Lymphatic Drainage-Promoting Effects by Engraftment of Artificial Lymphatic Vascular Tissue Based on Human Adipose Tissue-Derived Mesenchymal Stromal Cells in Mice

Figure 5

Regeneration of lymphatic drainage by popliteal transplantation of ASCLT. (a–g) Engraftment of ASCLT into deep tissue of left popliteal area. The histological analysis was performed at four weeks after the transplantation to the LDI model mice. (a–c) HE staining. The engrafted tissues are observed in both deep area near the muscle (b) and shallow subcutaneous area (c). (d–g) Immunohistochemistry. (d, e) The serial section corresponding to (b) and (c), respectively. The engrafted tissues are positive for human vimentin. (f, g) The serial section corresponding to (b) and (c), respectively. A few human podoplanin-positive structures are observed (yellow arrows, insets) suggesting that the engraftment of human-derived lymphatic vessels is restricted. The invasion of host vessels with CD31 immunoreaction is observed in the engrafted tissue. The nuclei of the cells in the dark field images were visualized by DAPI (blue color). (h–j) In vivo imaging of ICG-positive lymphatic drainage at three weeks after the transplantation of artificial lymphatic tissues. (h) The control with transplantation of ASCT (tissue constructed by hASCs alone without HDLECs and lymphatic network) into popliteal area (yellow circle). The formation of ICG-positive drainage is faintly observed at left side of the limb. (i, j) Two examples of ASCLT popliteal transplantation. ICG-positive drainage widely spread at the side of the left limb to abdomen. Red arrow indicates the ICG-positive external sacral lymph node in the intact lymphatic drainage at right limb without lymph node resection.