Background & aims: Current therapies for the treatment of alcohol-related liver disease (ALD) have proven largely ineffective. Patients relapse and the disease progresses even after liver transplantation. Altered epigenetic mechanisms are characteristic of alcohol metabolism given excessive acetate and NAD depletion and play an important role in liver injury. In this regard, novel therapeutic approaches based on epigenetic modulators are increasingly proposed. MicroRNAs, epigenetic modulators acting at the post-transcriptional level, appear to be promising new targets for the treatment of ALD.
Methods: MiR-873-5p levels were measured in 23 liver tissue from Patients with ALD, and GNMT levels during ALD were confirmed using expression databases (transcriptome n = 62, proteome n = 68). High-resolution proteomics and metabolomics in mice following the Gao-binge model were used to investigate miR-873-5p expression in ALD. Hepatocytes exposed to 50 mM alcohol for 12 h were used to study toxicity. The effect of anti-miR-873-5p in the treatment outcomes of ALD was investigated.
Results: The analysis of human and preclinical ALD samples revealed increased expression of miR-873-5p in the liver. Interestingly, there was an inverse correlation with NNMT, suggesting a novel mechanism for NAD depletion and aberrant acetylation during ALD progression. High-resolution proteomics and metabolomics identified miR-873-5p as a key regulator of NAD metabolism and SIRT1 deacetylase activity. Anti-miR-873-5p reduced NNMT activity, fuelled the NAD salvage pathway, restored the acetylome, and modulated the levels of NF-κB and FXR, two known SIRT1 substrates, thereby protecting the liver from apoptotic and inflammatory processes, and improving bile acid homeostasis.
Conclusions: These data indicate that targeting miR-873-5p, a repressor of GNMT previously associated with NAFLD and acetaminophen-induced liver failure. is a novel and attractive approach to treating alcohol-induced hepatoxicity.
Impact and implications: The role of miR-873-5p has not been explicitly examined in the progression of ALD, a pathology with no therapeutic options. In this study, inhibiting miR-873-5p exerted hepatoprotective effects against ALD through rescued SIRT1 activity and consequently restored bile acid homeostasis and attenuated the inflammatory response. Targeting hepatic miR-873-5p may represent a novel therapeutic approach for the treatment of ALD.
Keywords: Alcohol-related liver disease; NIAAA model; Nicotinamide adenine dinucleotide salvage pathway; SIRT1; microRNA.
© 2023 The Author(s).