Chyle Fat–Derived Stem Cells Conditioned Medium Inhibits Hypertrophic Scar Fibroblast Activity

BACKGROUND: Hypertrophic scars (HSs) generally form after injury to the deep layers of the dermis and are characterized by excessive collagen deposition. An increasing amount of evidence has determined that human adipose tissue-derived mesenchymal stem cells attenuate fibrosis in various conditions. We explored the effect and possible mechanism of chyle fat-derived stem cells (CFSCs) on HS formation. METHODS: Hypertrophic scar-derived fibroblasts (HSFs) and CFSCs were isolated from individual patients. Third-passage CFSCs were isolated and cultured using a mechanical emulsification method, and their surface CD markers were analyzed by flow cytometry. The adipogenic and osteogenic differentiation capacity of the CFSCs was determined using oil red O staining and alizarin red S staining, respectively. Then, the effects of CFSCs on HSFs were assessed in vitro. Hypertrophic scar-derived fibroblasts were treated with starvation-induced conditioned medium from the CFSCs (CFSC-CM). The change in HSF cellular behaviors, such as cell proliferation, migration, and protein expression of scar-related molecules, was evaluated by cell counting assay, scratch wound assay, enzyme-linked immunosorbent assay, and western blotting. All data were analyzed using SPSS 17.0. RESULTS: The CFSCs expressed CD90, CD105, and CD73 but did not express CD34, CD45, or CD31. The CFSCs differentiated into adipocytes and osteoblasts under the appropriate induction conditions. Chyle fat-derived stem cells conditioned medium inhibited HSF proliferation and migration. The in vitro and ex vivo studies revealed that CFSC-CM decreased type I collagen, type III collagen, and α smooth muscle actin expression. CONCLUSIONS: Our results suggest that CFSCs are associated with the inhibition of fibrosis in HSFs by a paracrine effect. The use of CFSC-CM may be a novel therapeutic strategy for HSs.