Expression of members of a novel membrane linked metalloproteinase family (ADAM) in human articular chondrocytes.

Using resting chondrocytes derived from human articular femoral head and a conditionally immortalised human articular chondrocyte cell line we have studied the expression of members of the novel metalloproteinase/disintegrin family termed ADAM. Using RT-PCR we can detect the expression of ADAM-12 a novel family member isolated from myeloma cells [1]. We also find expression of ADAM 10 a functional metalloproteinase/disintegrin first isolated from bovine brain and ADAM-15 a metallodisintegrin isolated from mammary derived epithelial cells. Northern blotting was used to confirm expression. One main transcript is visible for ADAM-12 whereas both ADAM-10 and ADAM-15 have multiple transcripts indicating possible RNA variants potentially derived from alternative splicing or alternative use of polyadenylation sites. Since chondrocytes are proposed as an important source of metalloproteinase enzymes involved in joint pathology the potential relevance of the expression of these molecules to connective tissue disorders is discussed.