TNFα-NF-κB activation through pathological α-Synuclein disrupts the BBB and exacerbates axonopathy

Dysfunction of the blood brain barrier (BBB) is recognized as a key factor in the progression of neurodegenerative diseases, but the detailed mechanisms behind its pathogenesis and impact on neurodegeneration remain elusive. This study aimed to reveal the pathological effects of α-Synuclein (α-Syn), an aggregation protein in Synucleinopathy, on BBB integrity and function, and identify therapeutic targets for α-Syn-related vasculopathy. Using a brain endothelial cell model, we investigated the pathological effect of preformed fibril α-Syn (PFF) on BBB integrity, employing generative adversarial network (GAN) deep learning to analyze pathological changes. We found that PFF activates immune responses, increasing endothelial monolayer permeability via the TNFα-NF-κB pathway. Further in vivo studies with PFF induced α-Synucleinopathy and transgenic animal model (G2-3) revealed that α-Syn aggregation, disrupts the BBB, leading to axonal degeneration that was mitigated by treatment with a non-BBB-penetrating TNFα inhibitor, Etanercept. These findings suggest that targeting brain endothelial TNFα signaling could be a potential therapeutic approach for Synucleinopathy-related NDs.