Figure 2.

Protective strategies of astrocytes during BBB disruption. In advanced stages of PD, BBB disruption takes place and causes a lost in barrier permeability, entrance of toxic substances and in some instances immune cell infiltration. Processes such as increased ROS production, reactive gliosis and cellular death will inevitably occur. Astrocytic response to BBB disruption includes the production of antioxidative molecules like GSH and ascorbate, generation of growth factors like Brain derived neurotrophic factor (BDNF) and GDNF that could alleviate the cellular death and promote angiogenesis. Furthermore, astrocytes are important in the genetic regulation of endothelial proteins from the tight junction like Occludin and ZO-1. During chronic brain damage, astrocytes also induce the liberation of cytokines like TNF-α, IL-1B, IL-6, important in microglial activation and neuronal death.