Prolonged cold ischemia induces necroptotic cell death in ischemia–reperfusion injury and contributes to primary graft dysfunction after lung transplantation

X Wang, ME O'Brien, J Yu, C Xu, Q Zhang… - American journal of …, 2019 - atsjournals.org
X Wang, ME O'Brien, J Yu, C Xu, Q Zhang, S Lu, L Liang, X An, JF McDyer, RK Mallampalli
American journal of respiratory cell and molecular biology, 2019atsjournals.org
Primary graft dysfunction (PGD) is a major cause of morbidity and mortality after lung
transplantation. Ischemia–reperfusion injury (IRI) is a key event that contributes to PGD,
though complex interactions affect donor lungs status, such as preceding brain death (BD),
hemorrhagic shock (HS), and pre-engraftment lung management, the latter recognized as
important risk factors for PGD. We hypothesized that a multi-hit isogenic mouse model of
lung transplantation is more closely linked to PGD than IRI alone. Left lung transplants were …
Primary graft dysfunction (PGD) is a major cause of morbidity and mortality after lung transplantation. Ischemia–reperfusion injury (IRI) is a key event that contributes to PGD, though complex interactions affect donor lungs status, such as preceding brain death (BD), hemorrhagic shock (HS), and pre-engraftment lung management, the latter recognized as important risk factors for PGD. We hypothesized that a multi-hit isogenic mouse model of lung transplantation is more closely linked to PGD than IRI alone. Left lung transplants were performed between inbred C57BL/6 mice. A one-hit model of IRI was established by inducing cold ischemia (CI) of the donor lungs at 0°C for 1, 72, or 96 hours before engraftment. Multi-hit models were established by inducing 24 hours of HS and/or 3 hours of BD before 24 hours of CI. The recipients were killed at 24 hours after transplant and lung graft samples were analyzed. In the one-hit model of IRI, up to 72-hour CI time resulted in minimal cellular infiltration near small arteries after 24-hour reperfusion. Extension of CI time to 96 hours led to increased cellular infiltration and necroptotic pathway activation, without evidence of apoptosis, after 24-hour reperfusion. In a multi-hit model of PGD, “HS + BD + IRI” demonstrated increased lung injury, cellular infiltration, and activation of necroptotic and apoptotic pathways compared with IRI alone. Treatment with an inhibitor of receptor-interacting protein kinase 1 kinase, necrostatin-1, resulted in a significant decrease of downstream necroptotic pathway activation in both single- and multi-hit models of IRI. Thus, activation of necroptosis is a central event in IRI after prolonged CI, though it may not be sufficient to cause PGD alone. Pathological evaluation of donor lungs after CI-induced IRI, in conjunction with pre-engraftment donor lung factors in our multi-hit model, demonstrated early evidence of lung injury consistent with PGD. Our findings support the premise that pre-existing donor lung status is more important than CI time alone for inflammatory pathway activation in PGD, which may have important clinical implications for donor lung retrieval.
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