Enhancing fat graft survival: thymosin beta-4 facilitates mitochondrial transfer from ADSCs via tunneling nanotubes by upregulating the Rac/F-actin pathway.

Autologous fat grafting is a widely used technique in plastic and reconstructive surgery, but its efficacy is often limited by the poor survival rate of transplanted adipose tissue. This study aims to enhance the survival of fat grafts by investigating the role of thymosin beta-4 (Tβ4) in facilitating mitochondrial transfer from adipose-derived stem cells (ADSCs) to adipocytes and newly formed blood vessels within the grafts via tunneling nanotubes (TNTs). We demonstrate that Tβ4 upregulates the Rac/F-actin pathway, leading to an increased formation of TNTs and subsequent transfer of mitochondria from ADSCs. This process mitigates oxidative stress, reduces apoptosis, and promotes revascularization, thereby improving the quality and volume retention of fat grafts. Our findings provide a novel mechanistic insight into the enhancement of fat graft survival and suggest Tβ4 as a potential therapeutic agent to improve clinical outcomes in autologous fat transfer procedures.