Alcohol-associated liver disease (ALD)

ALD progression is often associated with other comorbidities

Epidemiological studies have shown a strong causal relationship between alcohol use and metabolic dysfunction–associated steatotic liver disease (MASLD) or metabolic dysfunction–associated steatohepatitis (MASH)

a study in the Japanese population reported that

high alcohol consumption (>40 g/d) in the obese population leads to an almost 2–12 times higher risk of hepatocarcinogenesis than in the nonobese subjects

The coexistence of MASLD and ALD has recently been acknowledged in a separate category of steatotic liver disease known as MetALD

we aimed to develop a preclinical model for studying MetALD which recapitulates key features of human AH

Previous reports have shown that high fat-cholesterol-sugar diet–fed mice develop the metabolic syndrome and MASH by 27 weeks

progress to fibrosis and early HCC by 48 weeks

closely mimicking the progression of human MASLD and MASH

In this study, we used the high fat-cholesterol-sugar diet, (MASH diet), in combination with alcohol administration for 3 months

increase in epithelial-to-mesenchymal transition (EMT) markers

Chronic alcohol plus alcohol binges accelerate liver injury in MASH diet–fed mice

mice received a MASH diet for 3 months with or without chronic alcohol

Survival was >85% in MetALD mice that received alcohol plus MASH diet and 100% in chow, alcohol, and MASH-alone groups

MASH diet–fed mice showed a significant increase in their body weight, as compared to chow-fed mice

Alcohol consumption in MetALD mice and alcohol-alone–fed mice was comparable

blood alcohol levels in MetALD mice were significantly higher compared to alcohol-fed mice

measure cytochrome P450 2E1 (CYP2E1) and alcohol dehydrogenase (ADH1a)

significant increase in alanine aminotransferase in MetALD mice as compared to alcohol or MASH alone

significant increase in serum bilirubin levels in MetALD mice

MetALD mice exhibit increased liver steatosis

significant increase in triglyceride levels in mice fed on the MASH diet

significant increase in the level of circulating free fatty acids and total cholesterol in MetALD mice as compared to MASH diet mice

Oil-Red-O staining, which showed an increase in the MetALD mice

MetALD mice displayed a modest increase in fasting glucose as compared to chow mice

Alcohol and MASH synergistically promote inflammation and macrophage activation in the MetALD mice model

Monocyte chemoattractant protein-1 (MCP-1)

evaluated the number of activated hepatic macrophages by CD68 immunohistochemistry

Cd163 which was significantly higher in MetALD mice as compared to MASH or alcohol-alone controls

Alcohol promotes liver neutrophil infiltration in MASH diet–fed mice

significant increase in the hepatic expression of neutrophil chemokines such as Cxcl1 and Cxcl2 in MetALD mice

granulocyte chemotactic protein 2 (GCP-2/Cxcl5) was significantly increased in MetALD

mRNA expression of C-X-C Motif Chemokine Receptor 1 (Cxcr1) significantly increased

significant increase in the expression of neutrophil markers, CD11b (Itgam) mRNA

MetALD mice exhibit accelerated fibrosis and an increase in EMT

Severe AH is characterized by fibrosis which also increases the risk of progression to HCC.

procollagen1α (Col1a1), TGF-β (Tgfb), and tissue inhibitor of matrix metalloproteinases-1 (Timp1)

epithelial markers including occludin (Ocln) and claudin (Cldn1) were similarly downregulated in alcohol, MASH, and MetALD mice

mesenchymal markers such as Vimentin (Vim), Col1a1, and Tgfb were significantly increased in MetALD as compared to MASH or alcohol-alone mice

MetALD mice show hepatocyte proliferation, ductular reaction, and dysregulated hedgehog signaling

increase in TUNEL + cells in the liver of MetALD mice as compared to any other group

investigated hepatocyte proliferation

level of Ki67, a marker of proliferating cells, was significantly increased in MetALD mice as compared to all other groups both at the mRNA and protein levels

Liver synthetic function is impaired in MetALD mice

Hedgehog (Hh) signaling is upregulated in patients with MASH and it positively correlates with the severity of liver disease

vWF levels were measured from serum by ELISA