Astrocyte CD9-tGFP reporter mouse shows astrocyte EV cargo preferentially enriched at synaptic mitochondria
By crossing Aldh1l1-Cre with CD9-tGFP reporter mice, the authors generated an astrocyte-specific EV reporter mouse in which 13.2% ± 1.6% of brain-isolated EVs were CD9-tGFP positive and 89.3% ± 2.2% of primary astrocyte-derived EVs were positive; CD9-tGFP signal was detected in astrocytic processes, capillaries, and neurons in cortex, hippocampus, and cerebellum, STED and AI-assisted proximity analysis showed EV cargo enrichment at neuronal mitochondria in vitro, and isolated mitochondria showed 3-fold higher CD9-tGFP puncta density on synaptic versus non-synaptic mitochondria in vivo.