The Potential of Induced Pluripotent Stem Cells to Test Gene Therapy Approaches for Neuromuscular and Motor Neuron Disorders

Abstract

The reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) represents a major advance for the development of human disease models. The emerging of this technique fostered the concept of "disease in a dish," which consists into the generation of patient-specific models in vitro. Currently, iPSCs are used to study pathological molecular mechanisms caused by genetic mutations and they are considered a reliable model for high-throughput drug screenings. Importantly, precision-medicine approaches to treat monogenic disorders exploit iPSCs potential for the selection and validation of lead candidates. For example, antisense oligonucleotides (ASOs) were tested with promising results in myoblasts or motor neurons differentiated from iPSCs of patients affected by either Duchenne muscular dystrophy or Amyotrophic lateral sclerosis. However, the use of iPSCs needs additional optimization to ensure translational success of the innovative strategies based on gene delivery through adeno associated viral vectors (AAV) for these diseases. Indeed, to establish an efficient transduction of iPSCs with AAV, several aspects should be optimized, including viral vector serotype, viral concentration and timing of transduction. This review will outline the use of iPSCs as a model for the development and testing of gene therapies for neuromuscular and motor neuron disorders. It will then discuss the advantages for the use of this versatile tool for gene therapy, along with the challenges associated with the viral vector transduction of iPSCs.

Keywords: AAV; ASOs; IPSCs; MND; NMD; gene therapy.

FIGURE 1

Test and development of gene targeting approaches using iPSCs. This drawing summarizes the steps of development for drugs and gene therapy approaches, using induced pluripotent stem cells (iPSCs). Somatic cells, such as fibroblasts or blood cells (peripheral blood mononuclear cells, PBMCs) are obtained from patient’s biopsies. After reprogramming, the patient-derived iPSCs can be differentiated into disease-relevant cell types, such as skeletal muscle cells, neural or glial cells for neuromuscular or motor neuron disorders. These cells are then subjected to the classical high-throughput drug screening and in perspective will be used to test novel therapeutic entities, based on gene targeting approaches. As example, antisense oligonucleotides (ASOs) or adeno-associated viral vectors (AAV)-based strategies. After validations in animal models and the pre-clinical development process, these novel therapies could enter into clinical trials for patients affected by rare disorders. The use of iPSCs and gene targeting strategies will likely foster the development of personalized medicine approaches. Created with BioRender.com.