Abstract 9900: Implantation of Adipose-Derived Regenerative Cells Enhances Lymphangiogenesis and Improves Secondary Lymphedema
Introduction: Secondary lymphedema often occurs as a complication of surgery or radiotherapy for cancer. Although it deteriorates patient's quality of life, there are few therapeutic options. We previously reported that implantation of adipose-derived regenerative cells (ADRCs) augmented neovascularization. Accordingly, we tested our hypothesis that ADRCs implantation promotes lymphangiogenesis and improves secondary lymphedema.
Methods: ADRCs and bone-marrow mononuclear cells (BM-MNCs) were isolated from C57BL/6J or GFP-transgenic mice. We established a modified model of mouse tail lymphedema, and mice were randomly divided into four groups (ADRCs implantation (2×106/mouse), BM-MNCs implantation(2×106/mouse), recombinant VEGF-C injection(4μ g/mouse), or PBS injection). Real time RT-PCR and ELISA were performed at postoperative day 5. Four weeks after implantation, tail diameter was measured and histological analysis was performed to detect new lymphatic vessels using ant-LYVE-1 antibody. In vitro study, we performed migration and proliferation assay of human lymphatic endothelial cells (hLECs), which were stimulated by ADRCs conditioned medium (ADRC-CM). In addition, we measured phosphorylated eNOS and Erk, which have been shown to play an important role in promoting migration and proliferation of hLECs.
Results: Expression of VEGF-C mRNA at the edematous tissue and plasma VEGF-C levels were greater in the ADRC group compared to the PBS group (p<0.05). Lymphedema was significantly improved in ADRCs group to the level similar to VEGF-C or BM-MNCs groups at 4 weeks after cell therapy (p<0.001, vs PBS group). Moreover, lymphatic capillary density in the edematous tissue was greater in the ADRC group than in the PBS group (p<0.000005). Only few GFP positive cells were incorporated into new lymphatic vessels, and most of LECs constructing lymph vessels were negative for anti-GFP-FITC mAb. In vitro, we confirmed that ADRC-CM contained VEGF-C protein. Treatment of hLECs stimulated migration and proliferation of hLECs, and which was accompanied by increased phosphorylation of eNOS and Erk.
Conclusions: The implantation of ADRCs seemed to be a novel strategy for therapeutic lymphangiogenesis in secondary lymphedema.
- © 2011 by American Heart Association, Inc.