GDNF plasmid was transfected to macrophages. Extracellular vesicles were then isolated and purified. GDNF expression was quantified by Western blotting and subsequently analyzed for purity. Animals underwent intranasal injection with EV-GDNF or saline per their assigned treatment. Locomotor activity and rearing movements were evaluated with wire-hanging test, rotarod test and open-field test. Brain tissues were harvested at 16 months for histochemical and biochemical analysis.
Biochemical analysis of WT16-month, PD-Saline, and treated PD-GDNF tissues for the expression of senescence and autophagy-related genes was performed by PCR array.