A genetic hypothesis for burnt-out steatohepatitis

Impact of clonal hematopoiesis of indeterminate potential on hepatocellular carcinoma in individuals with steatotic liver disease

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global epidemic and is the most rapidly rising cause of HCC. Clonal hematopoiesis of indeterminate potential (CHIP) contributes to neoplastic and cardiometabolic disorders and is considered a harbinger of tissue inflammation. CHIP was recently associated with increased risk of liver disease. The aim of this study was to examine whether CHIP is associated with HCC development in patients with SLD.

APPROACH AND RESULTS

We considered individuals with MASLD-HCC (n=208) and controls with (n =414) and without (n =259) advanced fibrosis who underwent whole exome sequencing. CHIP was diagnosed when ≥2 variant callers identified a known myeloid mutation with variant allele frequency ≥2%. CHIP was observed in 116 participants (13.1%), most frequently in DNMT3A, TET2, TP53 , and ASXL1 , and correlated with age ( p <0.0001) and advanced liver fibrosis (p=0.001). Higher aspartate aminotransferase levels predicted non- DNMT3A -CHIP, in particular with variant allele frequency ≥10% (OR: 1.14, 1.03 -1.28 and OR: 1.30, 1.12 -1.49, respectively, p <0.05). After adjustment for sex, diabetes, and a polygenic risk, a score of inherited MASLD predisposition CHIP was associated with cirrhosis (2.00, 1.30 -3.15, p =0.02), and with HCC even after further adjustment for cirrhosis (OR: 1.81, 1.11 -2.00, 1.30 -3.15, p =0.002). Despite the strong collinearity among aging and development of CHIP and HCC, non- DNTM3A -CHIP, and TET2 lesions remained associated with HCC after full correction for clinical/genetics covariates and age (OR: 2.45, 1.35 -4.53; OR: 4.8, 1.60 -17.0, p =0.02).

CONCLUSIONS

We observed an independent association between CHIP, particularly related to non- DNTM3A and TET2 genetic lesions and MASLD-HCC.

The contribution of genetics and epigenetics to MAFLD susceptibility

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common liver disease worldwide. The risk of developing MAFLD varies among individuals, due to a combination of environmental inherited and acquired genetic factors. Genome-wide association and next-generation sequencing studies are leading to the discovery of the common and rare genetic determinants of MAFLD. Thanks to the great advances in genomic technologies and bioinformatics analysis, genetic and epigenetic factors involved in the disease can be used to develop genetic risk scores specific for liver-related complications, which can improve risk stratification. Genetic and epigenetic factors lead to the identification of specific sub-phenotypes of MAFLD, and predict the individual response to a pharmacological therapy. Moreover, the variant transcripts and protein themselves represent new therapeutic targets. This review will discuss the current status of research into genetic as well as epigenetic modifiers of MAFLD development and progression.

Editorial: Paradox of liver fat content in the spectrum of non-alcoholic fatty liver disease

This article is linked to Loomba et al paper. To view this article, visit https://doi.org/10.1111/apt.17783

Low liver fat in non-alcoholic steatohepatitis-related significant fibrosis and cirrhosis is associated with hepatocellular carcinoma, decompensation and mortality

BACKGROUND

Progression to cirrhosis in non-alcoholic steatohepatitis (NASH) is associated with a decrease in liver fat. However, the prognostic significance of liver fat content in NASH-related significant fibrosis and cirrhosis is unclear.

AIM

To investigate the risk of decompensation, hepatocellular carcinoma (HCC) and mortality stratified by liver fat content in NASH-related significant fibrosis and cirrhosis.

METHODS

In this meta-analysis of individual participant data, 456 patients with both magnetic resonance elastography (MRE) and MRI-derived protein density fat fraction (MRI-PDFF) were enrolled, and 296 patients with longitudinal follow-up were analysed. MRE combined with fibrosis-4 (MEFIB-index), and MRI-PDFF were used to measure liver fibrosis and fat, respectively. MEFIB-negative, MEFIB-positive+ MRI-PDFF ≥5% and MEFIB-positive+ MRI-PDFF <5% were defined as no significant liver fibrosis, NASH with significant fibrosis and higher liver fat content, and NASH with significant fibrosis and low liver fat content groups, respectively. The primary outcome was hepatic decompensation, HCC and death.

RESULTS

The rates of decompensation, HCC and mortality were highest in the NASH with significant fibrosis and low liver fat group (33%, 17% and 17%, respectively), followed by the NASH with significant fibrosis and higher liver fat group (18%, 13% and 13% respectively), and lowest in the no significant fibrosis (MEFIB-negative) group (0%, 1% and 2% respectively). In multivariable-adjusted analysis, low liver fat content was strongly associated (HR = 42.2 [95% CI: 7.5-235.5, p < 0.0001]) with HCC, decompensation and death. Sensitivity analyses for patients with cirrhosis (MRE ≥5 kPa) determined consistent findings.

CONCLUSIONS

Low liver fat content in patients with burnt-out NASH-related significant fibrosis and cirrhosis is associated with an increase in hepatic decompensation, HCC and mortality.

Synthesized HMGB1 peptide prevents the progression of inflammation, steatosis, fibrosis, and tumor occurrence in a non-alcoholic steatohepatitis mouse model

AIM

Non-alcoholic steatohepatitis (NASH) with fibrosis eventually leads to cirrhosis and hepatocellular carcinoma. Thus, the development of therapies other than dietary restriction and exercise, particularly those that suppress steatosis and fibrosis of the liver and have a long-term beneficial effect, is necessary. We aimed to evaluate the therapeutic effects of the HMGB1 peptide synthesized from box A using the melanocortin-4 receptor-deficient (Mc4r-KO) NASH model mouse.

METHODS

We performed short- and long-term administration of this peptide and evaluated the effects on steatosis, fibrosis, and carcinogenesis using Mc4r-KO mice. We also analyzed the direct effect of this peptide on macrophages and hepatic stellate cells in vitro and performed lipidomics and metabolomics techniques to evaluate the effect.

RESULTS

Although this peptide did not show direct effects on macrophages and hepatic stellate cells in vitro, in the short-term administration model, we could confirm the reduction of liver damage, steatosis, and fibrosis progression. The results of lipidomics and metabolomics suggested that the peptide might ameliorate NASH by promoting lipolysis via the activation of fatty acid β-oxidation and improving insulin resistance. In the long-term administration model, this peptide prevented progression to cirrhosis but retained the steatosis state, that is, the peptide prevents the progression to "burnt-out NASH." This peptide inhibited carcinogenesis by about one-third.

CONCLUSION

This HMGB1 peptide can reduce liver damage, improve fibrosis and steatosis, and inhibit carcinogenesis, suggesting that the peptide would be a new treatment candidate for NASH and can contribute to the long-term prognosis for patients with NASH.

Tumorigenesis from non-alcoholic steatohepatitis to hepatocellular carcinoma

Non-alcoholic steatohepatitis (NASH) with metabolic syndrome is increasing to be a main cause of hepatocellular carcinoma (HCC). However, the mechanism of tumorigenesis in NASH induced HCC is still not clear. In this perspective, we will discuss the recent progress that has been made to understand the genetic change and the immune microenvironment of HCC, and the remaining questions. Based on the current study, NASH-HCC is likely to have novel mechanism, which needs more investigation in future.

Nonalcoholic Steatohepatitis (NASH) and Atherosclerosis: Explaining Their Pathophysiology, Association and the Role of Incretin-Based Drugs

Nonalcoholic steatohepatitis (NASH) is the most severe manifestation of nonalcoholic fatty liver disease (NAFLD), a common complication of type 2 diabetes, and may lead to cirrhosis and hepatocellular carcinoma. Oxidative stress and liver cell damage are the major triggers of the severe hepatic inflammation that characterizes NASH, which is highly correlated with atherosclerosis and coronary artery disease. Regarding drug therapy, research on the role of GLP-1 analogues and DPP4 inhibitors, novel classes of antidiabetic drugs, is growing. In this review, we outline the association between NASH and atherosclerosis, the underlying molecular mechanisms, and the effects of incretin-based drugs, especially GLP-1 RAs, for the therapeutic management of these conditions.