Infection-induced signals generated at the plasma membrane epigenetically regulate Wnt signaling in vitro and in vivo.
Wnt signaling regulates immunomodulatory functions during infection and inflammation. Employing NCCIT and HCT116 cells, having high endogenous Wnt signaling, we observed elevated levels of low-density lipoprotein receptor-related protein 5/6 (LRP5/6) and Frizzled class receptor 10 (FZD10) and increases in β-catenin, doublecortin-like kinase 1 (DCLK1), CD44 molecule (CD44), and aldehyde dehydrogenase 1 family member A1 (ALDH1A1). siRNA-induced knockdown of these receptors antagonized TOPflash reporter activity and spheroid growth in vitro and elevated Wnt-inhibitory factor 1 (WIF1) activity. Elevated mRNA and protein levels of LRP5/6 and FZD10 paralleled expression of WNT2b and WNT4 in colonic crypts at days 6 and 12 post-infection with Citrobacter rodentium (CR) and tended to decline at days 20-34. The CR mutant escV or the tankyrase inhibitor XAV939 attenuated these responses. A three-dimensional organoid assay in colonic crypts isolated from CR-infected mice revealed elevated levels of LRP5/6 and FZD10 and β-catenin co-localization with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). Co-immunoprecipitation in the membrane fraction revealed that axin associates with LRP5/6 in CR-infected crypts, and this association was correlated with increased β-catenin. Colon tumors from either CR-infected ApcP  or azoxymethane/dextran sodium sulfate (AOM/DSS)-treated mice had high LRP5/6 or FZD10 levels, and chronic Notch blockade through the γ-secretase inhibitor dibenzazepine down-regulated LRP5/6 and FZD10 expression. In CR-responsive CT-26 cells, siRNA-induced LRP5/6 or FZD10 knockdown antagonized TOPflash reporter activity. Elevated miR-153-3p levels correlated with LRP5/6 and FZD10, and miR-153-3p sequestration via a plasmid-based miR inhibitor system attenuated Wnt signaling. We conclude that infection-induced signals from the plasma membrane epigenetically regulate Wnt signaling.
['Ahmed|Ishfaq|I|', 'Roy|Badal Chandra|BC|', 'Rao Jakkula|Laxmi Uma Maheswar|LUM|', 'Subramaniam|Dharmalingam|D|0000-0002-2710-485X', 'Dandawate|Prasad|P|0000-0002-1141-3703', 'Anant|Shrikant|S|', 'Sampath|Venkatesh|V|', 'Umar|Shahid|S|']
D002462:Cell Membrane D044082:Citrobacter rodentium D004756:Enterobacteriaceae Infections D044127:Epigenesis, Genetic D051157:Frizzled Receptors D045325:HCT116 Cells D057809:HEK293 Cells D006801:Humans D008024:Ligands D060492:Low Density Lipoprotein Receptor-Related Protein-5 D060488:Low Density Lipoprotein Receptor-Related Protein-6 D008297:Male D035683:MicroRNAs D009940:Organoids D051880:Receptors, Notch D060449:Wnt Signaling Pathway
Wnt inflammation Fzd10 β-catenin Citrobacter rodentium Notch LRP5 LRP6 Notch pathway bacterial infection bacterial pathogenesis beta-catenin cancer stem cells miR-153–3p microRNA (miRNA)