Methylation Status of Alu and LINE-1 Interspersed Repetitive Sequences in Behcet's Disease Patients

Yuksel S., Kucukazman S. O. , Karatas G. S. , ÖZTÜRK M. A. , Prombhul S., Hirankarn N.

BIOMED RESEARCH INTERNATIONAL, vol.2016, 2016 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 2016
  • Publication Date: 2016
  • Doi Number: 10.1155/2016/1393089


Behcet's Disease (BD) is a multisystem chronic inflammatory disease. The pathology is believed to involve both genetic susceptibility and environmental factors. Hypomethylation leading to activation of interspersed repetitive sequences (IRSs) such as LINE-1 and Alu contributes to the pathologies of autoimmune diseases and cancer. Herein, the epigenetic changes of IRSs in BD were evaluated using combined bisulfite restriction analysis-interspersed repetitive sequences (COBRA-IRS). DNA from neutrophils and peripheral blood mononuclear cells (PBMCs) of BD patients with ocular involvement that were in active or inactive states and healthy controls were used to analyze LINE-1 and Alu methylation levels. For Alu sequences, significant differences were observed in the frequency of (CC)-C-u-C-u alleles between PBMCs of patients and controls (p = 0.03), and between inactive patients and controls (p = 0.03). For neutrophils, the frequency of (CC)-C-u-C-u was significantly higher between patients and controls (p = 0.006) and between inactive patients and controls (p = 0.002). The partial methylation ((CC)-C-u-C-m + (CC)-C-m-C-u) frequencies of Alu between inactive patients and control samples also differed (p = 0.02). No statistically significant differences for LINE-1 were detected. Thus, changes in the methylation level of IRS elements might contribute to the pathogenesis of BD. The role of Alu transcripts in BD should be investigated further.