白色脂肪细胞衍生的外泌体 miR-23b 通过靶向 Elf4 调节 GLP-1R 转录来抑制产热。
White adipocyte-derived exosomal miR-23b inhibits thermogenesis by targeting Elf4 to regulate GLP-1R transcription.
机构信息
Functional Experiment Center, Department of Basic Medicine, Xi'an Medical University, Xi'an, 710021, China.
Department of Emergency, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China.
出版信息
Naunyn Schmiedebergs Arch Pharmacol. 2024 Aug;397(8):5847-5860. doi: 10.1007/s00210-024-02984-1. Epub 2024 Feb 9.
Promoting non-trembling thermogenesis of brown adipose tissue (BAT) and browning of white adipose tissue (WAT) helps prevent obesity. MiR-23b is highly expressed in adipose tissue-derived exosomes obtained from obese people, but the role of exosomal miR-23b in regulating thermogenesis and obesity progression remains to be further explored. Here, a mouse obesity model was established through high-fat diet (HFD), and inguinal WAT (iWAT)-derived exosomes and miR-23b antagomir were administered by intraperitoneal injection. The results showed that WAT-derived exosomal miR-23b upregulated body weight and adipocyte hypertrophy and enhanced insulin resistance. Moreover, exosomal miR-23b restrained mtDNA copy number and the expression of genes related to thermogenesis and mitochondrial biogenesis in BAT, and suppressed the expression of WAT browning-related genes under cold stimulation, indicating that exosomal miR-23b hindered non-trembling thermogenesis of BAT and WAT browning. Mechanism studies found that miR-23b targeted Elf4 to inhibit its expression. And Elf4 bound to the GLP-1R promoter region to promote GLP-1R transcription. In addition, silencing miR-23b effectively abolished the inhibitory effect of WAT-derived exosomes on thermogenic gene expression and mitochondrial respiration in adipocytes isolated from BAT and iWAT, which was reversed by GLP-1R knockdown. In conclusion, WAT-derived exosomal miR-23b suppressed thermogenesis by targeting Elf4 to regulate GLP-1R transcription, which contributed to the progression of obesity.
促进棕色脂肪组织(BAT)的非颤抖性产热和白色脂肪组织(WAT)的褐色化有助于预防肥胖。肥胖人群脂肪组织衍生的外泌体中高度表达 miR-23b,但外泌体 miR-23b 调节产热和肥胖进展的作用仍有待进一步探索。本研究通过高脂肪饮食(HFD)建立了肥胖小鼠模型,并通过腹腔注射腹股沟 WAT(iWAT)衍生的外泌体和 miR-23b 拮抗剂。结果表明,WAT 衍生的外泌体 miR-23b 上调了体重和脂肪细胞肥大,并增强了胰岛素抵抗。此外,外泌体 miR-23b 抑制了 BAT 中线粒体 DNA 拷贝数和产热及线粒体生物发生相关基因的表达,并抑制了冷刺激下 WAT 褐色化相关基因的表达,表明外泌体 miR-23b 抑制了 BAT 的非颤抖性产热和 WAT 的褐色化。机制研究发现,miR-23b 靶向 Elf4 抑制其表达。Elf4 结合 GLP-1R 启动子区域促进 GLP-1R 转录。此外,沉默 miR-23b 可有效消除 WAT 衍生的外泌体对 BAT 和 iWAT 分离的脂肪细胞产热基因表达和线粒体呼吸的抑制作用,而 GLP-1R 敲低可逆转这种抑制作用。总之,WAT 衍生的外泌体 miR-23b 通过靶向 Elf4 调节 GLP-1R 转录来抑制产热,从而促进肥胖的发生。