MFN1 and polyostotic fibrous dysplasia: Finally, immunoblot analysis showed that MFN1 protein expression level was increased in PFD rats, while α-SMA and Collagen I levels indicated a significant decrease trend; injection of BMSCs or mimic-NC-treated BMSCs slightly reduced MFN1 protein expression, while the effect of miR-181a-5p mimic-loaded BMSCs was better; rats injected with BMSCs transfected with miR-181a-5p mimic had enhanced fibroblast differentiation of BMSCs (Fig. 5 H, I).