We investigated the ability of fetal mesenchymal stem cells （fMSCs） to differentiate into brown and white adi- pocytes and compared the expression of a number of marker genes and key regulatory factors. We showed th...We investigated the ability of fetal mesenchymal stem cells （fMSCs） to differentiate into brown and white adi- pocytes and compared the expression of a number of marker genes and key regulatory factors. We showed that the expression of key adipocyte regulators and markers during differentiation is similar to that in other human and mu- rine adipocyte models, including induction of PPARy2 and FABP4. Notably, we found that the preadipocyte marker, Pref-1, is induced early in differentiation and then declines markedly as the process continues, suggesting that fMSCs first acquire preadipocyte characteristics as they commit to the adipogenic lineage, prior to their differentiation into mature adipocytes. After adipogenic induction, some stem cell isolates differentiated into cells resembling brown adi- pocytes and others into white adipocytes. Detailed investigation of one isolate showed that the novel brown fat-deter- mining factor PRDM16 is expressed both before and after differentiation. Importantly, these cells exhibited elevated basal UCP-1 expression, which was dependent on the activity of the orphan nuclear receptor ERRa, highlighting a novel role for ERRa in human brown fat. Thus fMSCs represent a useful in vitro model for human adipogenesis, and provide opportunities to study the stages prior to commitment to the adipocyte lineage. They also offer invaluable in- sights into the characteristics of human brown fat.展开更多
文摘We investigated the ability of fetal mesenchymal stem cells （fMSCs） to differentiate into brown and white adi- pocytes and compared the expression of a number of marker genes and key regulatory factors. We showed that the expression of key adipocyte regulators and markers during differentiation is similar to that in other human and mu- rine adipocyte models, including induction of PPARy2 and FABP4. Notably, we found that the preadipocyte marker, Pref-1, is induced early in differentiation and then declines markedly as the process continues, suggesting that fMSCs first acquire preadipocyte characteristics as they commit to the adipogenic lineage, prior to their differentiation into mature adipocytes. After adipogenic induction, some stem cell isolates differentiated into cells resembling brown adi- pocytes and others into white adipocytes. Detailed investigation of one isolate showed that the novel brown fat-deter- mining factor PRDM16 is expressed both before and after differentiation. Importantly, these cells exhibited elevated basal UCP-1 expression, which was dependent on the activity of the orphan nuclear receptor ERRa, highlighting a novel role for ERRa in human brown fat. Thus fMSCs represent a useful in vitro model for human adipogenesis, and provide opportunities to study the stages prior to commitment to the adipocyte lineage. They also offer invaluable in- sights into the characteristics of human brown fat.
