Preservation with α1-antitrypsin improves primary graft function of murine lung transplants

Abstract

BackgroundVascular damage and primary graft dysfunction increase with prolonged preservation times of transplanted donor lungs. Hence, storage and conservation of donated lungs in protein-free, dextran-containing electrolyte solutions, like Perfadex, is limited to about 6 hours. We hypothesized that transplanted lungs are protected against neutrophil-mediated proteolytic damage by adding α1-anti-trypsin (AAT), a highly abundant human plasma proteinase inhibitor, to Perfadex.MethodsA realistic clinically oriented murine model of lung transplantation was used to simulate the ischemia–reperfusion process. Lung grafts were stored at 4°C in Perfadex solution supplemented with AAT or an AAT mutant devoid of elastase-inhibiting activity for 18 hours. We examined wild-type and proteinase 3/neutrophil elastase (PR3/NE) double-deficient mice as graft recipients. Gas exchange function and infiltrating neutrophils of the transplanted lung, as well as protein content and neutrophil numbers in the bronchoalveolar lavage fluid, were determined.ResultsAAT as a supplement to Perfadex reduced the extent of primary graft dysfunction and early neutrophil responses after extended storage for 18 hours at 4°C and 4-hour reperfusion in the recipients. Double-knockout recipients that lack elastase-like activities in neutrophils were also protected from early reperfusion injury, but not lung grafts that were perfused with a reactive center mutant of AAT devoid of elastase-inhibiting activity.ConclusionsPR3 and NE, the principal targets of AAT, are major triggers of post-ischemic reperfusion damage. Their effective inhibition in the graft and recipient is a promising strategy for organ usage after storage for >6 hours.

Premedication with a cathepsin C inhibitor alleviates early primary graft dysfunction in mouse recipients after lung transplantation

“…In view of the promising phase I trials, CatC inhibitors can be rapidly translated into clinical practice. Independent of better protection of donor lungs during cold storage 8 , CatC inhibitors are a new promising drug class for the prevention of the early post-operative complications and the development of PDG in LTx.…”

“…Primary graft dysfunction (PGD) after LTx was induced as previously described 8,32,33 . 8 to 10 week-old male C57BL/6J were used as graft donors for ICatC or vehicle-treated C57BL/6J recipient mice.…”

“…It is caused by ischemia-reperfusion injury, associated with the release of neutrophil serine proteases (NSPs) during reperfusion of the ischemic lung transplant 4–7 . While alpha-1-antitrypsin (AAT) added to the preservation solution protects murine donor lungs during cold storage and initially during first blood passages after reperfusion by its anti-protease activity 8 , circulating neutrophils from the recipient still contain active serine proteases including neutrophil elastase (NE), proteinase (PR3), cathepsin G (CatG) and neutrophil serine protease 4 (NSP4), which are not all inhibited by AAT.…”

Endothelial Microvesicles Induce Pulmonary Vascular Leakage and Lung Injury During Sepsis

“…The BAL fluid was obtained by centrifugation at 500 × g for 20 min (4 • C), and the supernatant was used to measure protein concentration with Pierce BCA protein assay kit (Thermo Fisher Scientific, America). Then the sediment was suspended by 1 mL PBS, and the BAL cell counts were performed by cell counting chamber (Gotzfried et al, 2018;Izzotti et al, 2018).…”

Review 2: Primary graft dysfunction after lung transplant—pathophysiology, clinical considerations and therapeutic targets

“…In animal models of lung transplant, α 1 -antitrypsin administration has been associated with significantly reduced NF-κB expression and neutrophil infiltration, better gas exchange, and better lung compliance [ 129 , 130 ]. In addition, in EVLP only and in ischaemia/reperfusion models, α 1 -antitrypsin administration has also been associated with significantly reduced inflammatory cytokine expression, neutrophil infiltration and apoptosis, with better lung compliance [ 62 , 131 ].…”