Induced Pluripotent Stem Cell Models to Enable In Vitro Models for Screening in the Central Nervous System

Abstract

There is great need to develop more predictive drug discovery tools to identify new therapies to treat diseases of the central nervous system (CNS). Current nonpluripotent stem cell-based models often utilize non-CNS immortalized cell lines and do not enable the development of personalized models of disease. In this review, we discuss why in vitro models are necessary for translational research and outline the unique advantages of induced pluripotent stem cell (iPSC)-based models over those of current systems. We suggest that iPSC-based models can be patient specific and isogenic lines can be differentiated into many neural cell types for detailed comparisons. iPSC-derived cells can be combined to form small organoids, or large panels of lines can be developed that enable new forms of analysis. iPSC and embryonic stem cell-derived cells can be readily engineered to develop reporters for lineage studies or mechanism of action experiments further extending the utility of iPSC-based systems. We conclude by describing novel technologies that include strategies for the development of diversity panels, novel genomic engineering tools, new three-dimensional organoid systems, and modified high-content screens that may bring toxicology into the 21st century. The strategic integration of these technologies with the advantages of iPSC-derived cell technology, we believe, will be a paradigm shift for toxicology and drug discovery efforts.Disease Modeling D iseases of the central nervous system (CNS) affect a large number of people, but therapeutic intervention is hampered by the lack of useful models for many of these diseases. Current research on human subjects, particularly for drug discovery for CNS diseases, is severely (and appropriately) limited by ethical guidelines. Therefore, surrogate models are needed that share important anatomical, physiological, and genetic features to advance new treatments and therapies for CNS diseases [1].Developing rapid and effective therapies for CNS diseases requires the availability of in vitro models that accurately recapitulate disease phenotypes and predict patient treatment response. A proper model must be both sensitive and predictive while reflecting both normal and disease processes. Equally important, these models should enable the investigation of genetic and environmental risk factors contributing to diseases in a rapid and economical way. Currently used models often do not reflect a typical human response [2-4], despite efforts underway to better characterize these models and increase their preclinical value in predicting safety and efficacy in the clinic [5,6]. Therefore, there is a great need to develop disease-and patient-specific models from cells directly affected in CNS disorders. These cellbased models, we envision, could either replace or supplement current animal models and enable the efficient translation of basic research into the clinical setting. Limitations with current CNS modelsCurrently, drug discovery relies on the use of animalbased or cell-based models, ...

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