Abstract
The liver is a vital organ that plays an important role in metabolism, as well as the synthesis of proteins and maintenance of cholesterol homoeostasis. It is a highly regenerative organ but following some forms of chronic injury, the regenerative capacity of the liver can become impaired. This chapter will review suggested cell therapies for chronic liver injury. In discussing how cell therapy can be used in the treatment of liver injury, it is important to understand the structure and cell composition of the liver. Pathogenesis and the current treatments for the most common causes of liver injury will be addressed. This will shape the structure of this chapter, which is divided into three major areas. The first section will describe the normal roles and functions of the liver, including the different cellular compartments of the liver as well as its unique ability to heal itself. In this section, the pathogenesis of major liver injuries and the contribution of inflammatory cytokines to disease progression will be discussed. In the second section, we will describe current targeted therapies for chronic liver injuries. This will include the degradation of fibrosis, the downregulation of early myofibroblast activity, the elimination of the primary disease, and surgery. This section will cover the mechanisms, benefits and limitations of each treatment option. Finally, the use of cell therapy in relation to liver injuries will be examined, beginning with an explanation of how liver cells such as hepatocytes and macrophages can be used to replace damaged tissue and mediate fibrinolysis, respectively. We will also perform a comprehensive analysis of the potential uses of a variety of stem cells such as mesenchymal stem cells, embryonic stem cells, induced pluripotent stem cell and human amnion epithelial cells. Here, the mechanisms of action, pathways, benefits and limitations of such methods will be elaborated, before future research directions are considered.