The role of hyaluronan in cartilage

Abstract

Hyaluronan (HA) is a large, linear polymer of repeating disaccharide units composed of N-acetyl-D-glucosamine and D-glucuronic acid. Although HA has a very simple structure, it plays a key role in tissue organization and homeostasis through its physicochemical properties and its interactions with binding proteins and/or specific cell surface receptors. Recently, using Prx1-Cre transgenic mice, we generated conditional knockout mice, in which the Has2 gene was limb bud mesoderm-specific inactivated. In this review, we describe the role of HA during limb morphogenesis, which was analyzed in Has2 conditional knockout mice crossed with Prx1-Cre. We further discuss the biochemical and genetic studies of proteoglycan aggregates, which are mainly composed of HA, aggrecan, and link protein. We also focus briefly on the role of CD44, which is a major cell surface receptor of HA. Although much is known about the function of HA, much remains to be learned about how HA is regulated and/or how HA regulates tissue homeostasis. We hope this review provides an important opportunity to consider the roles of HA and that it may prove helpful in understanding the function of HA. © 2010 FCCA.