Unlocking the therapeutic potential of RARRES-1: innovative treatment strategy for liver fibrosis through bioenergetics regulation

Abstract

Background & aims: Liver fibrosis is ultimate outcome of all untreated liver-related diseases that can progress to cirrhosis, cancer and liver failure. Our epigenome-wide-association study suggested increased methylation at the RARRES-1 locus in metabolic dysfunction associated fatty liver disease (MAFLD) patients with advanced fibrosis. Hypermethylation of RARRES-1 causes transcriptional silencing in various cancers. The functional status of RARRES-1 in liver fibrosis is unknown.

Methods: The changes of RARRES-1 expression in liver fibrosis were investigated. Expression of RARRES-1 was restored by genome editing and pharmacological activation. The impact of RARRES1 on hepatic stellate cells activation and fibrosis was investigated at mRNA and protein levels using RTqPCR and immunofluorescence for the expression of fibrotic markers. Structural changes in mitochondria and autophagosomes with RARRES-1 activation were visualized using electron microscopy.

Results: The mRNA expression of RARRES-1 by RTqPCR was found to be downregulated in human in-vitro culture model (p <0.01), multiple mouse fibrotic models (p <0.05, for all) and in two cohorts of patients with hepatitis C virus (HCV) (p <0.01) and MAFLD (p <0.0001). Genetic and pharmacological activation of RARRES-1 significantly reduced the mRNA expression of fibrotic markers, namely alpha SMA, COL1A1, CTGF & TGF-β (p <0.05, for all). Mechanistically I found that RARRES-1 reduces energy release during myofibroblast activation via regulating autophagy initiation, mitochondrial function and preserving lipid droplets.

Discussion & conclusion: The data presented in this thesis indicates that the silencing of RARRES-1 is involved in liver fibrosis. Activation of RARRES-1 has the potential to reverse liver fibrosis by regulating ROS generation, autophagy, and lipid preservation. In conclusion, my findings highlight that regulating RARRES-1 may offer therapeutic benefits for treating liver fibrosis.