Animal model for liver cell banking from non-heart beating donors after prolonged ischaemia time

Cadaveric Stem Cells: Their Research Potential and Limitations

In the era of growing interest in stem cells, the availability of donors for transplantation has become a problem. The isolation of embryonic and fetal cells raises ethical controversies, and the number of adult donors is deficient. Stem cells isolated from deceased donors, known as cadaveric stem cells (CaSCs), may alleviate this problem. So far, it was possible to isolate from deceased donors mesenchymal stem cells (MSCs), adipose delivered stem cells (ADSCs), neural stem cells (NSCs), retinal progenitor cells (RPCs), induced pluripotent stem cells (iPSCs), and hematopoietic stem cells (HSCs). Recent studies have shown that it is possible to collect and use CaSCs from cadavers, even these with an extended postmortem interval (PMI) provided proper storage conditions (like cadaver heparinization or liquid nitrogen storage) are maintained. The presented review summarizes the latest research on CaSCs and their current therapeutic applications. It describes the developments in thanatotranscriptome and scaffolding for cadaver cells, summarizes their potential applications in regenerative medicine, and lists their limitations, such as donor’s unknown medical condition in criminal cases, limited differentiation potential, higher risk of carcinogenesis, or changing DNA quality. Finally, the review underlines the need to develop procedures determining the safe CaSCs harvesting and use.

Clinical hepatocyte transplantation: practical limits and possible solutions

Since the first human hepatocyte transplants (HTx) in 1992, clinical studies have clearly established proof of principle for this therapy as a treatment for patients with acquired or inherited liver disease. Although major accomplishments have been made, there are still some specific limitations to this technology, which, if overcome, could greatly enhance the efficacy and implementation of this therapy. Here, we describe what in our view are the most significant obstacles to the clinical application of HTx and review the solutions currently proposed. The obstacles of significance include the limited number and quality of liver tissues as a cell source, the lack of clinical grade reagents, quality control evaluation of hepatocytes prior to transplantation, hypothermic storage of cells prior to transplantation, preconditioning treatments to enhance engraftment and proliferation of donor cells, tracking or monitoring cells after transplantation, and the optimal immunosuppression protocols for transplant recipients.

Improvement of hepatocyte recovery from rat liver subjected to 1-hour warm ischemic injury by using citrate phosphate dextrose added to euro-collins perfusion solution

Warm ischemia (WI)-related injury interferes with recovery of primary hepatocyte after collagenase digestion of surgically resected or non-heart-beating donor livers as human cell sources. We speculated that digestion is impaired due to reduced microcirculation, caused by microembolism after WI. We sought to improve hepatocyte recovery after WI using a rat model. Anesthetized 9-week-old male Sprague-Dawley rats underwent a midline abdominal incision to insert a 22-gauge cannula into the portal vein. WI was initiated by ligating both the cannula and the hepatic artery. We compared Euro-Collins (EC) perfusion solution with 2 anticoagulants-heparin or citrate phosphate dextrose (CPD)-versus ethylene glycol tetraacetic acid (EGTA) combined with Ca(2+)- and Mg(2+)-free Hank's solution (CM-free Hank's solution). Use of CM-free Hank's solution yielded only 0.75 ± 0.15 × 10(8) and 0.82 ± 0.20 × 10(8) cells at 30 and 60 minutes WI respectively. However, CPD, but not heparin, added to the EC solution produced the best cell recovery (CPD: 2.15 ± 0.38 × 10(8); heparin: 1.63 ± 0.31 × 10(8)). During macroscopic observation, CPD added to EC solution also demonstrated best blood flushing. CPD added to EC solution achieved greater hepatocyte recovery than CM-free Hank's solution by restoring microcirculation during flushing of blood from liver tissue subjected to WI.

Molecular perturbations restrict potential for liver repopulation of hepatocytes isolated from non-heart-beating donor rats

Organs from non-heart-beating donors are attractive for use in cell therapy. Understanding the nature of molecular perturbations following reperfusion/reoxygenation will be highly significant for non-heart-beating donor cells. We studied non-heart-beating donor rats for global gene expression with Affymetrix microarrays, hepatic tissue integrity, viability of isolated hepatocytes, and engraftment and proliferation of transplanted cells in dipeptidyl peptidase IV-deficient rats. In non-heart-beating donors, liver tissue was morphologically intact for >24 hours with differential expression of 1, 95, or 372 genes, 4, 16, or 34 hours after death, respectively, compared with heart-beating donors. These differentially expressed genes constituted prominent groupings in ontological pathways of oxidative phosphorylation, adherence junctions, glycolysis/gluconeogenesis, and other discrete pathways. We successfully isolated viable hepatocytes from non-heart-beating donors, especially up to 4 hours after death, although the hepatocyte yield and viability were inferior to those of hepatocytes from heart-beating donors (P < 0.05). Similarly, although hepatocytes from non-heart-beating donors engrafted and proliferated after transplantation in recipient animals, this was inferior to hepatocytes from heart-beating donors (P < 0.05). Gene expression profiling in hepatocytes isolated from non-heart-beating donors showed far greater perturbations compared with corresponding liver tissue, including representation of pathways in focal adhesion, actin cytoskeleton, extracellular matrix-receptor interactions, multiple ligand-receptor interactions, and signaling in insulin, calcium, wnt, Jak-Stat, or other cascades.

CONCLUSION

Liver tissue remained intact over prolonged periods after death in non-heart-beating donors, but extensive molecular perturbations following reperfusion/reoxygenation impaired the viability of isolated hepatocytes from these donors. Insights into molecular changes in hepatocytes from non-heart-beating donors offer opportunities for improving donor cell viability, which will advance the utility of non-heart-beating donor organs for cell therapy or other applications.

Therapeutic liver reconstitution with murine cells isolated long after death

BACKGROUND & AIMS

Due to the shortage of donor organs, many patients needing liver transplantation cannot receive one. For some liver diseases, hepatocyte transplantation could be a viable alternative, but donor cells currently are procured from the same sources as whole organs, and thus the supply is severely limited.

METHODS

Here, we investigated the possibility of isolating viable hepatocytes for liver cell therapy from the plentiful source of morgue cadavers. To determine the utility of this approach, cells were isolated from the livers of non-heart-beating cadaveric mice long after death and transplanted into fumarylacetoacetate hydrolase-deficient mice, a model for the human metabolic liver disease hereditary tyrosinemia type I and a stringent in vivo model for hepatic cell transplantation.

RESULTS

Surprisingly, complete and therapeutic liver repopulation could be achieved with hepatocytes derived up to 27 hours post mortem.

CONCLUSIONS

Competitive repopulation experiments showed that cadaveric liver cells had a repopulation capacity similar to freshly isolated hepatocytes. Importantly, viable hepatocytes also could be isolated from cadaveric primate liver (monkey and human) efficiently. These data provide evidence that non-heart-beating donors could be a suitable source of hepatocytes for much longer time periods than previously thought possible.

Development of a biological resource center for cellular therapy and biobanking in a public polyclinic university hospital

A model of a university hospital facility for biobanking and clinical grade cell manipulation is described. The facility is based on the model of the Biological Resource Center described by the Organisation for the Economic Cooperation and Development in 1999. This model integrates several critical aspects of collection, characterization, storage and use of biological materials for research purposes and therapeutic applications, thus providing potential advantages of optimizing the use of resources, improving standardization, protecting the rights of both donors and recipients of biological materials, and facilitating international cooperation.