Influence of ex vivo perfusion on the biomolecular profile of rat lungs

Abstract

Despite increasing clinical adoption, biologic influences of ex vivo lung perfusion (EVLP) remain insufficiently elucidated. The aim of the current study was to investigate biomolecular changes induced by EVLP in rat lungs. EVLP was maintained for 180 min. Hyaluronan, mediators, and cells were assessed in the perfusate. Gene expression, signaling pathways, and ATP content were investigated in lung tissue. EVLP induced the release of medium-high molecular weight hyaluronan and transcription of hyaluronan synthases ( P< 0.001). Increasing concentrations of inflammatory mediators were detected in the perfusate ( P < 0.001). Perfused lungs exhibited a distinctive transcriptional signature compared with organs examined before or after surgery/procurement ( P = 0.003). Up-regulated genes were involved in inflammation and its regulation, apoptosis/survival, heat shock, and oxidative stress response ( q = 0). Down-regulated genes were related to lymphocyte function ( q = 0). The NF-κB, signal transducer and activator of transcription 3, ERK1/2, p38, Akt, and stress-activated protein kinase/JNK signaling pathways were modulated by EVLP ( P < 0.05). Most of these biomolecular changes were examined and confirmed in additional experiments that were performed in lungs procured from donation after cardiocirculatory death after 180 min of warm ischemia. The current study demonstrates that EVLP broadly affects the lung biomolecular phenotype. These findings improve our comprehension of the effects exerted by the procedure and encourage additional research in preclinical models to implement therapeutic interventions.-Lonati, C., Bassani, G. A., Brambilla, D., Leonardi, P., Carlin, A., Faversani, A., Gatti, S., Valenza, F. Influence of ex vivo perfusion on the biomolecular profile of rat lungs.

Treatment with 3-aminobenzamide during ex vivo lung perfusion of damaged rat lungs reduces graft injury and dysfunction after transplantation

“…Immune activation plays a major role in lung IR and the development of PGD . It depends primarily on the activation of NF‐κB, which can already occur during EVLP . Indeed, we recently reported that inhibiting NF‐κB during EVLP suppressed the expression of inflammatory mediators in damaged lung grafts ex vivo .…”

“…33 It depends primarily on the activation of NF-κB, 34 which can already occur during EVLP. 35 Indeed, we recently reported that inhibiting NF-κB during EVLP suppressed the expression of inflammatory mediators in damaged lung grafts ex vivo. 9 We therefore assume that such mechanisms triggered the release of cytokines noted at the end of EVLP, as well as after LTx in EVLPtreated lungs.…”

“…It seems intriguing at first glance that, despite an increased expression of inflammatory mediators, EVLP‐treated lungs displayed such reduction of inflammatory cell infiltration and improved histological status after LTx. It has been indeed frequently reported that EVLP upregulates the expression of many inflammatory genes, due to the activation of pro‐inflammatory signaling pathways, including NF‐κB, STAT‐3, and MAP kinases, following ex vivo reperfusion of the graft at normothermia, that is, at full metabolic activity. This apparent paradox has been recently worked out by Yeung et al, who showed that EVLP increased endothelial markers of inflammation, but at the same time reduced the expression of leukocyte‐specific inflammatory genes, due to the washout of circulating leukocytes during EVLP .…”

Isolated Lung Perfusion in the Management of Acute Respiratory Distress Syndrome

“…These data suggest that EVLP induces a shift of the L-arginine balance towards arginase, leading to nitric oxide deficiency in the lung. Using a rat model of EVLP, Lonati and colleagues described a remarkable anti-inflammatory response during EVLP, including the activation of protective and anti-apoptotic pathways [ 54 ]. They also detected resolution factors in perfused, uninjured lungs, including transcripts that encode for feedback inhibitors of Toll-like receptors and cytokine signaling, such as inhibitors of nuclear factor-κB (NF-κB) signaling IκB (inhibitor of κB), IL-1 receptor antagonist 1, lL-1 decoy receptor, and nonfunctional interleukin 1 receptor-associated kinase-M.…”

Evolving Trend of EVLP: Advancements and Emerging Pathways

“…Steen solution was believed to possess antioxidant properties via downregulation of NADPH oxidase activity and enhanced production of NO [93], exerting antioxidant effects on parenchymal cells [94]. Releasing of medium-high molecular weight hyaluronan and transcription of hyaluronan synthases were also induced by EVLP [95]. ATL802, an adenosine A2B receptor antagonist could augment reconditioning of EVLP with significantly improved lung function and attenuated pro-inflammatory cytokine production, such as IL-12, neutrophil infiltration, vascular permeability, and edema [96,97].…”