Where Ideas grow
Glial Cell Biology

ABOUT

We focus on myelination, the process by which axons are invested with myelin, a lipid-rich biological membrane, which forms multilamellar, spirally wrapped sheets around axons. Myelination enables rapid saltatory conductance of action potentials and is essential for axonal integrity. The devastating neurological effects caused by the destruction of myelin in the central (CNS) and peripheral nervous system (PNS) illustrate well the importance of the process.

Schwann cells (SC) in the PNS and oligodendrocytes (OL) in the CNS proliferate and migrate before undergoing the remarkable morphological changes associated with ensheathing and myelination of axons. Precise control of these processes derives, at least in part, from instructive cues originating within the extracellular environment, in which proteins of the extracellular matrix (ECM) are essential components. Cell-ECM contact is largely mediated by integrins, a major group of ubiquitous cell-adhesion receptors for the proteins of the ECM.

Using conditional transgenic approaches in mice together with appropriate cell culture systems, we are investigating how integrin and rhoGTPases regulate the different stages of SC and OL development and myelination. By proteomics and next generation sequencing, we have identified novel candidate molecules regulating neuron-glial interactions that might also be relevant to enhance remyelination and repair. Their functions are currently being investigated.

More recently, we also became interested in integrin and rhoGTPases regulation of microglia function. 

 

RESEARCH

Over the last years, using conditional transgenic approaches, we have reported essential roles for integrin-linked-kinase, particularly interesting Cys-His-rich protein (PINCH), and for the RhoGTPases cdc42, rac1 and rhoA and some of their effectors, such as the actin binding protein profilin 1, in the regulation of different stages of SC and OL development and myelination. We have also reported roles for some of these molecules in neuroepithelium organization and neural progenitor differentiation. Group members have been funded by the FCT, ON2-QREN, Marie Curie actions (Laura Montani and Sofia Domingues), and EMBO long-term fellowships (Ligia Tavares). Research in the lab has been funded by the FCT, FP7, ETH Zurich, Swiss National Science Foundation and by the International Foundation for Paraplegia. 

 

Inhibition of ROCK signaling facilitates axonal sorting in ILK mutant mice (Pereira et al., 2009). In the figure asterisks mark axons that have been recently sorted from the axon bundle by Schwann cells.