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BACKGROUND: This study aimed to investigate the cardioprotective effect of exosomes derived from human umbilical cord mesenchymal stem cells on donation after circulatory death (DCD) hearts preserved with normothermic ex vivo heart perfusion (EVHP) in a rat heart transplantation model. METHODS: Thirty-two male Lewis rats were divided into 2 groups: the control group and the exosome group. The donor-heart rats were subjected to the DCD procedure by suffering a 15-min warm ischemia injury, subsequently preserved with EVHP for 90 min, and then transplanted into recipients via abdominal heterotopic heart transplantation. Vehicle or exosome was added into the perfusate of normothermic EVHP in the control or exosome group. We evaluated left ventricular graft function, myocardial inflammation, and myocardial apoptosis of the donor heart 1.5 h after heart transplantation. Furthermore, we investigate the alternation of myocardial gene expression in the donor hearts between both groups by transcriptome sequencing. RESULTS: The treatment with exosome significantly enhanced cardiac function through increasing left ventricular developed pressure, dp/dtmax, and dp/dtmin of DCD hearts at 90 min after heart transplantation compared with the control group. The myocardial cells in the exosome group exhibited an orderly arrangement without obvious edema. Furthermore, exosome added into perfusate in the exosome group significantly attenuated the level of inflammatory response and apoptosis. Transcriptome sequencing and RT-qPCR showed the phosphoinositide 3-kinase/protein kinase B pathway was activated after exosome treatment. CONCLUSIONS: Normothermic EVHP combined with exosome can be a promising and novel DCD heart preservation strategy, alleviating myocardial ischemia-reperfusion injury in the DCD heart.
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Background: The utilization of donation after circulatory death (DCD) hearts can enlarge the donor pool. However, DCD hearts suffer from serious ischemia/reperfusion injury (IRI). Recent studies found that the activation of NLRP3 inflammasome could play a significant role in organ IRI. Mcc950, which is a novel inhibitor of the NLRP3 inflammasome, can be applied to treat various kinds of cardiovascular diseases. Therefore, we hypothesized that the treatment of mcc950 could protect DCD hearts preserved with normothermic ex vivo heart perfusion (EVHP) against myocardial IRI via inhibiting NLRP3 inflammasome in a rat heart transplantation model of DCD. Methods: Donor-heart rats were randomly divided into four groups: Control group; Vehicle group; MP-mcc950 group; and MP + PO-mcc950 group. Mcc950 was added into the perfusate of normothermic EVHP in the MP-mcc950 and MP + PO-mcc950 groups, and was injected into the left external jugular vein after heart transplantation in the MP + PO-mcc950 group. Cardiac functional assessment was performed. The level of oxidative stress, inflammatory response, apoptosis, and NLRP3 inflammasome-associated protein of donor hearts were evaluated. Results: The treatment with mcc950 significantly increased the developed pressure (DP), dP/dtmax, and dP/dtmin of the left ventricular of DCD hearts at 90â min after heart transplantation in both MP-mcc950 and MP + PO-mcc950 groups. Furthermore, mcc950 added into perfusate and injected after transplantation in both MP-mcc950 and MP + PO-mcc950 groups significantly attenuated the level of oxidative stress, inflammatory response, apoptosis, and NLRP3 inflammasome compared with the vehicle group. Conclusions: Normothermic EVHP combined with mcc950 treatment can be a promising and novel DCD heart preservation strategy, which can alleviate myocardial IRI via inhibiting NLRP3 inflammasome.
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Objective: Adopting hearts from donation after circulatory death (DCD) is a promising approach to enlarge the donor pool. Nevertheless, DCD hearts experience severe warm ischemia/reperfusion (I/R) injury. Recent studies have demonstrated that conditioned medium (CM) derived from bone marrow mesenchymal stem cells (BMSCs) has the potential of reducing organ I/R injury. Therefore, we investigated whether DCD heart preservation with normothermic ex vivo heart perfusion (EVHP) and BMSCs-CM treatment could alleviate myocardial warm I/R injury in the DCD hearts. Methods: We randomly divided donor rats into two groups: (1) DCD-Control group and (2) DCD-CM group. Before DCD heart preservation with the normothermic EVHP system for 105 minutes, rats suffered from a 25-minute warm ischemia injury in the DCD procedure. Vehicle or CM (300 µl) was added to the perfusate at the beginning of the perfusion process. The cardiac function of DCD hearts in the DCD-Control and DCD-CM groups was measured every 30 minutes. Besides, non-DCD hearts were harvested from the beating-heart rats. Results: The antibody array demonstrated that the CM contained 14 bioactive factors involved in apoptosis, inflammation, and oxidative stress. Warm ischemia injury resulted in a significant increase in the level of oxidative stress, inflammation, and apoptosis in the DCD hearts of DCD-Control group. Furthermore, compared with the DCD-Control group, CM treatment increased the developed pressure, dP/dtmax and dP/dtmin of the left ventricular in the DCD hearts during a 90-minute EVHP. Moreover, the administration of CM attenuated the level of oxidative stress, inflammation, and apoptosis in the DCD hearts of the DCD-CM group. Conclusions: Normothermic EVHP combined with CM treatment can alleviate warm I/R injury in the DCD hearts by decreasing the level of oxidative stress, inflammatory response, and apoptosis, which might alleviate the shortage of donor hearts by adopting DCD hearts.
