Expression analysis of the osteoarthritis genetic susceptibility mapping to the matrix Gla protein gene MGP.

MGP expression is subject to cis-acting regulators that correlate with the OA association signal. These are active in a range of joint tissues but have effects which are particularly strong in cartilage. An opposite effect is observed in blood, highlighting the context-specific nature of the regulation of this gene's expression. Recapitulation of the genetic deficit in cartilage chondrocytes is pro-catabolic.