Zhao Xiujuan, Xia Minghui, Peng Zhengxin, Du Qiuyang, Liu Yang, Xia Yu, Lv Panjing, Zhang Xiao, Yuan Shijie, Xie Xiaorong, Wang Jing, Sun Shuguo, Yang Xiang-Ping, He Ran
Department of Immunology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
The Second Affiliated Hospital of Guangzhou Medical University, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou, 510260, China.
Inflammation. 2024 Dec 27. doi: 10.1007/s10753-024-02202-3.
Intermittent fasting (IF) has been shown to ameliorate inflammation including DSS-induced colitis. It is well known that autophagy can limit inflammation and TFEB is a master transcriptional factor that regulates the processes of autophagy. However, whether TFEB is involved in the regulation of IF-mediated amelioration of inflammation and its mechanism remained unclear. In this study, we found that IF ameliorated DSS-induced colitis and induced TFEB. Nutrition deprivation induced TFEB puncta formation, which processes the characteristics of liquid-liquid phase separation (LLPS) showed by fluorescence recovery after photobleaching (FRAP) assay and 1,6-hexanediol treatment. We found the 24-33 amino acids of Coiled-Coil (CC) domain located in N terminus is essential for TFEB phase separation. Deletion of 24-33 amino acids within the CC domain inhibited TFEB-mediated target gene expression. In addition, we found transcription co-activators, EP300 and MED1, co-localized with TFEB condensate to formed a transcriptional hub that promotes the efficient expression of target genes. More importantly, TFEB inhibitor with ability to suppress TFEB puncta formation abolished the IF-mediated amelioration of DSS colitis. Together, these findings revealed a critical role of TFEB phase separation in the regulation of its transcriptional activity and anti-inflammatory functions induced by IF.
间歇性禁食（IF）已被证明可改善包括葡聚糖硫酸钠（DSS）诱导的结肠炎在内的炎症。众所周知，自噬可以限制炎症，而转录因子EB（TFEB）是调节自噬过程的主要转录因子。然而，TFEB是否参与IF介导的炎症改善调节及其机制仍不清楚。在本研究中，我们发现IF改善了DSS诱导的结肠炎并诱导了TFEB。营养剥夺诱导TFEB点状结构形成，通过光漂白后荧光恢复（FRAP）分析和1,6 -己二醇处理显示其具有液-液相分离（LLPS）的特征。我们发现位于N端的卷曲螺旋（CC）结构域的24 - 33个氨基酸对于TFEB相分离至关重要。CC结构域内24 - 33个氨基酸的缺失抑制了TFEB介导的靶基因表达。此外，我们发现转录共激活因子EP300和MED1与TFEB凝聚物共定位，形成促进靶基因有效表达的转录枢纽。更重要的是，具有抑制TFEB点状结构形成能力的TFEB抑制剂消除了IF介导的DSS结肠炎改善作用。总之，这些发现揭示了TFEB相分离在调节其转录活性和IF诱导的抗炎功能中的关键作用。
