Effect of poly-γ-glutamic acid on adipogenesis of 3T3-L1 preadipocyte

Abstract

Poly-γ-glutamic acid (γ-PGA) is a natural amino acid polymer with biodegradable, non-toxic, and edible properties. The aim of this study was to investigate the effect of γ-PGA isolated from Bacillus sp. SJ-10 on lipid differentiation of 3T3-L1 preadipocyte. During the adipocyte differentiation process, γ-PGA treatment inhibited the differentiation of 3T3-L1 preadipocyte into adipocyte. This inhibitory effect not only reduced the lipid droplet but also the expression of transcription factors involved in adipogenesis. In addition, we found that γ-PGA plays an important role at early stage of differentiation through different time treatment of γ-PGA. Therefore, we investigated the effect of γ-PGA on mitotic clonal expansion (MCE). We have found that γ-PGA inhibits MCE by counting the number of cells during MCE and decreasing the expression of cyclin A and CDK2, which are known to be cell cycle regulators involved in G1 / S transition. In conclusion, we have found that γ-PGA affects the inhibition of adipogenesis through involvement in the early stage of adipocyte differentiation.