Preconditioning of umbilical cord-derived mesenchymal stem cells by rapamycin increases cell migration and ameliorates liver ischaemia/reperfusion injury in mice via the CXCR4/CXCL12 axis

Objectives Transfusion of umbilical cord-derived mesenchymal stem cells (UC-MSCs) is a novel strategy for treatment of various liver diseases. However, the therapeutic effect of UC-MSCs is limited because only a few UC-MSCs migrate towards the damaged regions. In this study, we observed the effects of autophagy on the migration of UC-MSCs in vitro and in a model of liver ischaemia/reperfusion (I/R) injury. Materials and Methods We investigated the effects of autophagy on the status of the cell, release of anti-inflammatory factors and migration of UC-MSCs in vitro. The therapeutic effects and in vivo migration of rapamycin-preconditioned UC-MSCs were observed in a C57/B6 mouse model of liver I/R injury. Results Induction of autophagy by rapamycin enhanced the ability of UC-MSCs to migrate and release anti-inflammatory cytokines as well as increased expression of CXCR4 without affecting cell viability. Inhibition of CXCR4 activation markedly decreased migration of these cells. In a mouse model of liver I/R injury, we found significantly upregulated expression of CXCR12 in the damaged liver. More rapamycin-preconditioned UC-MSCs migrated towards the ischaemic regions than 3-methyladenine-preconditioned or non-preconditioned UC-MSCs, leading to improvement in hepatic performance, pathological changes and levels of inflammatory cytokines. These effects were abolished by AMD3100. Conclusions Preconditioning of UC-MSCs by rapamycin afforded increased protection against liver I/R injury by enhancing immunosuppression and strengthening the homing and migratory capacity of these cells via the CXCR4/CXCL12 axis.