stabilizing-hepatocellular-phenotype-using-optimized-synthetic

Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing ...

University of Edinburgh

The liver is a fascinating organ and performs a wide range of functions necessary for life. Because the hepatocyte is the major functional cell type found in the liver, it is important that we better understand its role in health and disease. Functional hepatocytes have been derived from many sources, including human stem cell populations. These models offer new opportunities to further our understanding of human liver biology from diverse genotypes and, in the future, to facilitate the development of novel medicines or cell-based therapies. This review discusses limitations in current cell-based models and the advantages offered by pluripotent stem cell-derived hepatocytes.

Pluripotent stem cell-derived hepatocytes: potential and challenges in pharmacology.

Faithfully recapitulating human physiology "in a dish" from a renewable source remains a holy grail for medicine and pharma. Many procedures have been described that, to a limited extent, exhibit human tissue-specific function in vitro. In particular, incomplete cellular differentiation and/or the loss of cell phenotype postdifferentiation play a major part in this void. We have developed an interdisciplinary approach to address this problem, using skill sets in cell biology, materials chemistry, and pharmacology. Pluripotent stem cells were differentiated to hepatocytes before being replated onto a synthetic surface. Our approach yielded metabolically active hepatocyte populations that displayed stable function for more than 2 weeks in vitro. Although metabolic activity was an important indication of cell utility, the accurate prediction of cellular toxicity in response to specific pharmacological compounds represented our goal. Therefore, detailed analysis of hepatocellular toxicity was performed in response to a custom-built and well-defined compound set and compared with primary human hepatocytes. Importantly, stem cell-derived hepatocytes displayed equivalence to primary human material. Moreover, we demonstrated that our approach was capable of modeling metabolic differences observed in the population. In conclusion, we report that pluripotent stem cell-derived hepatocytes will model toxicity predictably and in a manner comparable to current gold standard assays, representing a major advance in the field.

Developing high-fidelity hepatotoxicity models from pluripotent stem cells.

Despite major progress in the knowledge and management of human liver injury, there are millions of people suffering from chronic liver disease. Currently, the only cure for end-stage liver disease is orthotopic liver transplantation; however, this approach is severely limited by organ donation. Alternative approaches to restoring liver function have therefore been pursued, including the use of somatic and stem cell populations. Although such approaches are essential in developing scalable treatments, there is also an imperative to develop predictive human systems that more effectively study and/or prevent the onset of liver disease and decompensated organ function. We used a renewable human stem cell resource, from defined genetic backgrounds, and drove them through developmental intermediates to yield highly active, drug-inducible, and predictive human hepatocyte populations. Most importantly, stem cell-derived hepatocytes displayed equivalence to primary adult hepatocytes, following incubation with known hepatotoxins. In summary, we have developed a serum-free, scalable, and shippable cell-based model that faithfully predicts the potential for human liver injury. Such a resource has direct application in human modeling and, in the future, could play an important role in developing renewable cell-based therapies.

Accurate prediction of drug-induced liver injury using stem cell-derived populations.

In this study, human embryonic stem cell-derived hepatocytes (hESC-Heps) were investigated for their ability to support hepatitis C virus (HCV) infection and replication. hESC-Heps were capable of supporting the full viral life cycle, including the release of infectious virions. Although supportive, hESC-Hep viral infection levels were not as great as those observed in Huh7 cells. We reasoned that innate immune responses in hESC-Heps may lead to the low level of infection and replication. Upon further investigation, we identified a strong type III interferon response in hESC-Heps that was triggered by HCV. Interestingly, specific inhibition of the JAK/STAT signaling pathway led to an increase in HCV infection and replication in hESC-Heps. Of note, the interferon response was not evident in Huh7 cells. In summary, we have established a robust cell-based system that allows the in-depth study of virus-host interactions in vitro.

Modulating innate immunity improves hepatitis C virus infection and replication in stem cell-derived hepatocytes.

Despite major progress in the management of human liver disease, the only cure for a critically failing organ is liver transplantation. While a highly successful approach, the use of cadaveric organs as a routine treatment option is severely limited by organ availability. Therefore, the use of cell-based therapies has been explored to provide support for the failing liver. In addition to developing new treatments, there is also an imperative to develop better human models 'in a dish'. Such approaches will undoubtedly lead to a better understanding of the disease process, offering new treatment or preventative strategies. With both approaches in mind, we have developed robust hepatocyte differentiation methodologies for use with pluripotent stem cells. Importantly, our procedure is highly efficient (∼90%) and delivers active, drug-inducible, and predictive human hepatocyte populations. Curr. Protoc. Stem Cell Biol. 30:1G.5.1-1G.5.12. © 2014 by John Wiley & Sons, Inc.

Dagmara Szkolnicka

MRC Centre for Regenerative Medicine

University of Edinburgh

Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

Dagmara Szkolnicka

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University of Edinburgh

Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

MRC Centre for Regenerative Medicine