Phenotype correction of stem cell-derived hepatocyte hybrid cells

• Applicant: Dr. Patrick Nell
• Subject Area: Toxicology, Laboratory Medicine ; Gastroenterology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 551499217

Stem cell technology is considered to have enormous potential for providing alternatives to prevailing in vitro models for toxicity testing, which largely rely on primary cells and animal experimentation. Applications theoretically range from representing an entire human population based on a balanced panel of stem cell donors to highly personalized studies that focus on individuals with rare conditions. In particular, the implementation of induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells (HLC) for hepatotoxicity testing addresses several key challenges in modern liver toxicology, including the scarce availability of primary human hepatocytes (PHH), which are considered the gold standard model, as well as the high cost, ethical restrictions and poor accuracy of animal testing and the limited throughput of both. However, the establishment of high-throughput assays based on HLC requires that HLC accurately reflect the diverse metabolic activities that characterize freshly isolated primary human hepatocytes, to allow robust decisions on regulatory measures. To date, available methods for the derivation of HLC from iPSC produce hybrid cells that share characteristics of hepatocytes and intestinal cells within the same cells, indicating that these methods do not fully establish hepatocyte identity. Consequently, expression levels of hepatocyte metabolism associated enzymes and transporters often remain orders of magnitude below that of PHH, limiting their capacity to metabolize exogeneous compounds and model mechanisms of reactive metabolite induced hepatotoxicity and other liver-specific mechanisms of disease, such as steatosis. The present proposal aims at targeting these deficiencies of HLC by a comprehensive strategy to activate gene regulatory networks (GRNs) controlling hepatocyte metabolism and eliminate GRN activity related to hybrid differentiation, on the basis of a pre-established blue-print for targeted GRN manipulation and state-of-the-art genetic engineering and stem cell differentiation infrastructure and strategies. Our strategy specifically facilitates the development of stem cell based alternative in vitro systems with a focus on suitablility for hepatotoxicity and pharmacological testing. Importantly, direct benchmarking in comparison to primary hepatocytes ensures adequate interpretation of the impact of GRN manipulations, which are expected to finally overcome the roadblock preventing a complete cell fate commitment and maturation of stem-cell derived hepatocytes.

• DFG Programme: Research Grants