Neither single treatment nor the GSK + OCA co-treatment reduce hepatic steatosis, but all three treatments reduced hepatic inflammatory cytokines and fibrosis by a similar magnitude. The GSK + OCA co-treatment caused a higher degree of total bile acid pool reduction (∼55%) than either GSK or OCA treatment alone. However, such bile acid pool reduction was insufficient to cause increased fecal lipid loss. The GSK + OCA co-treatment prevented GSK-mediated induction of hepatic cholesterol 7alpha-hydroxylase but failed to induce ileal FGF15 expression. GSK did not reduce gallbladder OCA amount in the GSK + OCA group compared to the OCA group, suggesting that ASBT inhibition does not reduce hepatic OCA distribution. ConclusionsUnlike the GSK + AAV-FGF15 co-treatment, the GSK + OCA co-treatment does not provide improved efficacy against NASH and liver fibrosis than either single treatment in mice. The lack of synergistic effect may be partly attributed to the moderate reduction of total bile acid pool and the lack of high level of FGF15 exposure as seen in the GSK + AAV-FGF15 co-treatment.

Exosomal microRNAs and Progression of Nonalcoholic Steatohepatitis (NASH).

Nonalcoholic fatty liver disease (NAFLD)/metabolic associated fatty liver disease (MAFLD) is becoming a public health problem worldwide. Steatosis as the simple form and nonalcoholic steatohepatitis (NASH) as its progression form are commonly seen in liver biopsy specimens from patients with obesity, diabetes, hyperlipidemia, hypertension, and the use of certain drugs. Patients with NASH and advanced fibrosis were associated with increased risks of liver-related complications, including hepatocellular carcinoma (HCC). However, the mechanisms regarding the progression from simple steatosis to NASH fibrosis remain incompletely understood. Because NASH-caused liver injury is a complex process and multiple cell types are involved, intercellular communication is likely mediated by extracellular vesicles. Exosomes are a type of small extracellular vesicles and contain various cellular molecules, including proteins, messenger RNAs (mRNAs), and microRNAs (miRNAs). MiRNAs are short, non-coding RNA species that are important post-transcriptional regulators of gene expression and may play an important role in the pathogenesis of NALFD/NASH. In this article, we review the articles about NASH and exosomal miRNAs published in the most recent English literature through PubMed search and discuss the most recent criteria for histological diagnosis, pathogenesis from steatosis to NASH, roles of exosomal miRNAs in NASH pathogenesis and progression, as well as their potential in future clinical diagnosis and treatment for patients with NASH.

Does aerobic exercise reduce NASH and liver fibrosis in patients with non-alcoholic fatty liver disease? A systematic literature review and meta-analysis.

Exercise is an effective strategy for the prevention and regression of hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD), but it is unclear whether it can reduce advanced stages of NAFLD, i.e., steatohepatitis and liver fibrosis. Furthermore, it is not evident which modality of exercise is optimal to improve/attenuate NAFLD. The aim is to systematically review evidence for the effect of aerobic exercise (AE) on NAFLD, in particular non-alcoholic steatohepatitis (NASH) and liver fibrosis. A systematic literature search was conducted in Medline and Embase. Studies were screened and included according to predefined criteria, data were extracted, and the quality was assessed by Cochrane risk of bias tools by two researchers independently according to the protocol registered in the PROSPERO database (CRD42021270059). Meta-analyses were performed using a bivariate random-effects model when there were at least three randomized intervention studies (RCTs) with similar intervention modalities and outcome. The systematic review process resulted in an inclusion a total of 24 studies, 18 RCTs and six non-RCTs, encompassing 1014 patients with NAFLD diagnosed by histological or radiological findings. Studies were grouped based on the type of AE: moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT). A total of twelve meta-analyses were conducted. Compared to controls, MICT resulted in a mean difference (MD) in the NAFLD biomarkers alanine transaminase (ALT) and aspartate aminotransferase (AST) of -3.59 (CI: -5.60, -1.59, p<0.001) and -4.05 (CI: -6.39, -1.71, p<0.001), respectively. HIIT resulted in a MD of -4.31 (95% CI: -9.03, 0.41, p=0.07) and 1.02 (95% CI: -6.91, 8.94, p=0.8) for ALT and AST, respectively. Moreover, both AE types compared to controls showed a significantly lower magnetic resonance spectroscopy (MRS) determined liver fat with a MD of -5.19 (95% CI: -7.33, -3.04, p<0.001) and -3.41 (95% CI: -4.74, -2.08, p<0.001), for MICT and HIIT respectively. MICT compared to controls resulted in a significantly higher cardiorespiratory fitness (MD: 4.43, 95% CI: 0.31, 8.55, p=0.03). Liver fat is decreased by AE with a concomitant decrease of liver enzymes. AE improved cardiorespiratory fitness. Further studies are needed to elucidate the impact of different types of AE on hepatic inflammation andfibrosis. https://www.crd.york.ac.uk/prospero/, identifier (CRD42021270059).