Figure 3.

Mechanisms by which prion-like ALS-associated protein aggregates may transfer between cells. (Top left) Once formed, misfolded monomers and soluble oligomers can potentially exit the cell through diffusion and enter nearby cells either through diffusion or receptor-mediated endocytosis. (Top right) Cells that are dead or dying can potentially release larger insoluble aggregates that can be taken up into nearby naïve cells through micropinocytosis. (Bottom left) Misfolded and oligomeric proteins are capable of being loaded into either microvesicles or exosomes for transport to nearby cells. (Bottom right) Misfolded monomers or soluble oligomers are capable of being transported across axon terminals to naïve cells.