Neuroinflammatory profiles regulated by the redox environment predicted cognitive dysfunction in people living with HIV: A cross-sectional study

Abstract

Background: Despite effective combination antiretroviral therapy (cART), people living with HIV (PLWH) remain at risk for developing neurocognitive impairment primarily due to systemic inflammation that persists despite virologic suppression, albeit the mechanisms underlying such inflammation are poorly understood. Methods: Herein, we evaluate the predictive capacity of the mitochondrial redox environment on circulating neuro- and T-lymphocyte-related inflammation and concomitant cognitive function in 40 virally-suppressed PLWH and 40 demographically-matched controls using structural equation modeling. We used state-of-the-art systems biology approaches including Seahorse Analyzer of mitochondrial function, electron paramagnetic resonance (EPR) spectroscopy to measure superoxide levels, antioxidant activity assays, and Meso Scale multiplex technology to quantify inflammatory proteins in the periphery. Findings: We observed disturbances in mitochondrial function and the redox environment in PLWH compared to controls, which included reduced mitochondrial capacity (t(76) = −1.85, p = 0.034, 95% CI: −∞,−0.13), elevated levels of superoxide (t(75) = 1.70, p = 0.047, 95% CI: 8.01 E 3, ∞) and alterations in antioxidant defense mechanisms (t(74) = 1.76, p = 0.041, 95% CI: −710.92, ∞). Interestingly, alterations in both superoxide- and hydrogen peroxide-sensitive redox environments were differentially predictive of neuro-, but not T-lymphocyte-related inflammatory profiles in PLWH and controls, respectively (ps < 0.026). Finally, when accounting for superoxide-sensitive redox pathways, neuroinflammatory profiles significantly predicted domain-specific cognitive function across our sample (β = −0.24, p = 0.034, 95% CI: −0.09, −0.004 for attention; β = −0.26, p = 0.018, 95% CI: −0.10, −0.01 for premorbid function). Interpretation: Our results suggest that precursors to neuroinflammation apparent in PLWH (i.e., mitochondrial function and redox environments) predict overall functionality and cognitive dysfunction and importantly, may serve as a proxy for characterizing inflammation-related functional decline in the future.

Keywords

• Seahorse Analyzer
• EPR Spectroscopy
• Inflammation
• Mitochondrial Respiration
• Superoxide
• Hydrogen Peroxide