title: Changes in the pattern of DNA methylation associate with twin discordance in systemic lupus erythematosus.
abstract: Monozygotic (MZ) twins are partially concordant for most complex diseases, including autoimmune disorders. Whereas phenotypic concordance can be used to study heritability, discordance suggests the role of non-genetic factors. In autoimmune diseases, environmentally driven epigenetic changes are thought to contribute to their etiology. Here we report the first high-throughput and candidate sequence analyses of DNA methylation to investigate discordance for autoimmune disease in twins. We used a cohort of MZ twins discordant for three diseases whose clinical signs often overlap: systemic lupus erythematosus (SLE), rheumatoid arthritis, and dermatomyositis. Only MZ twins discordant for SLE featured widespread changes in the DNA methylation status of a significant number of genes. Gene ontology analysis revealed enrichment in categories associated with immune function. Individual analysis confirmed the existence of DNA methylation and expression changes in genes relevant to SLE pathogenesis. These changes occurred in parallel with a global decrease in the 5-methylcytosine content that was concomitantly accompanied with changes in DNA methylation and expression levels of ribosomal RNA genes, although no changes in repetitive sequences were found. Our findings not only identify potentially relevant DNA methylation markers for the clinical characterization of SLE patients but also support the notion that epigenetic changes may be critical in the clinical manifestations of autoimmune disease.
authors.affiliation: Chromatin and Disease Group, Cancer Epigenetics and Biology Programme (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona 08907, Spain.
authors.forename: Biola M
authors.initials: BM
authors.lastname: Javierre
authors.forename: Agustin F
authors.initials: AF
authors.lastname: Fernandez
authors.forename: Julia
authors.initials: J
authors.lastname: Richter
authors.forename: Fatima
authors.initials: F
authors.lastname: Al-Shahrour
authors.forename: J Ignacio
authors.initials: JI
authors.lastname: Martin-Subero
authors.forename: Javier
authors.initials: J
authors.lastname: Rodriguez-Ubreva
authors.forename: Maria
authors.initials: M
authors.lastname: Berdasco
authors.forename: Mario F
authors.initials: MF
authors.lastname: Fraga
authors.forename: Terrance P
authors.initials: TP
authors.lastname: O'Hanlon
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Rider
authors.forename: Filipe V
authors.initials: FV
authors.lastname: Jacinto
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Lopez-Longo
authors.forename: Joaquin
authors.initials: J
authors.lastname: Dopazo
authors.forename: Marta
authors.initials: M
authors.lastname: Forn
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Peinado
authors.forename: Luis
authors.initials: L
authors.lastname: Carreño
authors.forename: Amr H
authors.initials: AH
authors.lastname: Sawalha
authors.forename: John B
authors.initials: JB
authors.lastname: Harley
authors.forename: Reiner
authors.initials: R
authors.lastname: Siebert
authors.forename: Manel
authors.initials: M
authors.lastname: Esteller
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Miller
authors.forename: Esteban
authors.initials: E
authors.lastname: Ballestar
mesh_terms: D044503:5-Methylcytosine / Q000737:chemistry; D001172:Arthritis, Rheumatoid / Q000235:genetics; D001327:Autoimmune Diseases / Q000235:genetics; D015331:Cohort Studies; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation; D003882:Dermatomyositis / Q000235:genetics; D004200:Diseases in Twins / Q000235:genetics*; D005260:Female; D020459:Genes, rRNA; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics*; D008297:Male; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA / Q000379:methods; D014430:Twins, Monozygotic / Q000235:genetics*
chemical_list: D044503:5-Methylcytosine