Generation of Specialized, High-Value Cells and Tissues from Human Induced Pluripotent Stem Cells by Recapitulating Early Embryogenesis Using Gata Factor-Induced Endoderm

Technology 

The aim of the technology was to co-differentiate hiPSCs into cells of all germ layers, such that they can co-develop into a heterogeneous tissue mimicking the process of embryogenesis. Since ectoderm fate is the default pathway for differentiation, a symmetry break was induced by engineering a system to pulse the expression of Gata6, a master transcription factor that guides cell fate towards endoderm and mesoderm lineage. Gata6 was encoded under an inducible promoter and a lentiviral system was used to deliver the transgene in order to achieve heterogeneity in respect to the number of transgene copies received per cell, and consequently, expression level of Gata6. Since a threshold level of Gata6 is required to induce endoderm and mesoderm lineage, the system effectively creates a heterogeneous population of all three germ layers. With sufficient time in culture, paracrine signaling from cell populations results in an organized and heterogeneous tissue.  

Problem Addressed   

Human embryonic stem cells (hES) and human induced pluripotent stem cells (hiPSCs) have opened up the field of developmental biology and regenerative medicine with access to in vitro model system for understanding development and differentiation, and developing organoids of different cell types. However, most of the technologies so far have focused on generating homogeneous population of specialized cells from a single germ layer, or mixing cells to generate a mimic of complex tissue. This technology utilizes genetic engineering to induce cells of all germ layers that co-develop to form heterogeneous tissue similar to the embryogenesis process.  

Advantages

• This technology describes a method of generating complex homeostatic heterogeneous tissues from hiPSCs that co-develop, mimicking the process of embryogenesis.
• Heterogeneous tissues provide a better system for functional genetics and drug screening.
• Heterogeneous tissues derived from autologous hiPSCs could potentially be used for regenerative medicine.  

Publications

"Genetically Engineering Self-Organization of Human Pluripotent Stem Cells into a Liver Bud-Like Tissue Using Gata6." Nature Communications 7 (2016): 10243. https://doi-org.ezproxy.canberra.edu.au/10.1038/ncomms10243.