**2.5. Use of placental mesenchymal stem/stromal cells in liver diseases**

Cirrhosis is the common end-stage of most of the injuries affecting the liver such as virus infections, chronic alcoholism, metabolic diseases, or acute liver failure. A scar is formed by extracellular matrix, making the normal function of the liver difficult. Cirrhosis is an irreversible state that can become life-threatening and, frequently, liver transplantation is the only alternative for healing. Donor shortage and continuous need for immunosuppression are the main limitations to liver transplant and cell transplantation appears as a suitable alternative. In addition to fetal and adult hepatocytes, stem cells are considered for cell transplantation. PMSC can be helpful since their potential capacity to differentiate to hepatic-like cells and form functional three-dimensional structures have been reported [80].

Transplanted into animal models of disease, PMSC induced a significant reduction of fibrosis and of serum levels of transaminases. Liver regeneration has been proposed to be promoted by the induction of autophagy process [81], stimulation of liver cell proliferation [82], decreased apoptosis, and suppression of stellate cells activation [83]. Although no evidence of differentiation of the transplanted cells into hepatocytes was reported in a CCl4-induced fibrosis rat model [82], in other models, PMSC engraftment and expression of human albumin and α-fetoprotein have been reported [83–85].
