25-Hydroxycholesterol 3-sulfate is an endogenous ligand of DNA methyltransferases in hepatocytes

Abstract

The oxysterol sulfate, 25-hydroxycholesterol 3-sulfate (25HC3S), has been shown to play an important role in lipid metabolism, inflammatory response, and cell survival. However, the mechanism(s) of its function in global regulation is unknown. The current study investigates the molecular mechanism by which 25HC3S functions as an endogenous epigenetic regulator. To study the effects of oxysterols/sterol sulfates on epigenetic modulators, 12 recombinant epigenetic enzymes were used to determine whether 25HC3S acts as their endogenous ligand. The enzyme kinetic study demonstrated that 25HC3S specifically inhibited DNA methyltransferases (DNMTs), DNMT1, DNMT3a, and DNMT3b with IC 50 of 4.04, 3.03, and 9.05 × 10 −6 M, respectively. In human hepatocytes, high glucose induces lipid accumulation by increasing promoter CpG methylation of key genes involved in development of nonalcoholic fatty liver diseases. Using this model, whole genome bisulfate sequencing analysis demonstrated that 25HC3S converts the 5m CpG to CpG in the promoter regions of 1,074 genes. In addition, we observed increased expression of the demethylated genes, which are involved in the master signaling pathways, including MAPK-ERK, calcium-AMP-activated protein kinase, and type II diabetes mellitus pathways. mRNA array analysis showed that the upregulated genes encoded for key elements of cell survival; conversely, downregulated genes encoded for key enzymes that decrease lipid biosynthesis. Taken together, our results indicate that the expression of these key elements and enzymes are regulated by the demethylated signaling pathways. We summarized that 25HC3S DNA demethylation of 5m CpG in promoter regions is a potent regulatory mechanism.

Research methodologies to address clinical unmet needs and challenges in alcohol‐associated liver disease

“…DUR‐928 is an epigenetic regulator with a net effect of reducing the inflammation and improving regeneration. [ 52 ] In a pilot clinical trial, this drug improved response rate (as measured by Lille score) in patients with AH as compared with historical steroid treated controls. [ 53 ] Larger trials of this agent are ongoing.…”

25-Hydroxycholesterol 3-Sulfate Recovers Acetaminophen Induced Acute Liver Injury via Stabilizing Mitochondria in Mouse Models

“…A recent publication demonstrates a detailed molecular mechanism by which 25HC3S functions as an endogenous epigenetic regulator [ 30 ]. The enzyme kinetic study demonstrated that 25HC3S specifically inhibited DNA methyltransferases, DNMT1, DNMT3a, and DNMT3b with IC 50 at uM levels.…”

“…Subsequently, 25HC3S increased expression of the demethylated genes, which are involved in the master signaling pathways, including MAPK-ERK, calcium-AMPK, and type II diabetes mellitus pathways. Messenger RNA array analysis showed that the upregulated genes encoded for key elements of cell survival [ 30 ]. The present study shows that 25HC3S protected organ function and reduced mortality via retaining mitochondrial polarization.…”

“…As reported previously, administration of 25HC3S significantly alleviated injury in multiple organs and reduced mortality in the lipopolysaccharide (LPS)-induced endotoxin shock mouse model [ 29 ]. Recent studies have shown that 25HC and 25HC3S served as paired epigenetic regulators, playing an important role in global gene regulation by methylating and demethylating 5m CpG in key promoter regions involved in many cellular signaling pathways [ 30 ]. Regulation of gene expression via demethylation of 5m CpG in promoter regions may be the primary mechanism by which 25HC3S decreases lipid accumulation, reduces inflammation, and increases cell survival.…”

Multiple Targets for Oxysterols in Their Regulation of the Immune System

“…In addition, 25-HC can be sulfated at its 3-position by sulfotransferase 2B1b to generate 25-HC3S, which can be further sulfated by sulfotransferase 2A1 [29]. In contrast to 25-HC, 25-HC3S is a potent antagonist of DMNT-1, -3a and -3b, and opposes its actions on target genes [27,30,31]. In a lipopolysaccharide-induced model of acute lung injury, 25-OHC concentrations are elevated, potentially promoting inflammation and the recruitment of leukocytes [32].…”