Genome Editing in iPSC-Based Neural Systems: From Disease Models to Future Therapeutic Strategies

Abstract

Therapeutic advances for neurological disorders are challenging due to limited accessibility of the human central nervous system and incomplete understanding of disease mechanisms. Many neurological diseases lack precision treatments, leading to significant disease burden and poor outcome for affected patients. Induced pluripotent stem cell (iPSC) technology provides human neuronal cells that facilitate disease modeling and development of therapies. The use of genome editing, in particular CRISPR-Cas9 technology, has extended the potential of iPSCs, generating new models for a number of disorders, including Alzheimers and Parkinson Disease. Editing of iPSCs, in particular with CRISPR-Cas9, allows generation of isogenic pairs, which differ only in the disease-causing mutation and share the same genetic background, for assessment of phenotypic differences and downstream effects. Moreover, genome-wide CRISPR screens allow high-throughput interrogation for genetic modifiers in neuronal phenotypes, leading to discovery of novel pathways, and identification of new therapeutic targets. CRISPR-Cas9 has now evolved beyond altering gene expression. Indeed, fusion of a defective Cas9 (dCas9) nuclease with transcriptional repressors or activation domains allows down-regulation or activation of gene expression (CRISPR interference, CRISPRi; CRISPR activation, CRISPRa). These new tools will improve disease modeling and facilitate CRISPR and cell-based therapies, as seen for epilepsy and Duchenne muscular dystrophy. Genome engineering holds huge promise for the future understanding and treatment of neurological disorders, but there are numerous barriers to overcome. The synergy of iPSC-based model systems and gene editing will play a vital role in the route to precision medicine and the clinical translation of genome editing-based therapies.

Cell Cluster Sorting in Automated Differentiation of Patient-specific Induced Pluripotent Stem Cells Towards Blood Cells

“…Automation of iPS cell generation, culture, genetic manipulation, and differentiation into cells/tissues of interest is key to the large scale application of patient and disease specific iPS cells in disease modeling and drug screening ( Daniszewski et al, 2018 ; De Masi et al, 2020 ). Human iPS cells enable the recapitulation of patient and disease heterogeneity, which in turn requires a large number of iPS cell lines to faithfully model a particular pathology ( Ben Jehuda et al, 2018 ; McTague et al, 2021 ; Toledo et al, 2021 ). In addition, the CRISPR/Cas9 technology stands as a precise, particularly easy and versatile genetic engineering tool for iPS cells ( Hotta and Yamanaka, 2015 ), which requires the respective machinery and workflow for downstream processing.…”

Comparative efficacy of surgical approaches to disease modification in Parkinson disease

“…Hence, stem cell-based transplantation therapy shows promise and could overcome many of the limitations noted with embryonic dopamine cells 25 , 29 – 32 . Further, human iPSCs could undergo genome editing (i.e., clustered regularly interspaced short palindromic repeats [CRISPR] and CRISPR-associated protein 9 [Cas9]) for both disease model generation as well as to enhance the therapeutic potential once grafted 33 , 34 .…”

Genetics Matters: Voyaging from the Past into the Future of Humanity and Sustainability

“…Gene editing is not a new phenomenon; techniques for editing and knocking out genes have been available since the 1980s, when gene-editing technology was initially developed and introduced [ 26 ]. The use of genome editing has expanded the potential of therapeutic technologies, with induced pluripotent stem cells (iPSCs) being a recent example, which generate new models and treatments for a variety of disorders, including Alzheimer’s and Parkinson’s diseases [ 27 ].…”