Researchers reported on the problems with using in vitro differentiation of pluripotent stem cells into hepatocyte-like cells (HLCs) in liver disease research and therefore introduced potential solutions, such as different techniques for 3D differentiation, as published in Stem Cell Research.
Clinical research on liver diseases is often centered around in vitro liver models that are based on pluripotent stem cells. This is due to the lack of human liver organs for the purpose of clinical research, and the waiting list for liver transplantation is usually long.
Research into other diseases also makes use of pluripotent stem cells for the purpose of research. For liver diseases, HLCs are used extensively for liver disease modeling. For example, diseases such as Alagille syndrome (ALGS), alpha-1 antitrypsin deficiency (AATD), and Wolman disease, a type of lysosomal acid lipase deficiency (LAL-D), have benefited from research conducted using liver disease modeling.
“However, for broad application in drug development, stable expression of functional CYP450 enzymes still has to be established,” the authors wrote. “HLCs are also not mature enough to be used in transplantation settings as intermediate or permanent replacement for orthoptic liver transplantation because of their restricted functionality and poor homogeneity.”
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A proposed solution to these problems is the use of novel 3D-based models. One approach is to form 3D organoid or spheroid liver models. The difference between 3D organoid and spheroid liver models is that organoids consist of organ-related cell types that are organized structurally, while sphenoids usually consist of only a single isolated cell type. For hepatocytes, the environmental conditions of 3D cultures are superior to that of a 2D culture.
Currently, these protocols are not codified and are hence not optimized. However, the research world is increasingly moving towards the use of HLCs in hepatic diseases as direct therapeutics, and best practices are currently being developed for the future.
Graffmann N, Scherer B, Adjaye J. In vitro differentiation of pluripotent stem cells into hepatocyte like cells – basic principles and current progress. Stem Cell Res. 2022;61:102763. doi:10.1016/j.scr.2022.102763