Cryopreservation of Human Hepatocytes Alters the Mitochondrial Respiratory Chain Complex 1

Cell Transplantation

Article

Bruno Guigas¹  Louis Hue¹  Dung Khuu Ngoc²  Françoise Smets²  Etienne M. Sokal²  Mustapha Najimi²  Xavier Stéphenne² 

[1] Hormone and Metabolic Research Unit, School of Medicine, Université catholique de Louvain and Institute of Cellular Pathology, Brussels, Belgium;Laboratory of Paediatric Hepatology and Cell Therapy, Université catholique de Louvain and Cliniques St Luc, Brussels, Belgium;

关键词: Hepatocyte;    Cryopreservation;    Liver cell transplantation;    Mitochondria;    Complex;   

DOI  :  10.3727/000000007783464821

 received in 2006-08-03, accepted in 2006-10-31,  发布年份 2007

来源: Sage Journals

【 摘 要 】

Transplantation of human hepatocytes has recently been demonstrated as a safe alternative to partially correct liver inborn errors of metabolism. Cryopreservation remains the most appropriate way of cell banking. However, mitochondrial-mediated apoptosis has been reported after cryopreservation and little is known on the involved molecular mechanisms. The aim of this study was to investigate mitochondrial functions of freshly isolated and cryopreserved/thawed hepatocytes from mice and humans. We report here that cryopreservation induced a dramatic drop of ATP levels in hepatocytes. The oxygen consumption rate of cryopreserved/thawed hepatocytes was significantly lower compared to fresh cells. In addition, the uncoupling effect of 2,4-dinitrophenol was lost, in parallel with a reduction of mitochondrial membrane potential. Furthermore, a decrease in mitochondrial respiratory rate was evidenced on permeabilized hepatocytes in the presence of substrate for the respiratory chain complex 1. Interestingly, this effect was less marked with a substrate for complex 2. Electron microscopy examination indicated that mitochondria were swollen and devoid of cristae after cryopreservation. These changes could explain the cytosolic release of the proapoptotic protein cytochrome c in cryopreserved cells. Nevertheless, no caspase 9-3 activation and only few apoptotic and necrotic cells were found, indicating that the subsequent cell death program was not yet evidenced. Our results demonstrate that cryopreservation of hepatocytes induced alteration of the mitochondrial machinery. They also suggest that, in addition to technical progress in the cryopreservation procedure, protection of the respiratory chain complex 1 should be considered to improve the quality of cryopreserved hepatocytes.

【 授权许可】

Unknown   
© 2007 Cognizant Comm. Corp.