Epigenetic DNA Methylation of EBI3 Modulates Human Interleukin-35 Formation via NFkB Signaling: A Promising Therapeutic Option in Ulcerative Colitis

Abstract

Ulcerative colitis (UC), a severe chronic disease with unclear etiology that is associated with increased risk for colorectal cancer, is accompanied by dysregulation of cytokines. Epstein–Barr virus-induced gene 3 (EBI3) encodes a subunit in the unique heterodimeric IL-12 cytokine family of either pro- or anti-inflammatory function. After having recently demonstrated that upregulation of EBI3 by histone acetylation alleviates disease symptoms in a dextran sulfate sodium (DSS)-treated mouse model of chronic colitis, we now aimed to examine a possible further epigenetic regulation of EBI3 by DNA methylation under inflammatory conditions. Treatment with the DNA methyltransferase inhibitor (DNMTi) decitabine (DAC) and TNFα led to synergistic upregulation of EBI3 in human colon epithelial cells (HCEC). Use of different signaling pathway inhibitors indicated NFκB signaling was necessary and proportional to the synergistic EBI3 induction. MALDI-TOF/MS and HPLC-ESI-MS/MS analysis of DAC/TNFα-treated HCEC identified IL-12p35 as the most probable binding partner to form a functional protein. EBI3/IL-12p35 heterodimers (IL-35) induce their own gene upregulation, something that was indeed observed in HCEC cultured with media from previously DAC/TNFα-treated HCEC. These results suggest that under inflammatory and demethylating conditions the upregulation of EBI3 results in the formation of anti-inflammatory IL-35, which might be considered as a therapeutic target in colitis.

Adaptive plasticity of natural interleukin-35-induced regulatory T cells (Tr35) that are required for T-cell immune regulation

“…Epigenetic modifiers also contribute to the regulation of IL-35 expression. For instance, DNA methylation and histone acetylation both can modulate IL-35 expression in immune cells 37 , 38 . These findings highlight the importance of epigenetic regulation in controlling IL-35 expression and immune responses.…”

DNMT3a-Mediated Enterocyte Barrier Dysfunction Contributes to Ulcerative Colitis via Facilitating the Interaction of Enterocytes and B Cells

“…DNA methylation is an important and conserved epigenetic marker associated with genomic stability, inactive tran-scription, and environmental responses [46,47]. A number of studies have shown that DNA methylation exert predictive and targeted therapeutic effects in a variety of diseases, including UC [48][49][50]. A sequencing analysis of peripheral blood mononuclear cell DNA from ulcerative colitis patients suggested that DNMT3a was involved in the regulation of UC [51], which has not been identified in UC patients or models.…”

Interleukin-35: A key player in chronic inflammatory Type 1 and autoimmune diabetes

“…Both the genes IL-12A and EBI3 are network with various disease as represented in gure 1. The data in the PubMed database indicated a direct correlation between IL-35 and EBI3 genes in many immunein ammatory, autoimmune, cancer, and endocrine diseases [7]. Further from the PubMed database, we selected 10 protein/enzyme markers that have been clinically identi ed in relation to IL12A and EBI3.…”

“…Thereby, IL-35 plays a critical regulatory role in T1D by decreasing the in ltration of mononuclear cells in the islets [11][12]. Clinical research has provided additional insights, indicating that C-peptide-negative patients exhibit markedly lower serum levels of IL-35 [7][8][9][10]. This decrease is associated with a simultaneous reduction in the proportion of IL-35+ Treg cells, IL-35+ regulatory B cells, and IL-35-producing CD8+ FOXP3+ cells [12][13][14].…”