Background

Ex vivo lung perfusion (EVLP) enables assessment and rehabilitation of marginal donor lungs before transplantation. We previously demonstrated that adenosine A2A receptor (A 2A R) agonism attenuates lung ischemia-reperfusion injury. The current study utilizes a novel murine EVLP model to test the hypothesis that A 2A R agonist enhances EVLP-mediated rehabilitation of donation after circulatory death (DCD) lungs.

Methods

Mice underwent euthanasia and 60 minutes warm ischemia, and lungs were flushed with Perfadex and underwent cold static preservation (CSP, 60 minutes). Three groups were studied: no EVLP (CSP), EVLP with Steen solution for 60 minutes (EVLP), and EVLP with Steen solution supplemented with ATL1223, a selective A 2A R agonist (EVLP+ ATL1223). Lung function, wet/dry weight, cytokines and neutrophil numbers were measured. Microarrays were performed using the Affymetrix GeneChip Mouse Genome 430A 2.0 Array.

Results

Ex vivo lung perfusion significantly improved lung function versus CSP, which was further, significantly improved by EVLP+ ATL1223. Lung edema, cytokines, and neutrophil counts were reduced after EVLP and further, significantly reduced after EVLP+ ATL1223. Gene array analysis revealed differential expression of 1594 genes after EVLP, which comprise canonical pathways involved in inflammation and innate immunity including IL-1, IL-8, IL-6, and IL-17 signaling. Several pathways were uniquely regulated by EVLP+ ATL1223 including the downregulation of genes involved in IL-1 signaling, such as ADCY9, ECSIT, IRAK1, MAPK12, and TOLLIP.

Conclusions

Ex vivo lung perfusion modulates proinflammatory genes and reduces pulmonary dysfunction, edema, and inflammation in DCD lungs, which are further reduced by A 2A R agonism. This murine EVLP model provides a novel platform to study rehabilitative mechanisms of DCD lungs.