Developing a 3D culture model to study astrocyte-mediated clearance of protein aggregates

Astrocytes are glial cells that play important roles in central nervous system (CNS) homeostasis and function. In the past decades, astrocytes emerged as phagocytic cells of the brain, assisting microglia in the clearance of extracellular material, including alpha-synuclein (α-syn) aggregates, the pathological hallmark of synucleinopathies. It is now well recognized that the physical properties of the environment have profound effects on cell behavior and, with no exception, on the phagocytic process. In this regard, we set up a protocol for 3D cultures of primary astrocytes to recreate a more physiological condition compared to the traditional 2D systems used so far. Overall, our work shows that primary astrocytes are viable in Matrigel-embedded 3D cultures and adopt more in vivo-like branched morphologies compared to 2D astrocytes. Moreover, our preliminary data suggest that astrocytes are able to internalize α-syn aggregates in 3D, and therefore this 3D model could be used as a possible validation system for future studies of astrocyte-mediated clearance of protein aggregates.