In vitro generated hepatocyte-like cells: a novel tool in regenerative medicine and drug discovery

Hepatocyte-like cells [HLCs] are generated from either various human pluripotent stem cells [hPSCs] including induced pluripotent stem cells [iPSCs] and embryonic stem cells [ESCs], or direct cell conversion, mesenchymal stem cells as well as other stem cells like gestational tissues. They provide potential cell sources for biomedical applications. Liver transplantation is the gold standard treatment for the patients with end stage liver disease, but there are many obstacles limiting this process, like insufficient number of donated healthy livers. Meanwhile, the number of patients receiving a liver organ transplant for a better life is increasing. In this regard, HLCs may provide an adequate cell source to overcome these shortages. New molecular engineering approaches such as CRISPR/Cas system applying in iPSCs technology provide the basic principles of gene correction for monogenic inherited metabolic liver diseases, as another application of HLCs. It has been shown that HLCs could replace primary human hepatocytes in drug discovery and hepatotoxicity tests. However, generation of fully functional HLCs is still a big challenge; several research groups have been trying to improve current differentiation protocols to achieve better HLCs according to morphology and function of cells. Large-scale generation of functional HLCs in bioreactors could make a new opportunity in producing enough hepatocytes for treating end-stage liver patients as well as other biomedical applications such as drug studies. In this review, regarding the biomedical value of HLCs, we focus on the current and efficient approaches for generating hepatocyte-like cells in vitro and discuss about their applications in regenerative medicine and drug discovery

In vitro differentiation of human bone marrow mesenchy-mal stem cells into hepatocyte-like cells

Orthotropic liver transplantation [OLT] is the final procedure of both end stage and metabolic liver diseases. Hepatocyte transplantation is an alternative for OLT, but the sources of hepatocytes are limited. Bone marrow mesenchymal stem cells [BM-MSCs] can differentiate into hepatocyte-like cells and are a potential alternative source for hepatocytes. We aimed to investigate the differentiation potential of BM-MSCs into hepatocyte-like cells. Human BM-MSCs from a healthy donor were cultured and differentiated into hepatocyte-like cells. We investigated the expression of hepatocyte-specific markers in MSC-derived hepatocyte-like cells [MSC-HLC[s]] and evaluated their functionality using metabolic assays. MSC-HLCs expressed hepatocyte-specific markers at both mRNAand protein levels. In addition, the cells had the ability to uptake low density lipoprotein [LDL], clear ammonia, secrete albumin, and store glycogen. MSC-HLCs were transplanted into a familial hypercholesteromia patient. Human MSCs can be differentiated into partially functional hepatocyte-like cells. Thus, they could be a potential source for cell therapy in liver disorders

Autologous transplantation of bone marrow-derived mononuclear and cd133+ cells in patients with decompensated cirrhosis

Background: cirrhosis, the end stage of progressive hepatic fibrosis, is characterized by distortion of the hepatic architecture and the formation of regenerative nodules. Liver transplantation is one of the few available therapies for such patients. However, due to a severe shortage of organ donors, surgical complications, transplant rejection and the high cost of this procedure much interest has focused on research to find new treatment modalities for this disease. There is accumulating evidence for the contribution of bone marrow stem cells to participate in liver regeneration

Methods: here we report on six patients with end stage liver disease who were subjected to intraportal administration of autologous bone marrow-derived CD133+ in comparison to mononuclear cells in short-term [6 months] and long-term [24 months] follow up

Results: there were no adverse effects in any of the patients during the short- and long-term follow up period. Moreover, there were no significant alterations of liver function parameters, liver enzymes, serum albumin, creatinine, serum bilirubin and/or liver volume after transplantation of both types of autologous cells in these patients

Conclusion: our study has shown both the safety and feasibility of this type of liver cell therapy and may be a bridge to liver transplantation. The trial was registered with NIH clinical trials [www.clinicaltrials.gov] as identifier: NCT00713934

flowcytometry study of cd55 and cd59 expression on erythrocytes in rheumatoid arthritis patients

Inappropriate activation or blockage of the inhibition of complement system could cause tissue damages in autoimmune diseases particularly rheumatoid arthritis [RA]. Defect in complement component regulation may cause damages to tissues, on the other hand, or the damaged tissue might affect the unnecessary activation of complement components. To investigate the expression of CD55 and CD 59 complement regulatory proteins in RA patients. Fifty proved rheumatoid arthritis patients participated in this study and their blood were collected for investigations. CD55 and CD59 molecules expression on the erythrocytes was assayed using primary monoclonal antibody and secondary FITC conjugated Ab, then the prepared samples were run with a FACSCalibur flowcytometer [Becton-Dickinson] and the obtained data was analyzed using a Cell Quest software package. To evaluate the complement function, CH50 was performed using patient sera. All experiments were done with a matched healthy volunteer group. The mean fluorescence intensity for CD55 was 27.6 +/- 13.4 arbitrary unit for patients and 68.5 +/- 10.5 for healthy group. CD59 mean fluorescence intensity was 314 +/- 83 in patient group and 508 +/- 56 in healthy volunteers. In addition, there was a significant difference between CH50 in patients [54.5 +/- 15.5] and in healthy group [110 +/- 20]. A significant correlation between CD55 and CD59 expansion on the patient erythrocytes was found [P = 0.00, r = 0.576]. No association was found between CD59, or CD55 with CH50 [P > 0.05]. The expression of CD55 and CD59 is down-regulated on erythrocytes of patients with RA. Change in expression of regulatory complement components in RA may be a useful key for the assessment of disease progression or in patients' follow-up