Brain-Derived Extracellular Vesicles as Nanobiotechnology Biomarkers of Small Vessel Disease (CADASIL)

Background Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary small vessel disease (SVD) and currently lacks reliable biomarkers to monitor disease progression. Extracellular vesicles (EVs) are nanoscale carriers that cross the blood–brain barrier and provide a minimally invasive liquid biopsy of brain pathology. This study aimed to characterize brain cell–derived EVs in CADASIL and explore their potential as biomarkers of disease stage using advanced proteomic profiling. Results Plasma EVs were isolated from CADASIL patients stratified according to the NOTCH3-SVD staging system and further enriched into neuronal (nEVs), astrocytic (aEVs), and oligodendrocytic (oEVs) subpopulations by immunoaffinity capture. The analysis of canonical biomarkers showed that glial fibrillary acidic protein (GFAP), a marker of astrocytic activation, was significantly increased in aEVs from patients at intermediate/advanced stages. Similarly, myelin basic protein (MBP), reflecting oligodendrocyte integrity and myelin disruption, was elevated in oEVs in the same group. By contrast, neurofilament light chain (NfL), a marker of axonal injury, did not show significant stage-dependent changes in nEVs. Importantly, these differences were not detectable in plasma or in total EV fractions, highlighting the superior sensitivity of cell type–specific EV analysis. Complementary proteomic profiling identified stage-related molecular signatures in both plasma and EVs, including downregulation of proteins related to metabolism and cytoskeletal organization, and upregulation of immune and stress-response pathways. These molecular patterns suggest a shift toward a pro-inflammatory and neurodegenerative environment in patients with more advanced disease stages. Conclusions Brain cell–derived EVs constitute a nanobiotechnology platform for minimally invasive biomarker discovery in CADASIL. Cell type–specific EV profiling allows the detection of subtle glial alterations and proteomic shifts associated with disease progression, which are not evident in plasma or bulk EVs. These findings support the development of EV-based biomarkers as sensitive tools for monitoring disease course in CADASIL and potentially other small vessel diseases.