南方医科大学学报

南方医科大学学报 ›› 2023, Vol. 43 ›› Issue (11): 1881-1885.doi: 10.12122/j.issn.1673-4254.2023.11.07

• • 上一篇    下一篇

脂肪组织黏膜相关恒定T细胞通过分泌白介素4调节小鼠脂肪棕色化

叶 潇，宋迎香，赵 瑜，朱大龙   

  1. 南京医科大学鼓楼临床医学院内分泌科，江苏 南京 210008；浙江省人民医院内分泌科（杭州医学院附属人民医院），浙江 杭州 310014
  • 出版日期:2023-11-20 发布日期:2023-12-08

Cold stimulation promotes interleukin-4 secretion by mucosal-associated invariant T cells in the adipose tissue to promote adipose browning in mice

YE Xiao, SONG Yingxiang, ZHAO Yu, ZHU Dalong   

  1. Department of Endocrinology, Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing 210008, China; Department of Endocrinology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital of Hangzhou Medical College), Hangzhou 310014, China
  • Online:2023-11-20 Published:2023-12-08

RichHTML

13

PDF

140

摘要： 目的 探究黏膜相关恒定T（MAIT）细胞与脂肪棕色化之间的关系以及调节脂肪棕色化的分子机制。方法 构建MAIT细胞功能缺陷小鼠模型，对比野生型小鼠及MAIT细胞缺陷小鼠，通过Western blot和RT-PCR检测冷刺激前后小鼠脂肪棕色化标志物的水平差异，并通过流式细胞术检测了小鼠脂肪组织内MAIT细胞在冷刺激前后数量、活化水平以及细胞因子分泌能力的差异。采用MAIT细胞与脂肪细胞共培养的方式，通过Western blot和RT-PCR检测是否存在MAIT细胞以及是否加入白介素4（IL-4）封闭抗体的条件下脂肪细胞棕色化标志物的表达差异。利用MAIT细胞缺陷的小鼠模型，通过代谢笼、免疫组化、Western blot和Seahorse方法检测MAIT细胞缺陷小鼠在冷刺激条件下的脂肪棕色化相关指标。结果 Western blot和RT-PCR结果显示小鼠冷刺激后脂肪组织棕色化标志物UCP-1、PGC1-α的表达水平均上调，在此情景下小鼠脂肪组织内MAIT细胞数量差异无统计学意义（P>0.05），CD69的表达水平上调（P<0.05），效应细胞因子IL-4的表达水平上调（P<0.05）。体外共培养实验显示，脂肪细胞与MAIT细胞共培养后的棕色化水平上调（P<0.05），若阻断IL-4信号则棕色化水平下调（P<0.05）。对MAIT细胞缺陷的小鼠进行冷刺激后，其能量消耗水平低于野生型小鼠（P<0.05），脂肪棕色化水平低于野生型小鼠（P<0.05），且脂肪细胞代谢水平低于野生型小鼠。结论 本研究首次通过MAIT细胞功能缺陷小鼠模型验证MAIT细胞参与脂肪棕色化，动物实验及体外实验进一步显示冷刺激通过促进MAIT细胞分泌IL-4调控脂肪细胞棕色化。

关键词: 黏膜相关恒定T细胞；肥胖；棕色脂肪

Abstract: Objective To investigate the role of mucosal-associated invariant T (MAIT) cells in the regulatory mechanism of adipose browning. Methods A mouse model with functional deficiency of MAIT cells was established for comparison with the wild-type mice for levels of brown adipose tissue markers in response to cold stimulation using Western blotting and RT-PCR. Flow cytometry was used to analyze the changes in the number, activation level and cytokine secretion ability of MAIT cells in mouse adipose tissue after cold stimulation. In a co-culture system of MAIT cells and adipocytes, the effect of interleukin-4 (IL-4) blocking antibodies on the expressions of brown adipose tissue markers in the adipocytes was evaluated using Western blotting and RT-PCR. In a mouse model of MAIT cell deficiency, the changes in adipose browning-related indicators in response to cold stimulation were analyzed using metabolic cages, immunohistochemistry, Western blotting and the Seahorse method. Results In both the mouse models of functional deficiency of MAIT cells and wild-type mice, cold stimulation significantly increased the expression levels of brown adipose tissue markers UCP-1 and PGC1-α and upregulated CD69 and IL-4 expressions in the adipose tissue without significantly affecting the number of MAIT cells in the adipose tissue. In the co-culture experiment, the adipocytes showed obviously increased browning level after co-culture with MAIT cells (P<0.05), but blocking IL-4 signaling strongly downregulated the browning level (P<0.05). The MAIT cell-deficient mice showed obviously lower levels of energy expenditure, adipose browning and metabolism of the adipocytes compared with the wild-type mice in response to cold stimulation (P<0.05). Conclusion MAIT cells participate in adipose browning in mice, and cold stimulation promotes MAIT cell secretion of IL-4 to positively regulate adipose browning.

Key words: mucosal-associated invariant T cells; obesity; brown adipose tissue