Journal of Tissue Engineering and Reconstructive Surgery ›› 2024, Vol. 20 ›› Issue (6): 672-.

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Effect of Yes-related protein on the survival rate of fat transplantation and its mechanism

  

  • Online:2024-12-02 Published:2025-01-03

Abstract:

Objective To investigate the effect of YAP on fat graft survival and its possible mechanism. Methods 3T3L1 cells were cultured in vitro and treated with YAP siRNA or YAP-overexpression plasmids carried by lentiviral vectors,resulting in the following groups: negative control siRNA (NC), YAP-si1, YAP-si2, and YAP-si3; lentiviral vector(Vector) and YAP-overexpression (YAP). Cell proliferation was assessed using EdU staining. Differentiation into adipocyteswas induced, and early and late stages of differentiation were analyzed by Oil Red O staining, with lipid droplet accumulationquantified using Image-Pro Plus 6.0 software. Triglyceride content was measured using a triglyceride assay kit, and PCR andWestern blot were used to assess the expression of genes and proteins related to adipocyte differentiation. For in vivo experiments, a subcutaneous fat transplantation model in nude mice was established. A total of 8 mice were randomly divided into NC siRNA group, YAP knockdown (si-YAP) group, adeno-associated virus (AAV) vector group, and YAP overexpression (AAV-YAP) groups, with 2 mice per group. Each mouse received 0.2 mL of fat injection at four different sites, totaling 0.8 mL. Subsequent injections of 0.2 mL of NC siRNA, YAP siRNA, AAV vector, or AAV vector-mediated YAP-overexpression plasmid were administered into the transplanted fat. Fat was collected at 1,2, and 4 weeks post transplantation, and fat weight and volume were measured to evaluate survival rates. Hematoxylin-eosin staining and immunofluorescence were used to examine fat structure, number of oil droplets, and viable adipocytes. Results In cell experiments, YAP knockdown did not significantly affect proliferation or apoptosis of 3T3-L1 cells compared to controls, but resulted in increased Oil Red O staining area (P<0.05), higher triglyceride content (P<0.05), and elevated expression of adipogenic genes and proteins (P<0.05). Conversely, YAP overexpression led to increased proliferation of 3T3-L1 cells with unchanged apoptosis rates, decreased Oil Red O staining area (P<0.05), lower triglyceride content (P<0.05), and reduced expression of adipogenic genes and proteins (P<0.05) compared to the lentiviral vector group. In animal experiments, the si-YAP group exhibited increased fat weight and volume, more intact fat structure, reduced oil droplet number, and more viable adipocytes compared to the NC group. In contrast, the AAV-YAP group had decreased fat weight and volume, less intact fat structure, increased oil droplet number, and fewer viable adipocytes compared to the AAV vector group. Conclusion YAP significantly inhibits the survival rate of transplanted fat. Furthermore, YAP affects 3T3-L1 adipogenesis by modulating the PPARγ pathway.

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