Vascular profiling of the spinal cord and cortex reveals region-specific endothelial dysfunction and fibroblast remodeling in human ALS.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive degeneration of upper and lower motor neurons. Increasing evidence suggests that neurovascular dysfunction contributes to ALS pathogenesis, but a comprehensive understanding of vascular cell alterations in the human central nervous system remains lacking. Here, to systematically characterize neurovascular changes in ALS, we curated single-nucleus transcriptomic datasets from human spinal cord and cortical tissues with a specific focus on vascular cell populations. Comparative analyses revealed substantial vascular perturbations in the spinal cord compared to the cortex. Among vascular-associated cell populations, endothelial cells and fibroblasts exhibited the most pronounced transcriptional alterations. Endothelial cells from ALS spinal cords displayed reduced blood-brain barrier integrity signatures and increased expression of inflammatory and stress-response programs, with the greatest changes manifested in capillary endothelial cells. In parallel, we generated a refined cellular atlas of spinal cord fibroblasts and identified three major fibroblast populations, including a distinct LAMA1