La ténascine-C: Une molécule de la matrice extracellulaire impliquée dans le développement du système nerveux central

Composed of an etwork of different collagens, proteoglycans and glycoproteins, the extracellular matrix constitutes an essential substrate for tissular morphogenesis and provides support and flexibility to mature tissues. Moreover, it acts as an informational epigenetic entity in that it transduces and integrates extracellular signals from various receptors of the plasma membrane. Among the extracellular matrix molecules which are expressed during central nervous system (CNS) development, tenascin-C (TN-C) has a very singular pattern of expression based on its spatio-temporal distribution and synthesised isoforms. Numerous in vitro studies suggested specific roles for TN-C in CNS development, notably in neural precursor cells migration as well as in neurite guidance and outgrowth. Also, the production of TN-C null mutant, initially described without gross structural abnormalities, allowed to investigate in more details and in vivo the potential involvement of this glycoprotein in CNS ontogenesis. Recent works tend to emphasize ancient concepts but also to reveal new functions such as in the proliferation of oligodendrocyte precursor cells.