OBJECTIVETo explore the method for the isolation, cultivation, and purification of adipose-derived stem cells (ADSCs) and examine the oncogenesis and homing of ADSCs to the liver in vivo.

METHODSADSCs were isolated from female mice by digestion with 0.075% collagenase I and the morphology of the isolated cells was observed with examination of the cell surface markers and cell cycle. BALB/c mice were injected with 1×10(6) ADSCs on the back to evaluate the oncogenesis of ADSCs or with 1×10(6) ADSCs stained with 5, 6-carboxyfluorescein diacetate-succinimidyl ester (CFSE) via the tail vein to examine the cell homing to the liver.

RESULTSThe isolated ADSCs highly expressed CD29 and CD44 and were negative for CD34, CD45, CD11b and CD14. Cell cycle distribution analysis showed cell percentages in G0/G1, S, and G2/M phases of 80.1%, 7.9%, and 12%, respectively. The ADSCs had a low immunogenicity and did not express CD40, CD80, CD86, MHCI, MHCII or PDL-1. After stimulation with IFN-γ, the expression of CD40, CD80 and PDL-1 were up-regulated slightly in the cells. Dorsal injection of the ADSCs did not result in any tumor formation within 1 month, and ADSCs injected via the tail vein showed cell homing to the liver.

CONCLUSIONMurine ADSCs can be isolated and expanded effectively by collagenase digestion and adherent culture. The isolated ADSCs can successfully reside in the liver after implantation, and thus may serve as a promising candidate cell in stem cell therapy of liver diseases.