Liu Hui, Zhang Yisha, Ning Shoubin
Department of Gastroenterology, Air Force Medical Center, Air Force Medical University, Beijing, China.
Department of Internal Medicine, First Rongjun Youfu Hospital of Shandong, Jinan, China.
Front Immunol. 2025 Jun 16;16:1600685. doi: 10.3389/fimmu.2025.1600685. eCollection 2025.
Drug-induced liver injury (DILI) can provoke inflammation and fibrosis in the liver, potentially leading to severe liver diseases and mortality; however, effective treatments for liver fibrosis remain elusive. The objective of this study was to explore the cellular metabolic mechanism after carbon tetrachloride (CCl4)-induced liver injury.
Initially, we conducted a comprehensive analysis of ATAC-seq, RNA-seq, and scRNA-seq datasets derived from CCl4-induced chronic liver injury in mice. Subsequently, functional enrichment analysis and transcription factor analysis were performed. Finally, the expression changes of key substances and transcription factors were verified by cell and animal experiments.
Our investigation uncovered that hepatocyte histone acetylation intensified with prolonged injury durations. Subsequent functional enrichment analysis identified that fatty acid metabolism as the predominant pathway implicated in hepatocyte damage. The tricarboxylic acid cycle in hepatocytes exhibited partial slowdown and the mitochondrial electron transport chain (ETC) was inhibited in the early stage of CCl4-induced chronic injury. However, in the later stage of injury, there was a gradual restoration of the ETC functionality, coupled with an enhanced capacity for synthesis of fatty acids. This process of metabolic equilibrium restoration may be related to acute lipid accumulation during liver injury repair. Transcription factor analysis found that Zhx2, a crucial suppressor of ETC, experienced sustained increases in chromatin accessibility within injured hepatocytes, but its expression level increased first and then decreased. The key transcriptional repressor Zbtb20 could inhibit the expression of Zhx2, and its expression trend corresponded to that of Zhx2. Cellular experiments demonstrated that CCl4 induced upregulation of acetyl-CoA, Zhx2 and Zbtb20 in a time-dependent manner. The levels of acetyl-CoA and Zbtb20 increased with the duration of injury in animal experiments, but Zhx2 showed a rise in expression only at week 3, while expression returned to normal levels after week 6.
Our findings contribute to the understanding of the evolution and underlying CCl4-induced inflammatory mechanisms governing hepatocyte inflammatory injury and the subsequent metabolic shift from imbalance toward balance under chronic CCl4 exposure, offering novel perspectives and directions for targeted therapeutic interventions in DILI.
药物性肝损伤（DILI）可引发肝脏炎症和纤维化，可能导致严重肝脏疾病甚至死亡；然而，肝纤维化的有效治疗方法仍然难以捉摸。本研究的目的是探索四氯化碳（CCl4）诱导肝损伤后的细胞代谢机制。
首先，我们对来自CCl4诱导的小鼠慢性肝损伤的ATAC-seq、RNA-seq和scRNA-seq数据集进行了全面分析。随后，进行了功能富集分析和转录因子分析。最后，通过细胞和动物实验验证了关键物质和转录因子的表达变化。
我们的研究发现，随着损伤持续时间延长，肝细胞组蛋白乙酰化增强。随后的功能富集分析确定脂肪酸代谢是肝细胞损伤的主要相关途径。在CCl4诱导的慢性损伤早期，肝细胞中的三羧酸循环表现出部分减慢，线粒体电子传递链（ETC）受到抑制。然而，在损伤后期，ETC功能逐渐恢复，同时脂肪酸合成能力增强。这种代谢平衡恢复过程可能与肝损伤修复期间的急性脂质积累有关。转录因子分析发现，ETC的关键抑制因子Zhx2在受损肝细胞中的染色质可及性持续增加，但其表达水平先升高后降低。关键转录抑制因子Zbtb20可抑制Zhx2的表达，其表达趋势与Zhx2一致。细胞实验表明，CCl4以时间依赖性方式诱导乙酰辅酶A、Zhx2和Zbtb20上调。在动物实验中，乙酰辅酶A和Zbtb20的水平随损伤持续时间增加，但Zhx2仅在第3周时表达升高，而在第6周后表达恢复至正常水平。
我们的研究结果有助于理解CCl4诱导的肝细胞炎症损伤的演变及潜在炎症机制，以及在慢性CCl4暴露下随后从失衡向平衡的代谢转变，为DILI的靶向治疗干预提供了新的视角和方向。
