Infusion of endothelial progenitor cells ameliorates liver injury in mice after haematopoietic stem cell transplantation

Background & Aims: Injury to liver sinusoidal endothelial cells (LSECs) is thought to be the initial factor for Hepatic venoocclusive disease, a severe complication after haematopoietic stem cell transplantation (HSCT). Endothelial progenitor cells (EPCs) have the capacity to differentiate into endothelial cells and play a critical role in vasculogenesis, tissue regeneration and repair. Whether EPCs infusion ameliorates LSECs injury remains unclear. The aim of this study was to evaluate the effects of EPCs on liver injury in mice after HSCT. Methods: Mice received HSCT without or with EPCs infusion (HSCT + EPCs). Untreated mice were used as control. Liver and whole blood were collected post HSCT and used for the analysis of pathology of liver sinusoidal endothelial cells (LSECs) and hepatocytes, liver ultrastructure, function, level of IL-6, TNF-alpha and platelet activation. Results: Severe LSECs injury, hepatocyte damage, abnormal liver function was observed in HSCT group. In addition, increased P-selectin expression and secretion of IL-6, TNF-alpha was also found. However, all the above changes were alleviated in HSCT + EPCs at all the time points and normalized at the endpoint. Meanwhile, EPCs-induced repair of LSECs and hepatocytes was totally inhibited by the addition of anti-VE-cadherin antibody. Conclusions: EPCs infusion ameliorated the damage to LSECs and hepatocytes as well as reduced secretion of IL-6, TNF-alpha and inhibited platelet activation after HSCT, leading to improved liver function, suggesting EPCs might be a new therapeutic strategy in the prophylaxis of liver injury after HSCT.