PEG35 and Glutathione Improve Mitochondrial Function and Reduce Oxidative Stress in Cold Fatty Liver Graft Preservation

• Published in: Antioxidants 2022-01, Vol.11 (1), p.158
• Main Authors: Bardallo, Raquel G, Company-Marin, Idoia, Folch-Puy, Emma, Roselló-Catafau, Joan, Panisello-Rosello, Arnau, Carbonell, Teresa
• Format: Article
• Language: English
• Subjects: Acids; Adducts; Adenosine triphosphate; Animals; Antioxidants; Cryopreservation; Energy metabolism; Enzymes; Fatty liver; Glutathione; Heme; Heme oxygenase (decyclizing); Ischemia; Lipid peroxidation; Lipids; Liver; Liver transplantation; Malondialdehyde; Mitochondria; Mitochondrial uncoupling protein 2; Nrf2; Obesity; Oxidation; Oxidative phosphorylation; Oxidative stress; OXPHOS; Oxygenase; Phosphorylation; Polyethylene glycol; Proteins; PTEN protein; PTEN-induced putative kinase; Reperfusion; Superoxide dismutase; UCP2; Veins & arteries
• ISSN: 2076-3921; 2076-3921
• DOI: 10.3390/antiox11010158

The need to meet the demand for transplants entails the use of steatotic livers, more vulnerable to ischemia-reperfusion (IR) injury. Therefore, finding the optimal composition of static cold storage (SCS) preservation solutions is crucial. Given that ROS regulation is a therapeutic strategy for liver IR injury, we have added increasing concentrations of PEG35 and glutathione (GSH) to the preservation solutions (IGL-1 and IGL-2) and evaluated the possible protection against energy depletion and oxidative stress. Fatty livers from obese Zücker rats were isolated and randomly distributed in the control (Sham) preserved (24 h at 4 °C) in IGL-0 (without PEG35 and 3 mmol/L GSH), IGL-1 (1 g/L PEG35, and 3 mmol/L GSH), and IGL-2 (5 g/L PEG35 and 9 mmol/L GSH). Energy metabolites (ATP and succinate) and the expression of mitochondrial oxidative phosphorylation complexes (OXPHOS) were determined. Mitochondrial carrier uncoupling protein 2 (UCP2), PTEN-induced kinase 1 (PINK1), nuclear factor-erythroid 2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and the inflammasome (NLRP3) expressions were analyzed. As biomarkers of oxidative stress, protein oxidation (AOPP) and carbonylation (DNP derivatives), and lipid peroxidation (malondialdehyde (MDA)-thiobarbituric acid (TBA) adducts) were measured. In addition, the reduced and oxidized glutathione (GSH and GSSG) and enzymatic (Cu-Zn superoxide dismutase (SOD), CAT, GSH S-T, GSH-Px, and GSH-R) antioxidant capacities were determined. Our results showed that the cold preservation of fatty liver graft depleted ATP, accumulated succinate and increased oxidative stress. In contrast, the preservation with IGL-2 solution maintained ATP production, decreased succinate levels and increased OXPHOS complexes I and II, UCP2, and PINK-1 expression, therefore maintaining mitochondrial integrity. IGL-2 also protected against oxidative stress by increasing Nrf2 and HO-1 expression and GSH levels. Therefore, the presence of PEG35 in storage solutions may be a valuable option as an antioxidant agent for organ preservation in clinical transplantation.