Liver Regeneration Literature Review

Literature Review Report: Liver Regeneration

ABSTRACT

Liver regeneration is a well-orchestrated and very intricate tissue regrowth process. It is the body’s significant reaction after partial hepatectomy. The process takes place through three staged phases, namely: priming phase, proliferative phase and termination phase. The overall process make use of signalling cascade pathways which include cytokines, matrix remodelling, growth factors and several feedbacks which stimulate or inhibit signals related to growth. The primary phase aims to sensitise the hepatocytes to growth factors with compensation from certain cytokines, including Tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6). While the proliferation phase stimulates the growth

In summary the liver regeneration process takes place in three crucial steps; [7] The first step is the Priming phase, whereby the inactive hepatocytes move from G0 to G1 of the cell cycle when they are induced by various stimulation. The second step is the proliferative phase, in which the mitogens aid the hepatocytes to progress from G1 phase to the mitosis process. The last step is the termination phase whereby cells stop to proliferate, this step is controlled by negative factors such as transforming growth factor beta (TGF-β) and activin. During these three phases, multiple growth factors and cytokines play a role in cell signalling pathways to bring about biological effects. This review aims to highlight the important signalling molecules, understand liver regeneration malfunction in liver disease and ultimately develop ways in which liver regeneration can be used to heal liver related

[2] However, new technologies such as, cell transplantation therapy and liver bioengineering have been developed which are aimed at alleviating the dilemma caused by insufficient liver regeneration or shortage of liver donors, and they are becoming hotspots in the research field. [2] Cell transplantation, which is the process that make use of stem or progenitor cells, has been thoroughly studied throughout the years with regards to liver regeneration owing to the ability of the stem/progenitor cells to differentiate into hepatocytes. Studies have demonstrated that mesenchymal stem cells (MSC), foetal progenitor cell, and embryonic stem cells could improve liver injury to some extent. [2] Nevertheless, the application of cell therapy is limited by source of transplanted cells and immune and liveability rejection after being transplanted. While, liver bioengineering has two portions: decellularization and recellularization. [10] A decellularized liver scaffold (DLS) is characterized by retaining intact vasculature system and a fine web of matrix, providing necessary environment like a normal liver for cells to grow, proliferate, and differentiate. [11] The DLS would therefore regrow functional human cells and addition of recellularized liver scaffold with positive molecules for cell regeneration or differentiation, for example, granulocyte colony