Cell therapy as support or alternative to liver transplantation

How important is differentiation in the therapeutic effect of mesenchymal stromal cells in liver disease?

BACKGROUND AIMS

The protocols for differentiation of hepatocyte-like cells (HLCs) from mesenchymal stromal cells (MSCs) have been well established. Previous data have shown that MSCs and their derived HLCs were able to engraft injured liver and alleviate injuries induced by carbon tetrachloride. The goal of the current study was to determine the differences of MSCs and their derived HLCs in terms of therapeutic functions in liver diseases.

METHODS

After hepatic differentiation of umbilical cord-derived MSCs in vitro, we detected both MSC and HLC expressions of adhesion molecules and chemokine receptor CXCR4 by flow cytometry; immunosuppressive potential and hepatocyte growth factor expression were determined by means of enzyme-linked immunosorbent assay. We compared the therapeutic effect for fulminant hepatic failure in a mouse model.

RESULTS

MSC-derived-HLCs expressed lower levels of hepatocyte growth factor, accompanied by impaired immunosuppression in comparison with MSCs. Furthermore, undifferentiated MSCs showed rescuing potentials superior to those in HLCs for the treatment of fulminant hepatic failure.

CONCLUSIONS

After differentiation, HLCs lost several major properties in comparison with undifferentiated MSCs, which are beneficial for their application in liver diseases. Undifferentiated MSCs may be more appropriate than are HLCs for the treatment of liver diseases.

Improvement of liver function in liver cirrhosis patients after autologous mesenchymal stem cell injection: a phase I-II clinical trial

BACKGROUND

End-stage liver disease is a medical problem with high morbidity and mortality. We have investigated the feasibility, safety, and efficacy of using autologous mesenchymal stem cells (MSCs) as a treatment.

METHODS

Eight patients (four hepatitis B, one hepatitis C, one alcoholic, and two cryptogenic) with end-stage liver disease having Model for End-Stage Liver Disease score > or =10 were included. Autologous MSCs were taken from iliac crest. Approximately, 30-50 million MSCs were proliferated and injected into peripheral or the portal vein. Liver function and clinical features were evaluated at baseline and 1, 2, 4, 8, and 24 weeks after injection.

RESULTS

Treatment was well tolerated by all patients. Liver function improved as verified by the Model for End-Stage Liver Disease score, which decreased from 17.9+/-5.6 to 10.7+/-6.3 (P<0.05) and prothrombin complex from international normalized ratio 1.9+/-0.4 to 1.4+/-0.5 (P<0.05). Serum creatinine decreased from 114+/-35 to 80+/-18 micromol/l (P<0.05). Serum albumin changed from 30+/-5 to 33+/-5 g/l and bilirubin from 46+/-29 to 41+/-31 micromol/l. No adverse effects were noted.

CONCLUSION

Our data show that MSCs injection can be used for the treatment of end-stage liver disease with satisfactory tolerability. Furthermore, this treatment may improve clinical indices of liver function in end-stage liver disease.

Cellular Transplantation for Liver Diseases

Presently, the orthotropic liver transplantation (OLT) is still the most effective therapeutic for patients with acute or chronic hepatic failure. However, due to the shortage of donor livers, the number of patients benefited from this approach is limited. Therefore, some alternative modalities have been paid attention for restoring the liver function. The cell transplantation is one of the promising modalities to realize this purpose. The types of cells used in the cell transplantation include syngeneic hepatocytes, allogeneic hepatocytes, immortalized hepatocytes, and stem cells derived heptocytes. The stem cells, especially the adult stem cells from bone marrow, are shown as a promising cell source for liver repopulation. The mesenchymal bone marrow stem cells and embryonic stem cells can be induced to differentiate into the hepatic lineage and might be used in the cell transplantation for liver diseases. Compared to OLT, the advantages of cell-based therapy for liver disease are, but not limited to, less invasive, less expensive, easy manipulated, easy expansion of cells in vitro. Cells can be stored in a cell bank for future use. Though most of the current studies are experimental and animal based, the cellular therapy for liver disease is expected to be an effective alternative in clinical settings in near future.

Hybrid artificial liver support system for treatment of severe liver failure

AIM: To construct a novel hybrid artificial liver support system (HALSS) and to evaluate its efficacy in patients with severe liver failure.

METHODS: Hepatocytes were isolated from suckling pig by the modified Seglen’s method. Isolated hepatocytes were cultured in a spinner flask for 24 h to form spheroids before use and the functions of spheroids were detected. HALSS consisted of a plasma separator, a hemo-adsorba and a bioreactor with hepatocytes spheroids in its extra-fiber space. HALSS was applied to 10 patients with severe liver failure. The general condition and the biochemical indexes of the patients were studied just before and after the treatment.

RESULTS: The number of cells per liver was about 2-4×10¹⁰ (mean, 3.1±1.5×10¹⁰). The cell viabilities were more than 95%. After 24 h of spheroid culture, most hepatocytes formed spheroids. The levels of albumin and urea in the medium of spheroid culture were higher than those in supernatant of petri dish culture (P = 0.0015 and 0.0001, respectively). The capacity of albumin production and urea synthesis remained stable for more than one wk and declined rapidly after two weeks in vitro. In HALSS group, the duration of HALSS treatment was 6-10 h each time. All patients tolerated the treatment well without any fatal adverse reaction. After HALSS treatment, the general condition, psychic state, encephalopathy and hepatic function of the patients were improved. The survival rate of the HALSS group, Plasmapheresis group and control group was 30% (3/10), 20% (2/10) and 0% (0/10), respectively (P = 0.024). Two weeks after treatment, Tbil and ALT decreased and the PTA level elevated in HALSS group and pasmapheresis group (P value: 0.015 vs 0.020, 0.009 vs 0.012 and 0.032 vs 0.041, respectively). But there was no significant change of blood albumin concentration before and after treatment in HALSS group and Plasmapheresis group.

CONCLUSION: The HALSS established by us is effective in supporting liver function of patients with severe liver failure.