Role of CD44
Our laboratory is interested essentially in the characterization of the role of CD44 and of the importance of its interaction with hyaluronate (HA) in the mouse and human skin. CD44 is a polymorphic transmembrane glycoprotein and the principal cell surface receptor of HA, which was shown to form a complex with matrix metalloproteinase 7 (MMP-7), heparin binding epidermal growth factor (HB-EGF) precursor (pro-HB-EGF) and one of its receptors, erbB1. Previously we have shown that two major functions of CD44 in the mouse skin are the regulation of keratinocyte proliferation in response to extracellular stimuli and the maintenance of local HA homeostasis. We have observed a decrease in epidermal CD44 and HA expression in the extreme skin atrophy called as dermatoporosis of elderly people. We have also shown that HA fragments (HAF) of defined size reverse skin atrophy in mouse and human skin by a CD44-dependent mechanism and topical retionoids and HAF show a synergistic effect in this reversion. Currently we are working on:
1- The role of CD44-HA connection in skin aging
2- The effect of CD44 ligands on skin atrophy
3- Molecular mechanisms of primary or steroid-induced dermatoporosis
4- New pharmacological mechanisms of topical retinoids related to CD44-HA pathway
We are also working on the development of a molecular tool (gene microarrays) for the early diagnosis of skin diseases such as cutaneous lymphomas, graft-versus-host disease and drug eruptions.