Mass Spectrometry-Based Label-Free Quantitative Proteomic Analysis of CCl4-Induced Acute Liver Injury in Mice Intervened by Total Glycosides from Ligustri Lucidi Fructus

Abstract

Background: CCl4 Acute Liver Injury (ALI) is a classical model for experimental research. However, there are few reports involved in the fundamental research of CCl4-induced ALI. Ligustri Lucidi Fructus (LLF) and its prescription have been used to treat hepatitis illness clinically. LLF and its active ingredients displayed anti-hepatitis effects, but the mechanism of . function has not yet been fully clarified. Objective: To investigate the proteomic analysis of CCl4-induced ALI, and examine the effects of active Total Glycosides (TG) from LLF on ALI of mice4, including histopathological survey and proteomic changes of liver tissues, and delineate the possible underlying mechanism. Methods: CCl4 was used to produce the ALI mice model. The model mice were intragastrically administrated with TG and the liver histopathological changes of mice were examined. At the end of the test, mice liver samples were collected, and after protein denaturation, reduction, desalination and enzymatic hydrolysis, identification was carried out by nano LC-ESI-OrbiTrap MS/MS technology. The data was processed by Maxquant software. The differentially-expressed proteins were screened and identified, and their biological information was also analyzed based on GO and KEGG analysis. Key protein expression was validated by Western blot analysis. Results: A total of 705 differentially-expressed proteins were identified in the normal, model and administration groups. 9 significant differential proteins were focused based on the analysis. Liver protein expression changes of CCl4-induced ALI mice were mainly involved in several important signaling channels, namely FoxO signaling pathway, autophagy-animal, insulin signaling pathway. TG has an anti-liver damnification effect in ALI mice, the mechanism of which is related to FoxO1 and autophagy pathways. Conclusion: CCl4 inhibited expression of insulin-Like growth factor 1 (Igf1) and 3-phosphoinositide- dependent protein kinase 1 (Pdpk1) in liver cells and induced insulin resistance, thus interfering with mitochondrial autophagy and regeneration of liver cells and the metabolism of glucose and lipid, and causing hepatic necrosis in mice. TG resisted liver injury in mice. TG adjusted the expression level of key proteins Igf1 and Pdpk1 after liver injury and improved insulin resistance, thus promoting autophagy and resistance to liver damage.