Sex-associated changes in the murine brain microvascular mitochondrial and extracellular matrix proteomes during aging

Contributions of the cerebral microvasculature to age-associated cognitive impairment, dementias and Alzheimer’s disease are recognized, but mechanisms and details such as sex-dependency are unclear. We reported aging-associated changes in mitochondrial morphology and protein expression of mitochondria and other proteins in mice microvessels (MVs), but did not examine sex-differences. We tested the hypothesis that aging affects the brain microvascular proteomes differently in male and female mice. Cortical brain MVs were isolated from young, middle aged, and old male and female C57Bl6/J mice (YM, MM, OM, YF, MF, OF, respectively) and used for 16-plex TMT proteomics (n = 5/age/sex). Collapsed replicates to the mean were used in the Omics Playground software by BigOmics with the following settings: no imputation, max-median normalization, and latent batch effect correction by nearest pair matching. We used the MitoCarta3.0 and MatrisomeDB 2.0 databases to assess mitochondria and extracellular matrix (ECM) associated MVs proteomes.Aging decreased protein expression in both OM and OF groups that were associated with oxidative phosphorylation, mitochondrial dynamics and surveillance, and protein import and homeostasis compared with young, whereas changes were bidirectional in the middle-aged groups. The small molecule transport pathway-associated proteins were more prominent in the YM compared with the YF and both were decreased in the old groups. The MF group showed greater expression compared with the YF, whereas changes were bidirectional in the MM group. Overall, proteasome-associated proteins were highly expressed in the young groups compared with the old, whereas overall expression was different in the middle-aged. We identified eight collagens in our MVs. While Col1a1 and Col1a2 showed greater expression in the young groups, aging affected their expression differently between sexes (decreased in OM and MM vs. increased in OF and decreased in MF). The expression of the remaining collagen proteins increased in the old groups, whereas the expression was decreased in MF and increased in MM. In addition, aging increased expression of ECM associated proteoglycans and glycoproteins, whereas the middle-aged groups showed bidirectional changes.Our results support and extend our previous observations showing that aging has detrimental morphological and functional effects on the brain MVs proteome. We postulate that the observed differences between males and females in protein expression can contribute to sex-based differences in the manifestation of aging-associated cerebral pathologies. Furthermore, age-related changes are apparent in mid-life indicating early sex-specific treatment may delay or prevent brain pathologies. AG075988 (DB), HL148836 (DB), AG063345 (DB), AG083567 (IR), NS136041 (PC) This abstract was presented at the American Physiology Summit 2025 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.