TRANSLATIONAL AND CLINICAL MEDICINE - Georgian Medical Journal

Liver regeneration after procedures like hemi-hepatectomy is a fascinating and complex process that relies on a delicate interplay of various cytokines, growth factors, and signaling pathways. The liver’s response largely depends on the extent of tissue removal: when less than 25% is resected, the liver typically undergoes hypertrophic regeneration, where existing liver cells increase in size. In contrast, removing 50% or more of the liver triggers hyperplastic regeneration, which involves the production of new liver cells to restore mass.

Several key pathways, such as Wnt/β-catenin, Hippo-YAP, JAK/STAT, and PI3K/Akt/mTOR, play crucial roles in coordinating these regenerative processes. They regulate essential functions like cell growth, tissue remodeling, and overall organ size. Additionally, numerous other cytokines and growth factors, including hepatocyte growth factor (HGF) and epidermal growth factor (EGF), also participate in this intricate process, working alongside the major pathways to facilitate effective regeneration.

Changes in portal pressure and shear stress are significant factors in this regenerative response. Shear stress, caused by changes in blood flow dynamics, can act as one of the triggers for activating regeneration pathways. The alteration in mechanical forces on liver cells influences how they communicate and respond, thus playing a pivotal role in the overall regenerative process.