Customized Brain Cells for Stroke Patients Using Pluripotent Stem Cells

Long non-coding RNAs plasmacytoma variant translocation 1 regulates bone marrow mesenchymal stem cell transplantation to promote the repair of spinal cord injury

This study investigated the therapeutic potential of long non-coding RNAs plasmacytoma variant translocation 1 (lncRNA PVT1) in regulating the function of bone marrow mesenchymal stem cells (BMSCs) following experimental spinal cord injury (SCI). Rat BMSCs were isolated and characterized. Loss-of and gain-of-function experiments were performed to assess the effects of lncRNA PVT1 on BMSCs and Schwann cells (SCs). Fusion PCR mutation, dual-luciferase reporter, and RNA immunoprecipitation assays were employed to explore the binding region between lncRNA PVT1 and polypyrimidine tract binding protein 1 (PTBP1). LncRNA PVT1 increased the proliferation, migration, and apoptosis of BMSCs; lncRNA PVT1 knockdown had the opposite effects. LncRNA PVT1 inhibited PTBP1 expression. The promoting effect of lncRNA PVT1 on the proliferation and migration of BMSCs was suppressed by overexpression of PTBP1. LncRNA PVT1 also induced SC-like differentiation of BMSCs. LncRNA PVT1-modified BMSCs promoted the proliferation and migration of SCs and upregulated levels of neurotrophic factors and SC biomarkers. Transplantation of lncRNA PVT1-modified BMSCs also improved functional recovery of rats with SCI. Altogether, lncRNA PVT1 promoted the proliferation, migration, and differentiation of BMSCs by inhibiting PTBP1. LncRNA PVT1-modified BMSCs also influenced the function of SCs and promoted recovery in rats following SCI.

Compact transcription factor cassettes generate functional, engraftable motor neurons by direct conversion

Direct conversion generates patient-specific, disease-relevant cell types, such as neurons, that are rare, limited, or difficult to isolate from common and easily accessible cells, such as skin cells. However, low rates of direct conversion and complex protocols limit scalability and, thus, the potential of cell-fate conversion for biomedical applications. Here, we optimize the conversion protocol by examining process parameters, including transcript design; delivery via adeno-associated virus (AAV), retrovirus, and lentivirus; cell seeding density; and the impact of media conditions. Thus, we report a compact, portable conversion process that boosts proliferation and increases direct conversion of mouse fibroblasts to induced motor neurons (iMNs) to achieve high conversion rates of above 1,000%, corresponding to more than ten motor neurons yielded per cell seeded, which we achieve through expansion. Our optimized, direct conversion process generates functional motor neurons at scales relevant for cell therapies (>107 cells) that graft with the mouse central nervous system. High-efficiency, compact, direct conversion systems will support scaling to patient-specific, neural cell therapies.

Brain repair mechanisms after cell therapy for stroke

Cell-based therapies hold great promise for brain repair after stroke. While accumulating evidence confirms the preclinical and clinical benefits of cell therapies, the underlying mechanisms by which they promote brain repair remain unclear. Here, we briefly review endogenous mechanisms of brain repair after ischaemic stroke and then focus on how different stem and progenitor cell sources can promote brain repair. Specifically, we examine how transplanted cell grafts contribute to improved functional recovery either through direct cell replacement or by stimulating endogenous repair pathways. Additionally, we discuss recently implemented preclinical refinement methods, such as preconditioning, microcarriers, genetic safety switches and universal (immune evasive) cell transplants, as well as the therapeutic potential of these pharmacologic and genetic manipulations to further enhance the efficacy and safety of cell therapies. By gaining a deeper understanding of post-ischaemic repair mechanisms, prospective clinical trials may be further refined to advance post-stroke cell therapy to the clinic.

Pharmacological and stem cell therapy of stroke in animal models: Do they accurately reflect the response of humans?

Cerebrovascular diseases are the second leading cause of death worldwide. Despite significant research investment, the only available therapeutic options are mechanical thrombectomy and tissue plasminogen activator thrombolysis. None of the more than a thousand drugs tested on animal models have proven successful in human clinical trials. Several factors contribute to this poor translation of data from stroke-related animal models to human stroke patients. Firstly, our understanding of the molecular and cellular processes involved in recovering from an ischemic stroke is severely limited. Secondly, although the risk of stroke is particularly high among older patients with comorbidities, most drugs are tested on young, healthy animals in controlled laboratory conditions. Furthermore, in animal models, the tracking of post-stroke recovery typically spans only 3 to 28 days, with occasional extensions to 60 days, whereas human stroke recovery is a more extended and complex process. Thirdly, young animal models often exhibit a considerably higher rate of spontaneous recovery compared to humans following a stroke. Fourth, only a very limited number of animals are utilized for each condition, including control groups. Another contributing factor to the much smaller beneficial effects in humans is that positive outcomes from numerous animal studies are more readily accepted than results reported in human trials that do not show a clear benefit to the patient. Useful recommendations for conducting experiments in animal models, with increased chances of translatability to humans, have been issued by both the STEPS investigative team and the STAIR committee. However, largely, due to economic factors, these recommendations are largely ignored. Furthermore, one might attribute the overall failures in predicting and subsequently developing effective acute stroke therapies beyond thrombolysis to potential design deficiencies in clinical trials.

Ischemic and hemorrhagic stroke lesion environments differentially alter the glia repair potential of neural progenitor cell and immature astrocyte grafts

Using cell grafting to direct glia-based repair mechanisms in adult CNS injuries represents a potential therapeutic strategy for supporting functional neural parenchymal repair. However, glia repair directed by neural progenitor cell (NPC) grafts is dramatically altered by increasing lesion size, severity, and mode of injury. To address this, we studied the interplay between astrocyte differentiation and cell proliferation of NPC in vitro to generate proliferating immature astrocytes (ImA) using hysteretic conditioning. ImA maintain proliferation rates at comparable levels to NPC but showed robust immature astrocyte marker expression including Gfap and Vimentin. ImA demonstrated enhanced resistance to myofibroblast-like phenotypic transformations upon exposure to serum enriched environments in vitro compared to NPC and were more effective at scratch wound closure in vitro compared to quiescent astrocytes. Glia repair directed by ImA at acute ischemic striatal stroke lesions was equivalent to NPC but better than quiescent astrocyte grafts. While ischemic injury environments supported enhanced survival of grafts compared to healthy striatum, hemorrhagic lesions were hostile towards both NPC and ImA grafts leading to poor survival and ineffective modulation of natural wound repair processes. Our findings demonstrate that lesion environments, rather than transcriptional pre-graft states, determine the survival, cell-fate, and glia repair competency of cell grafts applied to acute CNS injuries.

Revolutionizing Stroke Recovery: Unveiling the Promise of Stem Cell Therapy

Stem cells, renowned for their unique regenerative capabilities, present significant hope in treating stroke, a major cause of disability globally. This review offers a detailed analysis of stem cell applications in stroke (ischemic and hemorrhagic) recovery. It examines therapies based on autologous (patient-derived), allogeneic (donor-derived), and Granulocyte-Colony Stimulating Factor (G-CSF) based stem cells, focusing on cell types such as Mesenchymal Stem/Stromal Cells (MSCs), Bone Marrow Mononuclear Stem Cells (BMMSCs), and Neural Stem/Progenitor Cells (NSCs). The paper compiles clinical trial data to evaluate their effectiveness and safety and addresses the ethical concerns of these innovative treatments. By explaining the mechanisms of stem cell-induced neurological repair, this review underscores stem cells' potential in revolutionizing stroke rehabilitation and suggests avenues for future research.

Stem Cell Therapy for Repair of the Injured Brain: Five Principles

Cell therapy holds great promise for regenerative treatment of disease. Despite recent breakthroughs in clinical research, applications of cell therapies to the injured brain have not yielded the desired results. We pinpoint current limitations and suggest five principles to advance stem cell therapies for brain regeneration. While we focus on cell therapy for stroke, all principles also apply for other brain diseases.

Comparative study of the efficacy of intra-arterial and intravenous transplantation of human induced pluripotent stem cells-derived neural progenitor cells in experimental stroke

Background

Cell therapy using neural progenitor cells (NPCs) is a promising approach for ischemic stroke treatment according to the results of multiple preclinical studies in animal stroke models. In the vast majority of conducted animal studies, the therapeutic efficacy of NPCs was estimated after intracerebral transplantation, while the information of the effectiveness of systemic administration is limited. Nowadays, several clinical trials aimed to estimate the safety and efficacy of NPCs transplantation in stroke patients were also conducted. In these studies, NPCs were transplanted intracerebrally in the subacute/chronic phase of stroke. The results of clinical trials confirmed the safety of the approach, however, the degree of functional improvement (the primary efficacy endpoint) was not sufficient in the majority of the studies. Therefore, more studies are needed in order to investigate the optimal transplantation parameters, especially the timing of cell transplantation after the stroke onset. This study aimed to evaluate the therapeutic effects of intra-arterial (IA) and intravenous (IV) administration of NPCs derived from induced pluripotent stem cells (iNPCs) in the acute phase of experimental stroke in rats. Induced pluripotent stem cells were chosen as the source of NPCs as this technology is perspective, has no ethical concerns and provides the access to personalized medicine.

Methods

Human iNPCs were transplanted IA or IV into male Wistar rats 24 h after the middle cerebral artery occlusion stroke modeling. Therapeutic efficacy was monitored for 14 days and evaluated in comparison with the cell transplantation-free control group. Additionally, cell distribution in the brain was assessed.

Results

The obtained results show that both routes of systemic transplantation (IV and IA) significantly reduced the mortality and improved the neurological deficit of experimental animals compared to the control group. At the same time, according to the MRI data, only IA administration led to faster and prominent reduction of the stroke volume. After IA administration, iNPCs transiently trapped in the brain and were not detected on day 7 after the transplantation. In case of IV injection, transplanted cells were not visualized in the brain. The obtained data demonstrated that the systemic transplantation of human iNPCs in the acute phase of ischemic stroke can be a promising therapeutic strategy.

Therapeutical growth in oligodendroglial fate induction via transdifferentiation of stem cells for neuroregenerative therapy

The merits of stem cell therapy and research are undisputed due to their widespread usage in the treatment of neurodegenerative diseases and demyelinating disorders. Cell replacement therapy especially revolves around stem cells and their induction into different cell lineages both adult and progenitor - belonging to each germ layer, prior to transplantation or disease modeling studies. The nervous system is abundant in glial cells and among these are oligodendrocytes capable of myelinating new-born neurons and remyelination of axons with lost or damaged myelin sheath. But demyelinating diseases generate tremendous deficit between myelin loss and recovery. To compensate for this loss, analyze the defects in remyelination mechanisms as well as to trigger full recovery in such patients mesenchymal stem cells (MSCs) have been induced to transdifferentiate into oligodendrocytes. But such experiments are riddled with problems like prolonged, tenuous and complicated protocols that stretch longer than the time taken for the spread of demyelination-associated after-effects. This review delves into such protocols and the combinations of different molecules and factors that have been recruited to derive bona fide oligodendrocytes from in vitro differentiation of embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and MSCs with special focus on MSC-derived oligodendrocytes.

The Ties That Bind: Glial Transplantation in White Matter Ischemia and Vascular Dementia

White matter injury is a progressive vascular disease that leads to neurological deficits and vascular dementia. It comprises up to 30% of all diagnosed strokes, though up to ten times as many events go undiagnosed in early stages. There are several pathologies that can lead to white matter injury. While some studies suggest that white matter injury starts as small infarcts in deep penetrating blood vessels in the brain, others point to the breakdown of endothelial function or the blood-brain barrier as the primary cause of the disease. Whether due to local endothelial or BBB dysfunction, or to local small infarcts (or a combination), white matter injury progresses, accumulates, and expands from preexisting lesions into adjacent white matter to produce motor and cognitive deficits that present as vascular dementia in the elderly. Vascular dementia is the second leading cause of dementia, and white matter injury-attributed vascular dementia represents 40% of all diagnosed dementias and aggravates Alzheimer's pathology. Despite the advances in the last 15 years, there are few animal models of progressive subcortical white matter injury or vascular dementia. This review will discuss recent progress in animal modeling of white matter injury and the emerging principles to enhance glial function as a means of promoting repair and recovery.

Deep learning-based behavioral profiling of rodent stroke recovery

BACKGROUND

Stroke research heavily relies on rodent behavior when assessing underlying disease mechanisms and treatment efficacy. Although functional motor recovery is considered the primary targeted outcome, tests in rodents are still poorly reproducible and often unsuitable for unraveling the complex behavior after injury.

RESULTS

Here, we provide a comprehensive 3D gait analysis of mice after focal cerebral ischemia based on the new deep learning-based software (DeepLabCut, DLC) that only requires basic behavioral equipment. We demonstrate a high precision 3D tracking of 10 body parts (including all relevant joints and reference landmarks) in several mouse strains. Building on this rigor motion tracking, a comprehensive post-analysis (with >100 parameters) unveils biologically relevant differences in locomotor profiles after a stroke over a time course of 3 weeks. We further refine the widely used ladder rung test using deep learning and compare its performance to human annotators. The generated DLC-assisted tests were then benchmarked to five widely used conventional behavioral set-ups (neurological scoring, rotarod, ladder rung walk, cylinder test, and single-pellet grasping) regarding sensitivity, accuracy, time use, and costs.

CONCLUSIONS

We conclude that deep learning-based motion tracking with comprehensive post-analysis provides accurate and sensitive data to describe the complex recovery of rodents following a stroke. The experimental set-up and analysis can also benefit a range of other neurological injuries that affect locomotion.

Lesion environments direct transplanted neural progenitors towards a wound repair astroglial phenotype in mice

Neural progenitor cells (NPC) represent potential cell transplantation therapies for CNS injuries. To understand how lesion environments influence transplanted NPC fate in vivo, we derived NPC expressing a ribosomal protein-hemagglutinin tag (RiboTag) for transcriptional profiling of transplanted NPC. Here, we show that NPC grafted into uninjured mouse CNS generate cells that are transcriptionally similar to healthy astrocytes and oligodendrocyte lineages. In striking contrast, NPC transplanted into subacute CNS lesions after stroke or spinal cord injury in mice generate cells that share transcriptional, morphological and functional features with newly proliferated host astroglia that restrict inflammation and fibrosis and isolate lesions from adjacent viable neural tissue. Our findings reveal overlapping differentiation potentials of grafted NPC and proliferating host astrocytes; and show that in the absence of other interventions, non-cell autonomous cues in subacute CNS lesions direct the differentiation of grafted NPC towards a naturally occurring wound repair astroglial phenotype.

Reliable generation of glial enriched progenitors from human fibroblast-derived iPSCs

White matter stroke (WMS) occurs as small infarcts in deep penetrating blood vessels in the brain and affects the regions of the brain that carry connections, termed the subcortical white matter. WMS progresses over years and has devastating clinical consequences. Unlike large grey matter strokes, WMS disrupts the axonal architecture of the brain and depletes astrocytes, oligodendrocyte lineage cells, axons and myelinating cells, resulting in abnormalities of gait and executive function. An astrocytic cell-based therapy is positioned as a strong therapeutic candidate after WMS. In this study we report, the reliable generation of a novel stem cell-based therapeutic product, glial enriched progenitors (GEPs) derived from human induced pluripotent stem cells (hiPSCs). By transient treatment of hiPSC derived neural progenitors (hiPSC-NPCs) with the small molecule deferoxamine, a prolyl hydroxylase inhibitor, for three days hiPSC-NPCs become permanently biased towards an astrocytic fate, producing hiPSC-GEPs. In preparation for clinical application, we have developed qualification assays to ensure identity, safety, purity, and viability of the cells prior to manufacture. Using tailored q-RT-PCR-based assays, we have demonstrated the lack of pluripotency in our final therapeutic candidate cells (hiPSC-GEPs) and we have identified the unique genetic profile of hiPSC-GEPs that is clearly distinct from the parent lines, hiPSCs and iPSC-NPCs. After completion of the viability assay, we have stablished the therapeutic window of use for hiPSC-GEPs in future clinical applications (7 h). Lastly, we were able to reliably and consistently produce a safe therapeutic final product negative for contamination by any human or murine viral pathogens, selected bacteria, common laboratory mycoplasmas, growth of any aerobes, anaerobes, yeast, or fungi and 100 times less endotoxin levels than the maximum acceptable value. This study demonstrates the reliable and safe generation of patient derived hiPSC-GEPs that are clinically ready as a cell-based therapeutic approach for WMS.

Particles Containing Cells as a Strategy to Promote Remyelination in Patients With Multiple Sclerosis

The repair of demyelinated lesions is a key objective in multiple sclerosis research. Remyelination fundamentally depends on oligodendrocyte progenitor cells (OPC) reaching the lesion; this is influenced by numerous factors including age, disease progression time, inflammatory activity, and the pool of OPCs available, whether they be NG2 cells or cells derived from neural stem cells. Administering OPCs has been proposed as a potential cell therapy; however, these cells can only be administered directly. This article discusses the potential administration of OPCs encapsulated within hydrogel particles composed of biocompatible biomaterials, via the nose-to-brain pathway. We also discuss conditions for the indication of this therapy, and such related issues as the influence on endogenous remyelination, migration of OPCs to demyelinated areas, and the immune response, given the autoimmune nature of multiple sclerosis. Chitosan and derivatives constitute the most promising biomaterial for this purpose, although these issues must be addressed. In conclusion, this line of research may yield an alternative to the remyelinating drugs currently being studied.

A Defined and Scalable Peptide-Based Platform for the Generation of Human Pluripotent Stem Cell-Derived Astrocytes

Astrocytes comprise the most abundant cell type in the central nervous system (CNS) and play critical roles in maintaining neural tissue homeostasis. In addition, astrocyte dysfunction and death has been implicated in numerous neurological disorders such as multiple sclerosis, Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and Parkinson’s disease (PD). As such, there is much interest in using human pluripotent stem cell (hPSC)-derived astrocytes for drug screening, disease modeling, and regenerative medicine applications. However, current protocols for generation of astrocytes from hPSCs are limited by the use of undefined xenogeneic components and two-dimensional (2D) culture surfaces, which limits their downstream applications where large-quantities of cells generated under defined conditions are required. Here, we report the use of a completely synthetic, peptide-based substrate that allows for the differentiation of highly pure populations of astrocytes from several independent hPSC lines, including those derived from patients with neurodegenerative disease. This substrate, which we demonstrate is compatible with both conventional 2D culture formats and scalable microcarrier (MC)-based technologies, leads to the generation of cells that express high levels of canonical astrocytic markers as well as display properties characteristic of functionally mature cells including production of apolipoprotein E (ApoE), responsiveness to inflammatory stimuli, ability to take up amyloid-β (Aβ), and appearance of robust calcium transients. Finally, we show that these astrocytes can be cryopreserved without any loss of functionality. In the future, we anticipate that these methods will enable the development of bioprocesses for the production of hPSC-derived astrocytes needed for biomedical research and clinical applications.

Therapeutic Plasticity of Neural Stem Cells

Neural stem cells (NSCs) have garnered significant scientific and commercial interest in the last 15 years. Given their plasticity, defined as the ability to develop into different phenotypes inside and outside of the nervous system, with a capacity of almost unlimited self-renewal, of releasing trophic and immunomodulatory factors, and of exploiting temporal and spatial dynamics, NSCs have been proposed for (i) neurotoxicity testing; (ii) cellular therapies to treat CNS diseases; (iii) neural tissue engineering and repair; (iv) drug target validation and testing; (v) personalized medicine. Moreover, given the growing interest in developing cell-based therapies to target neurodegenerative diseases, recent progress in developing NSCs from human-induced pluripotent stem cells has produced an analog of endogenous NSCs. Herein, we will review the current understanding on emerging conceptual and technological topics in the neural stem cell field, such as deep characterization of the human compartment, single-cell spatial-temporal dynamics, reprogramming from somatic cells, and NSC manipulation and monitoring. Together, these aspects contribute to further disentangling NSC plasticity to better exploit the potential of those cells, which, in the future, might offer new strategies for brain therapies.

Methods of Generation of Induced Pluripotent Stem Cells and Their Application for the Therapy of Central Nervous System Diseases

The use of induced pluripotent stem cells (IPSC) is a promising approach to the therapy of CNS diseases. The undeniable advantage of IPSC technology is the possibility of obtaining practically all types of somatic cells for autologous transplantation bypassing bioethical problems. The review presents integrative and non-integrative methods for obtaining IPSC and the ways of their in vitro and in vivo application for the study and treatment of neurological diseases.

Harnessing the anti-inflammatory properties of stem cells for transplant therapy in hemorrhagic stroke

Hemorrhagic stroke is a global health crisis plagued by neuroinflammation in the acute and chronic phases. Neuroinflammation approximates secondary cell death, which in turn robustly contributes to stroke pathology. Both the physiological and behavioral symptoms of stroke correlate with various inflammatory responses in animal and human studies. That slowing the secondary cell death mediated by this inflammation may attenuate stroke pathology presents a novel treatment strategy. To this end, experimental therapies employing stem cell transplants support their potential for neuroprotection and neuroregeneration after hemorrhagic stroke. In this review, we evaluate experiments using different types of stem cell transplants as treatments for stroke-induced neuroinflammation. We also update this emerging area by examining recent preclinical and clinical trials that have deployed these therapies. While further investigations are warranted to solidify their therapeutic profile, the reviewed studies largely posit stem cells as safe and potent biologics for stroke, specifically owing to their mode of action for sequestering neuroinflammation and promoting neuroregenerative processes.

Monitoring maturation of neural stem cell grafts within a host microenvironment

Neural stem cells (NSC) act as a versatile tool for neuronal cell replacement strategies to treat neurodegenerative disorders in which functional neurorestorative mechanisms are limited. While the beneficial effects of such cell-based therapy have already been documented in terms of neurodegeneration of various origins, a neurophysiological basis for improvement in the recovery of neurological function is still not completely understood. This overview briefly describes the cumulative evidence from electrophysiological studies of NSC-derived neurons, aimed at establishing the maturation of differentiated neurons within a host microenvironment, and their integration into the host circuits, with a particular focus on the neurogenesis of NSC grafts within the post-ischemic milieu. Overwhelming evidence demonstrates that the host microenvironment largely regulates the lineage of NSC grafts. This regulatory role, as yet underestimated, raises possibilities for the favoured maturation of a subset of neural phenotypes in order to gain timely remodelling of the impaired brain tissue and amplify the therapeutic effects of NSC-based therapy for recovery of neurological function.

Successes and Hurdles in Stem Cells Application and Production for Brain Transplantation

Brain regenerative strategies through the transplantation of stem cells hold the potential to promote functional rescue of brain lesions caused either by trauma or neurodegenerative diseases. Most of the positive modulations fostered by stem cells are fueled by bystander effects, namely increase of neurotrophic factors levels and reduction of neuroinflammation. Nevertheless, the ultimate goal of cell therapies is to promote cell replacement. Therefore, the ability of stem cells to migrate and differentiate into neurons that later become integrated into the host neuronal network replacing the lost neurons has also been largely explored. However, as most of the preclinical studies demonstrate, there is a small functional integration of graft-derived neurons into host neuronal circuits. Thus, it is mandatory to better study the whole brain cell therapy approach in order to understand what should be better comprehended concerning graft-derived neuronal and glial cells migration and integration before we can expect these therapies to be ready as a viable solution for brain disorder treatment. Therefore, this review discusses the positive mechanisms triggered by cell transplantation into the brain, the limitations of adult brain plasticity that might interfere with the neuroregeneration process, as well as some strategies tested to overcome some of these limitations. It also considers the efforts that have been made by the regulatory authorities to lead to better standardization of preclinical and clinical studies in this field in order to reduce the heterogeneity of the obtained results.

Neural Stem Cells Transfected with Reactive Oxygen Species-Responsive Polyplexes for Effective Treatment of Ischemic Stroke

Neural stem cells (NSCs), capable of ischemia-homing, regeneration, and differentiation, exert strong therapeutic potentials in treating ischemic stroke, but the curative effect is limited in the harsh microenvironment of ischemic regions rich in reactive oxygen species (ROS). Gene transfection to make NSCs overexpress brain-derived neurotrophic factor (BDNF) can enhance their therapeutic efficacy; however, viral vectors must be used because current nonviral vectors are unable to efficiently transfect NSCs. The first polymeric vector, ROS-responsive charge-reversal poly[(2-acryloyl)ethyl(p-boronic acid benzyl)diethylammonium bromide] (B-PDEA), is shown here, that mediates efficient gene transfection of NSCs and greatly enhances their therapeutics in ischemic stroke treatment. The cationic B-PDEA/DNA polyplexes can effectively transfect NSCs; in the cytosol, the B-PDEA is oxidized by intracellular ROS into negatively charged polyacrylic acid, quickly releasing the BDNF plasmids for efficient transcription and secreting a high level of BDNF. After i.v. injection in ischemic stroke mice, the transfected NSCs (BDNF-NSCs) can home to ischemic regions as efficiently as the pristine NSCs but more efficiently produce BDNF, leading to significantly augmented BDNF levels, which in turn enhances the mouse survival rate to 60%, from 0% (nontreated mice) or ≈20% (NSC-treated mice), and enables more rapid and superior functional reconstruction.

Promoting Brain Repair and Regeneration After Stroke: a Plea for Cell-Based Therapies

PURPOSE OF REVIEW

After decades of hype, cell-based therapies are emerging into the clinical arena for the purposes of promoting recovery after stroke. In this review, we discuss the most recent science behind the role of cell-based therapies in ischemic stroke and the efforts to translate these therapies into human clinical trials.

RECENT FINDINGS

Preclinical data support numerous beneficial effects of cell-based therapies in both small and large animal models of ischemic stroke. These benefits are driven by multifaceted mechanisms promoting brain repair through immunomodulation, trophic support, circuit reorganization, and cell replacement. Cell-based therapies offer tremendous potential for improving outcomes after stroke through multimodal support of brain repair. Based on recent clinical trials, cell-based therapies appear both feasible and safe in all phases of stroke. Ongoing translational research and clinical trials will further refine these therapies and have the potential to transform the approach to stroke recovery and rehabilitation.

Stem cell-based cell therapy for neuroprotection in stroke: A review

Neurological disorders, such as stroke, are triggered by a loss of neurons and glial cells. Ischemic stroke remains a substantial problem for industrialized countries. Over the previous few decades our understanding about the pathophysiology of stroke has enhanced, nevertheless, more awareness is required to advance the field of stroke recovery. Existing therapies are incapable to adequately relief the disease outcome and are not appropriate to all patients. Meanwhile, the majority of patients continue to show neurological deficits even subsequent effective thrombolysis, recuperative therapies are immediately required that stimulate brain remodeling and repair once stroke damage has happened. Cell therapy is emergent as a hopeful new modality for increasing neurological recovery in ischemic stroke. Numerous types of stem cells from various sources have been identified and their possibility and efficiency for the treatment of stroke have been investigated. Stem cell therapy in patients with stroke using adult stem cells have been first practiced in clinical trials since 15 years ago. Even though stem cells have revealed a hopeful role in ischemic stroke in investigational studies besides early clinical pilot studies, cellular therapy in human is still at a primary stage. In this review, we summarize the types of stem cells, various delivery routes, and clinical application of stem cell-based therapy for stroke treatment.