Sex-differences and brain microvascular vulnerability during aging in mice

Background: The microvascular etiology of age-associated cognitive impairment and dementias, including Alzheimer’s disease (AD), has been recognized but not completely explored. Further, while sex-differences are prevalent in disease pathology and manifestation, the underlying mechanisms are unclear. Therefore, we tested how aging affects the expression of AD model-associated proteins in brain microvessels (MVs) proteome of male and female mice. Methods: We analyzed 16-plex TMT proteomics data of mouse cortical brain MVs. MVs were isolated from young, middle aged, and old male and female C57Bl6/J mice (n = 5/age/sex) using gradient centrifugation and size filtering (70 mm). We used the Omics Playground software by BigOmics for protein expression analysis, heatmap and functional annotation module generation. The MVs proteomics data was filtered for a subset of proteins that were identified as common in male and female cortices in our in-house pilot AD brain transcriptomic analysis. Results: 129 proteins common in males and females were used to generate heatmaps and one functional annotation module with correlation for both sexes. For males, the top module included mTORC1 signaling, glycolysis, PI3K-AKT-mTOR signaling, and inflammatory response, whereas the female data set was associated with inflammatory response, mitotic spindle, PI3K-AKT-mTOR signaling, and TNFa-NFkB signaling. Mitochondria related functional annotations included glycolysis, oxidative phosphorylation, and reactive oxygen species for both, and fatty acid metabolism for the female data set only. In addition, the female functional annotation module had a stronger correlation compared with the male. We compared protein abundance of old vs. young groups using limma-trend (p≤0.05) and log2FC (30% change) cut offs for significance. In the male data set, we identified 13 proteins that were significant by p value and log2FC (6 down and 7 up), 48 proteins by p value, and one protein by log2FC (up). In addition, we found 11 proteins that were significant by p value and log2FC (3 down and 8 up), and 58 by p value, and one by log2FC (down) in the female data set. We found that five proteins (upregulated) were common within those meeting the p value and log2FC cut offs, and these included glial fibrillary acidic protein, laminin alpha 2, myelin-associated oligodendrocytic basic protein, nucleoporin 210, and palmitoyl-protein thioesterase 1. These proteins have been recognized and implicated in neurodegenerative processes and blood-brain barrier impairment. Conclusion: Our results indicate the convergence and divergence of sex-differences in microvascular aging that may contribute to brain vulnerability and the clinical manifestation of aging associated neuropathologies Funding: AG075988 (DWB), HL148836 (DWB), AG063345 (DWB), R01AG083567 (IR-G), R01NS136041 (PKC) This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.