The extracellular matrix (ECM) is composed of macromolecules surrounding the cells. They interact with each other and with the cells, cross-link and polymerize, ensuring the maintenance and the function of organs. The primary role of ECM is to support the cells by providing adhesion support, but its role goes beyond: the matrix is involved in many cellular functions, through its physico-chemical properties, its structure and its various ligands.
The cerebral ECM represents from 10% to 20% of the brain volume, and is composed of a dense network of proteins and glycans, that provide anchor points for cells and contribute to their physiological activity (G. Gritsenko, Ilina, and Friedl 2012). Moreover, it modulates, among other things, the brain plasticity necessary for neurons to create new synaptic connections (Ferrer-Ferrer and Dityatev 2018).
In some pathologies, the ECM is modified. For example, some modifications allow cancer cells to invade more easily the central nervous system (CNS). Moreover, the presence of neurodegenerative diseases such as Alzheimer’s or Parkinson’s disease have been correlated to an abnormal levels of glycans, including proteoglycans (van Horssen et al. 2003; Dwyer and Esko 2016; Freeze et al. 2015). Neurodegenerative disease cases are steadily increasing: Alzheimer’s disease currently affects 1 in 8 adults over 65, and it is estimated this disease will concern in 8 million people in 2030. It is thus essential to find therapies. The various and crucial roles of the cellular microenvironment makes the ECM an interesting target, since the ECM changes impact the cell behavior in pathological conditions.
Understanding the functions of ECM is the first step to study its involvement in brain pathologies. That is why HCS Pharma has developed BIOMIMESYS® Brain, a hyaluronic acid-based hydroscafold which mimics the ECM, with the aim to study in vitro neurodegenerative diseases by taking account the matricial microenvironment.
Thanks to Rémi Giraudet, engineer-student in AgroPariTech who participated in the writing of this article, as part of its bibliographical project about the importance of ECM in brain pathology, in collaboration with HCS Pharma.