Normothermic machine perfusion (NMP) is a technique of kidney preservation designed to restore cellular metabolism after cold ischemia. Kidneys are perfused with an oxygenated banked red blood cell (RBC) based solution for 1h at 36°C. During NMP, RBCs can become damaged, releasing free heme into the perfusate. This can act as a damage-associated molecular pattern (DAMP) activating inflammatory signalling pathways. The aim of this study was to measure the levels of free heme during NMP, assess the effect on kidney function and determine any association with inflammatory and stress related gene expression. Levels of free heme were measured in perfusate samples from a series of donation after circulatory death (DCD) kidneys undergoing NMP as part of a randomised controlled trial (RCT). The age of RBCs and levels of free heme were correlated with perfusion parameters. Changes in gene expression were analysed in a series of kidneys declined for transplantation using the NanoString nCounter Organ Transplant Panel and qRT-PCR. Older units of RBCs were associated with higher levels of free heme and levels increased significantly during NMP (Pre 8.56 ± 7.19µM vs 26.29 ± 15.18µM, P<0.0001). There was no association with levels of free heme and perfusion parameters during NMP (P > 0.05). Transcriptional and qPCR analysis demonstrated the upregulation of differentially expressed genes associated with apoptosis (FOS and JUN), inflammatory cytokines (IL-6, SOCS3, ATF3), chemokines (CXCL8, CXCL2, CC3/L1) and oxidative stress (KLF4) after NMP. However, these did not correlate with levels of free heme (P >0.05). A significant amount of free heme can be detected in the perfusate before and after NMP particularly when older units of red cells are used. Although transcriptional analysis demonstrated significant upregulation of genes involved with apoptotic, inflammatory and oxidative pathways these were not associated with high levels of free heme.
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http://dx.doi.org/10.3389/fimmu.2022.849742 | DOI Listing |
Scand J Clin Lab Invest
December 2024
Department of Cardiothoracic Surgery, Anaesthesia, Perfusion, and Intensive Care, Skåne University Hospital, Lund, Sweden.
Haemolysis occurring during cardiac surgery with cardiopulmonary bypass (CPB) is assumed to be a risk factor for postoperative acute kidney injury (AKI). Plasma alpha-1 microglobulin (A1M) may have a protective role as haem scavenger. The aim of this study was to evaluate the association between AKI and the degree of haemolysis and the course of A1M concentrations during cardiac surgery, respectively.
View Article and Find Full Text PDFToxins (Basel)
December 2024
Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany.
Hemolytic-uremic syndrome (HUS) is a systemic complication of an infection with Shiga toxin (Stx)-producing enterohemorrhagic , primarily leading to acute kidney injury (AKI) and microangiopathic hemolytic anemia. Although free heme has been found to aggravate renal damage in hemolytic diseases, the relevance of the heme-degrading enzyme heme oxygenase-1 (HO-1, encoded by ) in HUS has not yet been investigated. We hypothesized that HO-1 also important in acute phase responses in damage and inflammation, contributes to renal pathogenesis in HUS.
View Article and Find Full Text PDFJ Sci Food Agric
December 2024
Tianjin Key Laboratory of Food Quality and Health, Tianjin University of Science and Technology, Tianjin, China.
Background: Ferritin is a cage-like iron storage protein and can regulate the iron balance of life. It can be developed as a new type of iron supplement, while its function may be influenced by certain food bioactive components. To evaluate the effects of the typical food biomolecules, such as phenolic acid, on the physicochemical property of ferritin are of great importance to clarify the ferritin function in maintaining iron balance.
View Article and Find Full Text PDFJ Trauma Acute Care Surg
December 2024
From the Department of Surgery (J.T.R.), and Blood, Heart, Lung, and Immunology Research Center (J.T.R., K.E.R.), University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, Ohio; Department of Surgery (A.J.R., A.B., A.R.B., R.A.C.), University of California Davis, Sacramento, California; Department of Anesthesia and Critical Care (A.M., N.N.), Pontchaillou University Hospital of Rennes, Rennes, France; Department of Anesthesiology and Perioperative Medicine (J.D.R.), University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, Ohio; and Division of Pulmonary Critical Care Medicine, Department of Medicine (K.E.R.), University Hospitals of Cleveland, Case Western Reserve University School of Medicine, Cleveland, Ohio.
Background: Cell-free hemoglobin (CFH) and free heme are potent mediators of endotheliopathy and organ injury in sepsis, but their roles in other hemolytic pathologies are not well-defined. A prime example is trauma where early hemolysis may initiate damage and predict outcome. Here, we investigated the presence of plasma CFH, heme, and their major scavengers after traumatic injury.
View Article and Find Full Text PDFFront Immunol
December 2024
Department of Academic Affairs, National Jewish Health, Denver, CO, United States.
Granulomas, organized aggregates of immune cells which form in response to (), are characteristic but not exclusive of tuberculosis (TB). Despite existing investigations on TB granulomas, the determinants that differentiate host-protective granulomas from granulomas that contribute to TB pathogenesis are often disputed. Thus, the goal of this narrative review is to help clarify the existing literature on such determinants.
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