共抑制分子BTLA抑制白色脂肪米色化降低能量消耗的机制研究

白色脂肪米色化促进能量消耗从而抑制肥胖，但是转化机制不清。申请者前期研究发现btla-/-小鼠上调UCP1表达促进白色脂肪米色化且BTLA可与脂肪细胞上LEPROTL1结合活化NF-κB信号，提示BTLA可能通过LEPROTL1调节UCP1表达。本研究首先用RNAi、WB等明确BTLA通过LEPROTL1活化NF-κB信号调节UCP1表达；接着利用Co-IP、TAP质谱等技术全面解析BTLA-LEPROTL1轴调节白色脂肪米色化的分子机制；同时采用BTLA条件敲除小鼠建立肥胖模型，通过代谢笼、seahorse能量分析仪等明确T细胞来源的BTLA体内调节白色脂肪米色化的作用；最后利用BTLA阻断型抗体，明确体内阻断BTLA信号对高脂诱导肥胖调理效果。本研究将首次阐明T细胞来源的BTLA信号通过脂肪细胞的LEPROTL1受体调控白色脂肪米色化的分子机制，为肥胖及其相关代谢性疾病治疗提供新策略。

Beigeing of white adipocyte can inhibit obesity through increaseing energy expenditure , but the transformation mechanism is not clear. Our previous study found that btla-/- mice could up-regulate the expression of UCP1 and promote the beigeing of white fat. Furthermore, we found that BTLA can to activate intracellular NF-κB signal of 3T3-L1 adipocyte through binding with LEPROTL1 by using yeast diheterozygous and Co-IP. Take together, these results suggest that BTLA may regulate UCP1 expression by LEPROTL1. In this study, we firstly stimulated 3T3-L1 cells with BTLA-Fc fusion protein in vitro, and elucidated that BTLA regulated UCP1 expression through LEPROTL1 activation of NF-κB signal by RNAi, qPCR and WB. Then the molecular mechanism of BTLA-LEPROTL1 axis regulating the beige of white adipocyte was fully analyzed by using Co-IP, TAP mass spectrometry and other technologies. At the same time, we used BTLA conditional knockout mice to establish a model of obesity induced by high-fat diet. Metabolic changes were analyzed by metabolic cage, seahorse energy analyzer, etc., so as to determine the role of T-cell-derived BTLA in regulating the beige of white fat in vivo. Finally, the blocking antibody of BTLA was used to determine the effect of blocking BTLA signal in vivo on obesity induced by high fat. This study will for the first time elucidate the molecular mechanism by which the T-cell-derived BTLA signal regulates the beige of white adipocyte through its receptor LEPROTL1 on adipocyte, providing a new ideas for the clinical treatment of obesity and its related metabolic diseases.