[Stem cell properties of therapeutic potential]

Potentials of Differentiated Human Cord Blood-Derived Unrestricted Somatic Stem Cells in Treatment of Liver Cirrhosis

OBJECTIVES

Liver transplantation is the well-known treatment for chronic liver diseases; however, postoperative complications and lack of donors continue to be limitations with this treatment. Investigating new modalities for treatment of chronic liver illness is a must. In the present study, we aimed to clarify the effects of an in vitro hepatocyte-differentiated human unrestricted somatic stem cell transplant as a new cell-based therapy in an experimental model of chronic liver failure.

MATERIALS AND METHODS

Human umbilical cord blood-derived unrestricted somatic stem cells were isolated, cultured, propagated, and characterized. Cells were directed to differentiate into hepatocyte-like cells. An animal model of carbon tetrachloride cirrhotic liver failure was prepared, and the human in vitro differentiated unrestricted somatic stem cells were transplanted into the experimental model. Animals that did not receive transplant served as the pathologic control group. Animals were euthanized 12 weeks after transplant, and liver functions and histopathology were assessed.

RESULTS

Compared with the pathologic control group, the transplant group showed improvements in levels of alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin. Histopathologic examination of the transplant group also showed improvements in hydropic degeneration and fibrosis.

CONCLUSIONS

The use of unrestricted somatic stem cells, isolated and propagated from cord blood and then differentiated into hepatocyte-like cells, improved both fibrosis and normal function of cirrhotic livers. These cells could be considered as a line of cell-based therapy in cases of chronic liver disease.

The Therapeutic Potential of Human Umbilical Mesenchymal Stem Cells From Wharton's Jelly in the Treatment of Rat Peritoneal Dialysis-Induced Fibrosis

A major complication in continuous, ambulatory peritoneal dialysis in patients with end-stage renal disease who are undergoing long-term peritoneal dialysis (PD) is peritoneal fibrosis, which can result in peritoneal structural changes and functional ultrafiltration failure. Human umbilical mesenchymal stem cells (HUMSCs) in Wharton's jelly possess stem cell properties and are easily obtained and processed. This study focuses on the effects of HUMSCs on peritoneal fibrosis in in vitro and in vivo experiments. After 24-hour treatment with mixture of Dulbecco's modified Eagle's medium and PD solution at a 1:3 ratio, primary human peritoneal mesothelial cells became susceptible to PD-induced cell death. Such cytotoxic effects were prevented by coculturing with primary HUMSCs. In a rat model, intraperitoneal injections of 20 mM methylglyoxal (MGO) in PD solution for 3 weeks (the PD/MGO 3W group) markedly induced abdominal cocoon formation, peritoneal thickening, and collagen accumulation. Immunohistochemical analyses indicated neoangiogenesis and significant increase in the numbers of ED-1- and α-smooth muscle actin (α-SMA)-positive cells in the thickened peritoneum in the PD/MGO 3W group, suggesting that PD/MGO induced an inflammatory response. Furthermore, PD/MGO treatment for 3 weeks caused functional impairments in the peritoneal membrane. However, in comparison with the PD/MGO group, intraperitoneal administration of HUMSCs into the rats significantly ameliorated the PD/MGO-induced abdominal cocoon formation, peritoneal fibrosis, inflammation, neoangiogenesis, and ultrafiltration failure. After 3 weeks of transplantation, surviving HUMSCs were found in the peritoneum in the HUMSC-grafted rats. Thus, xenografts of HUMSCs might provide a potential therapeutic strategy in the prevention of peritoneal fibrosis. Significance: This study demonstrated that direct intraperitoneal transplantation of human umbilical mesenchymal stem cells into the rat effectively prevented peritoneal dialysis/methylglyoxal-induced abdominal cocoon formation, ultrafiltration failure, and peritoneal membrane alterations such as peritoneal thickening, fibrosis, and inflammation. These findings provide a basis for a novel approach for therapeutic benefits in the treatment of encapsulating peritoneal sclerosis.