CXCL13 promote angiogenesis by recruiting M2 macrophages and endothelial progenitor cells in beige adipose grafts

Fat grafting is an emerging clinical technique to address soft tissue deficiencies. This study investigates whether the secretory function of beige adipose tissue(BeigeAT) grafts is involved in promoting soft tissue regeneration in fat grafting. In this study, mice were randomly divided into white adipose tissue (WAT) and BeigeAT groups. Each type of adipose tissue (0.3 mL) was transplanted into the respective groups, and samples were harvested at 2, 4, and 12 week. Subsequently, mice were further divided into three groups, BeigeAT group, BeigeAT with CXCL13 treatment group, and BeigeAT with TAK-779 treatment group, to investigate the role of CXCL13 in BeigeAT transplants. Graft retention rate, vascularization, and fibrosis levels were compared among the groups. Compared to WAT transplants, BeigeAT transplants exhibited moderate inflammation, enhanced revascularization, reduced fibrosis, and increased infiltration of M2 macrophages and endothelial progenitor cells in the early stages following fat grafting. CXCL13 expression was significantly higher in BeigeAT transplants at 2, 4, and 12 week post-grafting. Additionally, modulation of CXCL13 expression affected the infiltration of M2 macrophages and endothelial progenitor cells. However, BeigeAT transplants exhibited superior retention rates compared to BeigeAT CXCL13 groups and BeigeAT TAK-779 groups after 12 weeks of fat grafting. BeigeAT transplants achieve improved retention rates through CXCL13-induced infiltration of M2 macrophages and endothelial progenitor cells.