Oxytocin, a protein hormone mainly produced by hypothalamus, has been shown to repress body weight gain in obese animals, in part, by reducing food intake and increasing energy expenditure. Till now, activation of brown fat tissue (BAT) thermogenesis and white adipose tissue (WAT) browning are considered as two main factors for oxytocin-induced energy expenditure. However, the underlying molecular mechanisms are still not understood well. Here, we observed that oxytocin expression in the hypothalamus and its receptor in adipose tissues were induced by cold exposure in mice. In differentiated adipocytes, oxytocin stimulated brown adipocyte specific gene expression by inducing PRDM16. In high fat diet induced obese mice, oxytocin delivery by osmotic minipumps increased body core temperature and decreased body weight gain. Glucose and insulin tolerance were improved by oxytocin. Hyperinsulinemia and fatty liver were ameliorated in oxytocin-treated animals. Moreover, oxytocin treatment induced thermogenic gene expressions in BAT, inguinal WAT (iWAT), and skeletal muscle. Taken together, our findings revealed a new aspect of oxytocin, i.e. oxytocin induces iWAT browning and stimulates thermogenesis in BAT, iWAT and skeletal muscle, through which oxytocin promotes thermogenesis and thus combats obesity and metabolic dysfunctions.

催产素是一种主要由下丘脑产生的蛋白质激素，已显示出可以抑制肥胖动物的体重增加，部分原因是通过减少食物摄入和增加能量消耗。到目前为止，棕色脂肪组织（BAT）生热的激活和白色脂肪组织（WAT）褐变被认为是催产素诱导的能量消耗的两个主要因素。然而，潜在的分子机制仍未得到很好的理解。在这里，我们观察到小鼠的低温暴露诱导了下丘脑中催产素的表达及其在脂肪组织中的受体。在分化的脂肪细胞中，催产素通过诱导PRDM16刺激棕色脂肪细胞特异性基因表达。在高脂饮食诱导的肥胖小鼠中，通过渗透性微型泵输送催产素会增加人体核心温度并降低体重增加。催产素改善了葡萄糖和胰岛素的耐受性。催产素治疗的动物的高胰岛素血症和脂肪肝得到改善。此外，催产素治疗诱导BAT，腹股沟WAT（iWAT）和骨骼肌中的热基因表达。综上所述，我们的发现揭示了催产素的一个新方面，即催产素诱导BAT，iWAT和骨骼肌中的iWAT褐变并刺激产热，催产素通过催产素促进产热，从而对抗肥胖和代谢功能障碍。