Paradoxical Associations between Exposure to Adverse Childhood Experiences, Vascular Endothelial Function, and Mitochondrial Superoxide Production

Introduction: Adverse childhood experiences (ACEs) are severe psychosocial stressors that occur during the first 18 years of life and are associated with impaired vascular endothelial function (VEF). Augmented mitochondrial reactive oxygen species (mtROS; i.e., superoxide) production contributes to oxidative stress and vascular dysfunction. Purpose: Therefore, we tested the hypothesis that young adults with (ACE+) versus without (ACE-) prior ACE exposure would be associated with augmented mtROS in association with reduced in vivo VEF. Methods: We used two different cohorts of young adults without cardiometabolic disease and different, but complementary models to test our hypothesis. In Study 1 (n=17; age = 23±3 years; BMI = 22±4 kg/m2), peripheral blood mononuclear cells were isolated from whole blood and T-cell mtROS was assessed by flow cytometry with fluorogenic staining (MitoSOX Green) and presented as median fluorescence intensity [MFI; arbitrary units (AU)]. T cell subtype frequency, T cell mtROS, and FMD in ACE- and ACE+ were compared with independent samples t-tests. Using an ex-vivo cell culture model in Study 2 (n=23; age = 24±5 years; BMI = 26±5 kg/m2), human aortic endothelial cells (HAECs) were cultured with 10% participant serum before fluorescent probe staining with CellROX for 30 minutes. Live HAECs were imaged using fluorescence microscopy and total mtROS was assessed. Total mtROS and FMD in ACE- and ACE+ were compared with independent samples t-test. In both studies, in vivo VEF was assessed using the brachial artery flow mediated dilation (FMD) technique and associations between mtROS and FMD were examined using Spearman’s correlation coefficients (ρ). Results: In Study 1, the frequency of T-helper (CD4+), total regulatory T (Treg), T-cytotoxic (CD8+) cells of total live T cells were not different between groups (all p > 0.49). However, T-helper (8477±564 AU vs 9337±654 AU, p = 0.011) and Treg (8635 ± 729 AU vs 9557 ± 746 AU, p = 0.021) mtROS was lower in ACE+ than ACE-, whereas the difference in T-cytotoxic (CD8+) mtROS was not significant ( p = 0.08). In Study 2, mtROS produced by HAECs was lower in the ACE+ group compared to the ACE- group (1285±121 AU vs 1416±127 AU, p = 0.019). In both Study 1 and 2, FMD was lower in ACE+ than ACE- (-4.2±1.3%, p = 0.007 and -3.4±1.2%, p < 0.01, respectively). Interestingly, there were moderate, non-significant, positive associations of T-helper (ρ = 0.46, p = 0.066) and Treg mtROS (ρ = 0.42, p = 0.098) with FMD in Study 1, and a significant positive association of endothelial mtROS with FMD (ρ = 0.50, p = 0.016) in Study 2. Conclusions: Our findings from two separate cohorts using different, but complimentary approaches provide strong initial evidence that ACE exposure is associated with counterintuitive reductions in mtROS production in both endothelial and T-cells. The use of the ex-vivo cell culture model suggests that this effect may be driven by, as of yet, unidentified factor(s) in circulation. Funding: Supported by NIH and AHA funding to NDMJ (R01HL167788, L30HL149066, & 24TPA1290435) and to DRS (R01AG066730). 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.