Secretory factors from rat adipose tissue explants promote adipogenesis and angiogenesis

Adipogenic differentiation of adipose-derived stem cells (ASCs) is known to be affected by many promoting and inhibiting factors, and correlated with surrounding cells and extracellular matrix. However, few studies have evaluated the effect of secreted biological molecules from adipose tissue explants on the growth of ASCs. In this study, ASCs were isolated and the secretory factors from adipose tissue explants (SFAE) were prepared from adipose tissue explants. The multilineage differentiation potential of ASCs was determined using different inductive media. The influence of SFAE on the colony formation and proliferation of ASCs was determined using colony-forming efficiency assay and Cell Counting Kit-8 assay, respectively. Real-time polymerase chain reaction and Western blot were performed to analyze the beneficial effect of SFAE on the adipogenesis and angiogenesis of ASCs. Utilizing gelatin scaffold, the influence of SFAE on ASCs was investigated in vivo. Subsequently, cell/gelatin constructs were cultured in a subcutaneous pocket on a rat dorsum for 2 and 9 weeks, and the resultant samples were histologically evaluated. Results showed that ASCs derived from adipose explants can differentiate along multiple lineages in vitro. Utilizing SFAE, the proliferation and colony-forming efficiency of ASCs were inhibited, while the expression of adipogenesis markers such as C/EBPβ, PPARγ2, and LPL, as well as angiogenesis factor VEGF-A were promoted. Moreover, the beneficial effect of SFAE on adipogenesis was revealed in vivo. In conclusion, our results suggested that SFAE has beneficial influence on adipogenesis and angiogenesis both in vitro and in vivo.