Iron-induced oxidative rat liver injury after non-heart-beating warm ischemia is mediated by tumor necrosis factor α and prevented by deferoxamine

Targeting the PANoptosome Using Necrostatin-1 Reduces PANoptosis and Protects the Kidney Against Ischemia-Reperfusion Injury in a Rat Model of Controlled Experimental Nonheart-Beating Donor

PURPOSE

Reducing renal ischemia is crucial for the function and survival of grafts from nonheartbeat donors, as it leads to inflammatory responses and tubulointerstitial damage. The primary concern with organs from nonheartbeat donors is the long warm ischemia period and reperfusion injury following renal transplantation. This study had two main goals; one goal is to determine how Necrostatin-1 targeting the PANoptosome affects PANoptosis in the nonheart-beating donor rat model. The other goal is to find out if Necrostatin-1 can protect the kidney from ischemic injury for renal transplantation surgery.

METHODS

Twenty-four rats were grouped randomly as control and Necrostatin-1 in this experimental animal study, and we administered 1.65 mg/kg of Necrostatin-1 intraperitoneally to the experimental group for 30 minutes before cardiac arrest. We removed the rats' left kidneys and measured various oxidative stress marker measures such as malondialdehyde, superoxide dismutase, catalase, GPx, and 8-hydroxy-2-deoxyguanosine levels. We then subjected the tissues to immunohistochemical analysis, electron microscopy, and histopathological analysis.

FINDINGS

The Necrostatin-1 group had a lower total tubular injury score (P < .001) and less Caspase-3, gasdermin D, and mixed lineage kinase domain-like protein expression. Additionally, the apoptotic index of the study group was lower (P < .001). Furthermore, the study group had higher levels of superoxide dismutase and GPx (P < .05), whereas malondialdehyde levels were reduced (P = .009). Electron microscopy also revealed a significant improvement in tissue structure in the Necrostatin-1 group.

CONCLUSION

Necrostatin-1 protects against ischemic acute kidney injury in nonheart-beating donor rats by inhibiting PANoptosis via the blockade of RIPK1. As a result of this, Necrostatin-1 may offer novel opportunities for protecting donor kidneys from renal ischemia-reperfusion injury during transplantation in patients with end-stage kidney disease requiring a renal transplantation.

Combination of Deferoxamine With Cyclosporine Synergistically Blunt Renal Cold Ischemia-Reperfusion Injury in Rat Transplantation Model

OBJECTIVES

Ferroptosis plays a pivotal role in the pathogenesis of renal ischemia-reperfusion injury, where the processes are mediated by free ferrous ions and mitochondrial-released reactive oxygen species. However, the administration of high doses of cyclosporine A (CsA) or deferoxamine (DFO) poses a significant risk of renotoxicity. In contrast, low doses of DFO act as a ferrous iron chelator, and CsA functions as a mitochondrial reactive oxygen species blocker. This study aims to explore the potential protective effects of donor treatment with low-dose CsA, DFO, or their combination against ischemia-reperfusion injury during renal transplantation in a rat model.

MATERIALS AND METHODS

In an ex vivo cold storage (CS) model utilizing renal slices, the impact of incorporating DFO, CsA, and a combination of both into the University of Wisconsin solution was assessed through the measurement of lactate dehydrogenase leakage. Additionally, their potential benefits were investigated in a rat donation after circulatory death (DCD) kidney transplant model, where the extent of damage was evaluated based on graft function, tubular necrosis, and inflammation.

RESULTS

The co-administration of DFO and CsA effectively decreased the release of lactate dehydrogenase induced by CS ( P ≥ .05). In the in vivo model, this combined supplementation demonstrated a mitigating effect on reperfusion injury, evidenced by lower blood urea nitrogen levels and acute tubular necrosis scores compared to the control group (allP ≤ .05). Furthermore, the combined treatment significantly reduced apoptotic levels compared to the control group (P ≥ .05).

CONCLUSIONS

The combined treatment with DFO and CsA mitigated the cold ischemia-reperfusion injury in the DCD kidney. Hence, this presents a new strategy for the CS of DCD kidney in clinical transplants.

Ferroptosis: a new target for hepatic ischemia-reperfusion injury?

Ischemia-reperfusion injury (IRI) can seriously affect graft survival and prognosis and is an unavoidable event during liver transplantation. Ferroptosis is a novel iron-dependent form of cell death characterized by iron accumulation and overwhelming lipid peroxidation; it differs morphologically, genetically, and biochemically from other well-known cell death types (autophagy, necrosis, and apoptosis). Accumulating evidence has shown that ferroptosis is involved in the pathogenesis of hepatic IRI, and targeting ferroptosis may be a promising therapeutic approach. Here, we review the pathways and phenomena involved in ferroptosis, explore the associations and implications of ferroptosis and hepatic IRI, and discuss possible strategies for modulating ferroptosis to alleviate the hepatic IRI.

Gp78 deficiency in hepatocytes alleviates hepatic ischemia-reperfusion injury via suppressing ACSL4-mediated ferroptosis

Ferroptosis, which is driven by iron-dependent lipid peroxidation, plays an essential role in liver ischemia-reperfusion injury (IRI) during liver transplantation (LT). Gp78, an E3 ligase, has been implicated in lipid metabolism and inflammation. However, its role in liver IRI and ferroptosis remains unknown. Here, hepatocyte-specific gp78 knockout (HKO) or overexpressed (OE) mice were generated to examine the effect of gp78 on liver IRI, and a multi-omics approach (transcriptomics, proteomics, and metabolomics) was performed to explore the potential mechanism. Gp78 expression decreased after reperfusion in LT patients and mice with IRI, and gp78 expression was positively correlated with liver damage. Gp78 absence from hepatocytes alleviated liver damage in mice with IRI, ameliorating inflammation. However, mice with hepatic gp78 overexpression showed the opposite phenotype. Mechanistically, gp78 overexpression disturbed lipid homeostasis, remodeling polyunsaturated fatty acid (PUFA) metabolism, causing oxidized lipids accumulation and ferroptosis, partly by promoting ACSL4 expression. Chemical inhibition of ferroptosis or ACSL4 abrogated the effects of gp78 on ferroptosis and liver IRI. Our findings reveal a role of gp78 in liver IRI pathogenesis and uncover a mechanism by which gp78 promotes hepatocyte ferroptosis by ACSL4, suggesting the gp78-ACSL4 axis as a feasible target for the treatment of IRI-associated liver damage.

Iron deficiency after kidney transplantation

Iron deficiency (ID) is highly prevalent in kidney transplant recipients (KTRs) and has been independently associated with an excess mortality risk in this population. Several causes lead to ID in KTRs, including inflammation, medication and an increased iron need after transplantation. Although many studies in other populations indicate a pivotal role for iron as a regulator of the immune system, little is known about the impact of ID on the immune system in KTRs. Moreover, clinical trials in patients with chronic kidney disease or heart failure have shown that correction of ID, with or without anaemia, improves exercise capacity and quality of life, and may improve survival. ID could therefore be a modifiable risk factor to improve graft and patient outcomes in KTRs; prospective studies are warranted to substantiate this hypothesis.

Preventive effect of Desferal on sperm motility and morphology

Transition metal ions, mainly iron, are involved in the generation of highly reactive hydroxyl radicals, which are the most powerful inducers of oxidative damage to all biomolecules. The lipids in sperm membranes are highly susceptible to oxidation. Sperm lipid peroxidation (LPO) leads to decrease of motility and reduction of likelihood for sperm-oocyte fusion. The excess radical production may affect also the spermatozoa morphology. The aim of the present study was to investigate the effect of Desferal on the LPO, motility, and morphology of boar sperm subjected to oxidative stress. After collection, the ejaculates were equally separated and diluted in a commercial semen extender (experiment 1) or in physiological saline (experiment 2). The ejaculates of the 2 experiments were divided into aliquots, which were incubated with one of the following agents: FeSO4 (0.1mM), H2 O2 (0.5mM), or FeSO4  + H2 O2 (Fenton system), in the presence or absence of Desferal. The application of Desferal in the incubation medium had a protective effect against FeSO4  + H2 O2 -induced sperm damage, namely, decrease of LPO; decrease the quantity of immotile spermatozoa and decrease the number of morphological abnormalities, regardless of the used medium. In experiment 2, the presence of FeSO4 in the incubation medium induced LPO in the same range as the combination FeSO4  + H2 O2 , in which the effect was reduced by Desferal. Thus, the supplement of Desferal to media used for sperm storage and processing could be a useful tool for diminishing oxidative injury and improving the quality of the semen.

Impact of the serum ferritin concentration in liver transplantation

The serum ferritin (SF) concentration is a widely available and objective laboratory parameter. SF is also widely recognized as an acute-phase reactant. The purpose of the present study was to identify the chronological changes in the recipient's SF concentration during liver transplantation (LT) and to clarify factors having an effect on the recipient's intraoperative SF level. In addition, the study retrospectively evaluated the usefulness of measuring SF during LT. Ninety-eight pediatric recipients were retrospectively analyzed. The data were analyzed and compared according to the SF level in the recipient. Patients were classified into 2 groups based on the intraoperative peak SF levels of ≤ 1000 ng/mL (low-SF group) or >1000 ng/mL (high-SF group). The SF value increased dramatically after reperfusion and fell to normal levels within the early postoperative period. The warm ischemia time (WIT) was significantly longer in the high-SF group (47.0 versus 58.5 minutes; P = 0.003). In addition, a significant positive correlation was observed between the peak SF value and WIT (r = 0.35; P < 0.001). There were significant positive correlations between the peak SF value and the donors' preoperative laboratory data, including transaminases, cholinesterase, hemoglobin, transferrin saturation, and SF, of which SF showed the strongest positive correlation (r = 0.74; P < 0.001). The multivariate analysis revealed that WIT and donor's SF level were a significant risk factor for high SF level in the recipient (P = 0.007 and 0.02, respectively). In conclusion, the SF measurement can suggest the degree of ischemia/reperfusion injury (IRI). A high SF level in the donor is associated with the risk of further acute reactions, such as IRI, in the recipient.

Iron metabolism in transplantation

Recipient's iron status is an important determinant of clinical outcome in transplantation medicine. This review addresses iron metabolism in solid organ transplantation, where the role of iron as a mediator of ischemia-reperfusion injury, as an immune-modulatory element, and as a determinant of organ and graft function is discussed. Although iron chelators reduce ischemia-reperfusion injury in cell and animal models, these benefits have not yet been implemented into clinical practice. Iron deficiency and iron overload are associated with reduced immune activation, whose molecular mechanisms are reviewed in detail. Furthermore, iron overload and hyperferritinemia are associated with poor prognosis in end-stage organ failure in patients awaiting kidney, or liver transplantation. This negative prognostic impact of iron overload appears to persist after transplantation, which highlights the need for optimizing iron management before and after solid organ transplantation. In contrast, iron deficiency and anemia are also associated with poor prognosis in patients with end-stage heart failure. Intravenous iron supplementation should be managed carefully because parenterally induced iron overload could persist after successful transplantation. In conclusion, current evidence shows that iron overload and iron deficiency are important risk factors before and after solid organ transplantation. Iron status should therefore be actively managed in patients on the waiting list and after transplantation.