ORCID

0000-0002-5473-1621 (Bohannon)

Document Type

Article

Publication Date

2026

DOI

10.1016/j.nbas.2026.100164

Publication Title

Aging Brain

Volume

10

Pages

100164

Abstract

Blood–brain barrier (BBB) integrity naturally declines with age. Brain endothelial cells (ECs) and pericytes (PCs) form the BBB, and aging impairs tight junctions, likely via altered PC-to-EC signaling. However, the molecular mechanisms underlying this impairment remain unclear. Using single-cell RNA sequencing, we profiled 68,316 brain ECs expressing 15,564 genes from young and old mice. Unsupervised clustering and annotation revealed five distinct EC subtypes—Capillary EC1, Capillary EC2, Arterial EC, Venous EC1, and Venous EC2—defined by marker genes Mfsd2a, Plvap, Bmx, Nr2f2, and Vcam1, respectively. Aging shifted EC subtype distribution, with reduced Capillary EC1 (45% vs. 57%) and increased Arterial (33% vs. 16%) and Venous ECs (12% vs. 2%) compared with young mice. Mio analysis further showed that Capillary EC1 and Venous EC2 neighborhoods were less abundant in aged brains. Biotin metabolism was decreased in old vs. young mice, particularly within Capillary EC1, Capillary EC2, and Arterial EC. Although widespread gene downregulation was observed across EC subsets, overall expression trends were largely consistent among clusters. Key genes—Ramp2, Hbb-bs, Ly6c1, Calm1—were less abundant, whereas Rasgrf2 was uniquely enriched in aged mice. Immunohistochemistry confirmed reduced LY6C and RAMP2 and elevated RASGRF2 in aged mouse and human brains. Cell–cell interaction analyses revealed age-associated remodeling of ligand-receptor signaling. Enrichment analyses implicated pathways involved in neurovascular integrity, inflammation, amyloid processing, and vascular remodeling. Collectively, these findings show that aging reprograms EC subtype composition, gene expression, and metabolism, thereby contributing to BBB disruption and neurovascular dysfunction.

Rights

© 2026 The Authors.

This is an open access article under the Creative Commons Attribution 4.0 International (CC BY 4.0) License.

Data Availability

Article states: "Data will be available from the corresponding author upon reasonable request."

Original Publication Citation

Nguyen, H. D., Siddiqui, S., Bohannon, D. G., Blair, R. V., Deng, H. W., Prat, A., & Kim, W. K. (2026). Single-cell transcriptomic analysis reveals age-related remodeling of brain endothelial cells. Aging Brain, 10, Article 100164. https://doi.org/10.1016/j.nbas.2026.100164

Additional Files
1-s2.0-S2589958926000095-mmc1.pdf (10484 kB)
Supplementary Material 1
1-s2.0-S2589958926000095-mmc2.xlsx (145 kB)
Supplementary Material 2
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