NOTCH3 R545C mutation drives vascular-neuronal dysfunction and cognitive impairment in CADASIL pathogenesis

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary small vessel disease caused by mutations in the NOTCH3 gene. However, its pathogenic mechanisms remain incompletely understood. Given the high prevalence of the NOTCH3 p.Arg544Cys (R544C) mutation in East Asian populations, we developed a novel CRISPR/Cas9-mediated mouse model harboring the NOTCH3 p.R545C point mutation (orthologous to human R544C) to dissect the underlying CADASIL pathogenesis. Comprehensive phenotyping revealed age-dependent cognitive deficits, including impaired spatial learning and recognition memory, accompanied by impaired hippocampal synaptic plasticity, dendritic atrophy, and reduced spine density in hippocampal neurons. Vascular pathology exhibited blood-brain barrier disruption, granular osmiophilic material deposition, and cerebrovascular degeneration. Potential neuroinflammation and dendritic network impairment were found to co-occur with vascular dysfunction, thereby implying the existence of a vascular-initiated neural damage in disease progression. RNA sequencing of hippocampal tissues identified dysregulated genes significantly enriched in neuroendocrine signaling, cytoskeletal organization, and inflammatory pathways, highlighting novel potential molecular mechanisms in CADASIL. Our NOTCH3 p.R545C model successfully recapitulates key clinical and pathological features of CADASIL that are frequently documented in East Asian populations, providing a platform for mechanistic studies and offering insights into potential therapeutic targets. • NOTCH3 R544C is the predominant pathogenic mutation in a Guangdong CADASIL cohort. • NOTCH3 p.R545C knock-in mice recapitulate core CADASIL phenotypes. • NOTCH3 p.R545C knock-in mice show BBB disruption, GOM deposition, and cerebrovascular loss. • R545C-driven vascular dysfunction precedes hippocampal synaptic and cognitive deficits. • Transcriptomics reveal dysregulated neuroendocrine and cytoskeletal pathways.