Cerebral Organoids and Antisense Oligonucleotide Therapeutics: Challenges and Opportunities

Abstract

The advent of stem cell-derived cerebral organoids has already advanced our understanding of disease mechanisms in neurological diseases. Despite this, many remain without effective treatments, resulting in significant personal and societal health burden. Antisense oligonucleotides (ASOs) are one of the most widely used approaches for targeting RNA and modifying gene expression, with significant advancements in clinical trials for epilepsy, neuromuscular disorders and other neurological conditions. ASOs have further potential to address the unmet need in other neurological diseases for novel therapies which directly target the causative genes, allowing precision treatment. Induced pluripotent stem cell (iPSC) derived cerebral organoids represent an ideal platform in which to evaluate novel ASO therapies. In patient-derived organoids, disease-causing mutations can be studied in the native genetic milieu, opening the door to test personalized ASO therapies and n-of-1 approaches. In addition, CRISPR-Cas9 can be used to generate isogenic iPSCs to assess the effects of ASOs, by either creating disease-specific mutations or correcting available disease iPSC lines. Currently, ASO therapies face a number of challenges to wider translation, including insufficient uptake by distinct and preferential cell types in central nervous system and inability to cross the blood brain barrier necessitating intrathecal administration. Cerebral organoids provide a practical model to address and improve these limitations. In this review we will address the current use of organoids to test ASO therapies, opportunities for future applications and challenges including those inherent to cerebral organoids, issues with organoid transfection and choice of appropriate read-outs.

Animal Models of Drug-Resistant Epilepsy as Tools for Deciphering the Cellular and Molecular Mechanisms of Pharmacoresistance and Discovering More Effective Treatments

“…While the focus of this review is the characterization of drug effects in animal models of DRE, such models are also useful for evaluating non-pharmacological strategies for epilepsy therapy. Such strategies include different types of neurostimulation, surgical approaches, dietary treatments, gene therapy, antisense oligonucleotide therapy (ASO), and neurotransplantation, some of which may even cure epilepsy [238][239][240][241][242]. A recent fascinating example of how animal models can be used to develop such strategies is a genetic closed-loop feedback system in mice that was designed to inhibit neurons that participate in seizure activity [243].…”

Experimental Model Systems Used in the Preclinical Development of Nucleic Acid Therapeutics

“…Examples include the blood–brain–retinal barriers on chip connected to microfluidic chambers that even allow multiplexing [ 50 , 51 ]. The development of these systems may allow the identification of chemical compounds for systemic delivery able to cross the blood barriers of the brain or the retina, accelerating the development and reducing the number of experimental animals used for this initial identification [ 13 , 20 , 24 ]. The 3D disease modeling system has potential not only in disease mechanism study but also for in vitro drug screening, hence accelerate novel NAT development.…”

Manipulating and studying gene function in human pluripotent stem cell models

“…Non‐viral transient nucleic acid delivery methods include the delivery of genetic material with chemically modified mRNAs (modRNA) or antisense oligonucleotides (ASO). modRNAs are stabilized to improve transgene expression and have been applied, for instance, for CRISPR editing of hPSCs through delivery of CRISPR/Cas9 components, leading to reduced off‐target effects, low toxicity, and outstanding KO efficiency when compared to plasmid‐based delivery [89]. This technology has also been applied to modify hPSC gene expression during differentiation [90].…”