Journal Article

Ob/ob Mouse Livers Show Decreased Oxidative Phosphorylation Efficiencies and Anaerobic Capacities after Cold Ischemia

Yeong, Mee-Ling, Zhang, Linda, Chu, Michael J. J., Tagaloa, Sherry, MacDonald, Julia R., Bartlett, Adam S. J. R., Phillips, Anthony R. J., Hickey, Anthony J. R., Dare, Anna J.

2014

Overview

Hepatic steatosis is a major risk factor for graft failure in liver transplantation. Hepatic steatosis shows a greater negative influence on graft function following prolonged cold ischaemia. As the impact of steatosis on hepatocyte metabolism during extended cold ischaemia is not well-described, we compared markers of metabolic capacity and mitochondrial function in steatotic and lean livers following clinically relevant durations of cold preservation. Livers from 10-week old leptin-deficient obese (ob/ob, n = 9) and lean C57 mice (n = 9) were preserved in ice-cold University of Wisconsin solution. Liver mitochondrial function was then assessed using high resolution respirometry after 1.5, 3, 5, 8, 12, 16 and 24 hours of storage. Metabolic marker enzymes for anaerobiosis and mitochondrial mass were also measured in conjunction with non-bicarbonate tissue pH buffering capacity. Ob/ob and lean mice livers showed severe (>60%) macrovesicular and mild (<30%) microvesicular steatosis on Oil Red O staining, respectively. Ob/ob livers had lower baseline enzymatic complex I activity but similar adenosine triphosphate (ATP) levels compared to lean livers. During cold storage, the respiratory control ratio and complex I-fueled phosphorylation deteriorated approximately twice as fast in ob/ob livers compared to lean livers. Ob/ob livers also demonstrated decreased ATP production capacities at all time-points analyzed compared to lean livers. Ob/ob liver baseline lactate dehydrogenase activities and intrinsic non-bicarbonate buffering capacities were depressed by 60% and 40%, respectively compared to lean livers. Steatotic livers have impaired baseline aerobic and anaerobic capacities compared to lean livers, and mitochondrial function indices decrease particularly from after 5 hours of cold preservation. These data provide a mechanistic basis for the clinical recommendation of shorter cold storage durations in steatotic donor livers.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adenosine / Adenosine Diphosphate - metabolism / Adenosine triphosphate / Adenosine Triphosphate - metabolism / Allopurinol / Anaerobiosis / Animals / ATP / ATP (Adenosine triphosphate) / Bicarbonates / Biochemistry / Biology and Life Sciences / Blood Glucose - metabolism / Body Weight / Brittleness / Buffers / Carbonates / Cell Respiration / Cold Ischemia / Cold storage / Cryopreservation / Dehydrogenases / Electron Transport / Electron transport chain / Enzymes / Fasting - blood / Fatty liver / Fatty Liver - blood / Fatty Liver - pathology / Glucose Intolerance - blood / Glucose Intolerance - pathology / Glutathione / Graft rejection / Grafts / Homeostasis / Hydrogen-Ion Concentration / Insulin / Insulin Resistance / Ischemia / L-Lactate dehydrogenase / Laboratory animals / Lactate dehydrogenase / Lactic acid / Leptin / Liver / Liver - metabolism / Liver - pathology / Liver diseases / Liver transplantation / Liver transplants / Male / Medicine and Health Sciences / Metabolic syndrome / Metabolism / Mice / Mice, Inbred C57BL / Mice, Obese / Mitochondria / Mitochondria, Liver - metabolism / Mitochondrial DNA / Muscle proteins / Obesity / Organ Preservation Solutions / Oxidative Phosphorylation / pH effects / Phosphorylation / Physiological aspects / Physiology / Raffinose / Research and Analysis Methods / Respiration / Respirometry / Risk factors / Rodents / Steatosis / Storage / Studies / Surgery / Temperature effects / Thinness - metabolism / Thinness - pathology / Transplantation / Transplants & implants