Gene expression-based, astrocyte treatments

Astrocytes, a major cell type found throughout the central nervous system have general roles in neuronal development, blood-brain barrier function, regulation of neuroimmune responses as well as metabolic support of other brain resident cells. Here we show that a distinct subtype of reactive astrocyte is induced by activated endothelial cells and is distinct from astrocytes classically activated by neuroinflammatory microglia. We show that activated endothelial cells strongly induce C3 + astrocytes that retain their phagocytic capacity while exhibiting a gain of neurotoxic function decreasing neuronal cell survival. We show that endothelial activated astrocytes have increased A1-astrocytic genes and exhibit a distinctive extracellular matrix remodeling profile. Finally, we show that endothelial activated astrocytes are Decorin positive and are associated to vascular amyloid deposits but not amyloid plaques in mouse models and AD/CAA patients. Taken together these findings show the existence of potentially extensive and subtle functional diversity of A1-reactive astrocytes. Astrocytes treated with Control or Activated Microglia or Endothelial Conditioned media To compare the transcriptional profiles for glial activation in Astrocytes to Microglia vs Endothelial Stimuli