AbstractBackgroundVascular dementia (VD) is the second most common cause of dementia behind Alzheimer’s disease. VD has been associated with various cardiovascular maladies, which are thought to contribute to the white matter abnormalities associated with dementia. Cerebrovascular impairment disrupts CNS blood supply resulting in inflammation, oxidative stress, and hypoxia. The aim of this project is to study the impact of the cytotoxic environment created by disruptions to the CNS vasculature, which could be detrimental to glial (microglia, astrocyte) viability and function. We examined age and sex‐matched VD and control human autopsy brain from the Honolulu Asia Aging Study.MethodUtilizing Nanostring’s GeoMx™ Digital Spatial Profiling (DSP), we analyzed autopsy brain to compare neuropathologic vascular dementia lesions (lacunar, macro, and chronic microinfarcts) in the basal ganglia across the disease spectrum (absent/mild, moderate, severe). DSP enables spatial analysis of expression levels for 73 proteins in multiple regions of interest on formalin‐fixed paraffin‐embedded sections. Morphology markers were IBA1 (microglia) and GFAP (astrocytes) (Figure 1a‐b).Indica Labs’ HALO object co‐localization module was used to determine astrocyte, microglia, and total nuclei counts.ResultFor chronic microinfarct severity, astrocyte and microglial counts decreased as the number of microinfarcts increased. By contrast, for macroinfarcts, astrocyte counts increased in addition to microglia steadily decreasing as the number of macroinfarcts increased. Analyses comparing increasing chronic microinfarct severity revealed numerous proteins with differential expression in both microglia and astrocytes, including pTauS404, IDE, p62, ATG5 and P2RX7 (Figure 2 microglia; Figure 3 astrocytes).ConclusionUsing a spatial proteomic technique, we demonstrated that various vascular dementing lesions have unique glial autophagy and inflammatory profiles at different disease stages. Overall, lower levels of vascular dementia lesions display lower levels of inflammation and increased upregulation of protective pathways that may contribute to maintenance of cognitive function. We also demonstrated basal ganglia cell population changes across different disease severities for chronic microinfarcts and macroinfarcts. Findings suggest that there is progressive astrocyte and microglial loss in the setting of chronic microinfarcts and increased astrogliosis in the setting of macroinfarcts. Whether there is a definitive inverse relationship in astrocyte counts between chronic microinfarcts and macroinfarcts remains unclear.