Interplay between metabolic dysfunction-associated fatty liver disease and renal function: An intriguing pediatric perspective

Over recent years, the nomenclature of non-alcoholic fatty liver disease has undergone significant changes. Indeed, in 2020, an expert consensus panel proposed the term "Metabolic (dysfunction) associated fatty liver disease" (MAFLD) to underscore the close association of fatty liver with metabolic abnormalities, thereby highlighting the cardiometabolic risks (such as metabolic syndrome, type 2 diabetes, insulin resistance, and cardiovascular disease) faced by these patients since childhood. More recently, this term has been further replaced with metabolic associated steatotic liver disease. It is worth noting that emerging evidence not only supports a close and independent association of MAFLD with chronic kidney disease in adults but also indicates its interplay with metabolic impairments. However, comparable pediatric data remain limited. Given the progressive and chronic nature of both diseases and their prognostic cardiometabolic implications, this editorial aims to provide a pediatric perspective on the intriguing relationship between MAFLD and renal function in childhood.

CX3CL1 represses autophagy via CX3CR1/ CaMKIIδ/HDAC4/Rubicon axis and exacerbates chronic intermittent hypoxia induced Kupffer cell apoptosis

BACKGROUND

Nocturnal hypoxemia is an established factor in the pathogenesis and exacerbation of term metabolic (dysfunction) associated fatty liver disease (MAFLD). Kupffer cells (KCs) are resident macrophages in the liver, and their activity is closely related to the progress of MAFLD. KC insufficient autophagy is involved in MAFLD pathogenesis. Herein, the regulatory mechanism of KC autophagy under chronic intermittent hypoxia (CIH) condition was investigated.

METHODS

Primary KCs and hepatic stellate cells (HSCs) were isolated from mouse liver. Immunofluorescence was employed to detect immunofluorescence intensity of LC3 protein and HDAC4 distribution. KC apoptosis was measured by TUNEL staining. Dual-luciferase reporter and ChIP assays were performed to analyze the interactions between HDAC4, MEF2C and RUBCN.

RESULTS

Herein, our results revealed that CIH-induced increased CX3CL1 in HSCs inhibited KC autophagy and promoted cell apoptosis by interacting with CX3CR1. Meanwhile, CX3CL1 treatment inhibited KC autophagy (p < 0.001, fold change: 0.059) and promoted cell apoptosis (p < 0.001, fold change: 8.18). Rubicon knockdown promoted KC autophagy (p < 0.001, fold change: 2.90) and inhibited cell apoptosis (p < 0.05, fold change: 0.23), while these effects were reversed by CX3CL1 treatment (p < 0.01, fold change: 6.59; p < 0.001, fold change: 0.35). Our mechanistic experiments demonstrated that HDAC4 overexpression transcriptionally inhibited RUBCN expression by interacting with MEF2C, thereby promoting KC autophagy and inhibiting cell apoptosis. Moreover, CaMKIIδ inhibition promoted the translocation of HDAC4 from the cytosol to the nucleus to promote KC autophagy and inhibit the apoptosis.

CONCLUSION

Taken together, CIH-induced increased CX3CL1 expression in HSCs inhibited KC autophagy and promoted apoptosis by regulating the CX3CR1/ CaMKIIδ/HDAC4/Rubicon axis.

Prevalence of metabolic associated fatty liver disease (MAFLD) in patients with gallstone disease. Study on a cohort of cases in South-Southeastern Mexico

INTRODUCTION

Metabolic (dysfunction) associated fatty liver disease (MAFLD) and gallstone disease are entities that share similar risk factors. Numerous publications confirm their elevated frequency, but few studies have considered their prevalence and possible association.

AIMS

To determine the prevalence of MAFLD in patients with gallstone disease and the usefulness of liver biopsy for diagnosing the liver disease.

MATERIALS AND METHODS

A prospective study was conducted on patients that underwent laparoscopic cholecystectomy, in whom liver biopsy was performed.

VARIABLES ANALYZED

Anthropometric characteristics, biochemical profile, conventional ultrasound, risk factors, and histopathologic study of the liver biopsy.

STATISTICAL ANALYSIS

Descriptive statistics were carried out for the quantitative variables and the Student's t test and multivariate analysis through binary logistic regression were employed for the continuous variables, utilizing IBM-SPSS, 25.0 (Windows) software.

RESULTS

A total of 136 patients were classified into 2 groups: 40 (29.41%) with normal liver and 96 (70.59%) with MAFLD. Of the 136 patients, 71 patients (52.21%) corresponded to hepatic steatosis, 21 (15.44%) to steatohepatitis, and 4 (2.94%) to cirrhosis. Perisinusoidal inflammation was found in 39 cases (28.68%) and fibrosis was found in 10 (7.35%). The risk factors for both groups were age, diabetes, high blood pressure, and obesity. Glucose, triglyceride, and aminotransferase levels were significantly higher in the MAFLD group and conventional ultrasound demonstrated moderate concordance for its detection.

DISCUSSION AND CONCLUSIONS

The results confirmed the elevated frequency of MAFLD associated with gallstone disease, justifying liver biopsy during cholecystectomy for diagnosing MAFLD.

Discriminatory Changes in Circulating Metabolites as a Predictor of Hepatocellular Cancer in Patients with Metabolic (Dysfunction) Associated Fatty Liver Disease

Introduction

The burden of metabolic (dysfunction) associated fatty liver disease (MAFLD) is rising mirrored by an increase in hepatocellular cancer (HCC). MAFLD and its sequelae are characterized by perturbations in lipid handling, inflammation, and mitochondrial damage. The profile of circulating lipid and small molecule metabolites with the development of HCC is poorly characterized in MAFLD and could be used in future studies as a biomarker for HCC.

Methods

We assessed the profile of 273 lipid and small molecule metabolites by ultra-performance liquid chromatography coupled to high-resolution mass spectrometry in serum from patients with MAFLD (n = 113) and MAFLD-associated HCC (n = 144) from six different centers. Regression models were used to identify a predictive model of HCC.

Results

Twenty lipid species and one metabolite, reflecting changes in mitochondrial function and sphingolipid metabolism, were associated with the presence of cancer on a background of MAFLD with high accuracy (AUC 0.789, 95% CI: 0.721-0.858), which was enhanced with the addition of cirrhosis to the model (AUC 0.855, 95% CI: 0.793-0.917). In particular, the presence of these metabolites was associated with cirrhosis in the MAFLD subgroup (p < 0.001). When considering the HCC cohort alone, the metabolic signature was an independent predictor of overall survival (HR 1.42, 95% CI: 1.09-1.83, p < 0.01).

Conclusion

These exploratory findings reveal a metabolic signature in serum which is capable of accurately detecting the presence of HCC on a background of MAFLD. This unique serum signature will be taken forward for further investigation of diagnostic performance as biomarker of early stage HCC in patients with MAFLD in the future.