Glabellar wrinkle correction by autologous fat transplantation and evidence of human adipose tissue regeneration in a nude mouse model

Background Fat grafts are increasingly applied in augmenting soft tissue defects and correcting static wrinkles, but the outcome is always unpredictable because of high absorption rate. Perilipin1 (Plin1) and perilipin2 (Plin2), two perilipin family proteins on lipid droplets in adipocytes, are reported to be used as biomarkers to evaluate adipocyte regeneration in vivo. Aims The aim of this study was to assess the efficacy of glabellar wrinkle correction with autologous fat grafting and to observe human adipose regeneration in a nude mouse model. Patients/methods Ten patients with 16 moderate or severe glabellar wrinkles underwent wrinkle correction by subcutaneously injecting autologous lipoaspirates obtained from the abdomen. The injection dose was 0.05 ml per 5 mm. The aspirated adipose tissue (0.05 ml) was also injected under the scalps of nude mice. Fat grafts were explanted at 3, 7, 15, 30, and 120 days after transplantation and the dynamic cellular changes were evaluated by HE staining and immunostaining of Plin1 and Plin2. Results Among the sixteen wrinkle lines, thirteen were obviously improved 4 months after procedure. Eight of the ten patients were satisfied with their wrinkle correction effects. The fat grafts demonstrated a continuous changing process from degeneration to regeneration in the mouse model without significant absorption and necrosis. It was Plin1, not Plin2 that was expressed in mature adipocytes. After transplantation, Plin1 expression was lost in dead fat cells while Plin2 expression was activated in newly regenerated adipocytes. After 120 days, all the surviving adipocytes were negative for Plin2 but positive for Plin1 again. Conclusions Micro-volume fat transplantation was an easy and safe method to improve glabellum wrinkle lines, and the regenerative process of human adipose tissue could be verified in the mouse model.