Alterations in liver triglyceride profiles in CCl₄-induced liver regeneration

Lipid metabolism, particularly triglyceride (TG) metabolism, is crucial for liver regeneration. During the early phase of liver regeneration, the liver temporarily accumulates a substantial amount of TG-dominated lipids. However, the specific composition of the TG profile during this phase is not yet fully understood. Here, we showed that the TG molecular composition in the liver was significantly altered during liver regeneration following carbon tetrachloride (CCl₄)-induced liver injury. Lipid accumulation in livers was observed as early as 12 hours after CCl₄ treatment, with transient regeneration-associated steatosis (TRAS) lasting until 24 hours. Hepatocyte proliferation began only after liver lipid levels returned to baseline at 48 hours. Furthermore, the profile of TG species changed significantly during liver regeneration. During the TRAS period, the accumulated TGs in the liver were mainly long-chain triglycerides, with most of the fatty acids constituting these triglycerides having fewer than 20 carbon atoms. In the proliferation phase, the fatty acid composition of these triglycerides shifted from long-chain to ultra-long-chain fatty acids. Our results suggest a significant TRAS-related change in the TG lipid profile of the liver during liver regeneration.