Hypermethylated promoter region of DR3, the death receptor 3 gene, in rheumatoid arthritis synovial cells
Article first published online: 28 FEB 2006
Copyright © 2006 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 54, Issue 3, pages 779–787, March 2006
How to Cite
Takami, N., Osawa, K., Miura, Y., Komai, K., Taniguchi, M., Shiraishi, M., Sato, K., Iguchi, T., Shiozawa, K., Hashiramoto, A. and Shiozawa, S. (2006), Hypermethylated promoter region of DR3, the death receptor 3 gene, in rheumatoid arthritis synovial cells. Arthritis & Rheumatism, 54: 779–787. doi: 10.1002/art.21637
- Issue published online: 28 FEB 2006
- Article first published online: 28 FEB 2006
- Manuscript Accepted: 10 NOV 2005
- Manuscript Received: 11 MAY 2005
- Ministry of Education, Culture, Sports, Science, and Technology of Japan. Grant Numbers: 14657117, 13204059
- 21st Century Center of Excellence Program (Center of Excellence for Signal Transduction Disease: Diabetes Mellitus as Model)
To examine the promoter activity and protein expression of the death receptor 3 gene DR3, a member of the apoptosis-inducing Fas gene family, with particular reference to the methylation status of its promoter region in rheumatoid arthritis (RA).
Genomic DNA was prepared from peripheral blood mononuclear cells obtained from healthy individuals and from patients with RA and synovial cells obtained from patients with RA and osteoarthritis. The methylation status of the DR3 promoter was analyzed by bisulfite genomic sequencing and methylation-specific polymerase chain reaction techniques. Gene promoter activity and protein expression were examined using the luciferase reporter and Western blotting techniques.
The promoter region of the DR3 gene contained many CpG motifs, including one CpG island that was specifically hypermethylated in synovial cells from patients with RA. Promoter assays showed that the promoter CpG island was essential for the transactivation of the DR3 gene and that forced hypermethylation of the CpG island with the bacterial methylase Sss I in vitro resulted in inhibition of the DR3 gene expression. Furthermore, the expression of DR-3 protein was down-modulated in association with methylation of the promoter CpG island in RA synovial cells.
The CpG island in the DR3 gene promoter was specifically methylated to down-modulate the expression of DR-3 protein in rheumatoid synovial cells, which may provide resistance to apoptosis in RA synovial cells.