Homing effect of adipose-derived stem cells to the injured liver: the shift of stromal cell-derived factor 1 expressions

BackgroundWhether systemically transplanted human adipose-derived stem cells (ADSCs) homed to the injured liver in nude mice under stress with subsequent hepatectomy (Hx) and ischemia-reperfusion (I/R) was investigated in the present study. The types of cells in the liver that were involved in the homing of ADSCs were clarified, with focus on the stromal-derived factor-1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR-4) axis. MethodsAdipose-derived stem cells were transplanted intravenously immediately after 70% Hx and I/R. ADSCs were traced by in vivo imaging for 24h after transplantation and ADSCs were histologically detected in the liver. SDF-1 and CXCR-4 expressions in the liver were evaluated by real time RT-PCR. The immunohistochemical analysis of SDF-1 was also performed to identify SDF-1 expressing cells in the liver. ResultsAdipose-derived stem cells were found in various organs immediately following transplantation and almost accumulated in remnant liver or spleen at 6h after transplantation. ADSCs were also histologically revealed in the harvested liver. Hx and I/R injury significantly enhanced SDF-1 expressions regardless of ADSCs transplantation, and only ADSC transplantation increased CXCR-4 expressions. The predominant SDF-1 positive cells in the liver were equally identified in parenchymal and non-parenchymal cells at 6h, but shifted to non-parenchymal cells at 24h after transplantation. ConclusionsSystemically transplanted ADSCs homed to the injured liver after transplantation, possibly based on the mechanisms of SDF-1/CXCR-4 axis. Therefore, systemic transplantation might be an effective and practical route for the transplantation of ADSCs.