Abstract

Background Mitochondrial dysfunction during lung ischemia-reperfusion injury (LIRI) contributes to organ dysfunction. Aconitase-2 (ACO2), by enhancing the mitochondrial TCA cycle in pulmonary vascular endothelial cells (PVECs), plays a critical role in maintaining cellular energy metabolic homeostasis. This study aims to explore the therapeutic potential of ACO2 in mitigating apoptosis under I/R conditions. Methods We employed single-cell RNA sequencing (scRNA-seq) to characterize cellular phenotypes in the lung tissue microenvironment of I/R mice. RNA sequencing (RNA-seq) was applied to identify differentially expressed genes in LIRI. Our cohort included 65 healthy donors and 48 LIRI patients to analyze the correlation between serum ACO2 contents and lung function. In vivo , we delivered an adeno-associated virus (AAV) for lung-specific ACO2 overexpression and ACO2 inhibitor to assess its effect on lung injury. In vitro , we isolated primary PVECs and subjected them to H/R, overexpression and knockout of ACO2 and the supplement of ACO2 downstream product derivative 4-OI to determine its role in mitochondrial function. Results Serum ACO2 levels were elevated in LIRI patients and showed a negative correlation with lung function. In I/R mice, ACO2 overexpression alleviated mitochondrial dysfunction and lung injury, whereas inhibition of ACO2 exacerbated the injury. In PVECs, ACO2 overexpression enhanced mitochondrial function and reduced apoptosis; conversely, ACO2 knockout produced the opposite effects. The supplementation with 4-OI mitigated the mitochondrial dysfunction and cellular apoptosis induced by ACO2 knockout. Conclusion ACO2 holds promise for improving mitochondrial function and reducing apoptosis, thereby positioning it as a promising therapeutic target for this condition.