From NAFLD to MAFLD: Aligning Translational In Vitro Research to Clinical Insights

Associations between intake of different types of vegetables and metabolic dysfunction-associated fatty liver disease: a population-based study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) presently poses a threat to approximately 24% of the global population. The consumption of healthy diets rich in an abundant assortment of vegetables has been scientifically validated to mitigate the progression of MAFLD. However, it remains uncertain whether all categories of vegetables confer benefits for MAFLD. The objective of this study is to investigate the impact of different types of vegetables on MAFLD, aiming to provide a scientific basis for developing more appropriate dietary recommendations for individuals at high risk of MAFLD.

METHODS

We investigated the associations between various types of vegetable consumption and the risk of MAFLD, utilizing data sourced from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 cycle. Employing multiple logistic regression and subgroup analyses, we estimated odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Our analysis encompassed a total of 3162 participants. Remarkably, heightened intake of dark green vegetables demonstrated an innovative association with reduced odds of MAFLD (OR = 0.54; 95% CI: 0.36-0.81; p-value = 0.01), while other kinds of vegetable shown no significant association with MAFLD in the full adjusted model (all p-vale > 0.05). In the subgroup analysis, a prominent inverse correlation between the consumption of dark green vegetables and MAFLD was discerned among female and non-Hispanic white people with higher educational attainment.

CONCLUSIONS

Our study conclusively demonstrates that a heightened intake of dark green vegetables is linked to diminished odds of MAFLD.

Cellular and molecular alterations in a human hepatocellular in vitro model of nonalcoholic fatty liver disease development and stratification

The rapidly increasing incidence of nonalcoholic fatty liver disease (NAFLD) is a growing health crisis worldwide. If not detected early, NAFLD progression can lead to irreversible pathological states, including liver fibrosis and cirrhosis. Using in vitro models to understand the molecular pathogenesis has been extremely beneficial; however, most studies have utilized only short-term exposures, highlighting a limitation in current research to model extended fat-induced liver injury. We treated Hep3B cells continuously with a low dose of oleic and palmitic free fatty acids (FFAs) for 7 or 28 days. Transcriptomic analysis identified dysregulated molecular pathways and differential expression of 984 and 917 genes after FFA treatment for 7 and 28 days respectively. DNA methylation analysis of altered DNA methylated regions (DMRs) found 7 DMRs in common. Pathway analysis of differentially expressed genes (DEGs) revealed transcriptomic changes primarily involved in lipid metabolism, small molecule biochemistry, and molecular transport. Western blot analysis revealed changes in PDK4 and CPT1A protein levels, indicative of mitochondrial stress. In line with this, there was mitochondrial morphological change demonstrating breakdown of the mitochondrial network. This in vitro model of human NAFL mimics results observed in human patients and may be used as a pre-clinical model for drug intervention.

Polymorphisms Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease Influence the Progression of End-Stage Liver Disease

BACKGROUND AND AIMS

Chronic liver injury that results in cirrhosis and end-stage liver disease (ESLD) causes more than 1 million deaths annually worldwide. Although the impact of genetic factors on the severity of metabolic dysfunction-associated steatotic liver disease (MASLD) and alcohol-related liver disease (ALD) has been previously studied, their contribution to the development of ESLD remains largely unexplored.

METHODS

We genotyped 6 MASLD-associated polymorphisms in healthy (n = 123), metabolic dysfunction-associated steatohepatitis (MASH) (n = 145), MASLD-associated ESLD (n = 72), and ALD-associated ESLD (n = 57) cohorts and performed multinomial logistic regression to determine the combined contribution of genetic, demographic, and clinical factors to the progression of ESLD.

RESULTS

Distinct sets of factors are associated with the progression to ESLD. The PNPLA3 rs738409:G and TM6SF2 rs58542926:T alleles, body mass index (BMI), age, and female sex were positively associated with progression from a healthy state to MASH. The PNPLA3 rs738409:G allele, age, male sex, and having type 2 diabetes mellitus were positively associated, while BMI was negatively associated with progression from MASH to MASLD-associated ESLD. The PNPLA3 rs738409:G and GCKR rs780094:T alleles, age, and male sex were positively associated, while BMI was negatively associated with progression from a healthy state to ALD-associated ESLD. The findings indicate that the PNPLA3 rs738409:G allele increases susceptibility to ESLD regardless of etiology, the TM6SF2 rs58542926:T allele increases susceptibility to MASH, and the GCKR rs780094:T allele increases susceptibility to ALD-associated ESLD.

CONCLUSION

The PNPLA3, TM6SF2, and GCKR minor alleles influence the progression of MASLD-associated or ALD-associated ESLD. Genotyping for these variants in MASLD and ALD patients can enhance risk assessment, prompting early interventions to prevent ESLD.

Problems and Challenges Associated with Renaming Non-alcoholic Fatty Liver Disease to Metabolic Associated Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has become the world’s largest chronic liver disease in the 21st century, affecting 20%–30% of the world’s population. As the epidemiology, etiology, and pathogenesis of NAFLD have been studied in-depth, it has been gradually recognized that most patients with NAFLD have one or more combined metabolic abnormalities known as metabolic syndrome. In 2020, the international expert group changed the name of NAFLD to metabolic-associated fatty liver disease (MAFLD) and proposed new diagnostic criteria for MAFLD and MAFLD-related liver cirrhosis, as well as the conceptual framework of other cause-related fatty liver diseases to avoid diagnosis based on the exclusion of other causes and better reflect its pathogenesis. However, there are still many ambiguities in the term, and changing the name does not address the unmet key needs in the field. The change from NAFLD to MAFLD was not just a change of definition. The problems and challenges are summarized as follows: epidemiology, children, rationality of “metabolism,” diagnostic criteria, double/multiple causes, drug discovery, clinical trials, and awareness raising. Metabolic-associated fatty liver disease has complex disease characteristics, and there are still some problems that need to be solved.