Chang, Y.; Yu, X.; Ahmed, T.; Zhao, Y.; He, S.; Ye, X.

Background: Moyamoya disease (MMD) is characterized by progressive arterial stenosis and abnormal collateral formation, but the spatial organization of vessel-wall abnormalities remains incompletely understood. Methods: We combined Xenium in situ spatial transcriptomics and multiplex immunofluorescence in superficial temporal artery samples from patients with MMD and controls, and performed gain- and loss-of-function experiments in human brain microvascular endothelial cells (HBMECs). Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), tube-formation, Transwell migration, and cell scratch assays were used to assess signaling and endothelial phenotypes. Results: MMD vascular tissue showed intimal hyperplasia, altered spatial cellular architecture, and enrichment of extracellular matrix- and proteoglycan-related programs, with upregulation of sulfatase 1 (SULF1). In HBMECs, SULF1 knockdown reduced, whereas SULF1 overexpression enhanced, vascular endothelial growth factor A165 (VEGF-A165)-induced vascular endothelial growth factor receptor 2 (VEGFR2), extracellular signal-regulated kinase 1/2 (ERK1/2), and protein kinase B (AKT) phosphorylation, migration, tube formation, and angiogenesis- and adhesion-related gene expression. Heparinase III attenuated the signaling effects associated with SULF1 overexpression. Conclusion: These findings suggest that SULF1-associated extracellular matrix alterations may contribute to local vessel-wall remodeling and enhanced endothelial responsiveness in MMD.