抄録
Cartilaginous extracellular matrix (ECM) is a unique assembly of macromolecules such as type II collagen and proteoglycans. In association with a number of accessory molecules, it confers special biological functions on cartilage. Among these various accessory molecules, growth-modulating functions have been identified only in several instances, and in many cases functional properties therefore remain to be elucidated. Chondromodulin-I (ChM-I) is a 25-kDa glycoprotein, which was initially identified in our laboratory as a cartilage-specific functional matrix component that stimulates the growth and matrix synthesis of primary chondrocytes in vitro. We subsequently purified an endothelial cell growth inhibitor from guanidinium extracts of fetal bovine cartilage, which was surprisingly found to be identical to ChM-I. Purified ChM-I was found to inhibit the proliferation of vascular endothelial cells as well as tube morphogenesis in vitro. The generation of a ChM-I null mouse has enabled us to examine the functional roles of this unique ECM component in vivo. In this review, we describe the identification and biological characterization of ChM-I as an example of a growth-modulating functional matrix in cartilage.
