Progenitor Cells, Regenerative Capacity, and Cognition

BackgroundImpaired endogenous vascular regenerative capacity, reflected by reduced levels of circulating progenitor cells (CPC), has been linked to age-related diseases, especially adverse cardiovascular outcomes. We have previously reported that CPC are associated with cognitive aging, but their impact on cognitive impairment and related brain phenotypes is unclear. Here we report the impact of CPC on cognitive and neuroimaging markers of cognitive impairment. MethodsWe analyzed data from 283 community-dwelling participants (59% female, 39% Black) enrolled in the Brain Stress, Hemodynamics and Risk Prediction (B-SHARP) program. Participants underwent (a) cognitive assessments (including Montreal Cognitive Assessment [MoCA]); (b) brain magnetic resonance imaging (MRI) to derive white matter hyperintensity (WMH) volumes, whole-brain cortical thickness and hippocampal volumes; and (c) flow cytometry for enumerating CPCs as CD45med mononuclear cells expressing CD34 with co-expression with either CD133, chemokine CXC motif receptor 4 (CXCR4), or vascular endothelial growth factor receptor-2 (VEGF2R). Linear regression models were adjusted for demographic and vascular risk factors. ResultsIn fully adjusted models, lower levels of CD34/CD133 CPCs were associated with worse global cognition (MoCA: {beta} = 0.59, p = 0.01), reduced cortical thickness ({beta} = 0.01, p = 0.01), and greater WMH burden ({beta} = -0.15, p = 0.01). Lower levels of CD34 and CD34/CXCR4 CPCs were significantly associated with greater WMH volume burden (CD34: {beta} = -0.27, p < 0.01; CD34/CXCR4: {beta} = -0.14, p = 0.03). Higher CD34/VEGFR2 CPCs were associated with higher MoCA scores ({beta} = 0.37, p < 0.01) and language performance on the Boston Naming Test ({beta} = 0.01, p = 0.03) but not with brain phenotypes. ConclusionsReduced regenerative capacity is associated with worse cognitive performance on global tests and with vascular brain injury, including WMH volume and cortical thinning. If validated in future studies, these findings may highlight regenerative capacity as a promising therapeutic target for mitigating cognitive decline.