Dedifferentiated Adipocytes Promote Adipose Tissue Generation within an External Suspension Device.

Background: Mature adipocytes can dedifferentiate into fibroblast-like cells in vitro and acquire proliferation and redifferentiation/transdifferentiation abilities. A soft-tissue expander can induce adipocyte dedifferentiation in vivo. This study combined a tissue expander and an external suspension device to generate a large volume of adipose tissue.
Methods: A soft-tissue expander was implanted beneath the dorsal adipose flaps of rabbits. After 7 days of expansion, the expander was removed and an external suspension device was applied. Samples were collected at various time points, and morphologic, histologic, immunohistochemical, and gene expression analyses were conducted. A silicone sheet was implanted as a control.
Results: After 7 days of expansion, the adipose flap was much thinner. Hematoxylin and eosin and whole-mount staining revealed that adipocytes became smaller (p < 0.05) and some contained multilocular lipid droplets. The number of Ki67 cells increased (p < 0.01), adipokine expression decreased (p < 0.01), and octamer-binding transcription factor 4 expression increased (p < 0.01). After the external suspension device was applied, the normalized volume of adipose flaps was much larger in the expanded group than in the control group (p < 0.05). The expanded group also exhibited more proliferating cells, a larger vascularized area, and higher adipokine expression (p < 0.05).
Conclusion: Dedifferentiated adipocytes in adipose flaps can participate in adipose tissue generation as seed cells and increase the volume of adipose tissue.