Modeling astrocytic contribution toward neurodegeneration with pluripotent stem cells: focus on Alzheimer's and Parkinson's diseases.

Astrocytes are an exceptionally complex type of cell observed throughout the brain and the spinal cord. They reveal heterogeneous identities and largely participate in brain activity. In this article we review astrocyte heterogeneity and function in the brain. We have also focused on their involvement in neurodegenerative diseases including Parkinson's and Alzheimer's diseases, discussing the contribution of this type of glial cell toward mechanisms that can lead to neuronal death, which was previously attributed exclusively to neurons. Furthermore, we also highlight the latest progress with stem cell technology for the generation of astrocytes from embryonic and induced pluripotent stem cells. We allude to the need for developing new models that better recapitulate astrocyte heterogeneity and their diverse function within the brain. Those models will greatly contribute in understanding astrocytes' contribution toward molecular mechanisms occurring in neurodegenerative pathologies affecting specific brain regions such as in Parkinson's and Alzheimer's diseases.