Cell transplantation therapy for stroke

Hydrogels-Assisted Cell Engraftment for Repairing the Stroke-Damaged Brain: Chimera or Reality

The use of advanced biomaterials as a structural and functional support for stem cells-based therapeutic implants has boosted the development of tissue engineering applications in multiple clinical fields. In relation to neurological disorders, we are still far from the clinical reality of restoring normal brain function in neurodegenerative diseases and cerebrovascular disorders. Hydrogel polymers show unique mechanical stiffness properties in the range of living soft tissues such as nervous tissue. Furthermore, the use of these polymers drastically enhances the engraftment of stem cells as well as their capacity to produce and deliver neuroprotective and neuroregenerative factors in the host tissue. Along this article, we review past and current trends in experimental and translational research to understand the opportunities, benefits, and types of tentative hydrogel-based applications for the treatment of cerebral disorders. Although the use of hydrogels for brain disorders has been restricted to the experimental area, the current level of knowledge anticipates an intense development of this field to reach clinics in forthcoming years.

Potential of Stem Cell-Based Therapy for Ischemic Stroke

Ischemic stroke is one of the major health problems worldwide. The only FDA approved anti-thrombotic drug for acute ischemic stroke is the tissue plasminogen activator. Several studies have been devoted to assessing the therapeutic potential of different types of stem cells such as neural stem cells (NSCs), mesenchymal stem cells, embryonic stem cells, and human induced pluripotent stem cell-derived NSCs as treatments for ischemic stroke. The results of these studies are intriguing but many of them have presented conflicting results. Additionally, the mechanism(s) by which engrafted stem/progenitor cells exert their actions are to a large extent unknown. In this review, we will provide a synopsis of different preclinical and clinical studies related to the use of stem cell-based stroke therapy, and explore possible beneficial/detrimental outcomes associated with the use of different types of stem cells. Due to limited/short time window implemented in most of the recorded clinical trials about the use of stem cells as potential therapeutic intervention for stroke, further clinical trials evaluating the efficacy of the intervention in a longer time window after cellular engraftments are still needed.

Potential benefits of mesenchymal stem cells and electroacupuncture on the trophic factors associated with neurogenesis in mice with ischemic stroke

The beneficial effects of mesenchymal stem cells (MSCs) and electroacupuncture (EA) on neurogenesis and related trophic factors remain unclear. Bone marrow MSCs (mBMSC) were transplanted into the striatum of mice with middle cerebral artery occlusion (MCAO), and EA stimulation was applied at two acupoints, Baihui and Dazhui. EA treatment significantly improved motor function, and a synergistic effect of combined mBMSC and EA treatment was observed. Combined mBMSC and EA treatment reduced prominent atrophic changes in the striatum and led to proliferation of neural progenitor cells in the subventricular zone (SVZ) and the surrounding areas of the striatum (SVZ + striatum) of MCAO mice. The mBMSC and EA treatment markedly enhanced mature brain-derived neurotrophic factor (mBDNF) expression in the SVZ + striatum and hippocampus of mice with MCAO, and combined treatment enhanced neurotrophin-4 (NT4) expression. The number of mBDNF- and NT4-positive neurons in the SVZ + striatum and hippocampus increased following EA treatment. Combined treatment led to an increase in the expression levels of phosphorylated cAMP response element binding protein in the neuroblasts of the striatum. Our results indicate that combined MSC and EA treatment may lead to a better therapeutic effect via co-regulation of neurotrophic factors in the brain, by regulating neurogenesis more than single therapy.

Bone marrow mesenchymal stem cell transplantation in acute brain trauma

Aim: This study was performed to evaluate the effects of intravenously transplanted rat bone-marrow derived mesenchymal stem cells (rBMSCs) in an acute brain trauma model using serial 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in rat models. Animals, methods: Trauma models were made using a controlled cortical impact injury device. The stem cell treatment group was treated with intravenous injections of BMSCs, and models without stem cell therapy comprised the control group. Serial 18F-FDG PET images were obtained 1, 7, 14, 21, and 28 days after trauma. The difference in 18F-FDG uptake between day 1 and each time point after trauma was analyzed with SPM2 (uncorrected p < 0.005). Results: The stem cell treatment group demonstrated significantly higher 18F-FDG uptake in the right parietal region at 14 days after trauma than at 1 day after trauma. An increase in glucose metabolism in the right parietal cortex appeared on days 21 and 28 after trauma in the group without stem cell treatment. The 18F-FDG uptake in the brain was improved over a broader area, including the right parietal and right primary somatosensory cortex, on days 21 and 28 after trauma in the stem cell treatment group compared with the group without stem cell treatment. Conclusion: BMSC therapy in trauma models led to improved glucose metabolism. This result might support the therapeutic effect of stem cells in brain trauma.

Clinical Outcomes of Repeated Intraventricular Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells in Chronic Haemorrhagic Stroke. A One-Year Follow Up

Object:

Stroke, one of the most devastating diseases, is a leading cause of death and disability throughout the world and is also associated with emotional and economic problems. The main goal of this study was to investigate the clinical outcome of the intraventricular transplantation of bone marrow mesenchymal stem cells (BM-MSCs) in post-haemorrhagic stroke patients.

Method:

This study was done consisting of eight patients with supratentorial haemorrhagic stroke, who had undergone 24 weeks of standard treatment of stroke with stable neurological deficits. All of the patients received stem cell transplantation intraventricularly using autologous BM-MSCs. Six months and Twelve months after stem cells treatment, the clinical outcomes were measured using the National Institute of Health Stroke Scale (NIHSS) and adverse effect also observed.

Result:

The results of this study showed improvement of NIHSS score values before and after the treatment in five patients. No adverse effects or complications were detected during the 1-year observation.

Conclusion:

Intraventricular transplantation of BM-MSCs has shown benefits in improving the functional status of post-haemorrhagic stroke patients with no adverse effect.

Brain-immune interactions in perinatal hypoxic-ischemic brain injury

Perinatal hypoxia-ischemia remains the primary cause of acute neonatal brain injury, leading to a high mortality rate and long-term neurological deficits, such as behavioral, social, attentional, cognitive and functional motor deficits. An ever-increasing body of evidence shows that the immune response to acute cerebral hypoxia-ischemia is a major contributor to the pathophysiology of neonatal brain injury. Hypoxia-ischemia provokes an intravascular inflammatory cascade that is further augmented by the activation of resident immune cells and the cerebral infiltration of peripheral immune cells response to cellular damages in the brain parenchyma. This prolonged and/or inappropriate neuroinflammation leads to secondary brain tissue injury. Yet, the long-term effects of immune activation, especially the adaptive immune response, on the hypoxic-ischemic brain still remain unclear. The focus of this review is to summarize recent advances in the understanding of post-hypoxic-ischemic neuroinflammation triggered by the innate and adaptive immune responses and to discuss how these mechanisms modulate the brain vulnerability to injury. A greater understanding of the reciprocal interactions between the hypoxic-ischemic brain and the immune system will open new avenues for potential immunomodulatory therapy in the treatment of neonatal brain injury.

Can adjunctive therapies augment the efficacy of endovascular thrombolysis? A potential role for activated protein C

In the management of acute ischemic stroke, vessel recanalization correlates with functional status, mortality, cost, and other outcome measures. Thrombolysis with intravenous tissue plasminogen activator has many limitations that restrict its applicability, but recent advances in the development of mechanical thrombectomy devices as well as improved systems of stroke care have resulted in greater likelihood of vessel revascularization. Nonetheless, there remains substantial discrepancy between rates of recanalization and rates of favorable outcome. The poor neurological recovery among some stroke patients despite successful recanalization confirms the need for adjuvant pharmacological therapy for neuroprotection and/or neurorestoration. Prior clinical trials of such drugs may have failed due to the inability of the agent to access the ischemic tissue beyond the occluded artery. A protocol that couples revascularization with concurrent delivery of a neuroprotectant drug offers the potential to enhance the benefit of thrombolysis. Analogs of activated protein C (APC) exert pleiotropic anti-inflammatory, anti-apoptotic, antithrombotic, cytoprotective, and neuroregenerative effects in ischemic stroke and thus appear to be promising candidates for this novel approach. A multicenter, prospective, double-blinded, dose-escalation Phase 2 randomized clinical trial has enrolled 110 patients to assess the safety, pharmacokinetics, and efficacy of human recombinant 3K3A-APC following endovascular thrombolysis. This article is part of the Special Issue entitled 'Cerebral Ischemia'.

Research on advanced intervention using novel bone marrOW stem cell (RAINBOW): a study protocol for a phase I, open-label, uncontrolled, dose-response trial of autologous bone marrow stromal cell transplantation in patients with acute ischemic stroke

Background

Stroke is a leading cause of death and disability, and despite intensive research, few treatment options exist. However, a recent breakthrough in cell therapy is expected to reverse the neurological sequelae of stroke. Although some pioneer studies on the use of cell therapy for treating stroke have been reported, certain problems remain unsolved. Recent studies have demonstrated that bone marrow stromal cells (BMSCs) have therapeutic potential against stroke. We investigated the use of autologous BMSC transplantation as a next-generation cell therapy for treating stroke. In this article, we introduce the protocol of a new clinical trial, the Research on Advanced Intervention using Novel Bone marrOW stem cell (RAINBOW).

Methods/design

RAINBOW is a phase 1, open-label, uncontrolled, dose-response study, with the primary aim to determine the safety of the autologous BMSC product HUNS001–01 when administered to patients with acute ischemic stroke. Estimated enrollment is 6–10 patients suffering from moderate to severe neurological deficits. Approximately 50 mL of the bone marrow is extracted from the iliac bone of each patient 15 days or later from the onset. BMSCs are cultured with allogeneic human platelet lysate (PL) as a substitute for fetal calf serum and are labeled with superparamagnetic iron oxide for cell tracking using magnetic resonance imaging (MRI). HUNS001–01 is stereotactically administered around the area of infarction in the subacute phase. Each patient will be administered a dose of 20 or 50 million cells. Neurological scoring, MRI for cell tracking, ¹⁸F–fuorodeoxyglucose positron emission tomography, and ¹²³I–Iomazenil single­photon emission computed tomography will be performed for 1 year after the administration.

Discussion

This is a first-in-human trial for HUNS001–01 to the patients with acute ischemic stroke. We expect that intraparenchymal injection can be a more favorable method for cell delivery to the lesion and improvement of the motor function than intravenous infusion. Moreover, it is expected that the bio-imaging techniques can clarify the therapeutic mechanisms.

Trial registration

The trial was registered at The University Hospital Medical Information Network on February 22, 2017 (UNIN ID: UMIN000026130). The findings of this trial will be disseminated to patients and through peer-reviewed publications and international presentations.

Protection of bone marrow, mononuclear, and CD34+ cells by enclosing within the biochemical compound solution during and after transplantation

We have chosen collagen, chitosan acetate, hyaluronic acid, and propolis as model biochemical compound solution to determine the influence of cell carrier mechanics on cell viability and functionality during and after transplantation. Suspending of bone marrow (BM), mononuclear (MN), and CD34+ cells into a biochemical compounds solution is an attractive tool to achieve to protect and ensure reproducible deliver. Hyperglycemic rats were randomly divided into 2 groups: to receive no cell treatment or approximately 1 × 10⁵ of BM, MN, and CD34+ cells within the PBS or biochemical compound solution. These cells were infused into the hyperglycemic rats on day 10 and again on day 20. At each time point, the animals were anaesthetized with ether, and 200 μL of blood was drawn from the tail vein. Samples were collected to determine whether BM, MN, and CD34+ cell affected glucose content and insulin production. Our results exhibit the use of biochemical compound solution method to overcome the cell transplantation problem during and after injection of these cells into rats. These findings are supported by resulting in significantly greater insulin production and more decreased glucose content than cells injected in PBS only (P < 0.05). These effects displayed the following hierarchy: hyaluronic acid > chitosan acetate > collagen > propolis solution. Our results showed that these compounds demonstrated a capacity to encapsulate the BM, MN, and CD34+ cells. It is proven by decreasing glucose content and increasing insulin secretion by pancreatic cells. The uniqueness of our study is the improvement of current transplantation efficiency.

Neural Stem Cell Transplantation Induces Stroke Recovery by Upregulating Glutamate Transporter GLT-1 in Astrocytes

Ischemic stroke is the leading cause of disability, but effective therapies are currently widely lacking. Recovery from stroke is very much dependent on the possibility to develop treatments able to both halt the neurodegenerative process as well as to foster adaptive tissue plasticity. Here we show that ischemic mice treated with neural precursor cell (NPC) transplantation had on neurophysiological analysis, early after treatment, reduced presynaptic release of glutamate within the ipsilesional corticospinal tract (CST), and an enhanced NMDA-mediated excitatory transmission in the contralesional CST. Concurrently, NPC-treated mice displayed a reduced CST degeneration, increased axonal rewiring, and augmented dendritic arborization, resulting in long-term functional amelioration persisting up to 60 d after ischemia. The enhanced functional and structural plasticity relied on the capacity of transplanted NPCs to localize in the peri-ischemic and ischemic area, to promote the upregulation of the glial glutamate transporter 1 (GLT-1) on astrocytes and to reduce peri-ischemic extracellular glutamate. The upregulation of GLT-1 induced by transplanted NPCs was found to rely on the secretion of VEGF by NPCs. Blocking VEGF during the first week after stroke reduced GLT-1 upregulation as well as long-term behavioral recovery in NPC-treated mice. Our results show that NPC transplantation, by modulating the excitatory-inhibitory balance and stroke microenvironment, is a promising therapy to ameliorate disability, to promote tissue recovery and plasticity processes after stroke.

SIGNIFICANCE STATEMENT

Tissue damage and loss of function occurring after stroke can be constrained by fostering plasticity processes of the brain. Over the past years, stem cell transplantation for repair of the CNS has received increasing interest, although underlying mechanism remain elusive. We here show that neural stem/precursor cell transplantation after ischemic stroke is able to foster axonal rewiring and dendritic plasticity and to induce long-term functional recovery. The observed therapeutic effect of neural precursor cells seems to underlie their capacity to upregulate the glial glutamate transporter on astrocytes through the vascular endothelial growth factor inducing favorable changes in the electrical and molecular stroke microenvironment. Cell-based approaches able to influence plasticity seem particularly suited to favor poststroke recovery.

Neural stem cell transplantation in ischemic stroke: A role for preconditioning and cellular engineering

Ischemic stroke continues to be a leading cause of morbidity and mortality throughout the world. To protect and/or repair the ischemic brain, a multitiered approach may be centered on neural stem cell (NSC) transplantation. Transplanted NSCs exert beneficial effects not only via structural replacement, but also via immunomodulatory and/or neurotrophic actions. Unfortunately, the clinical translation of such promising therapies remains elusive, in part due to their limited persistence/survivability within the hostile ischemic microenvironment. Herein, we discuss current approaches for the development of NSCs more amenable to survival within the ischemic brain as a tool for future cellular therapies in stroke.

Human Neural Stem Cell Therapy for Chronic Ischemic Stroke: Charting Progress from Laboratory to Patients

Chronic disability after stroke represents a major unmet neurologic need. ReNeuron's development of a human neural stem cell (hNSC) therapy for chronic disability after stroke is progressing through early clinical studies. A Phase I trial has recently been published, showing no safety concerns and some promising signs of efficacy. A single-arm Phase II multicenter trial in patients with stable upper-limb paresis has recently completed recruitment. The hNSCs administrated are from a manufactured, conditionally immortalized hNSC line (ReNeuron's CTX0E03 or CTX), generated with c-mycER^TAM technology. This technology has enabled CTX to be manufactured at large scale under cGMP conditions, ensuring sufficient supply to meets the demands of research, clinical development, and, eventually, the market. CTX has key pro-angiogenic, pro-neurogenic, and immunomodulatory characteristics that are mechanistically important in functional recovery poststroke. This review covers the progress of CTX cell therapy from its laboratory origins to the clinic, concluding with a look into the late stage clinical future.

Prospects of modeling poststroke epileptogenesis

This Review describes the current status of poststroke epilepsy (PSE) with an emphasis on poststroke epileptogenesis modeling for testing new therapeutic agents. Stroke is a leading cause of epilepsy in an aging population. Late-onset "epileptic" seizures have been reported in up to 30% cases after stroke. Nevertheless, the overall prevalence of PSE is 2-4%. Rodent models of stroke have contributed to our understanding of the relationship between seizures and the underlying ischemic damage to neurons. To understand whether acutely generated stroke events lead to a chronic phenotype more closely resembling PSE with recurrent seizures, a limited variety of approaches emerged in early 2000s. These limited methods of causing an occlusion in mice and rats show different infarct size and neurological deficits. The most often employed procedure for inducing focal ischemia is the middle cerebral artery occlusion. This mimics the pathophysiology seen in humans in terms of extent of damage to cortex and striatum. Photothrombosis and endothelin-1 models can similarly evoke episodes of ischemic stroke. These models are well suited to studying mechanisms and biomarkers of epileptogenesis or optimizing novel drug discoveries. However, modeling of PSE is tedious, is highly variable, and lacks validity; therefore, it is not widely implemented in epilepsy research. Moreover, the relevance of ischemic models to specific forms of human stroke remains unclear. Stroke modeling in young male rodents lacks clinical relevance to elderly populations and especially to women, likely as a result of sex differences. Nevertheless, because of the neuronal damage and epileptogenic insult that these models trigger, they are helpful tools in studying acquired epilepsy and prophylactic drug therapy. © 2016 Wiley Periodicals, Inc.

Intravenously Transplanted Human Bone Marrow Endothelial Progenitor Cells Engraft Within Brain Capillaries, Preserve Mitochondrial Morphology, and Display Pinocytotic Activity Toward Blood-Brain Barrier Repair in Ischemic Stroke Rats

Stroke is a life-threatening disease with limited therapeutic options. Cell therapy has emerged as an experimental stroke treatment. Blood-brain barrier (BBB) impairment is a key pathological manifestation of ischemic stroke, and barrier repair is an innovative target for neurorestoration in stroke. Here, we evaluated via electron microscopy the ability of transplanted human bone marrow endothelial progenitor cells (hBMEPCs) to repair the BBB in adult Sprague-Dawley rats subjected to transient middle cerebral artery occlusion (tMCAO). β-galactosidase prelabeled hBMEPCs were intravenously transplanted 48 hours post-tMCAO. Ultrastructural analysis of microvessels in nontransplant stroke rats revealed typical BBB pathology. At 5 days post-transplantation with hBMEPCs, stroke rats displayed widespread vascular repair in bilateral striatum and motor cortex, characterized by robust cell engraftment within capillaries. hBMEPC transplanted stroke rats exhibited near normal morphology of endothelial cells (ECs), pericytes, and astrocytes, without detectable perivascular edema. Near normal morphology of mitochondria was also detected in ECs and perivascular astrocytes from transplanted stroke rats. Equally notable, we observed numerous pinocytic vesicles within engrafted cells. Robust engraftment and intricate functionality of transplanted hBMEPCs likely abrogated stroke-altered vasculature. Preserving mitochondria and augmenting pinocytosis in cell-based therapeutics represent a new neurorestorative mechanism in BBB repair for stroke. Stem Cells 2017;35:1246-1258.

Niche astrocytes promote the survival, proliferation and neuronal differentiation of co-transplanted neural stem cells following ischemic stroke in rats

Niche astrocytes have been reported to promote neuronal differentiation through juxtacrine signaling. However, the effects of astrocytes on neuronal differentiation following ischemic stroke are not fully understood. In the present study, transplanted astrocytes and neural stem cells (NSCs) were transplanted into the ischemic striatum of transient middle cerebral artery occlusion (MCAO) model rats 48 h following surgery. It was observed that the co-transplantation of astrocytes and NSCs resulted in a higher ratio of survival and proliferation of the transplanted NSCs, and neuronal differentiation, in MCAO rats compared with NSC transplantation alone. These results demonstrate that the co-administration of astrocytes promotes the survival and neuronal differentiation of NSCs in the ischemic brain. These results suggest that the co-transplantation of astrocytes and NSCs is more effective than NSCs alone in the production of neurons following ischemic stroke in rats.

Intraventricular Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells via Ommaya Reservoir in Persistent Vegetative State Patients after Haemorrhagic Stroke: Report of Two Cases & Review of the Literature

Background: One of the most devastating diseases, stroke, is a leading cause of death and disability worldwide with severe emotional and economic consequences. The purpose of this article is mainly to report the effect of intraventricular transplantation via an Ommaya reservoir using autologous bone marrow mesenchymal stem cells (BM-MSCs) in haemorrhagic stroke patients. Case Presentations: Two patients, aged 51 and 52, bearing sequels of haemorrhagic stroke were managed by intraventricular transplantation of BM-MSCs obtained from their own bone marrow. Before the procedure, both patients were bedridden, tracheostomised, on nasogastric (NG) tube feeding and in hemiparesis. The cells were transplanted intraventricularly (20 x 10⁶ cells/2.5 ml) using an Ommaya reservoir, and then repeated transplantations were done after 1 and 2 months consecutively. The safety and efficacy of the procedures were evaluated 3, 6 and 12 months after treatment. The National Institute of Health Stroke Scale (NIHSS) was used to evaluate the patients' neurological status before and after treatment. No adverse events derived from the procedures or transplants were observed in the one-year follow-up period, and the neurological status of both patients improved after treatment. Conclusions: Our report demonstrates that the intraventricular transplantation of BM-MSCs via an Ommaya reservoir is safe and it improves the neurological status of post-haemorrhagic stroke patients. The repeated transplantation procedure is easier and safer to perform via a subcutaneously implanted Ommaya reservoir. Key Words: Haemorrhagic stroke, bone marrow mesenchymal stem cells (BM-MSCs), intraventricular transplantation.

Stichopus japonicus Polysaccharide, Fucoidan, or Heparin Enhanced the SDF-1α/CXCR4 Axis and Promoted NSC Migration via Activation of the PI3K/Akt/FOXO3a Signaling Pathway

Stichopus japonicus Polysaccharide (SJP) is a sulfated polysaccharide from the body wall of the sea cucumber, Stichopus japonicus. Fucoidan is a heparinoid compound that belongs to a family of sulfated polyfucose polysaccharides. Heparin is a glycosaminoglycan. SJP, fucoidan, and heparin profoundly promoted stromal cell-derived factor 1 alpha (SDF-1α)-induced neural stem cell (NSC) migration in a concentration-dependent manner. In addition, the basal migration capacity of cells was significantly promoted after incubation with SJP, fucoidan, or heparin. Interaction of SJP, fucoidan, or heparin with SDF-1α efficiently showed additive effects on the promotion of cell migration from the neurosphere. SJP, fucoidan, or heparin interaction with SDF-1α treatment could increase Nestin expression. SDF-1α modulated by SJP, fucoidan, or heparin activated the CXCR4 receptor and directed cellular migration via the activation of the PI3K/Akt/FOXO3a signaling pathway. Moreover, interaction of SJP, fucoidan, or heparin with SDF-1α effectively promoted NSC migration and induced SDF-1α and CXCR4 expressions. Results suggested that SJP, fucoidan, and heparin might be good candidates for alleviating injury-initiated signals to which NSCs respond.

Intra-arterial delivery of mesenchymal stem cells

While treatments have been developed to combat stroke, such as intravenous recombinant tissue plasminogen activator and endovascular recanalization therapies, their ability to decrease the long-term disability that accompanies stroke is limited. Currently, stem cell research focused on mesenchymal stem cells (MSCs). MSCs are multipotent, nonhematopoietic stem cells found in the stromal fraction of the bone marrow, along with the connective tissue of most organs. MSCs are an increasingly appealing cell source due to the relative ease in which they can be retrieved, developed, and handled in vitro. Despite the fact that numerous paths of stem cell transport to the brain in acute ischemic stroke (AIS) exist, the intra-arterial (IA) route of stem cell transport is most attractive. This is due to its great potential for clinical translation, especially considering the growing clinical application of endovascular treatment for AIS. Here, we evaluate research examining IA delivery of MSCs to the stroke region. The results of the study revealed the maximum tolerated dose and that the optimal time for administration was 24 h, following cerebral ischemia. It is important that future translational studies are performed to establish IA administration of MSCs as a widely used treatment for AIS.

Safety of Intra-Arterial Injection With Tumor-Activated T Cells to the Rabbit Brain Evaluated by MRI and SPECT/CT

Glioblastoma multiforme (GBM) is the most common and most severe form of malignant gliomas. The prognosis is poor with current combinations of pharmaceutical, radiotherapy, and surgical therapy. A continuous search for new treatments has therefore been ongoing for many years. Therapy with tumor-infiltrating lymphocytes (TILs) is a clinically promising strategy to treat various cancers, including GBM. An endovascular intra-arterial injection of TILs as a method of delivery may, instead of intravenous infusion, result in better retention of effector cells within the tumor. Prior to clinical trials of intra-arterial injections with any cells, preclinical safety data with special emphasis on embolic-ischemic events are necessary to obtain. We used native rabbits as a model for intra-arterial injections with routine clinical catheter material and a clinical angiography suite. We selectively infused a total dose of 20 million activated T cells at a cell concentration of 4,000 cells/μl over 8 min of injection time. The rabbits were evaluated for ischemic lesions by 9.4 T magnetic resonance imaging (MRI) (n = 6), and for tracking of injected cells, single-photon emission computed tomography/computed tomography (SPECT/CT) was used (n = 2). In this study, we show that we can selectively infuse activated T cells to a CNS volume of 3.5 cm3 (estimated from the volumetric MRI) without catastrophic embolic-ischemic adverse events. We had one adverse event with a limited basal ganglia infarction, probably due to catheter-induced mechanical occlusion of one of the lateral lenticulostriatal arteries. The cells pass through the native brain without leaving SPECT signals. The cells then, over the first hours, end up in the liver to a large extent and to a lesser degree by the spleen, pancreas, and kidneys. Virtually no uptake could be detected in the lungs. This indicates a difference in biodistribution as opposed to other cell types when infused intravenously.

Combination scaffolds of salmon fibrin, hyaluronic acid, and laminin for human neural stem cell and vascular tissue engineering

Human neural stem/progenitor cells (hNSPCs) are good candidates for treating central nervous system (CNS) trauma since they secrete beneficial trophic factors and differentiate into mature CNS cells; however, many cells die after transplantation. This cell death can be ameliorated by inclusion of a biomaterial scaffold, making identification of optimal scaffolds for hNSPCs a critical research focus. We investigated the properties of fibrin-based scaffolds and their effects on hNSPCs and found that fibrin generated from salmon fibrinogen and thrombin stimulates greater hNSPC proliferation than mammalian fibrin. Fibrin scaffolds degrade over the course of a few days in vivo, so we sought to develop a novel scaffold that would retain the beneficial properties of fibrin but degrade more slowly to provide longer support for hNSPCs. We found combination scaffolds of salmon fibrin with interpenetrating networks (IPNs) of hyaluronic acid (HA) with and without laminin polymerize more effectively than fibrin alone and generate compliant hydrogels matching the physical properties of brain tissue. Furthermore, combination scaffolds support hNSPC proliferation and differentiation while significantly attenuating the cell-mediated degradation seen with fibrin alone. HNSPCs express two fibrinogen-binding integrins, αVβ1 and α5β1, and several laminin binding integrins (α7β1, α6β1, α3β1) that can mediate interaction with the scaffold. Lastly, to test the ability of scaffolds to support vascularization, we analyzed human cord blood-derived endothelial cells alone and in co-culture with hNSPCs and found enhanced vessel formation and complexity in co-cultures within combination scaffolds. Overall, combination scaffolds of fibrin, HA, and laminin are excellent biomaterials for hNSPCs.

STATEMENT OF SIGNIFICANCE

Interest has increased recently in the development of biomaterials as neural stem cell transplantation scaffolds to treat central nervous system (CNS) injury since scaffolds improve survival and integration of transplanted cells. We report here on a novel combination scaffold composed of fibrin, hyaluronic acid, and laminin to support human neural stem/progenitor cell (hNSPC) function. This combined biomaterial scaffold has appropriate physical properties for hNSPCs and the CNS, supports hNSPC proliferation and differentiation, and attenuates rapid cell-mediated scaffold degradation. The hNSPCs and scaffold components synergistically encourage new vessel formation from human endothelial cells. This work marks the first report of a combination scaffold supporting human neural and vascular cells to encourage vasculogenesis, and sets a benchmark for biomaterials to treat CNS injury.

Synergistic and Superimposed Effect of Bone Marrow-Derived Mesenchymal Stem Cells Combined with Fasudil in Experimental Autoimmune Encephalomyelitis

Bone marrow-derived mesenchymal stem cells (MSCs) are the ideal transplanted cells of cellular therapy for promoting neuroprotection and neurorestoration. However, the optimization of transplanted cells and the improvement of microenvironment around implanted cells are still two critical challenges for enhancing therapeutic effect. In the current study, we observed the therapeutic potential of MSCs combined with Fasudil in mouse model of experimental autoimmune encephalomyelitis (EAE) and explored possible mechanisms of action. The results clearly show that combined intervention of MSCs and Fasudil further reduced the severity of EAE compared with MSCs or Fasudil alone, indicating a synergistic and superimposed effect in treating EAE. The addition of Fasudil inhibited MSC-induced inflammatory signaling TLR-4/MyD88 and inflammatory molecule IFN-γ, IL-1β, and TNF-α but did not convert M1 microglia to M2 phenotype. The delivery of MSCs enhanced the expression of glial cell-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) compared with that of Fasudil. Importantly, combined intervention of MSCs and Fasudil further increased the expression of BDNF and GDNF compared with the delivery of MSCs alone, indicating that combined intervention of MSCs and Fasudil synergistically contributes to the expression of neurotrophic factors which should be related to the expression of increased galactocerebroside (GalC) compared with mice treated with Fasudil and MSCs alone. However, a lot of investigation is warranted to further elucidate the cross talk of MSCs and Fasudil in the therapeutic potential of EAE/multiple sclerosis.

The Role of Stem Cells in the Treatment of Cerebral Palsy: a Review

Cerebral palsy (CP) is a neuromuscular disease due to injury in the infant's brain. The CP disorder causes many neurologic dysfunctions in the patient. Various treatment methods have been used for the management of CP disorder. However, there has been no absolute cure for this condition. Furthermore, some of the procedures which are currently used for relief of symptoms in CP cause discomfort or side effects in the patient. Recently, stem cell therapy has attracted a huge interest as a new therapeutic method for treatment of CP. Several investigations in animal and human with CP have demonstrated positive potential of stem cell transplantation for the treatment of CP disorder. The ultimate goal of this therapeutic method is to harness the regenerative capacity of the stem cells causing a formation of new tissues to replace the damaged tissue. During the recent years, there have been many investigations on stem cell therapy. However, there are still many unclear issues regarding this method and high effort is needed to create a technology as a perfect treatment. This review will discuss the scientific background of stem cell therapy for cerebral palsy including evidences from current clinical trials.

Deferoxamine Preconditioning of Neural-Like Cells Derived from Human Wharton's Jelly Mesenchymal Stem Cells as a Strategy to Promote Their Tolerance and Therapeutic Potential: An In Vitro Study

Transplantation of neural-like cells is considered as a promising therapeutic strategy developed for neurodegenerative disease in particular for ischemic stroke. Since cell survival is a major concern following cell implantation, a number of studies have underlined the protective effects of preconditioning with hypoxia or hypoxia mimetic pharmacological agents such as deferoxamine (DFO), induced by activation of hypoxia inducible factor-1 (HIF-1) and its target genes. The present study has investigated the effects of DFO preconditioning on some factors involved in cell survival, angiogenesis, and neurogenesis of neural-like cells derived from human Wharton's jelly mesenchymal stem cells (HWJ-MSCs) in presence of hydrogen peroxide (H2O2). HWJ-MSCs were differentiated toward neural-like cells for 14 days and neural cell markers were identified using immunocytochemistry. HWJ-MSC-derived neural-like cells were then treated with 100 µM DFO, as a known hypoxia mimetic agent for 48 h. mRNA and protein expression of HIF-1 target genes including brain-derived neurotrophic factors (BDNF) and vascular endothelial growth factor (VEGF) significantly increased using RT-PCR and Western blotting which were reversed by HIF-1α inhibitor, while, gene expression of Akt-1, Bcl-2, and Bax did not change significantly but pAkt-1 was up-regulated as compared to poor DFO group. However, addition of H2O2 to DFO-treated cells resulted in higher resistance to H2O2-induced cell death. Western blotting analysis also showed significant up-regulation of HIF-1α, BDNF, VEGF, and pAkt-1, and decrease of Bax/Bcl-2 ratio as compared to poor DFO. These results may suggest that DFO preconditioning of HWJ-MSC-derived neural-like cells improves their tolerance and therapeutic potential and might be considered as a valuable strategy to improve cell therapy.

Biomaterial Applications in Cell-Based Therapy in Experimental Stroke

Stroke is an important health issue corresponding to the second cause of mortality and first cause of severe disability with no effective treatments after the first hours of onset. Regenerative approaches such as cell therapy provide an increase in endogenous brain structural plasticity but they are not enough to promote a complete recovery. Tissue engineering has recently aroused a major interesting development of biomaterials for use into the central nervous system. Many biomaterials have been engineered based on natural compounds, synthetic compounds, or a mix of both with the aim of providing polymers with specific properties. The mechanical properties of biomaterials can be exquisitely regulated forming polymers with different stiffness, modifiable physical state that polymerizes in situ, or small particles encapsulating cells or growth factors. The choice of biomaterial compounds should be adapted for the different applications, structure target, and delay of administration. Biocompatibilities with embedded cells and with the host tissue and biodegradation rate must be considerate. In this paper, we review the different applications of biomaterials combined with cell therapy in ischemic stroke and we explore specific features such as choice of biomaterial compounds and physical and mechanical properties concerning the recent studies in experimental stroke.

Optogenetic modulation in stroke recovery

Stroke is one of the leading contributors to morbidity, mortality, and health care costs in the United States. Although several preclinical strategies have shown promise in the laboratory, few have succeeded in the clinical setting. Optogenetics represents a promising molecular tool, which enables highly specific circuit-level neuromodulation. Here, the conceptual background and preclinical body of evidence for optogenetics are reviewed, and translational considerations in stroke recovery are discussed.

Regenerative cellular therapies for neurologic diseases

The promise of stem cell regeneration has been the hope of many neurologic patients with permanent damage to the central nervous system. There are hundreds of stem cell trials worldwide intending to test the regenerative capacity of stem cells in various neurological conditions from Parkinson's disease to multiple sclerosis. Although no stem cell therapy is clinically approved for use in any human disease indication, patients are seeking out trials and asking clinicians for guidance. This review summarizes the current state of regenerative stem cell transplantation divided into seven conditions for which trials are currently active: demyelinating diseases/spinal cord injury, amyotrophic lateral sclerosis, stroke, Parkinson's disease, Huntington's disease, macular degeneration and peripheral nerve diseases. This article is part of a Special Issue entitled SI: PSC and the brain.

Effects of neural differentiation maturity status of human induced pluripotent stem cells prior to grafting in a subcortical ischemic stroke model

Neural cell grafting is a promising therapy for stroke, but the optimal differentiation status of the cells prior to grafting is unclear. We grafted cells at different maturity stages (days 28, 42, or 56 of in vitro neural differentiation) into the brains of eight-week-old rats one week after subcortical ischemic stroke, and assessed motor and sensory behavioral recovery over one month. We did not find a difference between the grafted or control groups on behavioral recovery, or on brain tissue outcomes including infarct size, microgliosis, or astrocytosis. Further research is needed into mechanisms of benefit of neural cell grafting for stroke.

Access to the brain parenchyma using endovascular techniques and a micro-working channel

OBJECTIVE Several older studies report a low risk for parenchymal access to the CNS by surgical techniques. In more recent studies, including those with post-puncture CT scans, there are indications that the risk of bleeding might approach 8%. New therapies, such as those that use viral vectors, modified mRNA, or cell transplantation, will probably warrant more parenchymal access to the CNS. Other minimally invasive routes might then be tempting to explore. This study was designed in 2 parts to address the possibility of using the endovascular route. The first aim was to test the ability to create a parenchymal micro-working channel to the CNS in macaque monkeys through the vessel wall. Second, the biocompatibility of a device-associated, detached, distal securing plug that was made of nitinol was investigated in swine for 1 year. METHODS Trans-vessel wall intervention in the middle cerebral artery and associated cerebral parenchyma was performed in 4 rhesus macaque monkeys using a full clinical angiography suite. A contrast agent and methylene blue were injected to test the working channel and then detached at the distal end to act as a securing plug through the vessel wall. One-year follow-ups were also performed using angiography and histological analysis in 10 swine with 24 implants that were distributed in the external carotid artery tree. RESULTS The cerebral interventions were performed without acute bleeding. Both the contrast agent and methylene blue were infused into the brain parenchyma and subarachnoidal space via the endovascular micro-working channel (7 injections in 4 animals). In the 1-year follow-up period, the implant that was left in the external carotid vessel wall in the swine was covered by the endothelium, which was followed by dislodgement just outside the blood vessel with thin capsule formation. No stenosis in the artery was detected on 1-year angiography. The animals showed normal behavior and blood sample results during the follow-up period. This is the first histological demonstration of nitinol biocompatibility when the implant is positioned through an arterial wall and indicates that the trans-vessel wall technique is not comparable with stent placement and its ability to induce intimal hyperplasia and restenosis. CONCLUSIONS This study demonstrates that the trans-vessel wall technique is applicable to brain intervention in macaque monkeys, providing a micro-working channel for delivery or sampling. The long-term follow-up study of the detached device in swine showed no clinical or biochemical complications and a normal angiography appearance.

Intravenous Injection of Clinical Grade Human MSCs After Experimental Stroke: Functional Benefit and Microvascular Effect

Stroke is the leading cause of disability in adults. Many current clinical trials use intravenous (IV) administration of human bone marrow-derived mesenchymal stem cells (BM-MSCs). This autologous graft requires a delay for ex vivo expansion of cells. We followed microvascular effects and mechanisms of action involved after an IV injection of human BM-MSCs (hBM-MSCs) at a subacute phase of stroke. Rats underwent a transient middle cerebral artery occlusion (MCAo) or a surgery without occlusion (sham) at day 0 (D0). At D8, rats received an IV injection of 3 million hBM-MSCs or PBS-glutamine. In a longitudinal behavioral follow-up, we showed delayed somatosensory and cognitive benefits 4 to 7 weeks after hBM-MSC injection. In a separate longitudinal in vivo magnetic resonance imaging (MRI) study, we observed an enhanced vascular density in the ischemic area 2 and 3 weeks after hBM-MSC injection. Histology and quantitative polymerase chain reaction (qPCR) revealed an overexpression of angiogenic factors such as Ang1 and transforming growth factor-1 (TGF-1) at D16 in hBM-MSC-treated MCAo rats compared to PBS-treated MCAo rats. Altogether, delayed IV injection of hBM-MSCs provides functional benefits and increases cerebral angiogenesis in the stroke lesion via a release of endogenous angiogenic factors enhancing the stabilization of newborn vessels. Enhanced angiogenesis could therefore be a means of improving functional recovery after stroke.

Brain Recovery after a Plane Crash: Treatment with Growth Hormone (GH) and Neurorehabilitation: A Case Report

The aim of this study is to describe the results obtained after growth hormone (GH) treatment and neurorehabilitation in a young man that suffered a very grave traumatic brain injury (TBI) after a plane crash. Methods: Fifteen months after the accident, the patient was treated with GH, 1 mg/day, at three-month intervals, followed by one-month resting, together with daily neurorehabilitation. Blood analysis at admission showed that no pituitary deficits existed. At admission, the patient presented: spastic tetraplegia, dysarthria, dysphagia, very severe cognitive deficits and joint deformities. Computerized tomography scanners (CT-Scans) revealed the practical loss of the right brain hemisphere and important injuries in the left one. Clinical and blood analysis assessments were performed every three months for three years. Feet surgery was needed because of irreducible equinovarus. Results: Clinical and kinesitherapy assessments revealed a prompt improvement in cognitive functions, dysarthria and dysphagia disappeared and three years later the patient was able to live a practically normal life, walking alone and coming back to his studies. No adverse effects were observed during and after GH administration. Conclusions: These results, together with previous results from our group, indicate that GH treatment is safe and effective for helping neurorehabilitation in TBI patients, once the acute phase is resolved, regardless of whether or not they have GH-deficiency (GHD).

The Synergistic Local Immunosuppressive Effects of Neural Stem Cells Expressing Indoleamine 2,3-Dioxygenase (IDO) in an Experimental Autoimmune Encephalomyelitis (EAE) Animal Model

Neurodegenerative diseases provoke robust immunological reactions in the central nervous system (CNS), which further deteriorate the neural tissue damage. We hypothesized that the expression levels of indoleamine 2,3-dioxygenase (IDO), an enzyme that has potent immune suppressive activities, in neural stem cells (NSCs) would have synergistic therapeutic effects against neurodegenerative diseases, since NSCs themselves have low IDO expression. In this study, the synergistic immune suppressive effects of rat fetal NSCs expressing IDO (rfNSCs-IDO) were validated by mixed leukocyte reaction (MLR) in vitro and an experimental autoimmune encephalomyelitis (EAE) animal model in vivo. rfNSCs-IDO showed significantly more suppressive effects on T cell proliferation in the MLR compared to control rfNSCs (rfNSCs-Cont). Importantly, IDO inhibition using 1-methyl-DL-tryptophan (1-MT), an IDO inhibitor, reversed the synergistic effects, confirming IDO-specific effects in rfNSCs-IDO. In the EAE animal model, systemic rfNSCs-IDO injections resulted in significant local immune suppression in the cervical lymph nodes and CNS, evidenced by a reduction in the number of activated T lymphocytes and an increase in regulatory T cell numbers, which induced significantly fewer clinical symptoms and faster recovery. In contrast, rfNSCs-Cont failed to reduce symptoms in the EAE animal models, although they showed local immune suppression, which was significantly less than that in rfNSCs-IDO. Taken together, IDO expression in NSCs synergistically potentiates the immune suppression activities of NSCs and could be applicable for the development of therapeutic modalities against various neurodegenerative diseases.

Neuronal cell reconstruction with umbilical cord blood cells in the brain hypoxia-ischemia

Background: Brain hypoxia-ischemia is a human neonatal injury that is considered a candidate for stem cell therapy. Methods: The possible therapeutic potential of human umbilical cord blood (HUCB) stem cells was evaluated in 14-day-old rats subjected to the right common carotid occlusion, a model of neonatal brain hypoxia-ischemia. Seven days after hypoxia-ischemia, rats received either saline solution or 4 × 10⁵ HUCB cells i.v. Rats in control group did not receive any injection. After two weeks, rats were assessed using two motor tests. Subsequently, rats were scarified for histological and immunohistochemical analyses. Results: Our immunohistochemical findings demonstrated selective migration of the injected HUCB cells to the ischemic area as well as reduction in infarct volume. Seven days after surgery, we found significant recovery in the behavioral performance in the test group (12.7 +/- 0.3) compared to the sham group (10.0 +/-0.05), a trend which continued to day 14 (15.3 ± 0.3 vs. 11.9 ± 0.5, P<0.05). Postural and motor asymmetries at days 7 and 14 in the test group showed a significant decrease in the percentage of right turns in comparison to the sham group (75% and 59% vs. 97% and 96%, P<0.05). Conclusion: The results show the potential of HUCB stem cells in reduction of neurologic deficits associated with neonatal hypoxia-ischemia.

Pre-differentiation of human neural stem cells into GABAergic neurons prior to transplant results in greater repopulation of the damaged brain and accelerates functional recovery after transient ischemic stroke

INTRODUCTION

Despite attempts to prevent brain injury during the hyperacute phase of stroke, most sufferers end up with significant neuronal loss and functional deficits. The use of cell-based therapies to recover the injured brain offers new hope. In the current study, we employed human neural stem cells (hNSCs) isolated from subventricular zone (SVZ), and directed their differentiation into GABAergic neurons followed by transplantation to ischemic brain.

METHODS

Pre-differentiated GABAergic neurons, undifferentiated SVZ-hNSCs or media alone were stereotaxically transplanted into the rat brain (n=7/group) 7 days after endothelin-1 induced stroke. Neurological outcome was assessed by neurological deficit scores and the cylinder test. Transplanted cell survival, cellular phenotype and maturation were assessed using immunohistochemistry and confocal microscopy.

RESULTS

Behavioral assessments revealed accelerated improvements in motor function 7 days post-transplant in rats treated with pre-differentiated GABAergic cells in comparison to media alone and undifferentiated hNSC treated groups. Histopathology 28 days-post transplant indicated that pre-differentiated cells maintained their GABAergic neuronal phenotype, showed evidence of synaptogenesis and up-regulated expression of both GABA and calcium signaling proteins associated with neurotransmission. Rats treated with pre-differentiated cells also showed increased neurogenic activity within the SVZ at 28 days, suggesting an additional trophic role of these GABAergic cells. In contrast, undifferentiated SVZ-hNSCs predominantly differentiated into GFAP-positive astrocytes and appeared to be incorporated into the glial scar.

CONCLUSION

Our study is the first to show enhanced exogenous repopulation of a neuronal phenotype after stroke using techniques aimed at GABAergic cell induction prior to delivery that resulted in accelerated and improved functional recovery.

Neuroprotective Strategies after Neonatal Hypoxic Ischemic Encephalopathy

Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating disease that primarily causes neuronal and white matter injury and is among the leading cause of death among infants. Currently there are no well-established treatments; thus, it is important to understand the pathophysiology of the disease and elucidate complications that are creating a gap between basic science and clinical translation. In the development of neuroprotective strategies and translation of experimental results in HIE, there are many limitations and challenges to master based on an appropriate study design, drug delivery properties, dosage, and use in neonates. We will identify understudied targets after HIE, as well as neuroprotective molecules that bring hope to future treatments such as melatonin, topiramate, xenon, interferon-beta, stem cell transplantation. This review will also discuss some of the most recent trials being conducted in the clinical setting and evaluate what directions are needed in the future.

Targeting the vasculature to improve neural progenitor transplant survival

Neural progenitor transplantation is a promising therapeutic option for several neurological diseases and injuries. In nearly all human clinical trials and animal models that have tested this strategy, the low survival rate of progenitors after engraftment remains a significant challenge to overcome. Developing methods to improve the survival rate will reduce the number of cells required for transplant and will likely enhance functional improvements produced by the procedure. Here we briefly review the close relationship between the blood vasculature and neural progenitors in both the embryo and adult nervous system. We also discuss previous studies that have explored the role of the vasculature and hypoxic pre-conditioning in neural transplants. From these studies, we suggest that hypoxic pre-conditioning of a progenitor pool containing both neural and endothelial cells will improve engrafted transplanted neuronal survival rates.

Robust neuroprosthetic control from the stroke perilesional cortex

Intracortical brain-machine interfaces (BMIs) may eventually restore function in those with motor disability after stroke. However, current research into the development of intracortical BMIs has focused on subjects with largely intact cortical structures, such as those with spinal cord injury. Although the stroke perilesional cortex (PLC) has been hypothesized as a potential site for a BMI, it remains unclear whether the injured motor cortical network can support neuroprosthetic control directly. Using chronic electrophysiological recordings in a rat stroke model, we demonstrate here the PLC's capacity for neuroprosthetic control and physiological plasticity. We initially found that the perilesional network demonstrated abnormally increased slow oscillations that also modulated neural firing. Despite these striking abnormalities, neurons in the perilesional network could be modulated volitionally to learn neuroprosthetic control. The rate of learning was surprisingly similar regardless of the electrode distance from the stroke site and was not significantly different from intact animals. Moreover, neurons achieved similar task-related modulation and, as an ensemble, formed cell assemblies with learning. Such control was even achieved in animals with poor motor recovery, suggesting that neuroprosthetic control is possible even in the absence of motor recovery. Interestingly, achieving successful control also reduced locking to abnormal oscillations significantly. Our results thus suggest that, despite the disrupted connectivity in the PLC, it may serve as an effective target for neuroprosthetic control in those with poor motor recovery after stroke.

Excess Integrins Cause Lung Entrapment of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are largely entrapped in the lungs after intravenous delivery. The underlying mechanisms have been poorly understood. Flow cytometry and Western blot analysis showed that the expression levels of many integrins such as β1, α5, and αVβ3 in MSCs increased markedly upon cultured expansion in 2D monolayers, whose ligands fibronectin and vitronectin were detected on the surface of vascular endothelial cells in the lungs by immunostaining and flow cytometry. Blockade of integrin β1, integrin α5, or integrins αVβ3 with functional blocking antibodies significantly decreased the amount of MSCs entrapped in the lungs following intravenous infusion as determined by real-time PCR and histological analysis; meanwhile, corresponding increases in the levels of circulating MSCs in the blood and MSCs homed to the ischemic myocardium and inflamed ear were found. Intriguingly, a short period of 3D spheroid culture of MSCs, which had been expanded for several passages in monolayers, substantially reduced the expression levels of many integrins and the number of MSCs entrapped in the lungs. Our results indicate that the excess expression and activation of integrins is a significant cause of lung entrapment of MSCs.

Isolation of Human Neural Stem Cells from the Amniotic Fluid with Diagnosed Neural Tube Defects

Human neural stem cells (NSCs) are particularly valuable for the study of neurogenesis process and have a therapeutic potential in treating neurodegenerative disorders. However, current progress in the use of human NSCs is limited due to the available NSC sources and the complicated isolation and culture techniques. In this study, we describe an efficient method to isolate and propagate human NSCs from the amniotic fluid with diagnosed neural tube defects (NTDs), specifically, anencephaly. These amniotic fluid-derived NSCs (AF-NSCs) formed neurospheres and underwent long-term expansion in vitro. In addition, these cells showed normal karyotypes and telomerase activity and expressed NSC-specific markers, including Nestin, Sox2, Musashi-1, and the ATP-binding cassette G2 (ABCG2). AF-NSCs displayed typical morphological patterns and expressed specific markers that were consistent with neurons, astrocytes, oligodendrocytes, and dopaminergic neurons after proper induction conditions. Furthermore, grafted AF-NSCs improved the physiological functions in a rat stroke model. The ability to isolate and bank human NSCs from this novel source provides a unique opportunity for translational studies of neurological disorders.

Neurorehabilitation: motor recovery after stroke as an example

The field of neurorehabilitation aims to translate neuroscience research toward the goal of maximizing functional recovery after neurological injury. A growing body of research indicates that the fundamental principles of neurological rehabilitation are applicable to a broad range of congenital, degenerative, and acquired neurological disorders. In this perspective, we will focus on motor recovery after acquired brain injuries such as stroke. Over the past few decades, a large body of basic and clinical research has created an experimental and theoretical foundation for approaches to neurorehabilitation. Recent randomized clinical trials all emphasize the requirement for intense progressive rehabilitation programs to optimally enhance recovery. Moreover, advances in multimodal assessment of patients with neuroimaging and neurophysiological tools suggest the possibility of individualized treatment plans based on recovery potential. There are also promising indications for medical as well as noninvasive brain stimulation paradigms to facilitate recovery. Ongoing or planned clinical studies should provide more definitive evidence. We also highlight unmet needs and potential areas of research. Continued research built upon a robust experimental and theoretical foundation should help to develop novel treatments to improve recovery after neurological injury.

Stem cell therapy in intracerebral hemorrhage rat model

Intracerebral hemorrhage (ICH) is a very complex pathology, with many different not fully elucidated etiologies and prognostics. It is the most severe subtype of stroke, with high mortality and morbidity rates. Unfortunately, despite the numerous promising preclinical assays including neuroprotective, anti-hypertensive, and anti-inflammatory drugs, to this moment only symptomatic treatments are available, motivating the search for new alternatives. In this context, stem cell therapy emerged as a promising tool. However, more than a decade has passed, and there is still much to be learned not only about stem cells, but also about ICH itself, and how these two pieces come together. To date, rats have been the most widely used animal model in this research field, and there is much more to be learned from and about them. In this review, we first summarize ICH epidemiology, risk factors, and pathophysiology. We then present different methods utilized to induce ICH in rats, and examine how accurately they represent the human disease. Next, we discuss the different types of stem cells used in previous ICH studies, also taking into account the tested transplantation sites. Finally, we summarize what has been achieved in assays with stem cells in rat models of ICH, and point out some relevant issues where attention must be given in future efforts.

Intra-arterial transplantation of low-dose stem cells provides functional recovery without adverse effects after stroke

Cell transplantation therapy for cerebral infarction has emerged as a promising treatment to reduce brain damage and enhance functional recovery. We previously reported that intra-arterial delivery of bone marrow mesenchymal stem cells (MSCs) enables superselective cell administration to the infarct area and results in significant functional recovery after ischemic stroke in a rat model. However, to reduce the risk of embolism caused by the transplanted cells, an optimal cell number should be determined. At 24 h after middle cerebral artery occlusion and reperfusion, we administered human MSCs (low dose: 1 × 10(4) cells; high dose: 1 × 10(6) cells) and then assessed functional recovery, inflammatory responses, cell distribution, and mortality. Rats treated with high- or low-dose MSCs showed behavioral recovery. At day 8 post-stroke, microglial activation was suppressed significantly, and interleukin (IL)-1β and IL-12p70 were reduced in both groups. Although high-dose MSCs were more widely distributed in the cortex and striatum of rats, the degree of intravascular cell aggregation and mortality was significantly higher in the high-dose group. In conclusion, selective intra-arterial transplantation of low-dose MSCs has anti-inflammatory effects and reduces the adverse effects of embolic complication, resulting in sufficient functional recovery of the affected brain.

Intranasal delivery of hypoxia-preconditioned bone marrow-derived mesenchymal stem cells enhanced regenerative effects after intracerebral hemorrhagic stroke in mice

Intracerebral hemorrhagic stroke (ICH) causes high mortality and morbidity with very limited treatment options. Cell-based therapy has emerged as a novel approach to replace damaged brain tissues and promote regenerative processes. In this study we tested the hypothesis that intranasally delivered hypoxia-preconditioned BMSCs could reach the brain, promote tissue repair and improve functional recovery after ICH. Hemorrhagic stroke was induced in adult C57/B6 mice by injection of collagenase IV into the striatum. Animals were randomly divided into three groups: sham group, intranasal BMSC treatment group, and vehicle treatment group. BMSCs were pre-treated with hypoxic preconditioning (HP) and pre-labeled with Hoechst before transplantation. Behavior tests, including the mNSS score, rotarod test, adhesive removal test, and locomotor function evaluation were performed at varying days, up to 21days, after ICH to evaluate the therapeutic effects of BMSC transplantation. Western blots and immunohistochemistry were performed to analyze the neurotrophic effects. Intranasally delivered HP-BMSCs were identified in peri-injury regions. NeuN+/BrdU+ co-labeled cells were markedly increased around the hematoma region, and growth factors, including BDNF, GDNF, and VEGF were significantly upregulated in the ICH brain after BMSC treatment. The BMSC treatment group showed significant improvement in behavioral performance compared with the vehicle group. Our data also showed that intranasally delivered HP-BMSCs migrated to peri-injury regions and provided growth factors to increase neurogenesis after ICH. We conclude that intranasal administration of BMSC is an effective treatment for ICH, and that it enhanced neuroregenerative effects and promoted neurological functional recovery after ICH. Overall, the investigation supports the potential therapeutic strategy for BMSC transplantation therapy against hemorrhagic stroke.

Cord blood for brain injury

Recovery from neurological injuries is typically incomplete and often results in significant and permanent disabilities. Currently, most available therapies are limited to supportive or palliative measures, aimed at managing the symptoms of the condition. Because restorative therapies targeting the underlying cause of most neurological diseases do not exist, cell therapies targeting anti-inflammatory, neuroprotective and regenerative potential hold great promise. Cord blood (CB) cells can induce repair through mechanisms that involve trophic or cell-based paracrine effects or cellular integration and differentiation. Both may be operative in emerging CB therapies for neurologic conditions, and there are numerous potential applications of CB-based regenerative therapies in neurological diseases, including genetic diseases of childhood, ischemic events such as stroke and neurodegenerative diseases of adulthood. CB appears to hold promise as an effective therapy for patients with brain injuries. In this Review, we describe the state of science and clinical applications of CB therapy for brain injury.

Therapeutic effects of human multilineage-differentiating stress enduring (MUSE) cell transplantation into infarct brain of mice

OBJECTIVE

Bone marrow stromal cells (BMSCs) are heterogeneous and their therapeutic effect is pleiotropic. Multilineage-differentiating stress enduring (Muse) cells are recently identified to comprise several percentages of BMSCs, being able to differentiate into triploblastic lineages including neuronal cells and act as tissue repair cells. This study was aimed to clarify how Muse and non-Muse cells in BMSCs contribute to functional recovery after ischemic stroke.

METHODS

Human BMSCs were separated into stage specific embryonic antigen-3-positive Muse cells and -negative non-Muse cells. Immunodeficient mice were subjected to permanent middle cerebral artery occlusion and received transplantation of vehicle, Muse, non-Muse or BMSCs (2.5×104 cells) into the ipsilateral striatum 7 days later.

RESULTS

Motor function recovery in BMSC and non-Muse groups became apparent at 21 days after transplantation, but reached the plateau thereafter. In Muse group, functional recovery was not observed for up to 28 days post-transplantation, but became apparent at 35 days post-transplantation. On immunohistochemistry, only Muse cells were integrated into peri-infarct cortex and differentiate into Tuj-1- and NeuN-expressing cells, while negligible number of BMSCs and non-Muse cells remained in the peri-infarct area at 42 days post-transplantation.

CONCLUSIONS

These findings strongly suggest that Muse cells and non-Muse cells may contribute differently to tissue regeneration and functional recovery. Muse cells may be more responsible for replacement of the lost neurons through their integration into the peri-infarct cortex and spontaneous differentiation into neuronal marker-positive cells. Non-Muse cells do not remain in the host brain and may exhibit trophic effects rather than cell replacement.