Extracellular Vesicles Released by Genetically Modified Macrophages Activate Autophagy and Produce Potent Neuroprotection in Mouse Model of Lysosomal Storage Disorder, Batten Disease.

Over the recent decades, the use of extracellular vesicles (EVs) has attracted considerable attention. Herein, we report the development of a novel EV-based drug delivery system for the transport of the lysosomal enzyme tripeptidyl peptidase-1 (TPP1) to treat Batten disease (BD). Endogenous loading of macrophage-derived EVs was achieved through transfection of parent cells with TPP1-encoding pDNA. More than 20% ID/g was detected in the brain following a single intrathecal injection of EVs in a mouse model of BD, ceroid lipofuscinosis neuronal type 2 (CLN2) mice. Furthermore, the cumulative effect of EVs repetitive administrations in the brain was demonstrated. TPP1-loaded EVs (EV-TPP1) produced potent therapeutic effects, resulting in efficient elimination of lipofuscin aggregates in lysosomes, decreased inflammation, and improved neuronal survival in CLN2 mice. In terms of mechanism, EV-TPP1 treatments caused significant activation of the autophagy pathway, including altered expression of the autophagy-related proteins LC3 and P62, in the CLN2 mouse brain. We hypothesized that along with TPP1 delivery to the brain, EV-based formulations can enhance host cellular homeostasis, causing degradation of lipofuscin aggregates through the autophagy-lysosomal pathway. Overall, continued research into new and effective therapies for BD is crucial for improving the lives of those affected by this condition.

Using Extracellular Vesicles Released by GDNF-Transfected Macrophages for Therapy of Parkinson Disease.

Extracellular vesicles (EVs) are cell-derived nanoparticles that facilitate transport of proteins, lipids, and genetic material, playing important roles in intracellular communication. They have remarkable potential as non-toxic and non-immunogenic nanocarriers for drug delivery to unreachable organs and tissues, in particular, the central nervous system (CNS). Herein, we developed a novel platform based on macrophage-derived EVs to treat Parkinson disease (PD). Specifically, we evaluated the therapeutic potential of EVs secreted by autologous macrophages that were transfected ex vivo to express glial-cell-line-derived neurotrophic factor (GDNF). EV-GDNF were collected from conditioned media of GDNF-transfected macrophages and characterized for GDNF content, size, charge, and expression of EV-specific proteins. The data revealed that, along with the encoded neurotrophic factor, EVs released by pre-transfected macrophages carry GDNF-encoding DNA. Four-month-old transgenic Parkin Q311(X)A mice were treated with EV-GDNF via intranasal administration, and the effect of this therapeutic intervention on locomotor functions was assessed over a year. Significant improvements in mobility, increases in neuronal survival, and decreases in neuroinflammation were found in PD mice treated with EV-GDNF. No offsite toxicity caused by EV-GDNF administration was detected. Overall, an EV-based approach can provide a versatile and potent therapeutic intervention for PD.