Neural Stem Cells Derived from Human-Induced Pluripotent Stem Cells and Their Use in Models of CNS Injury

Reprogramming iPSCs to study age-related diseases: Models, therapeutics, and clinical trials

The unprecedented rise in life expectancy observed in the last decades is leading to a global increase in the ageing population, and age-associated diseases became an increasing societal, economic, and medical burden. This has boosted major efforts in the scientific and medical research communities to develop and improve therapies to delay ageing and age-associated functional decline and diseases, and to expand health span. The establishment of induced pluripotent stem cells (iPSCs) by reprogramming human somatic cells has revolutionised the modelling and understanding of human diseases. iPSCs have a major advantage relative to other human pluripotent stem cells as their obtention does not require the destruction of embryos like embryonic stem cells do, and do not have a limited proliferation or differentiation potential as adult stem cells. Besides, iPSCs can be generated from somatic cells from healthy individuals or patients, which makes iPSC technology a promising approach to model and decipher the mechanisms underlying the ageing process and age-associated diseases, study drug effects, and develop new therapeutic approaches. This review discusses the advances made in the last decade using iPSC technology to study the most common age-associated diseases, including age-related macular degeneration (AMD), neurodegenerative and cardiovascular diseases, brain stroke, cancer, diabetes, and osteoarthritis.

Journey of organ on a chip technology and its role in future healthcare scenario

Organ on a chip refers to microengineered biomimetic system which reflects structural and functional characteristics of human tissue. It involves biomaterial technology, cell biology and engineering combined together in a miniaturized platform. Several models using different organs such as lungs on a chip, liver on a chip, kidney on a chip, heart on a chip, intestine on a chip and skin on a chip have been successfully developed. Food and Drug administration (FDA) has also shown confidence in this technology and has partnered with industries/institutes which are working with this technology. In this review, the concepts and applications of Organ on a chip model in different scientific domains including disease model development, drug screening, toxicology, pathogenesis study, efficacy testing and virology is discussed. It is envisaged that amalgamation of various organs on chip modules into a unified body on chip device is of utmost importance for diagnosis and treatment, especially considering the complications due to the ongoing COVID-19 pandemic. It is expected that the market demand for developing organ on chip devices to skyrocket in the near future.

Narrative review of stem cell therapy for ischemic brain injury

Ischemic brain injury is a common cause of long-term neurological deficits in children as well as adults, and no efficient treatments could reverse the sequelae in clinic till now. Stem cells have the capacity of self-renewal and multilineage differentiation. The therapeutic efficacy of stem cell transplantation for ischemic brain injury have been tested for many years. The grafts could survive and mature in the ischemic brain environment. Stem cell transplantation could improve functional recovery of ischemic brain injury models in pre-clinical trials. The potential mechanisms included cell replacement, release of neurotrophic and anti-inflammatory factors, immunoregulation as well as activation of endogenous neurogenesis. Besides, many clinical trials were conducted and some of trials already had preliminary results. From the current published data, cell transplantation for clinical application is safe and feasible. No severe adverse events and tumorigenesis were reported. While the therapeutic efficacy of stem cell therapy in clinic still needs more evidences. In this review, we overviewed the studies about stem cell therapy for ischemic brain injury. Different types of stem cells used for transplantation as well as the therapeutic mechanisms were discussed in detail. The related pre-clinical and clinical trials were summarized into two separate tables. In addition, we also discussed the unsolved problems and concerns about stem cell therapy for ischemic brain injury that need to be overcome before clinic transformation.

Human Pluripotent Stem Cells for Spinal Cord Injury

Spinal cord injury (SCI) as a serious public health issue and neurological insult is one of the most severe cause of long-term disability. To date, a variety of techniques have been widely developed to treat central nervous system injury. Currently, clinical treatments are limited to surgical decompression and pharmacotherapy. Because of their negative effects and inefficiency, novel therapeutic approaches are required in the management of SCI. Improvement and innovation of stem cell-based therapies have a huge potential for biological and future clinical applications. Human pluripotent stem cells (hPSCs) including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are defined by their abilities to divide asymmetrically, self-renew and ultimately differentiate into various cell lineages. There are considerable research efforts to use various types of stem cells, such as ESCs, neural stem cells (NSCs), and mesenchymal stem cells (MSCs) in the treatment of patients with SCI. Moreover, the use of patient-specific iPSCs holds great potential as an unlimited cell source for generating in vivo models of SCI. In this review, we focused on the potential of hPSCs in treating SCI.

Zinc Promotes Patient-Derived Induced Pluripotent Stem Cell Neural Differentiation via ERK-STAT Signaling

Nerve regeneration remains a challenge. Patient-derived induced pluripotent stem cell (iPSC)-differentiated neural stem cells (NSCs) provide a promising hope. Zinc is closely involved in central nervous system development and metabolism, but its role on iPSC neural differentiation is elusive and zinc detection methods in live cells are limited. In this study, intracellular zinc was detected in real time by a zinc fluorescent chemosensor and was shown to be increased during the iPSC neural induction process. iPSC neural differentiation was promoted with the addition of zinc chloride (ZnCl₂) and inhibited with the addition of zinc chelator N,N,N0,N0-tetrakis(2-pyridylmethyl)-ethylenediamine, indicated by western blot and enzyme-linked immunosorbent assay analysis of NSC marker Nestin expression and measurement of neurite-like structures. Mechanistically, the phosphorylation level of ERK1/2 and STAT3 was changed with the zinc level, suggesting that zinc may affect the neural differentiation of iPSCs through ERK-STAT signaling. In conclusion, our study shows the important role of zinc in iPSC neural differentiation and suggests a new idea for iPSC-derived NSC application in nerve regeneration.