Current status and future prospects of patient-derived induced pluripotent stem cells

Cellular models in autoinflammatory disease research

Systemic autoinflammatory diseases are a heterogeneous group of rare genetic disorders caused by dysregulation of the innate immune system. Understanding the complex mechanisms underlying these conditions is critical for developing effective treatments. Cellular models are essential for identifying new conditions and studying their pathogenesis. Traditionally, these studies have used primary cells and cell lines of disease-relevant cell types, although newer induced pluripotent stem cell (iPSC)-based models might have unique advantages. In this review, we discuss the three cellular models used in autoinflammatory disease research, their strengths and weaknesses, and their applications to inform future research in the field.

Biotechnological advances and applications of human pluripotent stem cell-derived heart models

In recent years, significant biotechnological advancements have been made in engineering human cardiac tissues and organ-like models. This field of research is crucial for both basic and translational research due to cardiovascular disease being the leading cause of death in the developed world. Additionally, drug-associated cardiotoxicity poses a major challenge for drug development in the pharmaceutical and biotechnological industries. Progress in three-dimensional cell culture and microfluidic devices has enabled the generation of human cardiac models that faithfully recapitulate key aspects of human physiology. In this review, we will discuss 3D pluripotent stem cell (PSC)-models of the human heart, such as engineered heart tissues and organoids, and their applications in disease modeling and drug screening.

How can clinical safety and efficacy concerns in stem cell therapy for spinal cord injury be overcome?

INTRODUCTION

Spinal cord injury (SCI) can lead to severe neurological dysfunction. Despite scientific and medical advances, clinically effective regenerative therapies including stem cells are lacking for SCI.

AREAS COVERED

This paper discusses translational challenges related to the safe, effective use of stem cells for SCI, with a focus on mesenchymal stem cells (MSCs), neural stem cells (NSCs), Schwann cells (SCs), olfactory ensheathing cells (OECs), oligodendrocyte precursor cells (OPCs), embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs). We discuss approaches to enhance the efficacy of cell-based strategies by i) addressing patient heterogeneity and enhancing patient selection; ii) selecting cell type, cell source, cell developmental stage, and delivery technique; iii) enhancing graft integration and mitigating immune-mediated graft rejection; and iv) ensuring availability of cells. Additionally, we review strategies to optimize outcomes including combinatorial use of rehabilitation and discuss ways to mitigate potential risks of tumor formation associated with stem cell-based strategies.

EXPERT OPINION

Basic science research will drive translational advances to develop stem cell-based therapies for SCI. Genetic, serological, and imaging biomarkers may enable individualization of cell-based treatments. Moreover, combinatorial strategies will be required to enhance graft survival, migration and functional integration, to enable precision-based intervention.

Generation of the First Human In Vitro Model for McArdle Disease Based on iPSC Technology

McArdle disease is a rare autosomal recessive disorder caused by mutations in the PYGM gene. This gene encodes for the skeletal muscle isoform of glycogen phosphorylase (myophosphorylase), the first enzyme in glycogenolysis. Patients with this disorder are unable to obtain energy from their glycogen stored in skeletal muscle, prompting an exercise intolerance. Currently, there is no treatment for this disease, and the lack of suitable in vitro human models has prevented the search for therapies against it. In this article, we have established the first human iPSC-based model for McArdle disease. For the generation of this model, induced pluripotent stem cells (iPSCs) from a patient with McArdle disease (harbouring the homozygous mutation c.148C>T; p.R50* in the PYGM gene) were differentiated into myogenic cells able to contract spontaneously in the presence of motor neurons and generate calcium transients, a proof of their maturity and functionality. Additionally, an isogenic skeletal muscle model of McArdle disease was created. As a proof-of-concept, we have tested in this model the rescue of PYGM expression by two different read-through compounds (PTC124 and RTC13). The developed model will be very useful as a platform for testing drugs or compounds with potential pharmacological activity.

A real-time pluripotency reporter for the long-term and real-time monitoring of pluripotency changes in induced pluripotent stem cells

To master the technology of reprogramming mouse somatic cells to induced pluripotent stem cells (iPSCs), which will lay a good foundation for setting up a technology platform on reprogramming human cancer cells into iPSCs. Mouse iPSCs (i.e., Oct4-GFP miPSCs) was successfully generated from mouse embryonic fibroblasts (MEFs) harboring Oct4-EGFP transgene by introducing four factors, Oct4, Sox2, c-Myc and Klf4, under mESC (Murine embryonic stem cells) culture conditions. Oct4-GFP miPSCs were similar to mESCs in morphology, proliferation, mESC-specific surface antigens and gene expression. Additionally, Oct4-GFP miPSCs could be cultured in suspension to form embryoid bodies (EBs) and differentiate into cell types of the three germ layers in vitro. Moreover, Oct4-GFP miPSCs could develop to teratoma and chimera in vivo. Unlike cell cycle distribution of MEFs, Oct4-GFP miPSCs are similar to mESCs in the cell cycle structure which consists of higher S phase and lower G1 phase. More importantly, our data demonstrated that MEFs harboring Oct4-EGFP transgene did not express GFP, until they were reprogrammed to the pluripotent stage (iPSCs), while the GFP expression was progressively lost when these pluripotent Oct4-GFP miPSCs exposed to EB-mediated differentiation conditions, suggesting the pluripotency of Oct4-GFP miPSCs can be real-time monitored over long periods of time via GFP assay. Altogether, our findings demonstrate that Oct4-GFP miPSC line is successfully established, which will lay a solid foundation for setting up a technology platform on reprogramming cancer cells into iPSCs. Furthermore, this pluripotency reporter system permits the long-term real-time monitoring of pluripotency changes in a live single-cell, and its progeny.

Considerations for a Reliable In Vitro Model of Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is widely recognized as a potentially severe toxicity that often leads to dose reduction or discontinuation of cancer treatment. Symptoms may persist despite discontinuation of chemotherapy and quality of life can be severely compromised. The clinical symptoms of CIPN, and the cellular and molecular targets involved in CIPN, are just as diverse as the wide variety of anticancer agents that cause peripheral neurotoxicity. There is an urgent need for extensive molecular and functional investigations aimed at understanding the mechanisms of CIPN. Furthermore, a reliable human cell culture system that recapitulates the diversity of neuronal modalities found in vivo and the pathophysiological changes that underlie CIPN would serve to advance the understanding of the pathogenesis of CIPN. The demonstration of experimental reproducibility in a human peripheral neuronal cell system will increase confidence that such an in vitro model is clinically useful, ultimately resulting in deeper exploration for the prevention and treatment of CIPN. Herein, we review current in vitro models with a focus on key characteristics and attributes desirable for an ideal human cell culture model relevant for CIPN investigations.