Department of Medicine, Naomi Berrie Diabetes Center, Columbia University, New York, NY 07043, USA.
Department of Pharmaceutics, Rutgers University, Piscataway, NJ 08854, USA.
Science. 2019 Mar 1;363(6430):989-993. doi: 10.1126/science.aaw2586.
To meet systemic metabolic needs, adipocytes release fatty acids and glycerol through the action of neutral lipases. Here, we describe a secondary pathway of lipid release from adipocytes that is independent of canonical lipolysis. We found that adipocytes release exosome-sized, lipid-filled vesicles (AdExos) that become a source of lipid for local macrophages. Adipose tissue from lean mice released ~1% of its lipid content per day via exosomes ex vivo, a rate that more than doubles in obese animals. AdExos and associated factors were sufficient to induce in vitro differentiation of bone marrow precursors into adipose tissue macrophage-like cells. Thus, AdExos are both an alternative pathway of local lipid release and a mechanism by which parenchymal cells can modulate tissue macrophage differentiation and function.
为了满足全身代谢的需要，脂肪细胞通过中性脂肪酶的作用释放脂肪酸和甘油。在这里，我们描述了脂肪细胞释放脂质的另一种途径，该途径不依赖于经典的脂肪分解。我们发现脂肪细胞释放出大小类似于外泌体、充满脂质的囊泡（AdExos），这些囊泡成为局部巨噬细胞的脂质来源。从瘦小鼠的脂肪组织中每天通过外泌体离体释放其脂质含量的约 1%，在肥胖动物中这一比率增加了一倍多。AdExos 及其相关因子足以诱导骨髓前体细胞在体外分化为脂肪组织巨噬细胞样细胞。因此，AdExos 既是局部脂质释放的另一种途径，也是实质细胞调节组织巨噬细胞分化和功能的一种机制。
