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

Abstract

Whether 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. Adipose-derived stem cells were transplanted intravenously immediately after 70% Hx and I/R. ADSCs were traced by in vivo imaging for 24 h 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. Adipose-derived stem cells were found in various organs immediately following transplantation and almost accumulated in remnant liver or spleen at 6 h 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 6 h, but shifted to non-parenchymal cells at 24 h after transplantation. Systemically 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.