Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing, China.
J Cell Mol Med. 2020 Jul;24(13):7201-7213. doi: 10.1111/jcmm.15230. Epub 2020 May 15.
Non-alcoholic fatty liver disease is a public health problem worldwide associated with high morbidity and hepatic steatosis, but no effective therapeutic interventions. Magnesium isoglycyrrhizinate (MGIG), a derivative of an active component of Glycyrrhiza glabra, is widely used for the treatment of inflammatory liver diseases due to its potent anti-inflammatory and hepatoprotective activities. Hence, this study aimed to study the effects of MGIG on hepatic steatosis in mice fed a high-fat diet (HFD). Oil Red O staining and transmission electron microscopy revealed a decrease in lipid accumulation in the liver after MGIG treatment along with improved mitochondrial ultramicrostructures. Metabonomic analysis demonstrated that MGIG intervention increased glutamate utilization in mitochondria by promoting the uptake of glutamate into the tricarboxylic acid (TCA) cycle. The NAD /NADH ratio and the expression of other lipid-metabolism-related genes were increased in MGIG-treated livers. Transcriptome sequencing showed that the expression of TLR4, an isoform of the innate immunity Toll-like receptors (TLRs), was significantly decreased after MGIG treatment, suggesting a link between the anti-inflammatory effects of MGIG and its suppression of lipidation. Our results reveal the potent effects of MGIG on lipid metabolism and suggest that hepatic TLR4 might be a crucial therapeutic target to regulate energy homeostasis in hepatic steatosis.
非酒精性脂肪性肝病是一个全球性的公共卫生问题,与高发病率和肝脂肪变性有关,但目前尚无有效的治疗干预措施。甘草酸异甘草素(MGIG)是甘草有效成分的衍生物,由于其强大的抗炎和保肝活性,被广泛用于治疗炎症性肝病。因此,本研究旨在研究 MGIG 对高脂肪饮食(HFD)喂养小鼠肝脂肪变性的影响。油红 O 染色和透射电镜显示,MGIG 治疗后肝脏脂质蓄积减少,线粒体超微结构得到改善。代谢组学分析表明,MGIG 干预通过促进谷氨酸进入三羧酸(TCA)循环来增加线粒体中谷氨酸的利用。MGIG 处理的肝脏中 NAD/NADH 比值和其他脂质代谢相关基因的表达增加。转录组测序显示,MGIG 治疗后先天免疫 Toll 样受体(TLRs)的一种同工型 TLR4 的表达显著降低,提示 MGIG 的抗炎作用与其抑制脂质化之间存在联系。我们的研究结果揭示了 MGIG 对脂质代谢的强大作用,并表明肝 TLR4 可能是调节肝脂肪变性中能量平衡的一个关键治疗靶点。