Enhancement of angiogenesis and neurogenesis by intracerebroventricular injection of secretome from human embryonic stem cell-derived mesenchymal stem cells in ischemic stroke model

Mechanism of inflammatory response and therapeutic effects of stem cells in ischemic stroke: current evidence and future perspectives

Ischemic stroke is a leading cause of death and disability worldwide, with an increasing trend and tendency for onset at a younger age. China, in particular, bears a high burden of stroke cases. In recent years, the inflammatory response after stroke has become a research hotspot: understanding the role of inflammatory response in tissue damage and repair following ischemic stroke is an important direction for its treatment. This review summarizes several major cells involved in the inflammatory response following ischemic stroke, including microglia, neutrophils, monocytes, lymphocytes, and astrocytes. Additionally, we have also highlighted the recent progress in various treatments for ischemic stroke, particularly in the field of stem cell therapy. Overall, understanding the complex interactions between inflammation and ischemic stroke can provide valuable insights for developing treatment strategies and improving patient outcomes. Stem cell therapy may potentially become an important component of ischemic stroke treatment.

Potential Mechanism and Perspectives of Mesenchymal Stem Cell Therapy for Ischemic Stroke: A Review

Mesenchymal stem cells (MSCs), as a stem cell type with multiple differentiation potentials and immune regulatory abilities, have shown broad prospects in the treatment of ischemic stroke in recent years. The main characteristics of MSCs include their self-renewal ability, differentiation potential for different types of cells, and the ability to secrete various bioactive factors such as cytokines, chemokines, and growth factors, which play a key role in tissue repair and regeneration. In the treatment of ischemic stroke, MSCs exert therapeutic effects through various mechanisms, including promoting vascular regeneration of damaged brain tissue, reducing inflammatory responses, and protecting neurons from damage caused by apoptosis. Research have shown that MSCs can promote the repair of ischemic areas by releasing neurotrophic factors and angiogenic factors, while inhibiting immune responses triggered by ischemia, thereby improving neurological function. With the in-depth study of its biological mechanism, MSCs have gradually shown good safety and effectiveness in clinical applications. Therefore, fully exploring and utilizing the potential of MSCs in the treatment of ischemic stroke may provide new ideas and solutions for future neural repair and regenerative medicine.

Research progress and challenges of stem cell therapy for ischemic stroke

Ischemic stroke is a significant global cause of death and disability. Currently, treatment options for acute ischemic stroke are limited to intravenous thrombolysis and mechanical recanalization. Therefore, novel neuroprotective strategies are imperative. Stem cell transplantation possesses the capabilities of differentiation, proliferation, neuronal replacement, nerve pathway reconstruction, secretion of nerve growth factors, and enhancement of the microenvironment; thus, it is a potential therapeutic approach for ischemic stroke. In addition, the immunomodulatory function of stem cells and the combined treatment of stem cells and exosomes exhibit a favorable protective effect on brain injury and neurological dysfunction following stroke. Meanwhile, the theory of microbiota-gut-brain axis provides us with a novel perspective for comprehending and managing neurological diseases. Lastly, stem cell transplantation has demonstrated promising outcomes not only in treating ischemic stroke but also in dealing with other neurological disorders, such as brain tumors. Furthermore, challenges related to the tissue source, delivery method, immune response, and timing of transplantation still need to be addressed to optimize the treatment.

The Therapeutic Effects of Blueberry-Treated Stem Cell-Derived Extracellular Vesicles in Ischemic Stroke

An ischemic stroke, one of the leading causes of morbidity and mortality, is caused by ischemia and hemorrhage resulting in impeded blood supply to the brain. According to many studies, blueberries have been shown to have a therapeutic effect in a variety of diseases. Therefore, in this study, we investigated whether blueberry-treated mesenchymal stem cell (MSC)-derived extracellular vesicles (B-EVs) have therapeutic effects in in vitro and in vivo stroke models. We isolated the extracellular vesicles using cryo-TEM and characterized the particles and concentrations using NTA. MSC-derived extracellular vesicles (A-EVs) and B-EVs were round with a lipid bilayer structure and a diameter of ~150 nm. In addition, A-EVs and B-EVs were shown to affect angiogenesis, cell cycle, differentiation, DNA repair, inflammation, and neurogenesis following KEGG pathway and GO analyses. We investigated the protective effects of A-EVs and B-EVs against neuronal cell death in oxygen-glucose deprivation (OGD) cells and a middle cerebral artery occlusion (MCAo) animal model. The results showed that the cell viability was increased with EV treatment in HT22 cells. In the animal, the size of the cerebral infarction was decreased, and the behavioral assessment was improved with EV injections. The levels of NeuN and neurofilament heavy chain (NFH)-positive cells were also increased with EV treatment yet decreased in the MCAo group. In addition, the number of apoptotic cells was decreased with EV treatment compared with ischemic animals following TUNEL and Bax/Bcl-2 staining. These data suggested that EVs, especially B-EVs, had a therapeutic effect and could reduce apoptotic cell death after ischemic injury.

Intermittent theta burst stimulation combined with cognitive training improves cognitive dysfunction and physical dysfunction in patients with post-stroke cognitive impairment

OBJECTIVE

Post-stroke cognitive impairment (PSCI) is a common complication of stroke. Intermittent theta burst stimulation (iTBS) can inducing motor learning. We observed the effects of combination of iTBS with cognitive training on physical/cognitive dysfunctions in PSCI patients.

METHODS

PSCI patients treated with basic treatment & cognitive training (Control group)/iTBS & cognitive training (iTBS group) were enrolled, with Mini-mental State Examination (MMSE)/Montreal Cognitive Assessment (MoCA)/Frontal Assessment Battery (FAB)/barthel index (BI)/Upper Limb Fugl-Meyer Assessment (U-FMA)/Action Research Arm Test (ARAT) scores compared. Gait spatiotemporal parameters/dynamic parameters were analyzed by 3D gait analysis. Correlations between MMSE/MoCA scores and gait parameters in PSCI patients after iTBS & cognitive training were analyzed by Spearman analysis.

RESULTS

Increased MMSE/MoCA/FAB/BI/U-FMA/ARAT scores, step speed, step frequency, stride length, step width, step length on the affected side, percentage of swing phase on the affected side, hip joint flexion angle on the affected side, knee joint flexion angle on the affected side, and ankle plantar flexion angle on the affected side and reduced gait period on the affected side and percentage of stance phase on the affected side were found in patients of both groups after treatment, with the effects in the iTBS group more profound.

CONCLUSION

iTBS & cognitive training obviously improved the cognitive function scores/upper limb function scores/gait parameters in PSCI patients versus cognitive training treatment. After combination therapy, the MMSE/MoCA scores of PSCI patients were significantly correlated with gait parameters. This provided more data support for iTBS & cognitive training application in the rehabilitation treatment of PSCI patients.

Therapeutic gene delivery by mesenchymal stem cell for brain ischemia damage: Focus on molecular mechanisms in ischemic stroke

Cerebral ischemic damage is prevalent and the second highest cause of death globally across patient populations; it is as a substantial reason of morbidity and mortality. Mesenchymal stromal cells (MSCs) have garnered significant interest as a potential treatment for cerebral ischemic damage, as shown in ischemic stroke, because of their potent intrinsic features, which include self-regeneration, immunomodulation, and multi-potency. Additionally, MSCs are easily obtained, isolated, and cultured. Despite this, there are a number of obstacles that hinder the effectiveness of MSC-based treatment, such as adverse microenvironmental conditions both in vivo and in vitro. To overcome these obstacles, the naïve MSC has undergone a number of modification processes to enhance its innate therapeutic qualities. Genetic modification and preconditioning modification (with medications, growth factors, and other substances) are the two main categories into which these modification techniques can be separated. This field has advanced significantly and is still attracting attention and innovation. We examine these cutting-edge methods for preserving and even improving the natural biological functions and therapeutic potential of MSCs in relation to adhesion, migration, homing to the target site, survival, and delayed premature senescence. We address the use of genetically altered MSC in stroke-induced damage. Future strategies for improving the therapeutic result and addressing the difficulties associated with MSC modification are also discussed.

Periplaneta Americana (L.) extract activates the ERK/CREB/BDNF pathway to promote post-stroke neuroregeneration and recovery of neurological functions in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Periplaneta americana (L.) (PA) has been used in traditional Chinese medicine for thousands of years for the effect of invigorating blood circulation and removing blood stasis. Modern pharmacological research shown that PA extract exhibits promising effects in promoting wound healing and regeneration, as well as in brain diseases such as Parkinson's disease (PD). However, whether it is effective for neuroregeneration and neurological function recovery after stroke still unknown.

AIM OF THE STUDY

This study aims to investigate the potential effect of PA extract to promote brain remodeling through the activation of endogenous neurogenesis and angiogenesis, in addition, preliminary exploration of its regulatory mechanism.

METHODS

Firstly, BrdU proliferation assay and immunofluorescence (IF) staining were used to evaluate the effect of PA extract on the neurogenesis and angiogenesis in vitro and in vivo. Subsequently, the effects of PA extract on brain injury in stroke rats were assessed by TTC and HE. While mNSS score, adhesive removal test, rota-rod test, and morris water maze test were used to assess the impact of PA extract on neurological function in post-stroke rats. Finally, the molecular mechanisms of PA extract regulation were explored by RNA-Seq and western blotting.

RESULTS

The number of BrdU+ cells in C17.2 cells, NSCs and BMECs dramatically increased, as well as the expression of astrocyte marker protein GFAP and neuronal marker protein Tuj-1 in C17.2 and NSCs. Moreover, PA extract also increased the number of BrdU+DCX+, BrdU+GFAP+, BrdU+CD31+ cells in the SGZ area of transient middle cerebral artery occlusion model (tMCAO) rats. TTC and HE staining revealed that PA extract significantly reduced the infarction volume and ameliorated the pathological damage. Behavioral tests demonstrated that treatment with PA extract reduced the mNSS score and the time required to remove adhesive tape, while increasing the time spent on the rotarod. Additionally, in the morris water maze test, the frequency of crossing platform and the time spent in the platform quadrant increased. Finally, RNA-Seq and Western blot revealed that PA extract increased the expression of p-ERK, p-CREB and BDNF. Importantly, PA extract mediated proliferation and differentiation of C17.2 and NSCs reversed by the ERK inhibitor SCH772984 and the BDNF inhibitor ANA-12, respectively.

CONCLUSION

Our study demonstrated that PA extract promoted neurogenesis and angiogenesis by activating the CREB/ERK signaling pathway and upregulating BDNF expression, thereby recovering neurological dysfunction in post-stroke.

Enhancing regenerative medicine: the crucial role of stem cell therapy

Stem cells offer new therapeutic avenues for the repair and replacement of damaged tissues and organs owing to their self-renewal and multipotent differentiation capabilities. In this paper, we conduct a systematic review of the characteristics of various types of stem cells and offer insights into their potential applications in both cellular and cell-free therapies. In addition, we provide a comprehensive summary of the technical routes of stem cell therapy and discuss in detail current challenges, including safety issues and differentiation control. Although some issues remain, stem cell therapy demonstrates excellent potential in the field of regenerative medicine and provides novel tactics and methodologies for managing a wider spectrum of illnesses and traumas.

Efficacy and safety of mesenchymal stem cells in patients with acute ischemic stroke: a meta-analysis

OBJECTIVE

This meta-analysis and systematic review were conducted to comprehensively evaluate the efficacy and safety of mesenchymal stem cells in patients with acute ischemic stroke.

METHOD

We conducted a manual search of electronic databases, including PubMed, Embase, the Cochrane Library, and Web of Science, with a search deadline set for February 1, 2023. Data analysis was performed using Stata version 15.0.

RESULT

A total of 9 randomized controlled studies were included, involving a total of 316 people, including 159 mesenchymal stem cells and 147 control groups. Results of meta-analysis: Compared to a placebo group, the administration of mesenchymal stem cells resulted in a significant reduction in the National Institutes of Health Stroke Scale (NIHSS) scores among patients diagnosed with acute ischemic stroke [SMD=-0.99,95% CI (-1.93, -0.05)]. Compared to placebo, barthel index [SMD = 0.48,95% CI (-0.55,1.51)], modified rankin score [SMD = 0.45, 95% CI (1.11, 0.21)], adverse events (RR = 0.68, 95% CI (0.40, 1.17)] the difference was not statistically significant.

CONCLUSION

Based on current studies, mesenchymal stem cell transplantation can ameliorate neurological deficits in patients with ischemic stroke to a certain extent without increasing adverse reactions. However, there was no significant effect on Barthel index and Modified Rankin score.

Therapeutic and Safety Promise of Mesenchymal Stem Cells for Liver Failure: From Preclinical Experiment to Clinical Application

Liver failure (LF) is serious liver damage caused by multiple factors, resulting in severe impairment or decompensation of liver synthesis, detoxification, metabolism, and biotransformation. The general prognosis of LF is poor with high mortality in non-transplant patients. The clinical treatments for LF are mainly internal medicine comprehensive care, artificial liver support system, and liver transplantation. However, none of the above treatment strategies can solve the problems of all liver failure patients and has its own limitations. Mesenchymal stem cells (MSCs) are a kind of stem cells with multidirectional differentiation potential and paracrine function, which play an important role in immune regulation and tissue regeneration. In recent years, MSCs have shown multiple advantages in the treatment of LF in pre-clinical experiments and clinical trials. In this work, we reviewed the biological characteristics of MSCs, the possible molecular mechanisms of MSCs in the treatment of liver failure, animal experiments, and clinical application, and also discussed the existing problems of MSCs in the treatment of liver failure.

Secretome as a Tool to Treat Neurological Conditions: Are We Ready?

Due to their characteristics, mesenchymal stem cells (MSCs) are considered a potential therapy for brain tissue injury or degeneration. Nevertheless, despite the promising results observed, there has been a growing interest in the use of cell-free therapies in regenerative medicine, such as the use of stem cell secretome. This review provides an in-depth compilation of data regarding the secretome composition, protocols used for its preparation, as well as existing information on the impact of secretome administration on various brain conditions, pointing out gaps and highlighting relevant findings. Moreover, due to the ability of MSCs to respond differently depending on their microenvironment, preconditioning of MSCs has been used to modulate their composition and, consequently, their therapeutic potential. The different strategies used to modulate the MSC secretome were also reviewed. Although secretome administration was effective in improving functional impairments, regeneration, neuroprotection, and reducing inflammation in brain tissue, a high variability in secretome preparation and administration was identified, compromising the transposition of preclinical data to clinical studies. Indeed, there are no reports of the use of secretome in clinical trials. Despite the existing limitations and lack of clinical data, secretome administration is a potential tool for the treatment of various diseases that impact the CNS.

Signaling pathways in brain ischemia: Mechanisms and therapeutic implications

Ischemic stroke occurs when the arteries supplying blood to the brain are narrowed or blocked, inducing damage to brain tissue due to a lack of blood supply. One effective way to reduce brain damage and alleviate symptoms is to reopen blocked blood vessels in a timely manner and reduce neuronal damage. To achieve this, researchers have focused on identifying key cellular signaling pathways that can be targeted with drugs. These pathways include oxidative/nitrosative stress, excitatory amino acids and their receptors, inflammatory signaling molecules, metabolic pathways, ion channels, and other molecular events involved in stroke pathology. However, evidence suggests that solely focusing on protecting neurons may not yield satisfactory clinical results. Instead, researchers should consider the multifactorial and complex mechanisms underlying stroke pathology, including the interactions between different components of the neurovascular unit. Such an approach is more representative of the actual pathological process observed in clinical settings. This review summarizes recent research on the multiple molecular mechanisms and drug targets in ischemic stroke, as well as recent advances in novel therapeutic strategies. Finally, we discuss the challenges and future prospects of new strategies based on the biological characteristics of stroke.

Oleoylethanolamide ameliorates motor dysfunction through PPARα-mediates oligodendrocyte differentiation and white matter integrity after ischemic stroke

BACKGROUND AND AIM

Our previous study has revealed that OEA promotes motor function recovery in the chronic stage of ischemic stroke. However, the neuroprotective mechanism of OEA on motor function recovery after stroke still is unexplored. Therefore, the aim of this study was to explore the effects of OEA treatment on angiogenesis, neurogenesis, and white matter repair in the peri-infarct region after cerebral ischemia.

EXPERIMENTAL PROCEDURE

The adult male rats were subjected to 2 h of middle cerebral artery occlusion. The rats were treated with 10 and 30 mg/kg OEA or vehicle daily starting from day 2 after ischemia induction until they were sacrificed.

KEY RESULTS AND CONCLUSIONS

The results revealed that OEA increased cortical angiogenesis, neural progenitor cells (NPCs) proliferation, migration, and differentiation. OEA treatment enhanced the survival of newborn neurons and oligodendrogenesis, which eventually repaired the cortical neuronal injury and improved motor function after ischemic stroke. Meanwhile, OEA treatment promoted the differentiation of oligodendrocyte progenitor cells (OPCs) and oligodendrogenesis by activating the PPARα signaling pathway. Our results showed that OEA restores motor function by facilitating cortical angiogenesis, neurogenesis, and white matter repair in rats after ischemic stroke. Therefore, we demonstrate that OEA facilitates functional recovery after ischemic stroke and propose the hypothesis that the long-term application of OEA mitigates the disability after stroke.

Hypoxic Extracellular Matrix Preserves Its Competence after Expansion of Human MSCs under Physiological Hypoxia In Vitro

Tissue-relevant O2 levels are considered as an important tool for the preconditioning of multipotent mesenchymal stromal cells (MSCs) for regenerative medicine needs. The present study investigated the quality and functions of the extracellular matrix (ECM) of MSCs under low O2 levels. Human adipose tissue-derived MSCs were continuously expanded under normoxia (20% O2, N) or "physiological" hypoxia (5% O2, Hyp). Decellularized ECM (dcECM) was prepared. The structure of the dcECM was analyzed using confocal laser and scanning electron microscopy. Collagen, dcECM-N, and dcECM-Hyp were recellularized with MSC-N and further cultured at normoxia. The efficacy of adhesion, spreading, growth, osteogenic potential, and paracrine activity of recellularized MSC-N were evaluated. At low O2, the dcECM showed an increased alignment of fibrillar structures and provided accelerated spreading of MSC-N, indicating increased dcECM-Hyp stiffness. We described O2-dependent "ECM-education" of MSC-N when cultured on dcECM-Hyp. This was manifested as attenuated spontaneous osteo-commitment, increased susceptibility to osteo-induction, and a shift in the paracrine profile. It has been suggested that the ECM after physiological hypoxia is able to ensure the maintenance of a low-commitment state of MSCs. DcECM, which preserves the competence of the natural microenvironment of cells and is capable of "educating" others, appears to be a prospective tool for guiding cell modifications for cell therapy and tissue engineering.

Crocetin Regulates Functions of Neural Stem Cells to Generate New Neurons for Cerebral Ischemia Recovery

Many neurons undergo apoptosis after ischemic stroke. In the brain, neurogenesis has the potential for neuronal replacement and can be activated by external conditions to repair the injury. Crocetin (CRO), naturally extracted from the plant saffron, acts as a neuroprotective agent for ischemic stroke. However, the underlying mechanism remains unknown. In this work, the effect of CRO on neural stem cell (NSC) behaviors and subventricular zone neurogenesis is investigated. Initially, NSCs are incubated with different concentrations of CRO to detect the cell proliferation and differentiation in vitro. Second, ischemic stroke induced rats are treated with CRO using nimodipine (NMDP) as a comparison. The behavioral functions, infarcted volume, and apoptotic Nissl bodies of rats are noticeably improved after CRO-treatment, comparable to those of NMDP. In addition, the increased regional cerebral blood flow and promoted neuronal differentiation are achieved by CRO-treatment. Brain tissue examination shows significantly increased neuronal regeneration in the focal ischemic injury area. Meanwhile, the length of neurites is prolonged, indicating that CRO could potentially promote neurite extension to enhance cell-cell communication. These findings demonstrate that CRO facilitated the neuronal differentiation of NSCs by activating subventricular zone neurogenesis in damaged cortex and striatum sites to repair ischemic stroke.

Micro-Fragmented Adipose Tissue as a Natural Scaffold for Targeted Drug Delivery in Brain Cancer

Major limitations in the effective treatment of neurological cancer include systemic cytotoxicity of chemotherapy, inaccessibility, and inoperability. The capability to successfully target a drug to the tumor site(s) without incurring serious side effects-especially in the case of aggressive tumors, such as glioblastoma and neuroblastoma-would represent a significant breakthrough in therapy. Orthotopic systems, capable of storing and releasing proteins over a prolonged period at the site of a tumor, that utilize nanoparticles, liposomes, and hydrogels have been proposed. One candidate for drug delivery is Micro-Fragmented Adipose Tissue (MFAT). Easily obtained from the patient by abdominal subcutaneous liposuction (autologous), and with a high content of Mesenchymal Stem Cells (MSCs), mechanically derived nanofat is a natural tissue graft with a structural scaffold organization. It has a well-preserved stromal vascular fraction and a prolonged capacity to secrete anti-tumorigenic concentrations of pre-absorbed chemotherapeutics within extracellular vesicles. This review discusses current evidence supporting the potential of drug-modified MFAT for the treatment of neurological cancer with respect to recent preclinical and in vitro studies. Possible limitations and future perspectives are considered.

Angiogenesis after ischemic stroke

Owing to its high disability and mortality rates, stroke has been the second leading cause of death worldwide. Since the pathological mechanisms of stroke are not fully understood, there are few clinical treatment strategies available with an exception of tissue plasminogen activator (tPA), the only FDA-approved drug for the treatment of ischemic stroke. Angiogenesis is an important protective mechanism that promotes neural regeneration and functional recovery during the pathophysiological process of stroke. Thus, inducing angiogenesis in the peri-infarct area could effectively improve hemodynamics, and promote vascular remodeling and recovery of neurovascular function after ischemic stroke. In this review, we summarize the cellular and molecular mechanisms affecting angiogenesis after cerebral ischemia registered in PubMed, and provide pro-angiogenic strategies for exploring the treatment of ischemic stroke, including endothelial progenitor cells, mesenchymal stem cells, growth factors, cytokines, non-coding RNAs, etc.

Transplantation of Exercise-Induced Extracellular Vesicles as a Promising Therapeutic Approach in Ischemic Stroke

Clinical evidence affirms physical exercise is effective in preventive and rehabilitation approaches for ischemic stroke. This sustainable efficacy is independent of cardiovascular risk factors and associates substantial reprogramming in circulating extracellular vesicles (EVs). The intricate journey of pluripotent exercise-induced EVs from parental cells to the whole-body and infiltration to cerebrovascular entity offers several mechanisms to reduce stroke incidence and injury or accelerate the subsequent recovery. This review delineates the potential roles of EVs as prospective effectors of exercise. The candidate miRNA and peptide cargo of exercise-induced EVs with both atheroprotective and neuroprotective characteristics are discussed, along with their presumed targets and pathway interactions. The existing literature provides solid ground to hypothesize that the rich vesicles link exercise to stroke prevention and rehabilitation. However, there are several open questions about the exercise stressors which may optimally regulate EVs kinetic and boost brain mitochondrial adaptations. This review represents a novel perspective on achieving brain fitness against stroke through transplantation of multi-potential EVs generated by multi-parental cells, which is exceptionally reachable in an exercising body.

Genomic Interplay between Neoneurogenesis and Neoangiogenesis in Carcinogenesis: Therapeutic Interventions

Angiogenesis, the generation of new blood vessels, is one of the hallmarks of cancer. The growing tumor requires nutrients and oxygen. Recent evidence has shown that tumors release signals to attract new nerve fibers and stimulate the growth of new nerve fibers. Neurogenesis, neural extension, and axonogenesis assist in the migration of cancer cells. Cancer cells can use both blood vessels and nerve fibers as routes for cells to move along. In this way, neurogenesis and angiogenesis both contribute to cancer metastasis. As a result, tumor-induced neurogenesis joins angiogenesis and immunosuppression as aberrant processes that are exacerbated within the tumor microenvironment. The relationship between these processes contributes to cancer development and progression. The interplay between these systems is brought about by cytokines, neurotransmitters, and neuromodulators, which activate signaling pathways that are common to angiogenesis and the nervous tissue. These include the AKT signaling pathways, the MAPK pathway, and the Ras signaling pathway. These processes also both require the remodeling of tissues. The interplay of these processes in cancer provides the opportunity to develop novel therapies that can be used to target these processes.

Metal protoporphyrin-induced self-assembly nanoprobe enabling precise tracking and antioxidant protection of stem cells for ischemic stroke therapy

Mesenchymal stem cell (MSC)-based therapy has provided a promising strategy for the treatment of ischemic stroke, which is still restricted by the lack of long-term cell tracking strategy as well as the poor survival rate of stem cells in ischemic region. Herein, a dual-functional nanoprobe, cobalt protoporphyrin-induced nano-self-assembly (CPSP), has been developed through a cobalt protoporphyrin IX (CoPP) aggregation-induced self-assembly strategy, which combines CoPP and superparamagnetic iron oxide (SPION) via a simple solvent evaporation-driven method. Without any additional carrier materials, the obtained CPSP is featured with good biocompatibility and high proportions of active ingredients. The SPIONs in CPSPs form a cluster-like structure, endowing this nano-self-assembly with excellent T2-weighted magnetic resonance (MR) imaging performance. Furthermore, the CoPP released from CPSPs could effectively protect MSCs by upregulating heme oxygenase 1 (HO-1) expression. The in vivo cell tracing capacity of CPSPs is confirmed by monitoring the migration of labeled MSCs with MR imaging in a middle cerebral artery occlusion mouse model. More importantly, the sustained release of CoPP from CPSPs improves the survival of transplanted MSCs and promotes neural repair and neurobehavioral recovery of ischemic mice. Overall, this work presents a novel dual-functional nanoagent with an ingenious design for advancing MSC-based therapy.

Neuroprotective Effects of Conditioned Medium of Mesenchymal Stem Cells (MSC-CM) as a Therapy for Ischemic Stroke Recovery: A Systematic Review

It has been reported that the therapeutic potential of stem cells is mainly mediated by their paracrine factors. In order to identify the effects of conditioned medium of mesenchymal stem cells (MSC-CM) against stroke, a systematic review was conducted. We searched PubMed, Scopus, and ISI Web of Science databases for all available articles relevant to the effects of MSC-CM against the middle cerebral artery occlusion (MCAO) model of ischemic stroke until August 2022. The quality of the included studies was evaluated using The STAIR scale. During the systematic search, a total of 356 published articles were found. A total of 15 datasets were included following screening for eligibility. The type of cerebral ischemia was the MCAO model and CM was obtained from MSCs. The results showed that the therapeutic time window can be considered a crucial factor when researchers use MSC-CM for stroke therapy. In addition, MSC-CM therapy contributes to functional recovery and reduces infarct volume after stroke by targeting different cellular signaling pathways. Our findings showed that MSC-CM therapy has the ability to improve functional recovery and attenuate brain infarct volume after ischemic stroke in preclinical studies. We hope our study accelerates needed progress towards clinical trials.

Paracrine Effects of Mesenchymal Stem Cells in Ischemic Stroke: Opportunities and Challenges

It is well acknowledged that neuroprotective effects of transplanted mesenchymal stem cells (MSCs) in ischemic stroke are attributed to their paracrine-mediated actions or bystander effects rather than to cell replacement in infarcted areas. This therapeutic plasticity is due to MSCs' ability to secrete a broad range of bioactive molecules including growth factors, trophic factors, cytokines, chemokines, and extracellular vesicles, overall known as the secretome. The secretome derivatives, such as conditioned medium (CM) or purified extracellular vesicles (EVs), exert remarkable advantages over MSC transplantation in stroke treating. Here, in this review, we used published information to provide an overview on the secretome composition of MSCs, underlying mechanisms of therapeutic effects of MSCs, and preclinical studies on MSC-derived products application in stroke. Furthermore, we discussed current advantages and challenges for successful bench-to-bedside translation.

Molecular mediators of angiogenesis and neurogenesis after ischemic stroke

The mechanisms governing neurological and functional recovery after ischemic stroke are incompletely understood. Recent advances in knowledge of intrinsic repair processes of the CNS have so far translated into minimal improvement in outcomes for stroke victims. Better understanding of the processes underlying neurological recovery after stroke is necessary for development of novel therapeutic approaches. Angiogenesis and neurogenesis have emerged as central mechanisms of post-stroke recovery and potential targets for therapeutics. Frameworks have been developed for conceptualizing cerebral angiogenesis and neurogenesis at the tissue and cellular levels. These models highlight that angiogenesis and neurogenesis are linked to each other and to functional recovery. However, knowledge of the molecular framework linking angiogenesis and neurogenesis after stroke is limited. Studies of potential therapeutics typically focus on one mediator or pathway with minimal discussion of its role within these multifaceted biochemical processes. In this article, we briefly review the current understanding of the coupled processes of angiogenesis and neurogenesis after stroke. We then identify the molecular mediators and signaling pathways found in pre-clinical studies to upregulate both processes after stroke and contextualizes them within the current framework. This report thus contributes to a more-unified understanding of the molecular mediators governing angiogenesis and neurogenesis after stroke, which we hope will help guide the development of novel therapeutic approaches for stroke survivors.

Long-term administration of salvianolic acid A promotes endogenous neurogenesis in ischemic stroke rats through activating Wnt3a/GSK3β/β-catenin signaling pathway

Stroke is the major cause of death and disability worldwide. Most stroke patients who survive in the acute phase of ischemia display various extents of neurological deficits. In order to improve the prognosis of ischemic stroke, promoting endogenous neurogenesis has attracted great attention. Salvianolic acid A (SAA) has shown neuroprotective effects against ischemic diseases. In the present study, we investigated the neurogenesis effects of SAA in ischemic stroke rats, and explored the underlying mechanisms. An autologous thrombus stroke model was established by electrocoagulation. The rats were administered SAA (10 mg/kg, ig) or a positive drug edaravone (5 mg/kg, iv) once a day for 14 days. We showed that SAA administration significantly decreased infarction volume and vascular embolism, and ameliorated pathological injury in the hippocampus and striatum as well as the neurological deficits as compared with the model rats. Furthermore, we found that SAA administration significantly promoted neural stem/progenitor cells (NSPCs) proliferation, migration and differentiation into neurons, enhanced axonal regeneration and diminished neuronal apoptosis around the ipsilateral subventricular zone (SVZ), resulting in restored neural density and reconstructed neural circuits in the ischemic striatum. Moreover, we revealed that SAA-induced neurogenesis was associated to activating Wnt3a/GSK3β/β-catenin signaling pathway and downstream target genes in the hippocampus and striatum. Edaravone exerted equivalent inhibition on neuronal apoptosis in the SVZ, as SAA, but edaravone-induced neurogenesis was weaker than that of SAA. Taken together, our results demonstrate that long-term administration of SAA improves neurological function through enhancing endogenous neurogenesis and inhibiting neuronal apoptosis in ischemic stroke rats via activating Wnt3a/GSK3β/β-catenin signaling pathway. SAA may be a potential therapeutic drug to promote neurogenesis after stroke.

Conditioned Medium of Human Pluripotent Stem Cell-Derived Neural Precursor Cells Exerts Neurorestorative Effects against Ischemic Stroke Model

Previous studies have shown that early therapeutic events of neural precursor cells (NPCs) transplantation to animals with acute ischemic stroke readily protected neuronal cell damage and improved behavioral recovery through paracrine mechanisms. In this study, we tested the hypothesis that administration of conditioned medium from NPCs (NPC-CMs) could recapitulate the beneficial effects of cell transplantation. Rats with permanent middle cerebral artery occlusion (pMCAO) were randomly assigned to one of the following groups: PBS control, Vehicle (medium) controls, single (NPC-CM(S)) or multiple injections of NPC-CM(NPC-CM(M)) groups. A single intravenous injection of NPC-CM exhibited strong neuroregenerative potential to induce behavioral recovery, and multiple injections enhanced this activity further by suppressing inflammatory damage and inducing endogenous neurogenesis leading to histopathological and functional recovery. Proteome analysis of NPC-CM identified a number of proteins that are known to be associated with nervous system development, neurogenesis, and angiogenesis. In addition, transcriptome analysis revealed the importance of the inflammatory response during stroke recovery and some of the key hub genes in the interaction network were validated. Thus, our findings demonstrated that NPC-CM promoted functional recovery and reduced cerebral infarct and inflammation with enhanced endogenous neurogenesis, and the results highlighted the potency of NPC-CM in stroke therapy.

Hippocampal neuroprotection mediated by secretome of human mesenchymal stem cells against experimental stroke

Aims

Regenerative medicine literature has demonstrated that the therapeutic potentials of mesenchymal stem cells (MSCs) in experimental stroke are attributed to secreted bioactive factors rather than to cell replacement. Here, we explored the effects of secretome or conditioned medium (CM) derived from human embryonic stem cell‐derived MSCs (hESC‐MSCs) on hippocampal neurogenesis, inflammation, and apoptosis in experimental stroke.

Methods

Ischemic stroke was induced by right middle cerebral artery occlusion (MCAO) in male Wistar rats, and CM was infused either one time (1‐h post‐stroke; CM1) or three times (1‐, 24‐, and 48‐h post‐stroke; CM3) into left lateral ventricle. Neurogenesis markers (Nestin, Ki67, Doublecortin, and Reelin) were assessed at transcript and protein levels in the dentate gyrus of the hippocampus on day seven following MCAO. In parallel, changes in the gene expression of markers of apoptosis (Bax and Bim, as well as an anti‐apoptotic marker of Bcl2), inflammation (IL‐1β and IL‐6, as well as IL‐10 as an anti‐inflammatory cytokine), trophic factors (BDNF, GDNF, NGF, and NT‐3), and angiogenesis (CD31 and VEGF) in the hippocampus were assessed.

Results

Our results demonstrate that CM3 treatment could stimulate neurogenesis and angiogenesis concomitant with inhibition of inflammation, apoptosis, and neuronal loss in ischemic brains. Furthermore, rats treated with CM3 exhibited upregulation in neurotrophic factors.

Conclusion

Our results suggest that hESC‐MSC‐CM could promote neurogenesis and protect brain tissue from ischemic injury, partly mediated by induction of angiogenesis and neurotrophic factors and inhibition of inflammatory and apoptotic factors expression.

Acupuncture at GV20 and ST36 Improves the Recovery of Behavioral Activity in Rats Subjected to Cerebral Ischemia/Reperfusion Injury

Traditional acupuncture and electroacupuncture (EA) have been widely performed to treat ischemic stroke. To provide experimental support for the clinical application of acupuncture to ameliorate post-stroke sequelae, in this study, we investigated the therapeutic effect of acupuncture and EA on CIRI following middle cerebral artery occlusion (MCAO) in rats. The animals were randomly divided into five groups: sham-operated (S), model (M), traditional acupuncture (A) treatment, electroacupuncture (EA) treatment, and drug (D; edaravone) therapies. Neurological behavioral characteristics (neurological deficit score, forelimb muscle strength, sensorimotor function, body symmetry, sucrose consumption, and mood) were examined in all the groups on days 1, 3, 5, and 7 after reperfusion. Expressions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) were detected by immunohistochemistry. Both acupuncture and EA significantly reduced neurological deficits and improved forelimb muscle strength, sensorimotor function, body symmetry recovery, and neurovascular regeneration in the rats after ischemia/reperfusion injury. The efficacies of both acupuncture and EA were comparable to that of edaravone, a commonly used medicine for stroke in the clinic. Thus, our data suggest that acupuncture and EA therapy at acupoints GV20 and ST36 might represent alternative or complementary treatments to the conventional management of ischemic stroke, providing additional support for the experimental evidence for acupuncture therapy in clinical settings. In summary, EA might provide alternative or complementary treatment strategies for treating patients with apoplexy in the clinic. However, potential mechanisms underlying the role of acupuncture require further investigation.

Ischemic Brain Stroke and Mesenchymal Stem Cells: An Overview of Molecular Mechanisms and Therapeutic Potential

Ischemic brain injury is associated with a high rate of mortality and disability with no effective therapeutic strategy. Recently, a growing number of studies are focusing on mesenchymal stem cell-based therapies for neurodegenerative disorders. However, despite having the promising outcome of preclinical studies, the clinical application of stem cell therapy remained elusive due to little or no progress in clinical trials. The objective of this study was to provide a generalized critique for the role of mesenchymal stem cell therapy in ischemic stroke injury, its underlying mechanisms, and constraints on its preclinical and clinical applications. Thus, we attempted to present an overview of previously published reports to evaluate the progress and provide molecular basis of mesenchymal stem cells (MSCs) therapy and its application in preclinical and clinical settings, which could aid in designing an effective regenerative therapeutic strategy in the future.

The Angiogenesis Effects Of Electro-acupuncture Treatment Via Exosomal miR-210 In Cerebral Ischemia-Reperfusion Rats

BACKGROUND

Acupuncture has been recommended as an alternative and complementary therapy for preventing and treating cerebral ischemia by the World Health Organization (WHO) for years. However, the mechanisms remain unclear. Accumulating evidence has shown that acupuncture can promote angiogenesis to attenuate brain damage after ischemic stroke. In recent years, exosome-carried microRNAs(miRNAs) activated by acupuncture has proven effective in regulating pathological changes. We, therefore, investigated whether electro-acupuncture(EA) enhanced angiogenesis in cerebral stroke via exosome-carried miR-210.

METHODS

We extracted and identified the exosomes from the serum of MCAO with EA treatment and injected them in MCAO rats for further observation. Simultaneously, miR-120 siRNA and HIF-1α inhibitor were transfected. Then, we evaluated the volume of infarction, pathological changes, and expression levels of angiogenic related factors of each group of rats by TTC and HE staining, transmission electron microscope(TEM), western blot, and quantitative PCR(qPCR).

RESULTS

Compared with the MCAO group, EA-Exosome(EA-EXO) treatment significantly decreased the infarct volume and the pathological damage, but miR-210 siRNA or HIF-1α inhibitor reversed the protective outcomes induced by EA-EXO. Moreover, EA-EXO treatment upregulated miR-210, and increases CD34、HIF-1α、VEGF、Notch1 protein and mRNA expressions compared with the MCAO group. MiR-210 siRNA or HIF-1α inhibitor treatments both down-regulated those angiogenic related proteins and mRNAs.

CONCLUSION

EA treatment could active the HIF-1α/VEGF/Notch 1 signal pathway to facilitate angiogenesis after ischemic stroke via exosomal miR-210.

Xenograft of Human Umbilical Mesenchymal Stem Cells Promotes Recovery from Chronic Ischemic Stroke in Rats

Stroke is a leading cause of adult disability. In our previous study, transplantation of human umbilical mesenchymal stem cells (HUMSCs) in Wharton’s jelly in the acute phase of ischemic stroke promotes recovery in rats. Unfortunately, there is no cure for chronic stroke. Patients with chronic stroke can only be treated with rehabilitation or supportive interventions. This study aimed to investigate the potential of xenograft of HUMSCs for treating chronic stroke in rats. Rats were subjected to 90 min middle cerebral artery occlusion and then reperfusion to mimic ischemic cerebral stroke. On day 14 following stroke, HUMSCs were transplanted into the damaged cerebral cortex. The motor function in rats of the Stroke + HUMSCs group exhibited significant improvement compared to that of the Stroke + Saline group, and the trend persisted until day 56 post stroke. The cerebral cortex changes were tracked using magnetic resonance imaging, showing that cerebral atrophy was found starting on day 7 and was reduced significantly in rats receiving HUMSCs compared to that in the Stroke + Saline group from day 21 to day 56. HUMSCs were found to be existed in the rats’ cerebral cortex on day 56, with signs of migration. The grafted HUMSCs did not differentiate into neurons or astrocytes and may release cytokines to improve neuroprotection, decrease inflammation and increase angiogenesis. Our results demonstrate that xeno-transplantation of HUMSCs has therapeutic benefits for chronic ischemic stroke. Most importantly, patients do not need to use their own HUMSCs, which is a gospel thing for clinical patients.

Enriched Environment and Exercise Enhance Stem Cell Therapy for Stroke, Parkinson’s Disease, and Huntington’s Disease

Stem cells, specifically embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), induced pluripotent stem cells (IPSCs), and neural progenitor stem cells (NSCs), are a possible treatment for stroke, Parkinson’s disease (PD), and Huntington’s disease (HD). Current preclinical data suggest stem cell transplantation is a potential treatment for these chronic conditions that lack effective long-term treatment options. Finding treatments with a wider therapeutic window and harnessing a disease-modifying approach will likely improve clinical outcomes. The overarching concept of stem cell therapy entails the use of immature cells, while key in recapitulating brain development and presents the challenge of young grafted cells forming neural circuitry with the mature host brain cells. To this end, exploring strategies designed to nurture graft-host integration will likely enhance the reconstruction of the elusive neural circuitry. Enriched environment (EE) and exercise facilitate stem cell graft-host reconstruction of neural circuitry. It may involve at least a two-pronged mechanism whereby EE and exercise create a conducive microenvironment in the host brain, allowing the newly transplanted cells to survive, proliferate, and differentiate into neural cells; vice versa, EE and exercise may also train the transplanted immature cells to learn the neurochemical, physiological, and anatomical signals in the brain towards better functional graft-host connectivity.

Montelukast suppresses the development of irritable bowel syndrome phenotype possibly through modulating NF-κB signaling in an experimental model

Irritable bowel syndrome (IBS) is a functional gut disorder with multi-factorial pathophysiology that causes recurring pain or discomfort in the abdomen, as well as altered bowel habits. Montelukast, a well-known cysteinyl leukotriene receptor 1 (CysLT1R) antagonist, is widely used for the anti-inflammatory management of asthma. The present study aimed to evaluate the effects of pharmacological inhibition of CysLT1R on acetic acid-induced diarrhea-predominant IBS (D-IBS) in rats. Behavioral pain responses to noxious mechanical stimulation were decreased in the montelukast-treated rats as compared to the model animals following colorectal distension (CRD)-induced visceral hypersensitivity. Stool frequency decreased dose-dependently by montelukast in IBS rats exposed to restraint stress. A significantly shorter immobility time was also observed in IBS rats who received montelukast vs IBS group in the forced swimming test (depression-like behavior). Furthermore, there were significant decreases in the NF-κB protein expression, inflammatory cytokine (TNF-α, and IL-1ß) levels, and histopathological inflammatory injuries concomitant with increased anti-inflammatory cytokine, IL-10, in montelukast-treated rats compared with the IBS group. Cysteinyl leukotriene production and CysLT1R mRNA expression showed no remarkable differences among the experimental groups. The present results suggest the possible beneficial effects of montelukast in the management of D-IBS symptoms. The molecular mechanism underlying such effects, at least to some extent, might be through modulating CysLT1R-mediated NF-κB signaling. Yet, more studies are required to demonstrate the clinical potential of this drug for IBS therapy.

Human pluripotent stem cell-derived ectomesenchymal stromal cells promote more robust functional recovery than umbilical cord-derived mesenchymal stromal cells after hypoxic-ischaemic brain damage

Aims: Hypoxic-ischaemic encephalopathy (HIE) is one of the most serious complications in neonates and infants. Mesenchymal stromal cell (MSC)-based therapy is emerging as a promising treatment avenue for HIE. However, despite its enormous potential, the clinical application of MSCs is limited by cell heterogeneity, low isolation efficiency and unpredictable effectiveness. In this study, we examined the therapeutic effects and underlying mechanisms of human pluripotent stem cell-derived ectomesenchymal stromal cells (hPSC-EMSCs) in a rat model of HIE.

Methods: hPSC-EMSCs were induced from either human embryonic stem cells or induced pluripotent stem cells. Stem cells or the conditioned medium (CM) derived from stem cells were delivered intracranially or intranasally to neonatal rats with HIE. Human umbilical cord-derived MSCs (hUC-MSCs) were used as the therapeutic comparison control and phosphate-buffered saline (PBS) was used as a negative control. Lesion size, apoptosis, neurogenesis, astrogliosis and microgliosis were evaluated. The rotarod test and Morris water maze were used to determine brain functional recovery. The PC-12 cell line, rat primary cortical neurons and neural progenitor cells were used to evaluate neurite outgrowth and the neuroprotective and neurogenesis effects of hPSC-EMSCs/hUC-MSCs. RNA-seq and enzyme-linked immunosorbent assays were used to determine the secretory factors that were differentially expressed between hPSC-EMSCs and hUC-MSCs. The activation and suppression of extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB) were characterised using western blotting and immunofluorescent staining.

Results: hPSC-EMSCs showed a higher neuroprotective potential than hUC-MSCs, as demonstrated by a more significant reduction in lesion size and apoptosis in the rat brain following hypoxia-ischaemia (HI). Compared with PBS treatment, hPSC-EMSCs promoted endogenous neurogenesis and alleviated astrogliosis and microgliosis. hPSC-EMSCs were more effective than hUC-MSCs. hPSC-EMSCs achieved a greater recovery of brain function than hUC-MSCs and PBS in rats with HIE. CM derived from hPSC-EMSCs had neuroprotective and neurorestorative effects in vitro through anti-apoptotic and neurite outgrowth- and neurogenesis-promoting effects. Direct comparisons between hPSC-EMSCs and hUC-MSCs revealed the significant enrichment of a group of secretory factors in hPSC-EMSCs, including nerve growth factor (NGF), platelet-derived growth factor-AA and transforming growth factor-β₂, which are involved in neurogenesis, synaptic transmission and neurotransmitter transport, respectively. Mechanistically, the CM derived from hPSC-EMSCs was found to potentiate NGF-induced neurite outgrowth and the neuronal differentiation of NPCs via the ERK/CREB pathway. Suppression of ERK or CREB abolished CM-potentiated neuritogenesis and neuronal differentiation. Finally, intranasal delivery of the CM derived from hPSC-EMSCs significantly reduced brain lesion size, promoted endogenous neurogenesis, mitigated inflammatory responses and improved functional recovery in rats with HIE.

Conclusion: hPSC-EMSCs promote functional recovery after HI through multifaceted neuromodulatory activities via paracrine/trophic mechanisms. We propose the use of hPSC-EMSCs for the treatment of HIE, as they offer an excellent unlimited cellular source of MSCs.

Application of mesenchymal stem cells derived from human pluripotent stem cells in regenerative medicine

Mesenchymal stem cells (MSCs) represent the most clinically used stem cells in regenerative medicine. However, due to the disadvantages with primary MSCs, such as limited cell proliferative capacity and rarity in the tissues leading to limited MSCs, gradual loss of differentiation during in vitro expansion reducing the efficacy of MSC application, and variation among donors increasing the uncertainty of MSC efficacy, the clinical application of MSCs has been greatly hampered. MSCs derived from human pluripotent stem cells (hPSC-MSCs) can circumvent these problems associated with primary MSCs. Due to the infinite self-renewal of hPSCs and their differentiation potential towards MSCs, hPSC-MSCs are emerging as an attractive alternative for regenerative medicine. This review summarizes the progress on derivation of MSCs from human pluripotent stem cells, disease modelling and drug screening using hPSC-MSCs, and various applications of hPSC-MSCs in regenerative medicine. In the end, the challenges and concerns with hPSC-MSC applications are also discussed.

Human amniotic fluid stem cells can improve cerebral vascular remodelling and neurological function after focal cerebral ischaemia in diabetic rats

Diabetes causes vascular injury and carries a high risk of ischaemic stroke. Human amniotic fluid stem cells (hAFSCs) can enhance cerebral vascular remodelling and have the potential to improve neurological function after stroke in diabetic rats. Five groups of female rats were examined: (1) normal control, (2) type 1 diabetic (T1DM) rats induced by streptozotocin injection (DM), (3) non‐DM rats receiving 60‐minute middle cerebral artery occlusion (MCAO), (4) T1DM rats receiving 60‐minute MCAO (DM + MCAO) and (5) T1DM rats receiving 60‐minute MCAO and injection with 5 × 10⁶ hAFSCs at 3 h after MCAO (DM + MCAO + hAFSCs). Neurological function was examined before, and at 1, 7, 14, 21 and 28 days, and cerebral infarction volume and haemorrhage, cerebral vascular density, angiogenesis and inflammatory were examined at 7 and 28 days after MCAO. hAFSCs treatment caused a significant improvement of neurological dysfunction, infarction volume, blood‐brain barrier leakage, cerebral arterial density, vascular density and angiogenesis and a reduction of brain haemorrhage and inflammation compared with non‐treatment. Our results showed that the effect of hAFSCs treatment against focal cerebral ischaemia may act through the recovery of vascular remodelling and angiogenesis and the reduction of inflammation in ischaemic brain.

Combination of Stem Cells and Rehabilitation Therapies for Ischemic Stroke

Stem cell transplantation with rehabilitation therapy presents an effective stroke treatment. Here, we discuss current breakthroughs in stem cell research along with rehabilitation strategies that may have a synergistic outcome when combined together after stroke. Indeed, stem cell transplantation offers a promising new approach and may add to current rehabilitation therapies. By reviewing the pathophysiology of stroke and the mechanisms by which stem cells and rehabilitation attenuate this inflammatory process, we hypothesize that a combined therapy will provide better functional outcomes for patients. Using current preclinical data, we explore the prominent types of stem cells, the existing theories for stem cell repair, rehabilitation treatments inside the brain, rehabilitation modalities outside the brain, and evidence pertaining to the benefits of combined therapy. In this review article, we assess the advantages and disadvantages of using stem cell transplantation with rehabilitation to mitigate the devastating effects of stroke.