Autophagy is suppressed in peripheral blood mononuclear cells during chronic obstructive pulmonary disease

Abstract Assessing autophagy may offer insights into the pathogenesis of chronic obstructive pulmonary disease (COPD). However, measuring the dynamic aspect of autophagy is challenging, and sample manipulation can cause signal fluctuations that deviate from physiological conditions. We applied an organotypic method to quantify autophagy in COPD, where it frequently demonstrates disease-related dysregulation. Blood from control and COPD participants were treated with or without chloroquine. LC3B-II abundance was quantified in peripheral blood mononuclear cells, and findings were validated by transmission electron microscopy. Our observations show that while basal LC3B-II abundance was similar between groups (P = 0.60), autophagic flux was significantly lower in the COPD cohort, suggesting disruption in the regulatory factors that direct autophagosome clearance (P = 0.004). This was supported by less frequent observations of autophagy-related vacuoles in the cytosol of COPD-derived PBMCs. Our findings indicate that the suppression of autophagy can be detected in the blood of individuals with COPD, which warrants further investigation into its contribution to extrapulmonary disease processes. Competing Interest Statement The authors have declared no competing interest. Footnotes The manuscript wording has ben improved. Figures have been improved. New confirmatory supplementary figures have been added. Funding bodies have been acknowledged.