Shen Fukui, Yang Wen, Luan Guoqing, Peng Jiamin, Li Zhenqiang, Gao Jie, Hou Yuanyuan, Bai Gang
State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300353, China.
State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300353, China.
Phytomedicine. 2024 Mar;125:155356. doi: 10.1016/j.phymed.2024.155356. Epub 2024 Jan 14.
Catalpol (CAT), a naturally occurring iridoid glycoside sourced from the root of Rehmannia glutinosa, affects mitochondrial metabolic functions. However, the mechanism of action of CAT against pyrexia and its plausible targets remain to be fully elucidated.
This study aimed to identify the specific targets of CAT for blocking mitochondrial thermogenesis and to unveil the unique biological mechanism of action of the orthogonal binding mode between the hemiacetal group and lysine residue on the target protein in vivo.
Lipopolysaccharide (LPS)/ carbonyl cyanide 3-chlorophenylhydrazone (CCCP)-induced fever models were established to evaluate the potential antipyretic effects of CAT. An alkenyl-modified CAT probe was designed to identify and capture potential targets. Binding capacity was tested using in-gel imaging and a cellular thermal shift assay. The underlying antipyretic mechanisms were explored using biochemical and molecular biological methods. Catalpolaglycone (CA) was coupled with protein profile identification and molecular docking analysis to evaluate and identify its binding mode to UCP2.
After deglycation of CAT in vivo, the hemiacetal group in CA covalently binds to Lys239 of UCP2 in the mitochondria of the liver via an ɛ-amine nucleophilic addition. This irreversible binding affects proton leakage and improves mitochondrial membrane potential and ADP/ATP transformation efficiency, leading to an antipyretic effect.
Our findings highlight the potential role of CA in modulating UCP2 activity or function within the mitochondria and open new avenues for investigating the therapeutic effects of CA on mitochondrial homeostasis.
梓醇（CAT）是一种从地黄根中提取的天然环烯醚萜苷，可影响线粒体代谢功能。然而，CAT解热的作用机制及其可能的靶点仍有待充分阐明。
本研究旨在确定CAT阻断线粒体产热的特定靶点，并揭示体内半缩醛基团与靶蛋白赖氨酸残基之间正交结合模式独特的生物学作用机制。
建立脂多糖（LPS）/羰基氰3-氯苯腙（CCCP）诱导的发热模型，以评估CAT的潜在解热作用。设计一种烯基修饰的CAT探针来识别和捕获潜在靶点。使用凝胶成像和细胞热迁移分析测试结合能力。采用生化和分子生物学方法探索潜在的解热机制。梓醇苷元（CA）与蛋白质谱鉴定和分子对接分析相结合，以评估和确定其与解偶联蛋白2（UCP2）的结合模式。
CAT在体内脱糖后，CA中的半缩醛基团通过ε-胺亲核加成与肝脏线粒体中UCP2的赖氨酸239共价结合。这种不可逆结合影响质子泄漏，改善线粒体膜电位和ADP/ATP转化效率，从而产生解热作用。
我们的研究结果突出了CA在调节线粒体内UCP-2活性或功能方面的潜在作用，并为研究CA对线粒体稳态的治疗作用开辟了新途径。
