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Abstrato

Long-term Existence of Donor Adipose-derived Stem Cells in the Recipient May Modulate the Vascularized Composite Tissue Allotransplantation Survival in a Rodent Model

Chien-Chang Chen, Shigeru Goto, Chia-Chun Tsai and Yur-Ren Kuo

Our previous studies have demonstrated donor adipose-derived stem cells (ASCs) combined with short-term immunosuppressant therapy could prolong vascularized composite tissue allotransplantation (VCA) survival in a rodent hind-limb model. In this study, we investigated whether the homing and migration of donor ASCs may modulate VCA survival. Orthotopic hind-limb transplants from male Wistar to Lewis rats were performed (day 0). Donor ASCs were propagated from the adipose-tissue and subculture originated from green fluorescent protein (GFP) transgenic Wistar rats. The transplanted rat (GFP-negative Lewis) received the immunosuppressive protocol similar to our previous design including short-term cyclosporine-A (CsA, days 0-+20), anti-lymphocyte serum (ALS; 0.5 ml i.p.; -4, +1), and three rounds of GFP+-ASCs (2 × 106 cells/time, i.v. on days +1, +7, and +21). The engraftment assessment of various donor and recipient tissues were performed by using immuno-fluorescent staining. Flow cytometry was performed to quantify the GFP+-ASCs. The results revealed allotransplant survival was significantly prolonged (>100 days) exclusively in ASC-ALS-CsA group which was well correlated with long-term existence of donor GFP-positive ASCs in the recipient. Flow cytometric analysis also revealed GFP+-ASCs apparent expression in the recipient peripheral blood in 2 weeks post-ASC infusion but skewing decrease post-transplantation. The immunofluorscent staining performed on tissue biopsy samples revealed the GFP positive cells existed in the alloskin and recipient skin and liver and spleen parenchymal tissues 2 weeks post-ASC injection. However, no apparent expressions of GFP+-ASCs were found in recipient tissues at 16 weeks post-transplantation except in recipient spleen parenchyma. These indicated donor ASCs long-term existed in the recipient spleen tissue and circulating blood may lead to prolong allograft survival.