本文亮点：

　　冷刺激可诱导脂联素（adiponectin）在皮下白色脂肪中产生特异性累积

　　adiponecitn敲除小鼠抵抗冷刺激诱导的皮下脂肪组织棕色化

　　冷刺激诱导的皮下脂肪组织内M2型巨噬细胞增殖需要adiponecitn的作用

　　M2型巨噬细胞利用T-cadherin结合 adiponecin

　　近日，来自香港大学的研究人员在国际学术期刊Cell metabolism在线发表了一项最新研究进展，他们发现慢性冷刺激可诱导adiponectin在皮下脂肪累积，adiponectin可进一步通过促进皮下脂肪组织内M2型巨噬细胞增殖促进皮下脂肪棕色化的发生。

　　Adiponectin是一种重要的脂肪因子，其在对抗肥胖相关的代谢紊乱方面发挥着非常重要的保护作用，同时其作用机制也比较多样化。但一直以来关于adiponectin在适应性产热方面发挥的作用鲜有研究。

　　在这项研究中，研究人员发现慢性冷刺激会导致皮下白色脂肪细胞产生更多的adiponecitn，大量的adiponectin会与SVF中的M2型巨噬细胞结合。随后研究人员利用adiponectin敲除小鼠进行研究发现，当adiponectin发生缺失，慢性冷刺激诱导的皮下脂肪组织中M2型巨噬细胞累积，米色脂肪细胞激活以及产热基因表达都受到明显损伤，而将adiponectin进行回补可逆转这些损伤现象。

　　在对机制进行研究的过程中，研究人员发现adiponectin能够通过与M2型巨噬细胞表面的T-cadherin结合募集到M2型巨噬细胞表面，激活 Akt信号途径促进细胞增殖，再由M2型巨噬细胞进一步激活米色脂肪细胞。

　　总得来说，这些研究结果揭示了adiponectin在冷冻诱导的适应性产热方面发挥的重要作用，并且这种作用是通过调节皮下脂肪组织成熟脂肪细胞与M2型巨噬细胞之间的"对话"实现的。这为拓展人们对脂联素的认识提供了重要信息。

　　DOI: http://dx.doi.org/10.1016/j.cmet.2015.06.004

　　Adiponectin Enhances Cold-Induced Browning of Subcutaneous Adipose Tissue via Promoting M2 Macrophage Proliferation

　　Adiponectin is an abundant adipokine with pleiotropic protective effects against a cluster of obesity-related cardiometabolic disorders. However, its role in adaptive thermogenesis has scarcely been explored. Here we showed that chronic cold exposure led to a markedly elevated production of adiponectin in adipocytes of subcutaneous white adipose tissue (scWAT), which in turn bound to M2 macrophages in the stromal vascular fraction. Chronic cold exposure-induced accumulation of M2 macrophages, activation of beige cells, and thermogenic program were markedly impaired in scWAT of adiponectin knockout (ADN KO) mice, whereas these impairments were reversed by replenishment with adiponectin. Mechanistically, adiponectin was recruited to the cell surface of M2 macrophages via its binding partner T-cadherin and promoted the cell proliferation by activation of Akt, consequently leading to beige cell activation. These findings uncover adiponectin as a key efferent signal for cold-induced adaptive thermogenesis by mediating the crosstalk between adipocytes and M2 macrophages in scWAT.