[Chondromodulin-I and its related gene Tenomodulin]

During endochondral bone formation, vascular invasion into the cartilaginous rudiments triggers the subsequent replacement of cartilage by bone. We have found that the cartilage-derived glycoprotein, Chondromodulin- I (ChM- I ), is involved in the anti-angiogenic property of cartilage, and that its absence creates a permissive microenvironment for vascular invasion in cartilage. Recently, we reported that a novel ChM- I related molecule, Tenomodulin (TeM), is specifically expressed in tendon, epimysium, ligaments, sclera, and cornea, all of which are hypovascular or avascular. In contrast to ChM- I that is secreted and accumulates in the extracellular matrix, TeM is expressed on the cell surface as a type II transmembrane protein. Anti-angiogenic properties of TeM and ChM- I in mesenchyme will be reviewed.