Fig. 4

Astrocyte-microglia interactions to promote clearance of unwanted and toxic materials in the cells. (A) Under normal conditions where the unwanted materials are within the clearance capacity of astrocytes, phagocytic/autophagic degradation of the accumulated materials can proceed. During chronic exposure to these unwanted materials, lysosomal functions are impaired, and this reduces the capacity of astrocytes to degrade, leading to the accumulation of toxic materials within the astrocytes and their subsequent dysfunction. (B) Astrocytes-microglia crosstalk through tunneling nanotubes (TNTs). In astrocyte-microglia interaction, unwanted and toxic cellular materials such as impaired lysosomes, undegraded autophagosomes, and damaged mitochondria can migrate to microglia, where the latter can assist in more effective degradation of these toxic products. The figure was created with BioRender.com