Ob/ob mouse livers show decreased oxidative phosphorylation efficiencies and anaerobic capacities after cold ischemia

PLoS One. 2014 Jun 23;9(6):e100609. doi: 10.1371/journal.pone.0100609. eCollection 2014.

Abstract

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine
  • Adenosine Diphosphate / metabolism
  • Adenosine Triphosphate / metabolism
  • Allopurinol
  • Anaerobiosis
  • Animals
  • Blood Glucose / metabolism
  • Body Weight
  • Buffers
  • Cell Respiration
  • Cold Ischemia*
  • Electron Transport
  • Fasting / blood
  • Fatty Liver / blood
  • Fatty Liver / pathology
  • Glucose Intolerance / blood
  • Glucose Intolerance / pathology
  • Glutathione
  • Hydrogen-Ion Concentration
  • Insulin
  • Insulin Resistance
  • Liver / metabolism*
  • Liver / pathology*
  • Male
  • Mice, Inbred C57BL
  • Mice, Obese
  • Mitochondria, Liver / metabolism
  • Organ Preservation Solutions
  • Oxidative Phosphorylation*
  • Raffinose
  • Thinness / metabolism
  • Thinness / pathology

Substances

  • Blood Glucose
  • Buffers
  • Insulin
  • Organ Preservation Solutions
  • University of Wisconsin-lactobionate solution
  • Adenosine Diphosphate
  • Allopurinol
  • Adenosine Triphosphate
  • Glutathione
  • Adenosine
  • Raffinose

Grant support

This work was directly supported by the University of Auckland Faculty Research Development Fund, Maurice Wilkins Centre for Biodiscovery and the Maurice & Phyllis Paykel Trust. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.