去泛素化酶USP2对米色脂肪产热功能的影响

Effect of Ubiquitin-specific Protease 2 in the Process of White Fat Browning

目的探讨去泛素化酶2(ubiquitin-specific protease 2,USP2)在白色脂肪棕色化过程中的作用及其潜在机制。方法运用实时定量PCR和Western blot法检测USP2在小鼠代谢组织中的表达谱。检测米色脂肪细胞诱导分化过程中(0、2、4、6、8天)USP2 mRNA和蛋白表达。建立小鼠白色脂肪棕色化模型,检测USP2 mRNA的表达。利用药物干预成熟脂肪细胞激活交感神经-肾上腺素通路,检测USP2 mRNA和蛋白表达。使用USP2特异性抑制剂ML364处理成熟米色脂肪细胞,检测产热相关基因的变化。结果USP2在小鼠代谢器官中均有表达,且在肌肉中表达最高。USP2在米色脂肪细胞自然分化过程中表达量逐渐增加。在寒冷刺激和游泳训练建立的小鼠白色脂肪棕色化模型中,其皮下腹股沟白色脂肪组织和肩胛部棕色脂肪组织中USP2的mRNA表达显著升高。利用ISO和cAMP干预成熟米色脂肪细胞后,USP2 mRNA和蛋白表达明显升高。利用USP2特异性抑制剂ML364干预成熟米色脂肪细胞后,产热相关基因mRNA表达明显下调,UCP1蛋白表达下降。结论USP2参与米色脂肪细胞的发生、发展过程,抑制USP2的活性会影响其产热功能。

Objective To explore the effect of ubiquitin-specific protease 2(USP2)in the process of white fat browning and its underlying mechanism.Methods Real-time quantitative PCR(RT-qPCR)and Western blotting were used to detect the expression profile of USP2 in mouse metabolic tissues.The expression of USP2 mRNA and protein during the differentiation(0,2,4,6,8 day)of beige adipocytes was detected.The expression of USP2 mRNA in mouse white fat browning model by cold stimulation and exercise training was detected.Chemicals was used to interfere with mature beige adipocytes to activate the sympathetic nerve-adrenaline pathway,and then USP2 mRNA and protein expression was detected.Mature beige adipocytes was treated with USP2 specific inhibitor ML364,then the expression of genes related to thermogenesis was detected.Results USP2 was expressed in the metabolic organs of mice,and the expression was higher in muscle.The expression of USP2 increased gradually during the differentiation of beige adipocytes.The mRNA expression of USP2 in the inguinal subcutaneous white adipose tissue(iWAT)and interscapular brown adipose tissue(iBAT)were significantly increased in cold-treated and swim-treated mouse.When ISO and cAMP interfered with mature beige adipocytes,the expression of USP2 increased significantly.The thermogenesis related genes reduced significantly after the treatment of USP2 specific inhibitor ML364.Conclusion USP2 is involved in the occurrence and development of the browning process of white fat and inhibit the activity of USP2 can damage the function of thermogenesis.