Fat graft survival requires metabolic reprogramming toward the glycolytic pathway.

BACKGROUND: Fat grafts are widely used as natural fillers in reconstructive and cosmetic surgery. However, the mechanisms underlying fat graft survival are poorly understood. Here, we performed an unbiased transcriptomic analysis in a mouse fat graft model to determine the molecular mechanism underlying free fat graft survival. METHODS: We conducted RNA-sequencing (RNA-seq) analysis in a mouse free subcutaneous fat graft model on days 3 and 7 following grafting (n = 5). High-throughput sequencing was performed on paired-end reads using NovaSeq6000. The calculated transcripts per million (TPM) values were processed for principal component analysis (PCA), unsupervised hierarchically clustered heatmap generation, and gene set enrichment analysis. RESULTS: PCA and heatmap data revealed global differences in the transcriptomes of the fat graft model and the non-grafted control. The top meaningful upregulated gene sets in the fat graft model were related to the epithelial-mesenchymal transition, hypoxia on day 3, and angiogenesis on day 7. Mechanistically, the glycolytic pathway was upregulated in the fat graft model at days 3 (FDR q = 0.012) and 7 (FDR q = 0.084). In subsequent experiments, pharmacological inhibition of the glycolytic pathway in mouse fat grafts with 2-deoxy-D-glucose (2-DG) significantly suppressed fat graft retention rates, both grossly and microscopically (n = 5). CONCLUSIONS: Free adipose tissue grafts undergo metabolic reprogramming toward the glycolytic pathway. Future studies should examine whether targeting this pathway can enhance the graft survival rate.