Abstract: Objective To investigate the role of adipose-derived stem cell (ASC) -derived exosomes in white fat browning. Methods The mouse ASC cells were isolated, cultured and identified. Lentivirus transfection was used to construct ASC cells overexpressing miR-27. The exosomes secreted by overexpression ASC cells were extracted by differential gradient ultra-high speed centrifugation. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to analyze the expression of miR-27 in exosomes. High-fat feeding was used to construct obese mouse models. The exosomes overexpressing miR-27 (overexpression group), normal ASC exosomes (normal expression group) and physiological saline(control group) were injected separately. The body weight changes were detected under cold exposure conditions. The epidermal subcutaneous fat tissues and scapular fat tissues of mice were striped and compared between the three groups.Western blot assay was used to detect uncoupling protein1 (UCP1), peroxisome proliferators-activated receptor γ (PPARγ),positive regulatory domain zinc finger protein 16 (PRDM16) and peroxisome proliferators-activated receptor γ coactivator-1α (PGC-1α) expressions. Results ASC and its exosomes were successfully extracted and transfected with miR-27. The expressions of miR-27 were significantly higher in ASC and its exosomes than those in white adipose tissues (P＜0.05).Compared with the control group, the body weights of mice decreased slightly in the overexpression group and the normal expression group, and the effect was more obvious with time (P＜0.05). The epididymal subcutaneous adipose tissues were slightly larger in the overexpression group and the normal expression group than those in the control group, while there were no significant changes in the scapular adipose tissues between three groups. The expression levels of UCP1, PPARγ,PRDM16 and PGC-1α were significantly lower in the normal expression group and the overexpression group than those in the control group (P＜0.05). Conclusion Adipose stem cell-derived exosomes can inhibit the browning of white adipose cells.

Key words: exosomes, miR-27, white fat；brown fat, browning of white adipose cells, adipose-derived stem cells