Multi-omic profiling reveals pericyte and smooth muscle cell contributions to CADASIL pathology in cell-specific Notch3 mutant mice.

Cerebral ischemic small vessel disease (SVD) is a leading cause of vascular dementia and stroke. Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common monogenic SVD, is caused by dominant missense mutations in Notch3 expressed in smooth muscle cells (SMCs) and pericytes. However, cell-type-specific contributions driving CADASIL remain unknown. Here, we generate two conditional knockin mouse models carrying the CADASIL-causing Notch3R170C mutation in SMCs or pericytes. Both Notch3R170C models show perivascular accumulation of the NOTCH3 yet develop distinct neurovascular changes. These changes are associated with regionally distinct vascular and neuroinflammatory pathology and memory deficits. Proteomic profiling of brain vessels reveals distinct cell-specific responses, with metabolic pathway dysregulation in pericyte-Notch3R170C mice and immune signaling in SMC-Notch3R170C mice. Integration with single-cell RNA sequencing (RNA-seq) suggests that these changes may also involve brain endothelial cells. Together, these findings define mural cell-specific mechanisms that contribute to the CADASIL-associated vascular pathology.