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Objective: To investigate the potential protective effect of Shexiang Tongxin dropping pills (STDP) on ischemia-reperfusion injury and its underlying mechanisms in improving endothelial cell function in coronary microvascular disease (CMVD). Methods: A rat model of myocardial ischemia-reperfusion injury with CMVD was established using ligation and reperfusion of the left anterior descending artery. The effect of STDP (21.6 mg/kg) on cardiac function was evaluated using echocardiography, hematoxylin-eosin staining, and Evans blue staining. The effects of STDP on the microvascular endothelial barrier were assessed based on nitric oxide production, endothelial nitric oxide synthase expression, structural variety of tight junctions (TJs), and the expression of zonula occludens-1 (ZO-1), claudin-5, occludin, and vascular endothelial (VE)-cadherin proteins. The mechanisms of STDP (50 and 100 ng/mL) were evaluated by examining the expression of sphingosine 1-phosphate receptor 2 (S1PR2), Ras Homolog family member A (RhoA), and Rho-associated coiled-coil-containing protein kinase (ROCK) proteins and the distribution of ZO-1, VE-cadherin, and F-actin proteins in an oxygen and glucose deprivation/reoxygenation model. Results: The administration of STDP on CMVD rat model significantly improved cardiac and microvascular endothelial cell barrier functions (all P

DL-3-n-butylphthalide (NBP) exhibits promising pharmacological efficacy against ischemia-reperfusion injury, but its protective effects may involve many mechanisms that are yet to be fully understood. This study aimed to profile the metabolic alterations induced by NBP during the process of ischemia-reperfusion using spatial metabolomics. Our study found that NBP could significantly reduce the ischemic area and restore physical function by potentially modulating pathways of the citrate cycle, pyruvate metabolism, autophagy, and unsaturated fatty acid biosynthesis. During the process of ischemia-reperfusion, NBP played a therapeutic role in improving energy supply, decreasing autophagy, and improving unsaturated fatty acid biosynthesis. Subsequent studies confirmed improvements in relevant indices of mitochondrial morphology, autophagy, and ferroptosis after treatment with NBP. These findings shed light on novel mechanisms underlying the efficacy of NBP in treating cerebral ischemia/reperfusion injury associated with ischemic stroke.

Objective: This study investigates the effects of caloric restriction (CR) on renal injury and fibrosis following ischemia-reperfusion injury (IRI), with a focus on the roles of the mechanistic/mammalian target of rapamycin complex 1 (mTORC1) signaling and autophagy. Methods: A mouse model of unilateral IRI with or without CR was used. Renal function was assessed through serum creatinine and blood urea nitrogen levels, while histological analysis and molecular assays evaluated tubular injury, fibrosis, mTORC1 signaling, and autophagy activation. Inducible renal tubule-specific Atg7 knockout mice and autophagy inhibitor 3-MA were used to elucidate autophagy's role in renal outcomes. Results: CR exacerbated renal dysfunction, tubular injury, and fibrosis in IRI mice, associated with suppressed mTORC1 signaling and enhanced autophagy. Rapamycin, an mTORC1 inhibitor, mimicked the effects of CR, further supporting the involvement of mTORC1-autophagy pathway. Tubule-specific Atg7 knockout and autophagy inhibitor 3-MA mitigated these effects, indicating a central role for autophagy in CR-induced renal damage. Glucose supplementation, but not branched-chain amino acids (BCAAs), alleviated CR-induced renal fibrosis and dysfunction by restoring mTORC1 activation. Finally, we identified leucyl-tRNA synthetase 1 (LARS1) as a key mediator of nutrient sensing and mTORC1 activation, demonstrating its glucose dependency under CR conditions. Conclusion: Our study provides novel insights into the interplay between nutrient metabolism, mTORC1 signaling, and autophagy in IRI-induced renal damages, offering potential therapeutic targets for mitigating CR-associated complications after renal IRI.

Ischemic heart disease is the most common cause of death and disability globally which is caused by reduced or complete cessation of blood flow to a portion of the myocardium. One of its clinical manifestations is myocardial infarction, which is commonly treated by restoring of blood flow through reperfusion therapies. However, serious ischemia-reperfusion injury (IRI) can occur, significantly undermining clinical outcomes, for which there is currently no effective therapy. This review revisits several potential pharmacological IRI intervention strategies that have entered preclinical or clinical research phases. Here, we discuss what we have learned through translational failures over the years, and propose possible ways to enhance translation efficiency.

Lung transplantation (LTx) significantly improves outcomes for patients with end-stage respiratory failure. However, primary graft dysfunction (PGD) remains one of the most relevant hurdles. Although PGD is attributed to ischemia-reperfusion injury (IRI), immune responses, primarily T cell-mediated, may play a pivotal role in its pathogenesis. Additionally, innate immune activation following IRI links PGD to adaptive alloimmunity, highlighting the impact of early events on LTx outcomes. Immune checkpoints (ICPs) such as PD-1/PD-L1, CD40/CD40LG, and OX40/OX40L, regulate post-LTx T cell responses, and dysregulation of microRNAs (miRNAs) has been implicated in altering ICP expression, influencing the amplification of immune responses.In this preliminary study, we used the taqMan low-density array (TLDA) cards to investigate miRNA dysregulation's prognostic potential as a PGD marker in pre-transplant back-table lung biopsies. Our analysis revealed differential miRNA expression in donor lung tissues, potentially associated with PGD onset, targeting immune regulatory pathways. Specifically, deregulated miRNAs targeted key ICP proteins, including PD-L1, CD40LG, and OX40L. Moreover, the differential expression of these miRNAs was observed in grafts with future PGD compared to grafts without PGD, suggesting a potential prognostic benefit and a possible role for lung tissue miRNAs in the onset of early graft dysfunction.These findings provide a basis for future investigations into their mechanistic roles and therapeutic potential for PGD. Although based on a limited number of cases, our results imply that miRNAs might be involved in early graft dysfunction. While requiring validation in larger cohorts, our data raise the possibility that the evaluation of the aforementioned markers during the pre-transplant phase, might offer a prognostic benefit in monitoring the onset of PGD. Additionally, the use of compounds that can modulate the function of these molecules could be evaluated for the management of LTx patients.

Ferroptosis plays a pivotal role in the pathogenesis of ischemia-reperfusion injury (IRI). Liraglutide, as a GLP-1 receptor (GLP-1R) agonist, has exhibited extensive biological effects beyond its hypoglycemic action. Recent studies have shed light on the regulatory influence of Liraglutide on ferroptosis, yet the precise underlying mechanism remains elusive. GLP-1(9–37), as a metabolite of GLP-1, has a low affinity to GLP-1R. Its effect on ferroptosis remains unknown. In this study, we investigated the effects of Liraglutide and GLP-1(9–37) on the ferroptosis during hepatic ischemia-repferfusion (I/R), as well as the underlying specific mechanisms. We found that the administration of Liraglutide alleviated I/R-induced liver injury with less iron accumulation and lower lipid peroxidation, which was not entirely dependent on the presence of GLP-1R. Similarly, GLP-1(9–37) also exhibited these effects. Besides, both of them increased GPX4 expression and decreased COX2 expression. These effects were reversed by a High-Iron Diet. In vitro study showed similar results. In mechanism study, we found that both Liraglutide and GLP-1(9–37) treatment promoted the nuclear translocation of Nrf2 by inhibiting GSK-3β, thereby reducing lipid peroxides. Furthermore, they increased FTH and FTL expression via the SMAD159/Hepcidin pathway, which contributed to the decreased iron accumulation. In conclusion, this study determined that both Liraglutide and GLP-1(9–37) alleviated hepatic ischemia-reperfusion injury (HIRI) by suppressing ferroptosis via the activation of the GSK3β/Nrf2 pathway and the SMAD159/Hepcidin/FTH pathway.

Flap transplantation is a critical part of the recovery process for patients who have undergone tumor resection. However, the process of ischemia-reperfusion injury during flap transplantation and the resulting high-risk thrombotic microenvironment are unavoidable. In this study, based on an in-depth investigation of the ischemia time and prognosis of transplanted flaps, we propose a treatment strategy using sequential thrombolysis and ischemia-reperfusion injury prevention tailored to the ischemia time. This approach is designed to minimize the likelihood of thrombus formation and to clear the intravascular inflammatory microenvironment, with the aim of preventing and salvaging ischemic flaps. Specifically, we have successfully constructed a clinical-grade bionic vesicle, UK-PBNZ@PM, a system that cleverly incorporates drug components that have been widely used in clinical applications, thereby demonstrating a high degree of clinical translational potential. Prussian blue nano-enzymes (PBNZ) are the core component and demonstrate remarkable efficacy against ischemia-reperfusion injury due to their excellent biocompatibility, robust reactive oxygen species (ROS) scavenging capacity and anti-inflammatory properties. At the same time, urokinase (UK), a key pharmaceutical agent in antithrombotic therapy, has been effectively incorporated into the system, enhancing its ability to prevent and treat thrombosis. In addition, the integration of a platelet membrane (PM) has endowed the bionic vesicles with precise targeting and delivery capabilities, ensuring that the drugs can reach the lesion directly and facilitate efficient and precise release. The experimental results demonstrated that an ischemia-timed strategy can not only efficiently promote thrombolysis, but also effectively remove harmful elements in the microenvironment of ischemia-reperfusion injury. This discovery represents a new and promising approach to the treatment of thrombosis.

Ischemia-reperfusion injury (IRI) commonly occurs in clinical settings, particularly in medical practices such as organ transplantation, cardiopulmonary resuscitation, and recovery from acute trauma, posing substantial challenges in clinical therapies. Current systemic therapies for IRI are limited by poor drug targeting, short efficacy, and significant side effects. Owing to their exceptional biocompatibility, biodegradability, excellent mechanical properties, targeting capabilities, controlled release potential, and properties mimicking the extracellular matrix (ECM), hydrogels not only serve as superior platforms for therapeutic substance delivery and retention, but also facilitate bioenvironment cultivation and cell recruitment, demonstrating significant potential in IRI treatment. This review explores the pathological processes of IRI and discusses the roles and therapeutic outcomes of various hydrogel systems. By categorizing hydrogel systems into depots delivering therapeutic agents, scaffolds encapsulating mesenchymal stem cells (MSCs), and ECM-mimicking hydrogels, this article emphasizes the selection of polymers and therapeutic substances, and details special crosslinking mechanisms and physicochemical properties, as well as summarizes the application of hydrogel systems for IRI treatment. Furthermore, it evaluates the limitations of current hydrogel treatments and suggests directions for future clinical applications.

Oxidative stress caused by reactive oxygen species (ROS) is involved in the pathogenesis of renal ischemia-reperfusion injury (I/R injury), a major cause of acute kidney injury and delayed graft function (DGF). DGF is an early transplant complication that worsens graft prognosis and patient survival, but the underlying molecular changes are unclear. The proteasome is a multicatalytic enzyme complex that degrades both normal and damaged proteins, and recent studies have revealed that the immunoproteasome, a specific proteasome isoform whose proteolytic activity enhances the generation of antigenic peptides, plays critical roles in the cellular response against oxidative stress. In this study, we demonstrate the impact of the immunoproteasome in human DGF and in a mouse model of I/R injury. In patients with DGF, the expression of β5i, a specific immunoproteasome subunit, was decreased in vascular endothelial cells. In a mouse model, β5i knockout (KO) exacerbated renal I/R injury. KO mice showed greater inflammation, oxidative stress, and endothelial damage compared with wild-type mice. Impaired immunoproteasomal activity also caused increased cell death, ROS production, and expression of inflammatory factors in mouse renal vascular endothelial cells under conditions of hypoxia and reoxygenation. In conclusion, reduced expression of the immunoproteasomal catalytic subunit β5i exacerbates renal I/R injury in vivo, potentially increasing the risk of DGF. Further research targeting β5i expression in DGF could lead to the development of novel therapeutic strategies and biomarkers.

Clinical studies have previously established the role of olive products in cardiovascular disease (CVD) prevention, whilst the identification of the responsible constituents for the beneficial effects is still pending. We sought to assess and compare the cardioprotective potential of oleuropein (OL), hydroxytyrosol (HT), oleocanthal (OC) and oleanolic Acid (OA), regarding Ischemia/Reperfusion Injury (IRI) and CVD risk factors alleviation. The scope of the study was to design a potent and safe combinatorial therapy for high-cardiovascular-risk patients on a bench-to-bedside approach. We evaluated the IRI-limiting potential of 6-weeks treatment with OL, HT, OC or OA at nutritional doses, in healthy and metabolic syndrome (MS)-burdened mice. Three combinatorial regimens were designed and the mixture with preponderant benefits (OL-HT-OC, Combo 2), including infarct sparing and antiglycemic potency, compared to the isolated compounds, was further investigated for its anti-atherosclerotic effects. In vivo experiments revealed that the combination regimen of Combo 2 presented the most favorable effects in limiting infarct size and hyperglycemia, which was selected to be further investigated in the clinical setting in Chronic Coronary Artery Syndrome (CCAS) patients. Cardiac function, inflammation markers and oxidative stress were assessed at baseline and after 4 weeks of treatment with the OL-HT-OC supplement in the clinical study. We found that OL, OC and OA significantly reduced infarct size in vivo compared to Controls. OL exhibited antihyperglycemic properties and OA attenuated hypercholesterolemia. OL-HT-OA, OL-HT-OC and OL-HT-OC-OA combination regimens were cardioprotective, whereas only OL-HT-OC mitigated hyperglycemia. Combo 2 cardioprotection was attributed to apoptosis suppression, enhanced antioxidant effects and upregulation of antioxidant enzymes. Additionally, it reduced atherosclerotic plaque extent in vivo. OL-HT-OC supplement ameliorated cardiac, vascular and endothelial function in the small-scale clinical study. Conclusively, OL-HT-OC combination therapy exerts potent cardioprotective, antihyperglycemic and anti-atherosclerotic properties in vivo, with remarkable and clinically translatable cardiovascular benefits in high-risk patients.

Summary: Background: A better understanding of the molecular events during liver normothermic machine perfusion (NMP) is warranted to develop a data-based approach for the identification of biomarkers representative of graft quality and posttransplant outcome. We analysed the dynamic transcriptional changes during NMP and linked them to clinical and biochemical parameters. Methods: 50 livers subjected to NMP for up to 24 h were enrolled. Bulk RNA sequencing was performed in serial biopsies collected pre and during NMP, and after reperfusion. Perfusate was sampled to monitor liver function. qPCR and immunohistochemistry were performed to validate findings. Molecular profiles were compared between transplanted and non-transplanted livers, and livers with and without early allograft dysfunction. Findings: Pathways related to immune and cell stress responses, cell trafficking and cell regulation were activated during NMP, while cellular metabolism was downregulated over time. Anti-inflammatory responses and genes involved in tissue remodelling were induced at later time-points, suggesting a counter-response to the immediate damage. NMP strongly induced a gene signature associated with ischemia-reperfusion injury. A 7-gene signature corresponds with the benchmarking criteria for transplantation or discard at 6 h NMP (area under curve 0.99). CD274 gene expression (encoding programmed cell-death ligand-1) showed the highest predictive value. LEAP2 gene expression at 6 h NMP correlated with impaired graft function. Interpretation: Assessment of gene expression markers could serve as a reliable tool to evaluate liver quality during NMP and predicts early graft function after transplantation. Funding: The research was supported by “In Memoriam Dr. Gabriel Salzner Stiftung”, Tiroler Wissenschaftsfond, Jubiläumsfonds-Österreichische Nationalbank and MUI Start grant.

Background and aims: The beneficial effect of myokine irisin on ischemia-reperfusion of skin flaps has been rarely reported in clinical studies. This study was designed to determine whether irisin plays a protective role in flap transplantation and identify the factors affecting serum irisin levels. Materials and methods: We analyzed the changes in serum irisin levels and flap blood flow before and after surgery in 40 patients who underwent skin-flap transplantation. Factors affecting serum irisin levels were analyzed by metabolic parameter measurements. Results: Preoperative serum irisin levels were positively correlated with blood flow in the skin flap 7 days post-surgery. The increase in serum irisin levels in the first 3 days after surgery positively correlated with flap blood flow. A longer duration of high-intensity exercise, higher skeletal muscle content, lower body mass index, and waist-to-hip ratio were associated with higher irisin levels. Fasting blood glucose and glycosylated hemoglobin levels showed significant negative correlations with serum irisin levels. Several other indicators, including sex, were not associated with serum irisin levels. Conclusions: Serum irisin levels benefit blood flow recovery during flap transplantation. Better outcomes may be achieved by adjusting the timing and intensity of the exercise and controlling the patient's body size.

Background/objectives: Inflammation and oxidative stress play a significant role in renal ischemia-reperfusion injury (RIRI). This study aimed to investigate the possible protective effects of pretreatment with sodium selenite on RIRI, emphasizing anti-inflammatory effects. Method: A total of 24 male Wistar rats (200±20 g) were divided into four groups (six per each): 1- Sham (surgery without renal pedicle clamping), 2- Sham-Se (0.5 mg/kg sodium selenite for 7 consecutive days, ip), 3- RIRI (ischemia was induced by clamping the renal pedicle for 45 min), and 4- IRIR-Se (0.5 mg/kg sodium selenite for 7 consecutive days before I/R induction). All animals were sacrificed under anesthesia 24 h after I/R induction. Blood and tissue sample were collected for biochemical and histological analyses. Results: The results showed that sodium selenite pretreatment significantly reduced the changes induced by the ischemia-reperfusion injury, including the reduction of serum Cr and BUN, decreased the renal tissue content of NF-κB, TNF-α, IL-1β, and miR-494, and increased IL-10 and GPx content of kidney (P< 0.05). Also, sodium selenite pretreatment significantly reduced renal ischemia-reperfusion-induced histopathological changes. Conclusion: Pretreatment with sodium selenite significantly improved ischemia-reperfusion-induced renal dysfunction and mitigated RIRI, probably regarding its potent anti-inflammatory and antioxidant effects.

Ischemia-reperfusion (IR) or reoxygenation injury is the paradoxical exacerbation of cellular impairment following restoration of blood flow after a period of ischemia during surgical procedures or other conditions. Acute interruption of blood supply to the liver and subsequent reperfusion can result in hepatocyte injury, apoptosis, and necrosis. Since the liver requires a continuous supply of oxygen for many biochemical reactions, any obstruction of blood flow can rapidly lead to hepatic hypoxia, which could quickly progress to absolute anoxia. Reoxygenation results in the increased generation of reactive oxygen species and oxidative stress, which lead to the enhanced production of proinflammatory cytokines, chemokines, and other signaling molecules. Consequent acute inflammatory cascades lead to significant impairment of hepatocytes and nonparenchymal cells. Furthermore, the expression of several vascular growth factors results in the heterogeneous closure of numerous hepatic sinusoids, which leads to reduced oxygen supply in certain areas of the liver even after reperfusion. Therefore, it is vital to identify appropriate therapeutic modalities to mitigate hepatic IR injury and subsequent tissue damage. This review covers all the major aspects of cellular and molecular mechanisms underlying the pathogenesis of hepatic ischemia-reperfusion injury, with special emphasis on oxidative stress, associated inflammation and complications, and prospective therapeutic approaches.

Background: Non-compressible torso hemorrhage (NCTH) presents the ultimate challenge in pre-hospital care. While external hemorrhage control devices (EHCDs) such as the Abdominal Aortic and Junctional Tourniquet (AAJT) and SAM Junctional Tourniquet (SJT) have been invented, the current design and application strategy requires further improvement. Therefore, researchers devised a novel apparatus named Modified EHCD (M-EHCD) and implemented intermittent hemostasis (IH) as a preventive measure against ischemia-reperfusion injury. The objective of this study was to ascertain the combined effect of M-EHCD and IH on the hemostatic effect of NCTH. Methods: Eighteen swine were randomized to M-EHCD, AAJT or SJT. The NCTH model was established by inducing Class Ⅲ hemorrhagic shock and performing a hemi-transection of common femoral artery (CFA). EHCDs were rapidly fastened since the onset of free bleeding (T0min). The IH strategy was implemented by fully releasing M-EHCD at T40min, T70min and T100min, respectively, whereas AAJT and SJT maintained continuous hemostasis (CH) until T120min. All groups underwent CFA bridging at T110min, and EHCDs were removed at T120min. Reperfusion lasted for 60 min, after which euthanasia was performed. Hemodynamics, intra-vesical pressure (IVP), and blood samples were collected periodically. Histological examinations were also conducted. Results: M-EHCD demonstrated the fastest application time (M-EHCD: 26.38 ± 6.32s vs. SJT: 30.84 ± 5.62s vs. AAJT: 54.28 ± 5.45s, P

Cerebral ischemia-reperfusion injury (I/RI) is one of the principal pathogenic factors in the poor prognosis of ischemic stroke, for which current therapeutic options to enhance neurological recovery are notably insufficient. Dental pulp stem cell-derived extracellular vesicles (DPSC-EVs) have promising prospects in stroke treatment and the specific underlying mechanisms have yet to be fully elucidated. The present study observed that DPSC-EVs ameliorated the degree of cerebral edema and infarct volume by reducing the apoptosis of neurons. Furthermore, the miRNA sequencing and functional enrichment analysis identified that miR-877–3p as a key component in DPSC-EVs, contributing to neuroprotection and anti-apoptotic effects. Following target prediction and dual-luciferase assay indicated that miR-877–3p interacted with Bcl-2-associated transcription factor (Bclaf1) to play a function. The miR-877–3p inhibitor or Bclaf1 overexpression reversed the neuroprotective effects of DPSC-EVs. The findings reveal a novel therapeutic pathway where miR-877–3p, transferred via DPSC-EVs, confers neuroprotection against cerebral I/RI, highlighting its potential in promoting neuronal survival and recovery post-ischemia.

Introduction and Objectives: Epigenetic changes represent a mechanism connecting external stresses with long-term modifications of gene expression programs. In solid organ transplantation, ischemia-reperfusion injury (IRI) appears to induce epigenomic changes in the graft, although the currently available data are extremely limited. The present study aimed to characterize variations in DNA methylation and their effects on the transcriptome in liver transplantation from brain-dead donors. Patients and Methods: 12 liver grafts were evaluated through serial biopsies at different timings in the procurement-transplantation process: T0 (warm procurement, in donor), T1 (bench surgery), and T2 (after reperfusion, in recipient). DNA methylation (DNAm) and transcriptome profiles of biopsies were analyzed using microarrays and RNAseq. Results: Significant variations in DNAm were identified, particularly between T2 and T0. Functional enrichment of the best 1000 ranked differentially methylated promoters demonstrated that 387 hypermethylated and 613 hypomethylated promoters were involved in spliceosomal assembly and response to biotic stimuli, and inflammatory immune responses, respectively. At the transcriptome level, T2 vs. T0 showed an upregulation of 337 and downregulation of 61 genes, collectively involved in TNF-α, NFKB, and interleukin signaling. Cell enrichment analysis individuates macrophages, monocytes, and neutrophils as the most significant tissue-cell type in the response. Conclusions: In the process of liver graft procurement-transplantation, IRI induces significant epigenetic changes that primarily act on the signaling pathways of inflammatory responses dependent on TNF-α, NFKB, and interleukins. Our DNAm datasets are the early IRI methylome literature and will serve as a launch point for studying the impact of epigenetic modification in IRI.

Introduction: In kidney transplantation (KT), the role of the intravascular innate immune system (IIIS) in response to ischemia-reperfusion injury (IRI) is not well-understood. Here, we studied parallel changes in the generation of key activation products of the proteolytic cascade systems of the IIIS following living donor (LD) and deceased donor (DD) transplantation and evaluated potential associations with clinical outcomes. Methods: In a cohort study, 63 patients undergoing LD (n = 26) and DD (n = 37) transplantation were prospectively included. Fifteen DD kidneys were preserved with hypothermic machine perfusion (HMP), and the remaining were cold stored. Activation products of the kallikrein-kinin, coagulation, and complement systems were measured in blood samples obtained systemically at baseline and locally from the transplant renal vein at 1, 10, and 30 minutes after reperfusion. Results: DD kidneys exhibited a prompt and interlinked activation of all 3 cascade systems of IIIS postreperfusion, indicating a robust and local thrombo-inflammatory response to IRI. In this initial response, the complement activation product sC5b-9 exhibited a robust correlation with other IIIS activation markers and displayed a strong association with short-term and mid-term (24-month) graft dysfunction. In contrast, LD kidneys did not exhibit this thrombo-inflammatory response. The use of HMP was associated with reduced thromboinflammation and preserved mid-term kidney function. Conclusion: Kidneys from DD are vulnerable to a prompt thrombo-inflammatory response to IRI, which adversely affects both short-term and long-term allograft function. Strategies aimed at minimizing graft immunogenicity prior to reperfusion are crucial to mitigate the intricate inflammatory response to IRI.

Background: Shenfu (SF) injection, a traditional Chinese medication, would improve microcirculation in cardiogenic shock and infectious shock. This study was aimed to explore the therapeutic potential of the SF injection in gut ischemia-reperfusion (I/R) injury after severe hemorrhagic shock (SHS) and resuscitation. Furthermore, we also investigated the optimal adm？ inistration timing. Methods: Twenty-four male SD rats were randomly divided into four groups: Sham group (sham, n = 6), Control group (n = 6), SF injection group (SF, n = 6), and Delayed Shenfu injection administration group (SF-delay, n = 6). In SHS and resuscitation model, rats were induced by blood draw to a mean arterial pressure (MAP) of 40 ± 5 mmHg within 1 h and then maintained for 40 min; HR, MAP ‘were recorded, microcirculation index [De Backer score, perfused small vessel density (PSVD), total vessel density (TVD), microcirculation flow index score (MFI), flow heterogeneity index (HI)] were analyzed. The blood gas index was detected, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), diamine oxidase (DAO), malondialdehyde (MDA) were measured by ELISA; ZO-1, and claudin-1 were measured by Western blotting. In addition, hematoxylin-eosin (HE) and periodic acid schiff (PAS) staining pathological sections of the intestinal mucosal tissues were also performed. Results: SF injection increased the MAP, relieved the metabolic acidosis degree associated with the hypoperfusion, and improved the intestinal microcirculatory density and perfusion quality after I/R injury. The expression of DAO, MDA in intestinal tissue, and plasma IL-6, TNF-α significantly decreased in the SF injection group compared to the control group. The concentration of ZO-1 and claudin-1 is also higher in the SF injection group. In addition, the HE and PAS staining results also showed that SF injection could decrease mucosal damage and maintain the structure. In the SF-delay group, the degree of intestinal tissue damage was intermediate between that of the control group and SF injection group. Conclusions: SF injection protect the intestine from I/R injury induced by SHS and resuscitation, the mechanism of which might be through improving intestinal microcirculation, reducing the excessive release of inflammatory factors and increasing intestinal mucosal permeability. Furthermore, the protection effect is more pronounced if administration during the initial resuscitation phase.

Ischemia‒reperfusion (I/R) injury is a frequently observed complication after flap surgery, and it affects skin flap survival and patient prognosis. Currently, there are no proven safe and effective treatment options to treat skin flap I/R injury. Herein, the potential efficacies of the bioactive peptide from maggots (BPM), as well as its underlying mechanisms, were explored in a rat model of skin flap I/R injury and LPS- or H2O2-elicited RAW 264.7 cells. We demonstrated that BPM significantly ameliorated the area of flap survival, and histological changes in skin tissue in vivo. Furthermore, BPM could markedly restore or enhance Nrf2 and HO-1 levels, and suppress the expression of pro-inflammatory cytokines, including TLR4, p-IκB, NFκB p65, p-p65, IL-6, and TNF-α in I/R-injured skin flaps. In addition, BPM treatment exhibited excellent biocompatibility with an adequate safety profile, while it exhibited superior ROS-scavenging ability and the upregulation of antioxidant enzymes in vitro. Mechanistically, the above benefits related to BPM involved the activation of Nrf2/HO-1 and suppression of TLR4/NF-κB pathway. Taken together, this study may provide a scientific basis for the potential therapeutic effect of BPM in the prevention of skin flap I/R injury and other related diseases.

Background: Liver donation after cardiac death (DCD) makes up a small percentage of the organs used in transplantation and poses a higher risk of graft loss compared to donation after brain death (DBD); this is a result of ischemia reperfusion for which the exact injury mechanisms are currently not fully understood. However, reperfusion injury has been shown to lead to necrosis as well as apoptosis through oxidative stress and mitochondrial dysfunction. In this work, we propose that use of the pro-survival, anti-apoptotic CEPT cocktail in post-ischemia normothermic machine perfusion (NMP) may improve recovery in rat livers subjected to extended durations of warm ischemia. Materials and Methods: Livers procured from male Lewis rats were subjected to 90 min of warm ischemia, followed by 6 h of NMP where they were treated either with the survival-enhancing anti-apoptotic cocktail (CEPT), the vehicle (DMSO) or the base media with no additives. Results: The CEPT-treated group exhibited lower expression of hepatic injury biomarkers, and improvement in a range of hepatocellular symptoms associated with the hepatic parenchyma, biliary epithelium and the sinusoidal endothelium, including recovery of bile secretion and lowered vascular resistance. Conclusions: This study's findings suggest apoptosis plays a more significant role in ischemia-reperfusion injury than previously understood, and provide useful insight for further investigation of the specific underlying mechanisms and development of novel treatment methods.

Objectives: Ischemia–reperfusion injury often coincides with a cytokine storm, which can result in primary graft dysfunction following lung transplantation. Our previous research has demonstrated allograft improvement by cytokine adsorption during ex vivo lung perfusion. The aim of this study was to investigate the effect of in vivo extracorporeal cytokine adsorption in a large animal model. Materials and Methods: Pig left lung transplantation was performed following 24 hours of cold ischemic storage. Observation period after transplantation was 24 hours. In the treatment group (n = 6), extracorporeal CytoSorb adsorption was started 30 minutes before reperfusion and continued for 6 hours. A control group (n = 3) did not receive adsorber treatment. Results: During adsorption, we consistently noticed a significant decrease in plasma proinflammatory interleukin (IL)-2, trends of less proinflammatory, tumor necrosis factor- α, IL-1α, and granulocyte-macrophage colony-stimulating factor as well as significantly reduced systemic neutrophils. In addition, a significantly lower peak airway pressure was detected during the 6 hours of adsorption. After 24 hours of observation, when evaluating the left lung allograft independently, we observed significantly improved CO2 removal, partial pressure of oxygen/inspired oxygen fraction ratio, and less acidosis in the treatment group. At autopsy, bronchoalveolar lavage results exhibited significantly lower recruitment of cells and less pro-inflammatory IL-1α, IL-1β, IL-6, and IL-8 in the treatment group. Histologically, the treatment group had a strong trend, indicating less neutrophil invasion into the alveolar space. Conclusions: Based on our findings, cytokine adsorption during and after reperfusion is a viable approach to reducing posttransplant inflammation following lung transplantation. CytoSorb may increase the acceptance of extended criteria donor lungs, which are more susceptible to ischemia–reperfusion injury.

Background: Ischemia-reperfusion injury presents a substantial concern in various medical scenarios, notably in reconstructive surgery involving tissue flaps. Despite reports on the protective benefits of Propionyl-l-carnitine against ischemia-reperfusion injury, a thorough assessment of its efficacy in epigastric island flap models is currently lacking. Methods: Sixteen male Sprague-Dawley rats underwent epigastric island flap surgery and were divided into two groups: a Propionyl-l-carnitine group that received intraperitoneal Propionyl-l-carnitine prior to ischemia induction and a sham group that received saline treatment. A comprehensive evaluation was performed including macroscopic, biochemical and histological assessments encompassing measurements of flap survival areas, lipid peroxidation (malondialdehyde), glutathione, myeloperoxidase, nitric oxide and peripheral neutrophil counts. Results: The Propionyl-l-carnitine group demonstrated significantly increased flap survival areas when compared to the sham group. Administration of Propionyl-l-carnitine led to reduced malondialdehyde levels and elevated glutathione levels indicating a reduction in oxidative stress. Furthermore, the Propionyl-l-carnitine group exhibited lower myeloperoxidase levels, higher nitric oxide levels and reduced peripheral neutrophil counts, suggesting a decrease in the inflammatory response. Histopathological analysis revealed decreased levels of inflammation, necrosis, polymorphonuclear leukocyte infiltration and edema in the Propionyl-l-carnitine group. Additionally, vascularity was enhanced in the Propionyl-l-carnitine group. Conclusion: This study provides compelling evidence that Propionyl-l-carnitine administration effectively mitigates the deleterious effects of ischemia-reperfusion injury in epigastric island flaps. This is substantiated by the improved flap survival, diminished oxidative stress and inflammation, as well as the enhanced vascularity observed. Propionyl-l-carnitine emerges as a promising therapeutic intervention to enhance tissue flap survival in reconstructive surgery, warranting further exploration through larger-scale investigations.

Background: The potential effect of removing danger-associated molecular patterns (DAMPs) from gut lymph on reducing acute lung injury (ALI) induced by gut ischemia-reperfusion injury (GIRI) is uncertain. This study aimed to investigate whether gut lymph purification (GLP) could improve GIRI-induced acute lung injury in rats by clearing danger-associated molecular patterns. Materials and methods: Rats were divided into four groups: Sham, GIRI, GIRI + gut lymph drainage (GLD), and GIRI + GLP. After successful modeling, lung tissue samples were collected from rats for hematoxylin-eosin (HE) staining and detection of apoptotic indexes. We detected the DAMPs levels in blood and lymph samples. We observed the microstructure of AEC Ⅱ and measured the expression levels of apoptosis indexes. Results: The GIRI group showed destruction of alveolar structure, thickened alveolar walls, and inflammatory cell infiltration. This was accompanied by significantly increased levels of high mobility group protein-1 (HMGB-1) and Interleukin-6 (IL-6), while reduced levels of heat shock protein 70 (HSP 70) and Interleukin-10 (IL-10) in both lymph and serum. In contrast, the lung tissue damage in the GIRI + GLP group was significantly improved compared to the GIRI group. This was evidenced by a reduction in the expression levels of HMGB-1 and IL-6 in both lymph and serum and an increase in HSP 70 and IL-10 levels. Additionally, organelle structure of AEC II was significantly improved in the GIRI + GLP group compared to the GIRI group. Conclusions: GLP inhibits inflammation and cell apoptosis in GIRI-induced ALI by blocking the link between DAMPs and mononuclear phagocytes, reducing the severity of ALI.

Ischemia-reperfusion injury (IRI) is a significant contributor to acute kidney injury (AKI) and is associated with substantial morbidity and mortality rates. In this study, we aimed to investigate the role of NAT10 and its ac4C RNA modification in IRI-induced renal injury. Our findings revealed that both the expression level of NAT10 and the RNA ac4C level in the kidneys were elevated in the IRI group compared to the sham group. Functionally, we observed that inhibition of NAT10 activity with Remodelin or the specific knockout of NAT10 in the kidney led to a significant attenuation of IRI-induced renal injury. Furthermore, in vitro experiments demonstrated that NAT10 inhibition and specific knockout of NAT10 in the kidney markedly suppressed global ac4C RNA modification, providing protection against hypoxia/reoxygenation-induced tubular epithelial cell injury and ferroptosis. Mechanistically, our study uncovered that NAT10 promoted ac4C RNA modification of NCOA4 mRNA, thereby enhancing its stability and contributing to IRI-induced ferroptosis in tubular epithelial cells (TECs). These findings underscore the potential of NAT10 and ac4C RNA modification as promising therapeutic targets for the treatment of AKI. Overall, our study sheds light on the critical involvement of NAT10 and ac4C RNA modification in the pathogenesis of IRI-induced renal injury, offering valuable insights for the development of novel AKI treatment strategies.

Background: Ginsenoside compound K (CK) stimulated activation of the PI3K-Akt signaling is one of the major mechanisms in promoting cell survival after stroke. However, the underlying mediators remain poorly understood. This study aimed to explore the docking protein of ginsenoside CK mediating the neuroprotective effects. Materials and methods: Molecular docking, surface plasmon resonance, and cellular thermal shift assay were performed to explore ginsenoside CK interacting proteins. Neuroscreen-1 cells and middle cerebral artery occlusion (MCAO) model in rats were utilized as in-vitro and in-vivo models. Results: Ginsenoside CK interacted with recombinant human PTP1B protein and impaired its tyrosine phosphatase activity. Pathway and process enrichment analysis confirmed the involvement of PTP1B and its interacting proteins in PI3K-Akt signaling pathway. PTP1B overexpression reduced the tyrosine phosphorylation of insulin receptor substrate 1 (IRS1) after oxygen-glucose deprivation/reoxygenation (OGD/R) in neuroscreen-1 cells. These regulations were confirmed in the ipsilateral ischemic hemisphere of the rat brains after MCAO/R. Ginsenoside CK treatment reversed these alterations and attenuated neuronal apoptosis. Conclusion: Ginsenoside CK binds to PTP1B with a high affinity and inhibits PTP1B-mediated IRS1 tyrosine dephosphorylation. This novel mechanism helps explain the role of ginsenoside CK in activating the neuronal protective PI3K-Akt signaling pathway after ischemia-reperfusion injury.

Cardiomyocyte death is one of the major mechanisms contributing to the development of myocardial infarction (MI) and myocardial ischemia/reperfusion (MI/R) injury. Due to the limited regenerative ability of cardiomyocytes, understanding the mechanisms of cardiomyocyte death is necessary. Pyroptosis, one of the regulated programmed cell death pathways, has recently been shown to play important roles in MI and MI/R injury. Pyroptosis is activated by damage-associated molecular patterns (DAMPs) that are released from damaged myocardial cells and activate the formation of an apoptosis-associated speck-like protein containing a CARD (ASC) interacting with NACHT, LRR, and PYD domains-containing protein 3 (NLRP3), resulting in caspase-1 cleavage which promotes the activation of Gasdermin D (GSDMD). This pathway is known as the canonical pathway. GSDMD has also been shown to be activated in a non-canonical pathway during MI and MI/R injury via caspase-4/5/11. Suppression of GSDMD has been shown to provide cardioprotection against MI and MI/R injury. Although the effects of MI or MI/R injury on pyroptosis have previously been discussed, knowledge concerning the roles of GSDMD in these settings remains limited. In this review, the evidence from in vitro, in vivo, and clinical studies focusing on cardiac GSDMD activation during MI and MI/R injury is comprehensively summarized and discussed. Implications from this review will help pave the way for a new therapeutic target in ischemic heart disease.

Spinal cord ischemia reperfusion (SCIR) injury leads to spinal cord function injury, neural dysfunction and sometimes paralysis or even paraplegia, which severely impair the physical and mental health of individuals. Mesenchymal stem cells (MSCs) are a group of stem cells that have been widely studied for treatment of various diseases. This work aimed to study the therapeutic potential of hypoxia-induced exosomal circular RNA OXNAD1 from human umbilical cord mesenchymal stem cells (HucMSCs) against SCIR. We established an in vivo rat spinal cord injury (SCI) model and conducted treatment with exosomes that isolated from hypoxia-HucMSCs. Hypoxia-HucMSCs-derived exosomal circOXNAD1 alleviated the spinal cord tissue injury in SCI, improved limb motor function, decreased production of inflammatory factors including the IL-1 β, IL-6, and TNF-α. The in vitro hypoxia and reoxygenation (H/R) model demonstrated that Hypoxia-HucMSCs-derived exosomal circOXNAD1 improved neuron proliferation and alleviated apoptosis. Mechanistically, circOXNAD1 directly interact with miR-29a-3p and miR-29a-3p targets the 3′UTR of FOXO3a in neurons. Inhibition of miR-29a-3p and overexpression of FOXO3a reversed the effects of circOXNAD1 depletion in PC12 cell phenotypes. In conclusion, Hypoxia elevated the level circOXNAD1 in exosomes that derived from HuMSCs. The exosomal circOXNAD1 alleviated SCI through sponging miR-29a-3p and consequently elevated the FOXO3a expression. Our findings provided novel evidence for MSC-derived exosomal circOXNAD1in the treatment of SCI.

Background: This study tested whether combined dapagliflozin and entresto treatment would be superior to either one alone for preserving the left-ventricular ejection-fraction (LVEF) in rat after ischemia-reperfusion (IR) injury. Methods: Cell culture using H9C2 cells and IR injury in rat with dapagliflozin-entresto treatment were conducted in the present study. Results: In vitro flow-cytometric result showed that the intracellular and mitochondrial reactive oxygen species and mitochondrial permeability transition pore, and protein levels of oxidative-stress/DNA-damaged markers [NADPH-oxidase-1 (NOX-1)/NOX-2/oxidized-protein/γ-H2A-histone-family member X (γ-H2AX)] were significantly higher in hydrogen peroxide (H2O2) (300μM)-treated H9C2 cells as compared with the controls that were significantly reversed in sacubitril/valsartan and dapagliflozin therapy in the same H2O2-treated condition, whereas the protein expressions of antioxidants [Sirtuin-1 (SIRT1)/SIRT3/superoxide dismutase/catalase/glutathione peroxidase) exhibited an opposite pattern among the groups (all p

This study is to investigate the effects of dexmedetomidine on myocardial ischemia-reperfusion (I/R) injury and its molecular mechanisms. H9c2 cell injury model was constructed by the hypoxia/normoxia (H/R) conditions. Besides, cAMP response element-binding protein (CREB) overexpression and knockdown cell lines were constructed. Cell viability was determined by cell-counting kit 8. Biochemical assays were used to detect oxidative stress-related biomarkers, cell apoptosis, and ferroptosis-related markers. Our results showed that dexmedetomidine's protective effects on H/R-induced cell damage were reversed by the inhibition of protein kinase A (PKA), CREB, and extracellular signal regulated kinase 1/2 (ERK1/2). Treatment of dexmedetomidine ameliorated oxidative stress in the cardiomyocytes induced by H/R, whereas inhibition of PKA, CREB, or ERK1/2 reversed these protective effects. Cell death including cell necrosis, apoptosis, and ferroptosis was found in the cells under H/R insult. Interestingly, targeting CREB ameliorated ferroptosis and oxidative stress in these cells. In conclusion, dexmedetomidine attenuates myocardial I/R injury by suppressing ferroptosis through the cAMP/PKA/CREB signaling pathway.

Background: Ischemia-reperfusion injury (IRI) plays a crucial role in the development of primary graft dysfunction (PGD) following lung transplantation. A promising novel approach to optimize donor organs before transplantation and reduce the incidence of PGD is mitochondrial transplantation., Methods: In this study, we explored the delivery of isolated mitochondria in 4 hours ex vivo lung perfusion (EVLP) before transplantation as a means to mitigate IRI. To provide a fresh and viable source of mitochondria, as well as to streamline the workflow without the need for donor muscle biopsies, we investigated the impact of autologous, allogeneic, and xenogeneic mitochondrial transplantation. In the xenogeneic settings, isolated mitochondria from mouse liver were utilized while autologous and allogeneic sources came from pig skeletal muscle biopsies., Results: Treatment with mitochondrial transplantation increased the P/F ratio and reduced pulmonary peak pressure of the lungs during EVLP, compared to lungs without any mitochondrial transplantation, indicating IRI mitigation. Extensive investigations using advanced light and scanning electron microscopy did not reveal evidence of acute rejection in any of the groups, indicating safe xenotransplantation of mitochondria., Conclusions: Future work is needed to further explore this novel therapy for combating IRI in lung transplantation, where xenotransplantation of mitochondria may serve as a fresh, viable source to reduce IRI., Competing Interests: Disclosure statement All authors declare no conflicts of interest. The authors gratefully acknowledge funding received by the EU Interreg Öresund-Kattegat-Skagerrak, by grants from the Swedish State under the agreement between the Swedish Government and the county councils, the ALF-agreement, the Swedish Research Council, and the Center and by the Vinnova Foundation., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Ischemia-reperfusion injury (IRI) often results in renal impairment. While the presence of neutrophil extracellular traps (NETs) is consistently observed, their specific impact on IRI is not yet defined. Sivelestat sodium, an inhibitor of neutrophil elastase which is crucial for NET formation, may offer a therapeutic approach to renal IRI, warranting further research., Methods: A mouse model was established for early-stage renal IRI, confirmed by injury markers and histological assessments. The involvement of NETs in renal I/R was demonstrated using immunofluorescence and Western blot. Renal function and pathology were further evaluated through a comprehensive set of methods, including Periodic Acid-Schiff staining (PAS) and Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling (TUNEL) staining, enzyme-linked immunosorbent assay (ELISA), Real time Glomerular Filtration Rate (RT-GFR) monitoring, Polymerase Chain Reaction (PCR), biochemical analysis, and additional Western blot and immunofluorescence assays., Results: We firstly quantified NET expression in renal IRI mice, noting a peak at 24 h. Subsequently, sivelestat sodium treatment was administered, resulting in decreased MPO, CitH3, and attenuated tubular damage. Moreover, it resulted in a decrease in serum levels of creatinine, blood urea nitrogen (BUN), as well as neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1). Additionally, it lowered the abundance of renal tissue inflammatory markers interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and mitigated the levels of oxidative stress indicators malondialdehyde (MDA) and 4 Hydroxynonenal (4HNE), accompanied by a decline in renal cell apoptosis and an enhancement of GFR in renal I/R mice., Conclusion: Sivelestat sodium ameliorates renal IRI by downregulating neutrophil NETs, reducing inflammation, oxidative stress, and apoptosis, thereby enhancing renal function., Competing Interests: Declarations of competing interest No competing interests to declare., (Copyright © 2025 Elsevier Inc. All rights reserved.)

Heart transplantation is a critical treatment for end-stage heart failure. However, its clinical efficacy is hindered by some challenges, such as ischemia-reperfusion injury (IRI) and post-transplant rejection. These complications significantly contribute to graft dysfunction and compromise patient survival. Emerging evidence underscores the involvement of proteasome in the pathophysiology of both IRI and post-transplant rejection. Proteasome inhibition has demonstrated potential in attenuating IRI by limiting oxidative damage and apoptosis while also mitigating rejection through the regulation of adaptive and innate immune responses. Recent advances in the development of proteasome inhibitors, particularly in optimizing specificity and minimizing adverse effects, have further strengthened their prospects for clinical application. This review focuses on the roles of the proteasome and its inhibitors in heart transplantation, with an emphasis on their mechanisms and therapeutic applications in managing IRI and rejection., Competing Interests: Declaration of competing interest The authors have no competing interests., (Copyright © 2025 Elsevier Inc. All rights reserved.)

Severe ischemia-reperfusion injury (IRI) causes acute and chronic kidney allograft damage. As therapeutic interventions to reduce damage are limited yet, research on how to promote kidney repair has gained significant interest. To address this question, we performed genome-wide transcriptome and epigenome profiling in progenitor cells isolated from the urine of deceased (severe IRI) and living (mild IRI) donor human kidney transplants and identified LIM homeobox-1 (LHX1) as an epigenetically regulated gene whose expression depends on the IRI severity. Using a mouse model of IRI, we observed a relationship between IRI severity, LHX1 promoter hypermethylation, and LHX1 gene expression. Using functional studies, we confirmed that LHX1 expression is involved in the proliferation of epithelial tubular cells and podocyte differentiation from kidney progenitor cells. Our results provide evidence that severe IRI may reduce intrinsic mechanisms of kidney repair through epigenetic signaling., Competing Interests: Declaration of competing interest The authors of this manuscript have no conflicts of interest to disclose as described by the American Journal of Transplantation., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The lack of effective drugs for treating ischemia-reperfusion injury (IRI) in lung transplants (LTx) remains an issue. Traditional Chinese medicine (TCM) ingredients are promising but poorly studied in LTx. This study aimed to identify potential ingredients and elucidate their mechanisms., Methods: Ten TCM ingredients, including (-)-epigallocatechin-3-gallate, quercetin, wogonin, triptolide, berberine, fisetin, coumestrol, luteolin, nobiletin, and baicalein, were identified as promising candidates using a network pharmacology approach. All the candidates were tested for their ability to improve clamp-induced IRI. Multiple-dose validation was conducted in LTx models, with a focus on baicalein. The pharmacological efficacy of baicalin was verified in an ex-vivo rat lung perfusion model., Results: All ten TCM ingredients improved clamp-induced IRI. Multiple-dose validation confirmed that baicalein mitigated IRI-induced graft damage and dysfunction. Baicalein reduced the elevated levels of advanced glycation endproducts (AGEs) and their downstream pathogenic effects induced by IRI. Exogenous AGEs counteracted the therapeutic effect of baicalein., Conclusions: Baicalein inhibited AGE formation by modulating glucose oxidation rather than polyol metabolism. This study provides a laboratory foundation for the use of TCM ingredients in the treatment of IRI in LTx., (Copyright © 2025. Published by Elsevier Inc.)

Ischemia-reperfusion injury (IRI) is an inherent issue in organ transplantation. Because of the allograft shortage, more and more extended criteria donor (ECD) organs are used, unfortunately these grafts are more susceptible to IRI. Although machine perfusion technology has brought hope to alleviate IRI, this technology is still unable to eradicate IRI-related organ damage. Ischemia-free liver transplantation (IFLT) can completely avoid IRI, thereby improve graft function and recipient outcome, and allow to expand organ pool. This review summarized the latest progresses in IFLT, and speculated the future development of this concept., (Copyright © 2024 First Affiliated Hospital, Zhejiang University School of Medicine in China. Published by Elsevier B.V. All rights reserved.)

Background: Ischemia-reperfusion injury (IRI) stands as a major trigger for primary graft dysfunction (PGD) in lung transplantation (LTx). Especially in LTx from donation after cardiac death (DCD), effective control of IRI following warm ischemia (WIRI) is crucial to prevent PGD. This study aimed to identify the key factors affecting WIRI in LTx from DCD., Methods: Previously reported RNA-sequencing dataset of lung WIRI was reanalyzed to identify nuclear receptor subfamily 4 group A member 1 (NR4A1) as the immediate early gene for WIRI. Dynamics of NR4A1 expression were verified using a mouse hilar clamp model. To investigate the role of NR4A1 in WIRI, a mouse model of LTx from DCD was established using Nr4a1 knockout (Nr4a1 -/- ) mice., Results: NR4A1 was located around vascular cells, and its protein levels in the lungs increased rapidly and transiently during WIRI. LTｘ from Nr4a1 -/- donors significantly improved pulmonary graft function compared to wild-type donors. Histological analysis showed decreased microvascular endothelial cell death, neutrophil infiltration, and albumin leakage. Evans blue permeability assay demonstrated maintained pulmonary microvascular barrier integrity in grafts from Nr4a1 -/- donors, correlating with diminished pulmonary edema. However, NR4A1 did not significantly affect the inflammatory response during WIRI, and IRI was not suppressed when a wild-type donor lung was transplanted into the Nr4a1 -/- recipient., Conclusions: Donor NR4A1 plays a specialized role in the positive regulation of endothelial cell injury and microvascular hyperpermeability. These findings demonstrate the potential of targeting NR4A1 interventions to alleviate PGD and improve outcomes in LTx from DCD., Competing Interests: Disclosure statement The authors have no conflicts of interest to disclose. This study was supported by the Japan Society for the Promotion of Science KAKENHI (Grant no. 20KK0203 and 23K08320 to M.O.). We thank Tetsuo Kawakami and staff of the Department of Animal Resources, Advanced Science Research Center, Okayama University., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Ischemia-reperfusion injury is a common cause of cardiovascular and cerebrovascular diseases. The reoxygenation during reperfusion leads to an overproduction of reactive oxygen species (ROS). As an antioxidant, H 2 S can scavenge ROS to inhibit oxidative stress and inflammatory reaction, thus attenuating ischemia-reperfusion injury. In this process, the changes of cellular microenvironment (polarity or viscosity) have not been fully discussed. In order to real-time track the changes of cellular microenvironment during the treatment of ischemia-reperfusion injury with H 2 S. It is necessary to develop highly selective and sensitive probes that can cascade response to hydrogen sulfide and cellular microenvironment., Results: We designed and synthesized a fluorescent probe TPEC-DNBS which can produce cascade response to H 2 S and microenvironment. An intermediate TPEC-OH is produced after highly selective and sensitive response to H 2 S, which can further respond to polarity and viscosity. In addition, due to the aggregation-induced emission (AIE) and twisted intramolecular charge transfer (TICT) effects, polarity can promote the fluorescence emission wavelength and intensity of TPEC-OH to produce double response characteristics, and its change trend (from weak green fluorescence at low polarity to strong red fluorescence at high polarity) is opposite to that of traditional polar probes (from strong green fluorescence at low polarity to weak red fluorescence at high polarity). Viscosity can only induce the change of fluorescence intensity. By constructing the cardiomyocyte model and hepatocyte model of ischemia-reperfusion, we further prove that after ischemia-reperfusion injury, the cells are in an environment of low polarity, and the microenvironment can be recovered after H 2 S treatment., Significance: An AIE-TICT fluorescence probe capable of cascading responses to H 2 S, polarity and viscosity was constructed by using tetraphenylethylene and coumarin moieties. This probe provides a more intuitive and convenient condition for real-time tracking the changes of cellular microenvironment (polarity or viscosity) before and after H 2 S treatment of ischemia-reperfusion injury., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Summary: Background: Ischemia of the bile duct is a common feature in liver disease and transplantation, which represents a major cause of morbidity and mortality, especially after liver transplantation. Detailed knowledge of its pathogenesis remains incomplete due to the lack of appropriate in vitro models. Methods: To recapitulate biliary damage induced by ischemia and reperfusion in vitro, human intrahepatic cholangiocyte organoids (ICOs) were grown at low oxygen levels of 1% up to 72 h, followed by re-oxygenation at normal levels. Findings: ICOs stressed by ischemia and subsequent re-oxygenation represented the dynamic change in biliary cell proliferation, upregulation of epithelial–mesenchymal transition (EMT)-associated markers, and the evocation of phase-dependent cell death programs similar to what is described in patients. Clinical-grade alpha-1 antitrypsin was identified as a potent inhibitor of both ischemia-induced apoptosis and necroptosis. Interpretation: These findings demonstrate that ICOs recapitulate ischemic cholangiopathy in vitro and enable drug assessment studies for the discovery of new therapeutics for ischemic cholangiopathies. Funding: Dutch Digestive Foundation MLDS D16-26; TKI-LSH (Topconsortium Kennis en Innovatie-Life Sciences & Health) grant RELOAD, EMC-LSH19002; Medical Delta program “Regenerative Medicine 4D”; China Scholarship Council No. 201706230252.

Mitochondria-targeted H2S donors are thought to protect against acute ischemia-reperfusion (IR) injury by releasing H2S that decreases oxidative damage. However, the rate of H2S release by current donors is too slow to be effective upon administration following reperfusion. To overcome this limitation here we develop a mitochondria-targeted agent, MitoPerSulf that very rapidly releases H2S within mitochondria. MitoPerSulf is quickly taken up by mitochondria, where it reacts with endogenous thiols to generate a persulfide intermediate that releases H2S. MitoPerSulf is acutely protective against cardiac IR injury in mice, due to the acute generation of H2S that inhibits respiration at cytochrome c oxidase thereby preventing mitochondrial superoxide production by lowering the membrane potential. Mitochondria-targeted agents that rapidly generate H2S are a new class of therapy for the acute treatment of IR injury.

Cell models of cardiac ischemia-reperfusion (IR) injury are essential to facilitate understanding, but current monolayer cell models poorly replicate the in vivo IR injury that occurs within a three-dimensional tissue. Here we show that this is for two reasons: the residual oxygen present in many cellular hypoxia models sustains mitochondrial oxidative phosphorylation; and the loss of lactate from cells into the incubation medium during ischemia enables cells to sustain glycolysis. To overcome these limitations, we incubated isolated adult mouse cardiomyocytes anoxically while inhibiting lactate efflux. These interventions recapitulated key markers of in vivo ischemia, notably the accumulation of succinate and the loss of adenine nucleotides. Upon reoxygenation after anoxia the succinate that had accumulated during anoxia was rapidly oxidized in association with extensive mitochondrial superoxide/hydrogen peroxide production and cell injury, mimicking reperfusion injury. This cell model will enable key aspects of cardiac IR injury to be assessed in vitro.

Recent studies have shown that programmed cell death 4 (PDCD4) modulates distinct signal transduction pathways in different pathological conditions. Despite acute and chronic immune responses elicited by ischemia contributing to the functional deterioration of the kidney, the contributions and mechanisms of PDCD4 in acute kidney injury (AKI) have remained unclear. Using two murine AKI models including renal ischemia/reperfusion injury (IRI) and cisplatin-induced AKI, we found that PDCD4 deficiency markedly ameliorated renal dysfunction and inflammatory responses in AKI mice. Consistently, upregulation of PDCD4 was also confirmed in the kidneys from patients with biopsy confirmed acute tubular necrosis from a retrospective cohort study. Moreover, we found that overexpression of Fgr, a member of the tyrosine kinase family, dramatically aggravated renal injury and counteracted the protective effects of PDCD4 deficiency in AKI mice. We discovered that FGR upregulated NOTCH1 expression through activating STAT3. Most importantly, we further found that systemic administration of ponatinib, a tyrosine kinase inhibitor, significantly ameliorated AKI in mice. In summary, we identified that PDCD4 served as an important regulator, at least in part, of FGR/NOTCH1-mediated tubular apoptosis and inflammation in AKI mice. Furthermore, our findings suggest that ponatinib-mediated pharmacologic targeting of this pathway had therapeutic potential for mitigating AKI.

Roles of the renin-angiotensin system in autophagy and ischemia/reperfusion (I/R) injury in the kidney have not been fully characterized. Here we examined the hypothesis that modest activation of the angiotensin II (Ang II) receptor upregulates autophagy and increases renal tolerance to I/R injury. Sprague–Dawley rats were assigned to treatment with a vehicle or a non-pressor dose of Ang II (200 ng/kg/min) for 72 h before 30-min renal I/R. LC3-immunohistochemistry showed that Ang II treatment increased autophagosomes in proximal tubular cells by 2.7 fold. In Ang II-pretreated rats, autophagosomes were increased by 2.5 fold compared to those in vehicle-treated rats at 4 h after I/R, when phosphorylation of Akt and S6 was suppressed and ULK1-Ser555 phosphorylation was increased. Serum creatinine and urea nitrogen levels, incidence of oliguria, and histological score of tubular necrosis at 24 h after I/R were attenuated by Ang II-pretreatment. In NRK-52E cells, Ang II induced LC3-II upregulation, which was inhibited by losartan but not by A779. The results indicate that a non-pressor dose of Ang-II promotes autophagy via ULK1-mediated signaling in renal tubular cells and attenuates renal I/R injury. The AT1 receptor, but not the Mas receptor, contributes to Ang–II–induced autophagy and presumably also to the renoprotection.

Objective: Spinal cord ischemia–reperfusion injury (SC-IRI) occurs in many medical conditions such as aneurysm surgical repair but no treatment of SC-IRI is available in clinical practice. The objective of the present study was to develop a novel medical device for the treatment of SC-IRI. Methods: A rat model of SC-IRI was used. A novel transrectal intracolon (TRIC) temperature management device was developed to maintain an intracolon wall temperature at either 37°C (TRIC37°C) or 12°C (TRIC12°C). The upper body temperature was maintained as close as possible to 37°C in both groups. A 2F Fogarty balloon catheter was inserted via the left common carotid artery to block the distal aortic blood flow to the spinal cord. The proximal blood pressure was controlled by the withdrawal and infusion of blood via the jugular vein catheter, such that the distal tail artery blood pressure was maintained at ∼10 mmHg for 13 and 20 minutes, respectively. Next, the balloon was deflated, and TRIC temperature management was continued for an additional 30 minutes to maintain the colon wall temperature at either 37°C or 12°C during the reperfusion period. Results: All the rats subjected to 13 minutes of spinal cord ischemia in the TRIC37°C group had developed paraplegia during the postischemic phase. In striking contrast, TRIC at 12°C completely prevented the paraplegia, dramatically improved the arterial blood gas parameters, and avoided the histopathologic injuries to the spinal cord in rats subjected to 13 minutes of spinal cord ischemia. Furthermore, TRIC12°C allowed for the extension of the ischemia duration from 13 minutes to 20 minutes, with significantly reduced functional deficits. Conclusions: Directly cooling the intestine focally with the TRIC device offered an exceptional survival rate and functional improvement after aortic occlusion-induced spinal cord ischemia. : Clinical Relevance: The present study showed that the use of the transrectal intracolon (TRIC) device to directly cool the intestine offers outstanding clinical benefits against spinal cord ischemia–reperfusion injury and prevents mortality in the rat aortic occlusion spinal cord ischemia model. The translational value of the present study could be high because the protection was so dramatic, the TRIC device is easy to use, and the TRIC cooling adverse effects were minimal. This novel TRIC management modality can offer fast cooling of the gut from 37°C to 12°C within 5 minutes, and the upper body temperature can be maintained in a tolerable temperature range, minimizing the fatal adverse effects of whole-body deep cooling.

Systematic administration of anti-inflammatory cytokine interleukin 4 (IL-4) has been shown to improve recovery after cerebral ischemic stroke. However, whether IL-4 affects neuronal excitability and how IL-4 improves ischemic injury remain largely unknown. Here we report the neuroprotective role of endogenous IL-4 in focal cerebral ischemia–reperfusion (I/R) injury. In multi-electrode array (MEA) recordings, IL-4 reduces spontaneous firings and network activities of mouse primary cortical neurons. IL-4 mRNA and protein expressions are upregulated after I/R injury. Genetic deletion of Il-4 gene aggravates I/R injury in vivo and exacerbates oxygen-glucose deprivation (OGD) injury in cortical neurons. Conversely, supplemental IL-4 protects Il-4−/− cortical neurons against OGD injury. Mechanistically, cortical pyramidal and stellate neurons common for ischemic penumbra after I/R injury exhibit intrinsic hyperexcitability and enhanced excitatory synaptic transmissions in Il-4−/− mice. Furthermore, upregulation of Nav1.1 channel, and downregulations of KCa3.1 channel and α6 subunit of GABAA receptors are detected in the cortical tissues and primary cortical neurons from Il-4−/− mice. Taken together, our findings demonstrate that IL-4 deficiency results in neural hyperexcitability and aggravates I/R injury, thus activation of IL-4 signaling may protect the brain against the development of permanent damage and help recover from ischemic injury after stroke.

Objective: Cardiosphere-derived cells (CDCs) have been shown to reduce infarct size after myocardial infarction (MI). In the present study we investigated the safety and efficacy of global intracoronary administration (GIA) of CDCs or CDC-conditioned medium (CM) immediately after reperfusion in a rat model of ischemia-reperfusion. Methods: CDCs were grown from myocardial biopsies obtained from male Wistar Kyoto rats (WKY). Female WKY rats underwent MI for 45minutes, followed by reperfusion for 1hour. Infarcted rats were randomized to receive GIA of CDCs (CDC group), CM (CM group) or vehicle (control group) immediately after the onset of reperfusion. Cell retention was quantified by PCR for the male specific SRY gene; area at risk (AR) and no reflow area (NR) were measured by histopathology. Cardiac function was evaluated by echocardiography at 1 and 2 months post-MI. Results: Cell retention at 1hour after GIA was 25.1% ±5.1. The myocardial AR and NR (measured at 1 hour post-reperfusion) were similar between groups [AR: 28.8% ±7.4 of LV mass in control vs 27.2% ±8 in CM vs 27% ±7 in CDCs group. NR: 7.0% ±3.3 in control vs 7.3% ±3.8 in CM vs 7.1% ±3.6 in CDCs]. One and 2 months post-MI, systolic function and LV volumes did not differ between control and CM groups. Conclusion: Intracoronary administration of CDCs during the acute phase of MI, at the beginning of reperfusion, does not aggravate microvascular obstruction and results in high cell retention. Delivery of CM in the acute phase of MI did not confer long-term cardiac functional benefits.

Background: Hepatic ischemia reperfusion (I/R) injury remains a major problem for liver surgery leading to graft dysfunction. The use of compounds of natural origin as fucoidan, a sulfated polysaccharide from brown seaweed, could have a potential clinical benefit in the treatment of ischemic diseases. Nevertheless, the accurate mechanisms of action of fucoidan on endoplasmic reticulum (ER) stress response and mitochondria after warm hepatic ischemia have not been yet investigated. Thus, the present study focused on the modulation of fucoidan effects on the signaling pathways involving the mitochondria and the ER in ischemic rat liver. Methods: Male Wistar rats were subjected to either sham operation or one hour of partial warm ischemia (70%) followed by two hours of reperfusion. Before ischemia, rats were treated with 0.9% NaCl (I/R group), fucoidan (100 mg/kg body weight) orally for 7 consecutive days (I/R-Fuc group), TUDCA (tauroursodeoxycholic acid, inhibitor of ER stress) (100 mg / kg body weight, i.v.) 10 min before ischemia (I/R-TUDCA group) or fucoidan with TUDCA (I/R-Fuc-TUDCA group). Results: Our results showed that fucoidan and TUDCA reduced cytolysis and induced a significant improvement in antioxidant status, as compared to I/R. Interestingly, preconditioning with fucoidan resulted in significant decreased ER stress, as reflected by GRP78, p-PERK, ATF-6, XBP-1 and TRAF2. Furthermore, the phosphorylation of MAPKs (ERK, JUNK and P38) significantly diminished after fucoidan treatment. Rats undergoing fucoidan treatment protected liver against mitochondrial stress, which was correlated with low induction of apoptosis (caspase-3). Inhibition of ER stress by TUDCA administration boosted all the protective effects of fucoidan. Conclusion: In conclusion, fucoidan treatment may represent an effective strategy in reducing liver I/R injury through mitochondrial stress attenuation and ER inhibition.

Background: RNA N6-methyladenosine (m6A) regulators are essential for numerous biological processes and are implicated in various diseases. However, the comprehensive role of m6A regulators in the context of liver transplantation (LT) remains poorly understood. This study aimed to illustrate the relationship between m6A regulators and ischemia-reperfusion injury (IRI) following LT., Methods: Datasets were acquired from the Gene Expression Omnibus database. Differential analysis of the merged data identified the differentially expressed m6A regulators. Random forest (RF) models and nomograms were used to forecast the incidence and assess the IRI risk following LT. m6A regulators were classified into distinct subgroups using cluster analysis. The differential gene expression was validated using immunohistochemistry, immunofluorescence, and Western blotting., Results: We found significant disparities in the gene expression levels of the three m6A regulators between patients with and without LT. Wilms' tumor 1-associating protein (WTAP) expression was upregulated following LT. The RF models exhibited a high degree of accuracy in predicting IRI risk. Immune infiltration analysis showed that WTAP was an immune-associated m6A regulator that was closely associated with T and B cells. WTAP expression in the rat LT model was upregulated after 24 h of reperfusion, which was consistent with the results of the bioinformatics analysis., Conclusion: WTAP has a high diagnostic value for IRI in LT and influences the immune status of patients. Hence, WTAP, as a significant regulator of m6A, is a potential biomarker for the detection and implementation of immunotherapy for IRI following LT., (Copyright © 2024. Published by Elsevier B.V.)

The endoplasmic reticulum (ER) is an important organelle in eukaryotic cells, responsible for a range of biological functions such as the secretion, modification and folding of proteins, maintaining Ca 2+ homeostasis and the synthesis of steroids/lipids, secreted proteins and membrane proteins. When cells are affected by internal or external factors, including abnormal energy metabolism, disrupted Ca 2+ balance, altered glycosylation, drug toxicity, and so on, the unfolded or misfolded proteins accumulate in the ER, leading to the unfolded protein response (UPR) and ER stress. The abnormal ER stress has been reported to be involved in various pathological processes. MicroRNAs (miRNAs) are non-coding RNAs with the length of approximately 19-25 nucleotides. They control the expression of multiple genes through posttranscriptional gene silencing in eukaryotes or some viruses. Increasing evidence indicates that miRNAs are involved in various cellular functions and biological processes, such as cell proliferation and differentiation, growth and development, and metabolic homeostasis. Hence, miRNAs participate in multiple pathological processes. Recently, many studies have shown that miRNAs play an important role by regulating ER stress in ischemia-reperfusion (I/R) injury, but the relevant mechanisms are not fully understood. In this review, we reviewed the current understanding of ER stress, as well as the biogenesis and function of miRNAs, and focused on the role of miRNAs regulation of ER stress in I/R injury, with the aim of providing new targets for the treatment of I/R injury., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)