Expression of ADAMTS-4 by chondrocytes in the surface zone of human osteoarthritic cartilage is regulated by epigenetic DNA de-methylation

Cheung, K. S., Hashimoto, K., Yamada, N. and Roach, H. I. (2008) Expression of ADAMTS-4 by chondrocytes in the surface zone of human osteoarthritic cartilage is regulated by epigenetic DNA de-methylation. Rheumatology International, 29 (5), 525-534. (doi:10.1007/s00296-008-0744-z).

Abstract

The two major aggrecanases involved in osteoarthritis (OA) are ADAMTS-4 and ADAMTS-5. Knock-out studies suggested that ADAMTS-5, but not ADAMTS-4, is the major aggrecanase in murine OA. However, studies of human articular cartilage suggest that ADAMTS-4 also contributes to aggrecan degradation in human OA. This study investigated ADAMTS-4 in human OA. While ADAMTS-4 was virtually absent in control cartilage, numerous ADAMTS-4 immuno-positive chondrocytes were present in OA cartilage and their numbers increased with disease severity. RT-PCR confirmed expression, especially in the surface zone. DNA methylation was lost at specific CpG sites in the ADAMTS-4 promoter in OA chondrocytes, suggesting that the increased gene expression was more than a simple up-regulation, but involved loss of DNA methylation at specific CpG sites, resulting in a heritable and permanent expression of ADAMTS-4 in OA chondrocytes. These results suggest that ADAMTS-4 is epigenetically regulated and plays a role in aggrecan degradation in human OA

This record has no associated files available for download.

Contributors

Download statistics