title: DNA demethylation of inflammasome-associated genes is enhanced in patients with cryopyrin-associated periodic syndromes.
abstract: Inflammasomes are cytosolic multiprotein complexes in macrophages. They assemble after infection- or stress-associated stimuli, activating both caspase-1-mediated inflammatory cytokine secretion and pyroptosis. Increased inflammasome activity resulting from gene mutations is related to monogenic autoinflammatory syndromes. However, variable penetrance among patients with the same gene mutations suggests involvement of additional mechanisms associated with inflammasome gene regulation.
  
  
  
  We sought to investigate the role of DNA demethylation in activating inflammasome genes during macrophage differentiation and monocyte activation in healthy control subjects and patients with autoinflammatory syndrome.
  
  
  
  Inflammasome-related genes were tested for DNA methylation and mRNA levels by using bisulfite pyrosequencing and quantitative RT-PCR in monocytes in vitro differentiated to macrophages and exposed to inflammatory conditions. The contribution of Tet methylcytosine dioxygenase 2 (TET2) and nuclear factor κB to DNA demethylation was tested by using chromatin immunoprecipitation, small interfering RNA-mediated downregulation, and pharmacologic inhibition.
  
  
  
  We observed that inflammasome-related genes are rapidly demethylated in both monocyte-to-macrophage differentiation and on monocyte activation. Demethylation associates with increased gene expression, and both mechanisms are impaired when TET2 and nuclear factor κB are downregulated. We analyzed DNA methylation levels of inflammasome-related genes in patients with cryopyrin-associated periodic syndromes (CAPS) and familial Mediterranean fever, 2 archetypical monogenic autoinflammatory syndromes. Under the above conditions, monocytes from untreated patients with CAPS undergo more efficient DNA demethylation than those of healthy subjects. Interestingly, patients with CAPS treated with anti-IL-1 drugs display methylation levels similar to those of healthy control subjects.
  
  
  
  Our study is the first to demonstrate the involvement of DNA methylation-associated alterations in patients with monogenic autoinflammatory disease and opens up possibilities for novel clinical markers.
authors.affiliation: Chromatin and Disease Group, Cancer Epigenetics and Biology Programme (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Roser
authors.initials: R
authors.lastname: Vento-Tormo
authors.affiliation: Chromatin and Disease Group, Cancer Epigenetics and Biology Programme (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain. Electronic address: dalvarez@idibell.cat.
authors.forename: Damiana
authors.initials: D
authors.lastname: Álvarez-Errico
authors.affiliation: Chromatin and Disease Group, Cancer Epigenetics and Biology Programme (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Garcia-Gomez
authors.affiliation: Autoinflammatory Diseases Clinical Unit and Vasculitis Research Unit, Department of Autoimmune Diseases, Hospital Clinic, IDIBAPS, Barcelona, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Hernández-Rodríguez
authors.affiliation: Internal Medicine, Autoimmune and Systemic Diseases Services, Hospital Vall d'Hebron, Barcelona, Spain.
authors.forename: Segundo
authors.initials: S
authors.lastname: Buján
authors.affiliation: Allergy Department, Hospital Universitari Germans Trias i Pujol, Universitat Autonoma de Barcelona, Badalona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Basagaña
authors.affiliation: Department of Pediatrics, Hospital Universitari Germans Trias i Pujol, Universitat Autonoma de Barcelona, Badalona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Méndez
authors.affiliation: Department of Immunology-CDB, Hospital Clinic, IDIBAPS, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Yagüe
authors.affiliation: Department of Immunology-CDB, Hospital Clinic, IDIBAPS, Barcelona, Spain.
authors.forename: Manel
authors.initials: M
authors.lastname: Juan
authors.affiliation: Department of Immunology-CDB, Hospital Clinic, IDIBAPS, Barcelona, Spain.
authors.forename: Juan I
authors.initials: JI
authors.lastname: Aróstegui
authors.affiliation: Chromatin and Disease Group, Cancer Epigenetics and Biology Programme (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain. Electronic address: eballestar@idibell.cat.
authors.forename: Esteban
authors.initials: E
authors.lastname: Ballestar
mesh_terms: D056587:Cryopyrin-Associated Periodic Syndromes / Q000235:genetics* / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D049308:Dioxygenases; D010505:Familial Mediterranean Fever / Q000235:genetics / Q000378:metabolism; D006801:Humans; D058847:Inflammasomes / Q000235:genetics*; D008264:Macrophages / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics
chemical_list: D016207:Cytokines; D004268:DNA-Binding Proteins; D058847:Inflammasomes; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D049308:Dioxygenases; C541081:TET2 protein, human
keywords: Cryopyrin-associated periodic syndromes; DNA methylation; active demethylation; autoinflammatory diseases; epigenetics; familial Mediterranean fever; inflammasome