Stem cell transplantation for ischemic stroke

Ginsenoside CK cooperates with bone mesenchymal stem cells to enhance angiogenesis post-stroke via GLUT1 and HIF-1α/VEGF pathway

The transplantation of bone marrow mesenchymal stem cells (MSCs) in stroke is hindered by the restricted rates of survival and differentiation. Ginsenoside compound K (CK), is reported to have a neuroprotective effect and regulate energy metabolism. We applied CK to investigate if CK could promote the survival of MSCs and differentiation into brain microvascular endothelial-like cells (BMECs), thereby alleviating stroke symptoms. Therefore, transwell and middle cerebral artery occlusion (MCAO) models were used to mimic oxygen and glucose deprivation (OGD) in vitro and in vivo, respectively. Our results demonstrated that CK had a good affinity for GLUT1, which increased the expression of GLUT1 and the production of ATP, facilitated the proliferation and migration of MSCs, and activated the HIF-1α/VEGF signaling pathway to promote MSC differentiation. Moreover, CK cooperated with MSCs to protect BMECs, promote angiogenesis and vascular density, enhance neuronal and astrocytic proliferation, thereby reducing infarct volume and consequently improving neurobehavioral outcomes. These results suggest that the synergistic effects of CK and MSCs could potentially be a promising strategy for stroke.

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.

Metabolomic discoveries for early diagnosis and traditional Chinese medicine efficacy in ischemic stroke

Ischemic stroke (IS), a devastating cerebrovascular accident, presents with high mortality and morbidity. Following IS onset, a cascade of pathological changes, including excitotoxicity, inflammatory damage, and blood-brain barrier disruption, significantly impacts prognosis. However, current clinical practices struggle with early diagnosis and identifying these alterations. Metabolomics, a powerful tool in systems biology, offers a promising avenue for uncovering early diagnostic biomarkers for IS. By analyzing dynamic metabolic profiles, metabolomics can not only aid in identifying early IS biomarkers but also evaluate Traditional Chinese Medicine (TCM) efficacy and explore its mechanisms of action in IS treatment. Animal studies demonstrate that TCM interventions modulate specific metabolite levels, potentially reflecting their therapeutic effects. Identifying relevant metabolites in cerebral ischemia patients holds immense potential for early diagnosis and improved outcomes. This review focuses on recent metabolomic discoveries of potential early diagnostic biomarkers for IS. We explore variations in metabolites observed across different ages, genders, disease severity, and stages. Additionally, the review examines how specific TCM extracts influence IS development through metabolic changes, potentially revealing their mechanisms of action. Finally, we emphasize the importance of integrating metabolomics with other omics approaches for a comprehensive understanding of IS pathophysiology and TCM efficacy, paving the way for precision medicine in IS management.

Exploring Research Trend and Hotspots on Oxidative Stress in Ischemic Stroke (2001-2022): Insights from Bibliometric

Oxidative stress is widely involved in the pathological process of ischemic stroke and ischemia-reperfusion. Several research have demonstrated that eliminating or reducing oxidative stress can alleviate the pathological changes of ischemic stroke. However, current clinical antioxidant treatment did not always perform as expected. This bibliometric research aims to identify research trends, topics, hotspots, and evolution on oxidative stress in the field of ischemic stroke, and to find potentially antioxidant strategies in future clinical treatment. Relevant publications were searched from the Web of Science (WOS) Core Collection databases (2001-2022). VOSviewer was used to visualize and analyze the development trends and hotspots. In the field of oxidative stress and ischemic stroke, the number of publications increased significantly from 2001 to 2022. China and the USA were the leading countries for publication output. The most prolific institutions were Stanford University. Journal of Cerebral Blood Flow and Metabolism and Stroke were the most cited journals. The research topics in this field include inflammation with oxidative stress, mitochondrial damage with oxidative stress, oxidative stress in reperfusion injury, oxidative stress in cognitive impairment and basic research and clinical translation of oxidative stress. Moreover, "NLRP3 inflammasome," "autophagy," "mitophagy," "miRNA," "ferroptosis," and "signaling pathway" are the emerging research hotspots in recent years. At present, multi-target regulation focusing on multi-mechanism crosstalk has progressed across this period, while challenges come from the transformation of basic research to clinical application. New detection technology and new nanomaterials are expected to integrate oxidative stress into the clinical treatment of ischemic stroke better.

Stem Cell Treatment and Cerebral Palsy: A Systematic Review and Meta-Analysis

OBJECTIVE

We designed this systematic review and meta-analysis to estimate the pooled efficacy and safety profile of different types of stem cells in treating patients with cerebral palsy (CP).

METHODS

We systematically searched PubMed, Scopus, EMBASE, Web of Science, Google Scholar, and also gray literature, including references of the included studies which were published before November 2021. We extracted data regarding the total number of participants, first author, publication year, country of origin, mean age, cell type, cell dose, cell source, method of transplantation, duration of follow-up, Gross motor function, Ashworth scale, and adverse events.

RESULTS

We found 2073 articles by literature search; after deleting duplicates, 1194 remained. Nine articles remained for meta-analysis. The SMD of GMF-66 score (after-before) treatment was 1.5 (95% CI:0.7-2.3) (I2 = 89.9%, P < 0.001). The pooled incidence of Gastrointestinal (GI) complications after transplantation was 21% (95% CI:9-33%) (I2 = 56%, P = 0.08). The pooled incidence of fever after transplantation was 18 % (95% CI:6-30%) (I2 = 87.9%, P = 0.08 < 0.001) Conclusion: The result of this systematic review and meta-analysis show that stem cell therapy in cerebral palsy has neuroprotective properties from anti-inflammatory and anti-apoptotic activities. Stem cell therapy seems to be a promising adjunct to traditional therapies for cerebral palsy patients.

Efficacy and Safety of Bone Marrow Derived Stem Cell Therapy for Ischemic Stroke: Evidence from Network Meta-analysis

BACKGROUND

Several types of stem cells are available for the treatment of stroke patients. However, the optimal type of stem cell remains unclear.

OBJECTIVE

To analyze the effects of bone marrow-derived stem cell therapy in patients with ischemic stroke by integrating all available direct and indirect evidence in network meta-analyses.

METHODS

We searched several databases to identify randomized clinical trials comparing clinical outcomes of bone marrow-derived stem cell therapy vs. conventional treatment in stroke patients. Pooled relative risks (RRs) and mean differences (MDs) were reported. The surface under the cumulative ranking (SUCRA) was used to rank the probabilities of each agent regarding different outcomes.

RESULTS

Overall, 11 trials with 576 patients were eligible for analysis. Three different therapies, including mesenchymal stem cells (MSCs), mononuclear stem cells (MNCs), and multipotent adult progenitor cells (MAPCs), were assessed. The direct analysis demonstrated that stem cell therapy was associated with significantly reduced all-cause mortality rates (RR 0.55, 95% CI 0.33 to 0.93; I2=0%). Network analysis demonstrated MSCs ranked first in reducing mortality (RR 0.42, 95% CrI 0.15 to 0.86) and improving modified Rankin Scale score (MD -0.59 95% CI -1.09 to -0.09), with SUCRA values 80%, and 98%, respectively. Subgroup analysis showed intravenous transplantation was superior to conventional therapy in reducing all-cause mortality (RR 0.53, 95% CrI 0.29 to 0.88).

CONCLUSION

Using stem cell transplantation was associated with reduced risk of death and improved functional outcomes in patients with ischemic stroke. Additional large trials are warranted to provide more conclusive evidence.

Functional Roles of Mesenchymal Stem Cell-derived Exosomes in Ischemic Stroke Treatment

Stroke is a life-threatening disease and one of the leading causes of death and physical disability worldwide. Currently, no drugs on the market promote neural recovery after stroke insult, and spontaneous remodeling processes are limited to induce recovery in the ischemic regions. Therefore, promoting a cell-based therapy has been needed to elevate the endogenous recovery process. Mesenchymal stem cells (MSCs) have been regarded as candidate cell sources for therapeutic purposes of ischemic stroke, and their therapeutic effects are mediated by exosomes. The microRNA cargo in these extracellular vesicles is mostly responsible for the positive effects. When it comes to the therapeutic viewpoint, MSCsderived exosomes could be a promising therapeutic strategy against ischemic stroke. The aim of this review is to discuss the current knowledge around the potential of MSCs-derived exosomes in the treatment of ischemic stroke.

Cerebrolysin for acute ischaemic stroke

BACKGROUND

Cerebrolysin is a mixture of low-molecular-weight peptides and amino acids derived from porcine brain, which has potential neuroprotective properties. It is widely used in the treatment of acute ischaemic stroke in Russia, Eastern Europe, China, and other Asian and post-Soviet countries. This is an update of a review first published in 2010 and last updated in 2020.

OBJECTIVES

To assess the benefits and harms of Cerebrolysin or Cerebrolysin-like agents for treating acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Trials Register, CENTRAL, MEDLINE, Embase, Web of Science Core Collection, with Science Citation Index, and LILACS in May 2022 and a number of Russian databases in June 2022. We also searched reference lists, ongoing trials registers, and conference proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing Cerebrolysin or Cerebrolysin-like agents started within 48 hours of stroke onset and continued for any length of time, with placebo or no treatment in people with acute ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Three review authors independently applied the inclusion criteria, assessed trial quality and risk of bias, extracted data, and applied GRADE criteria to the evidence.

MAIN RESULTS

Seven RCTs (1773 participants) met the inclusion criteria of the review. In this update we added one RCT of Cerebrolysin-like agent Cortexin, which contributed 272 participants. We used the same approach for risk of bias assessment that was re-evaluated for the previous update: we added consideration of the public availability of study protocols and reported outcomes to the selective outcome reporting judgement, through identification, examination, and evaluation of study protocols. For the Cerebrolysin studies, we judged the risk of bias for selective outcome reporting to be unclear across all studies; for blinding of participants and personnel to be low in three studies and unclear in the remaining four; and for blinding of outcome assessors to be low in three studies and unclear in four studies. We judged the risk of bias for generation of allocation sequence to be low in one study and unclear in the remaining six studies; for allocation concealment to be low in one study and unclear in six studies; and for incomplete outcome data to be low in three studies and high in the remaining four studies. The manufacturer of Cerebrolysin supported three multicentre studies, either totally, or by providing Cerebrolysin and placebo, randomisation codes, research grants, or statisticians. We judged two studies to be at high risk of other bias and the remaining five studies to be at unclear risk of other bias. We judged the study of Cortexin to be at low risk of bias for incomplete outcome data and at unclear risk of bias for all other domains. All-cause death: Cerebrolysin or Cortexin probably result in little to no difference in all-cause death (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.65 to 1.41; 6 trials, 1689 participants; moderate-certainty evidence). None of the included studies reported on poor functional outcome, defined as death or dependence at the end of the follow-up period, early death (within two weeks of stroke onset), quality of life, or time to restoration of capacity for work. Only one study clearly reported on the cause of death: cerebral infarct (four in the Cerebrolysin and two in the placebo group), heart failure (two in the Cerebrolysin and one in the placebo group), pulmonary embolism (two in the placebo group), and pneumonia (one in the placebo group). Non-death attrition (secondary outcome): Cerebrolysin or similar peptide mixtures may result in little to no difference in non-death attrition, but the evidence is very uncertain, with a considerable level of heterogeneity (RR 0.72, 95% CI 0.38 to 1.39; 6 trials, 1689 participants; very low-certainty evidence). Serious adverse events (SAEs): Cerebrolysin probably results in little to no difference in the total number of people with SAEs (RR 1.16, 95% CI 0.81 to 1.66; 3 trials, 1335 participants; moderate-certainty evidence). This comprised fatal SAEs (RR 0.90, 95% CI 0.59 to 1.38; 3 trials, 1335 participants; moderate-certainty evidence) and an increase in the total number of people with non-fatal SAEs (RR 2.39, 95% CI 1.10 to 5.23; 3 trials, 1335 participants; moderate-certainty evidence). In the subgroup of dosing schedule 30 mL for 10 days (cumulative dose 300 mL), the increase was more prominent (RR 2.87, 95% CI 1.24 to 6.69; 2 trials, 1189 participants). Total number of people with adverse events: Cerebrolysin or similar peptide mixtures may result in little to no difference in the total number of people with adverse events (RR 1.03, 95% CI 0.92 to 1.14; 4 trials, 1607 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Moderate-certainty evidence indicates that Cerebrolysin or Cerebrolysin-like peptide mixtures derived from cattle brain probably have no beneficial effect on preventing all-cause death in acute ischaemic stroke. Moderate-certainty evidence suggests that Cerebrolysin probably has no beneficial effect on the total number of people with serious adverse events. Moderate-certainty evidence also indicates a potential increase in non-fatal serious adverse events with Cerebrolysin use.

Using Intervention Mapping and Behavior Change Techniques to Develop a Digital Intervention for Self-Management in Stroke: Development Study

BACKGROUND

Digital therapeutics, such as interventions provided via smartphones or the internet, have been proposed as promising solutions to support self-management in persons with chronic conditions. However, the evidence supporting self-management interventions through technology in stroke is scarce, and the intervention development processes are often not well described, creating challenges in explaining why and how the intervention would work.

OBJECTIVE

This study describes a specific use case of using intervention mapping (IM) and the taxonomy of behavior change techniques (BCTs) in designing a digital intervention to manage chronic symptoms and support daily life participation in people after stroke. IM is an implementation science framework used to bridge the gap between theories and practice to ensure that the intervention can be implemented in real-world settings. The taxonomy of BCTs consists of a set of active ingredients designed to change self-management behaviors.

METHODS

We used the first 4 steps of the IM process to develop a technology-supported self-management intervention, interactive Self-Management Augmented by Rehabilitation Technologies (iSMART), adapted from a face-to-face stroke-focused psychoeducation program. Planning group members were involved in adapting the intervention. They also completed 3 implementation measures to assess the acceptability, appropriateness, and feasibility of iSMART.

RESULTS

In step 1, we completed a needs assessment consisting of assembling a planning group to codevelop the intervention, conducting telephone surveys of people after stroke (n=125) to identify service needs, and performing a systematic review of randomized controlled trials to examine evidence of the effectiveness of digital self-management interventions to improve patient outcomes. We identified activity scheduling, symptom management, stroke prevention, access to care resources, and cognitive enhancement training as key service needs after a stroke. The review suggested that digital self-management interventions, especially those using cognitive behavioral theory, effectively reduce depression, anxiety, and fatigue and enhance self-efficacy in neurological disorders. Step 2 identified key determinants, objectives, and strategies for self-management in iSMART, including knowledge, behavioral regulation, skills, self-efficacy, motivation, negative and positive affect, and social and environmental support. In step 3, we generated the intervention components underpinned by appropriate BCTs. In step 4, we developed iSMART with the planning group members. Especially, iSMART simplified the original psychoeducation program and added 2 new components: SMS text messaging and behavioral coaching, intending to increase the uptake by people after stroke. iSMART was found to be acceptable (mean score 4.63, SD 0.38 out of 5), appropriate (mean score 4.63, SD 0.38 out of 5), and feasible (mean score 4.58, SD 0.34 out of 5).

CONCLUSIONS

We describe a detailed example of using IM and the taxonomy of BCTs for designing and developing a digital intervention to support people after stroke in managing chronic symptoms and maintaining active participation in daily life.

Stem cell-based interventions for the prevention and treatment of intraventricular haemorrhage and encephalopathy of prematurity in preterm infants

BACKGROUND

Germinal matrix-intraventricular haemorrhage (GMH-IVH) and encephalopathy of prematurity (EoP) remain substantial issues in neonatal intensive care units worldwide. Current therapies to prevent or treat these conditions are limited. Stem cell-based therapies offer a potential therapeutic approach to repair, restore, or regenerate injured brain tissue. These preclinical findings have now culminated in ongoing human neonatal studies. This is an update of the 2019 review, which did not include EoP.

OBJECTIVES

To evaluate the benefits and harms of stem cell-based interventions for prevention or treatment of GM-IVH and EoP in preterm infants.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was April 2022.

SELECTION CRITERIA

We attempted to include randomised controlled trials, quasi-randomised controlled trials, and cluster trials comparing 1. stem cell-based interventions versus control; 2. mesenchymal stromal cells (MSCs) of type or source versus MSCs of other type or source; 3. stem cell-based interventions other than MSCs of type or source versus stem cell-based interventions other than MSCs of other type or source; or 4. MSCs versus stem cell-based interventions other than MSCs. For prevention studies, we included extremely preterm infants (less than 28 weeks' gestation), 24 hours of age or less, without ultrasound diagnosis of GM-IVH or EoP; for treatment studies, we included preterm infants (less than 37 weeks' gestation), of any postnatal age, with ultrasound diagnosis of GM-IVH or with EoP.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. all-cause neonatal mortality, 2. major neurodevelopmental disability, 3. GM-IVH, 4. EoP, and 5. extension of pre-existing non-severe GM-IVH or EoP. We planned to use GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We identified no studies that met our inclusion criteria. Three studies are currently registered and ongoing. Phase 1 trials are described in the 'Excluded studies' section.

AUTHORS' CONCLUSIONS

No evidence is currently available to evaluate the benefits and harms of stem cell-based interventions for treatment or prevention of GM-IVH or EoP in preterm infants. We identified three ongoing studies, with a sample size range from 20 to 200. In two studies, autologous cord blood mononuclear cells will be administered to extremely preterm infants via the intravenous route; in one, intracerebroventricular injection of MSCs will be administered to preterm infants up to 34 weeks' gestational age.

Perspective insights into hydrogels and nanomaterials for ischemic stroke

Ischemic stroke (IS) is a neurological disorder prevalent worldwide with a high disability and mortality rate. In the clinic setting, tissue plasminogen activator (tPA) and thrombectomy could restore blood flow of the occlusion region and improve the outcomes of IS patients; however, these therapies are restricted by a narrow time window. Although several preclinical trials have revealed the molecular and cellular mechanisms underlying infarct lesions, the translatability of most findings is unsatisfactory, which contributes to the emergence of new biomaterials, such as hydrogels and nanomaterials, for the treatment of IS. Biomaterials function as structural scaffolds or are combined with other compounds to release therapeutic drugs. Biomaterial-mediated drug delivery approaches could optimize the therapeutic effects based on their brain-targeting property, biocompatibility, and functionality. This review summarizes the advances in biomaterials in the last several years, aiming to discuss the therapeutic potential of new biomaterials from the bench to bedside. The promising prospects of new biomaterials indicate the possibility of an organic combination between materialogy and medicine, which is a novel field under exploration.

The factors affecting neurogenesis after stroke and the role of acupuncture

Stroke induces a state of neuroplasticity in the central nervous system, which can lead to neurogenesis phenomena such as axonal growth and synapse formation, thus affecting stroke outcomes. The brain has a limited ability to repair ischemic damage and requires a favorable microenvironment. Acupuncture is considered a feasible and effective neural regulation strategy to improve functional recovery following stroke via the benign modulation of neuroplasticity. Therefore, we summarized the current research progress on the key factors and signaling pathways affecting neurogenesis, and we also briefly reviewed the research progress of acupuncture to improve functional recovery after stroke by promoting neurogenesis. This study aims to provide new therapeutic perspectives and strategies for the recovery of motor function after stroke based on neurogenesis.

Trilobatin promotes angiogenesis after cerebral ischemia-reperfusion injury via SIRT7/VEGFA signaling pathway in rats

Angiogenesis plays a pivotal role in the recovery of neurological function after ischemia stroke. Herein, we investigated the effect of trilobatin (TLB) on angiogenesis after cerebral ischemia-reperfusion injury (CIRI). The effect of TLB on angiogenesis after CIRI were investigated in mouse brain microvascular endothelium bEnd.3 cells and middle cerebral artery occlusion (MCAO)-induced CIRI rat model. The cell proliferation and angiogenesis were observed using immunofluorescence staining. The cell cycle, expressions of cell cycle-related proteins and SIRT 1-7 were determined by flow cytometry and western blot, respectively. The binding affinity of TLB with SIRT7 was predicted by molecular docking. The results showed that TLB concentration-dependently promoted bEnd.3 cell proportion in the S-phase. TLB significantly increased the protein expressions of SIRT6, SIRT7, and VEGFA, but not affected SIRT1-SIRT5 protein expressions. Moreover, TLB not only dramatically alleviated neurological impairment after CIRI, but also enhanced post-stroke neovascularization and newly formed functional vessels in cerebral ischemic penumbra. Furthermore, TLB up-regulated the protein expressions of CDK4, cyclin D1, VEGFA and its receptor VEGFR-2. Intriguingly, TLB not only directly bound to SIRT7, but also increased SIRT7 expression at day 28. Our findings reveal that TLB promotes cerebral microvascular endothelial cells proliferation, and facilitates angiogenesis after CIRI via mediating SIRT7/VEGFA signaling pathway in rats. Therefore, TLB might be a novel restorative agent to rescue ischemia stroke.

Toward Generalizable Trajectory Planning for Human Intracerebral Trials and Therapy

<b><i>Introduction:</i></b> Stereotactic neurosurgical techniques are increasingly used to deliver biologics, such as cells and viruses, although standardized procedures are necessary to ensure consistency and reproducibility. <b><i>Objective:</i></b> We provide an instructional guide to help plan for complex image-guided trajectories; this may be of particular benefit to surgeons new to biologic trials and companies planning such trials. <b><i>Methods:</i></b> We show how nuclei can be segmented and multiple trajectories with multiple injection points can be created through a single or multiple burr hole(s) based on preoperative images. Screenshots similar to those shown in this article can be used for planning purposes and for quality control in clinical trials. <b><i>Results:</i></b> This method enables the precise definition of 3-D target structures, such as the putamen, and efficient planning trajectories for biologic injections. The technique is generalizable and largely independent of procedural format, and thus can be integrated with frame-based or frameless platforms to streamline reproducible therapeutic delivery. <b><i>Conclusions:</i></b> We describe an easy-to-use and generalizable protocol for intracerebral trajectory planning for stereotactic delivery of biologics. Although we highlight intracerebral stem cell delivery to the putamen using a frame-based stereotactic delivery system, similar strategies may be employed for different brain nuclei using different platforms. We anticipate this will inform future advanced and fully automated neurosurgical procedures to help unify the field and decrease inherent variability seen with manual trajectory planning.

Stem Cell Therapies for Cerebral Palsy and Autism Spectrum Disorder-A Systematic Review

Autism spectrum disorder (ASD) and cerebral palsy (CP) are some of the most common neurodevelopmental diseases. They have multifactorial origin, which means that each case may manifest differently from the others. In patients with ASD, symptoms associated with deficits in social communication and characteristic, repetitive types of behaviors or interests are predominant, while in patients with CP, motor disability is diagnosed with accompanying cognitive impairment of various degrees. In order to minimize their adverse effects, it is necessary to promptly diagnose and incorporate appropriate management, which can significantly improve patient quality of life. One of the therapeutic possibilities is stem cell therapy, already known from other branches of medicine, with high hopes for safe and effective treatment of these diseases. Undoubtedly, in the future we will have to face the challenges that will arise due to the still existing gaps in knowledge and the heterogeneity of this group of patients. The purpose of this systematic review is to summarize briefly the latest achievements and advances in stem cell therapy for ASD and CP.

Current status of ischemic stroke treatment: From thrombolysis to potential regenerative medicine

Ischemic stroke is a major cause of death and disability worldwide and is expected to increase in the future with the aging population. Currently, there are no clinically available treatments for damage sustained during an ischemic stroke, but much research is being conducted in this area. In this review, we will introduce current ischemic stroke treatments along with their limitations, as well as research on potential short and long-term future treatments. There are advantages and disadvantages in these potential treatments, but our understanding of these methods and their effectiveness in clinical trials are improving. We are confident that some future treatments introduced in this review will become commonly used in clinical settings in the future.

Secretome of endothelial progenitor cells from stroke patients promotes endothelial barrier tightness and protects against hypoxia-induced vascular leakage

BACKGROUND

Cell-based therapeutic strategies have been proposed as an alternative for brain repair after stroke, but their clinical application has been hampered by potential adverse effects in the long term. The present study was designed to test the effect of the secretome of endothelial progenitor cells (EPCs) from stroke patients (scCM) on in vitro human models of angiogenesis and vascular barrier.

METHODS

Two different scCM batches were analysed by mass spectrometry and a proteome profiler. Human primary CD34+-derived endothelial cells (CD34+-ECs) were used for designing angiogenesis studies (proliferation, migration, and tubulogenesis) or in vitro models of EC monolayer (confluent monolayer ECs-CMECs) and blood-brain barrier (BBB; brain-like ECs-BLECs). Cells were treated with scCM (5 μg/mL) or protein-free endothelial basal medium (scEBM-control). CMECs or BLECs were exposed (6 h) to oxygen-glucose deprivation (OGD) conditions (1% oxygen and glucose-free medium) or normoxia (control-5% oxygen, 1 g/L of glucose) and treated with scCM or scEBM during reoxygenation (24 h).

RESULTS

The analysis of different scCM batches showed a good reproducibility in terms of protein yield and composition. scCM increased CD34+-EC proliferation, tubulogenesis, and migration compared to the control (scEBM). The proteomic analysis of scCM revealed the presence of growth factors and molecules modulating cell metabolism and inflammatory pathways. Further, scCM decreased the permeability of CMECs and upregulated the expression of the junctional proteins such as occludin, VE-cadherin, and ZO-1. Such effects were possibly mediated through the activation of the interferon pathway and a moderate downregulation of Wnt signalling. Furthermore, OGD increased the permeability of both CMECs and BLECs, while scCM prevented the OGD-induced vascular leakage in both models. These effects were possibly mediated through the upregulation of junctional proteins and the regulation of MAPK/VEGFR2 activity.

CONCLUSION

Our results suggest that scCM promotes angiogenesis and the maturation of newly formed vessels while restoring the BBB function in ischemic conditions. In conclusion, our results highlight the possibility of using EPC-secretome as a therapeutic alternative to promote brain angiogenesis and protect from ischemia-induced vascular leakage.

Combination of endothelial progenitor cells and BB-94 significantly alleviates brain damage in a mouse model of diabetic ischemic stroke

Ischemic stroke is a complication of chronic macrovascular disease in type 2 diabetes. However, the pathogenesis of diabetic ischemic stroke has not yet been fully clarified. The aim of the present study was to investigate the underlying effects of endothelial progenitor cells (EPCs) and the matrix metalloproteinase inhibitor BB-94 on diabetic stroke. In vitro experiments were performed using oxygen-glucose deprivation/reoxygenation (OGD/R) model cells, established using HT22 mouse hippocampal cells. MTT assays and flow cytometry revealed that BB-94 prominently induced the proliferation of the OGD/R model cells and prevented their apoptosis. When EPCs and BB-94 were applied to the OGD/R model cells in combination, proliferation was further accelerated and oxidative damage was attenuated. In vivo experiments were also performed using a middle cerebral artery occlusion (MCAO) mouse model. The results of modified neurological severity scoring and oxidative stress marker analysis demonstrated that EPCs and BB-94 prominently alleviated cerebral ischemia/reperfusion injury in the MCAO model mice. Furthermore, reverse transcription-quantitative PCR and western blot assays revealed that EPCs in combination with BB-94 significantly downregulated the expression of matrix metalloproteinases (MMPs) and upregulated the expression of tissue inhibitor of metalloproteinases 1 in OGD/R cells and MCAO model mice. The results suggest that EPCs were successfully isolated and identified, and the OGD/R cell and MCAO mouse models were successfully established. They also indicate that EPCs alone or in combination with BB-94 may exert protective effects against ischemic stroke via the reduction of MMP expression.

Stem Cell Therapy in Ischemic Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and Objective:

Stem cell therapy has emerged as a potential therapy for the treatment of stroke. We performed a systematic review and meta-analysis of published randomized controlled studies using various types of stem cell therapies in patients with ischemic stroke (IS).

Method:

Literature search was carried out using PubMed, Google Scholar, Cochrane library, and clinicaltrial.gov to identify studies on stem cell therapy in IS from its inception till January 2020. Data were extracted independently by two reviewers. STATA version 13 was used for carrying out meta- analysis. We included only randomized controlled trials (RCTs) if any of the stem cell therapy was used to treat patients with IS in any phase after the index stroke.

Results:

We included a total of eight randomized controlled studies involving 459 subjects (217 intervention and 242 controls) in the meta-analysis. We did not observe statistically significant reduction in mean NIHSS score in the intervention group (SMD - 0.34, 95% CI - 0.76 to 0.08) in patients with acute or sub-acute stroke. However, a statistically significant reduction (SMD - 1.57, 95% CI -2.22 to -0.92) was observed in patients with chronic ischemic stroke. Statistically non-significant reduction in mean mRS in the intervention group (SMD 0.04, 95% CI -0.20 to 0.28) in patients with acute or sub-acute ischemic stroke was observed, however a statistically significant reduction (SMD - 1.07, 95% CI - 1.94 to -0.19) was noted in patients with chronic stroke. We did not observe statistically significant reduction in mean Barthel index score (SMD 0.24, 95%CI -1.69 to 2.17) in chronic stroke. Statistically non-significant lower mortality rate was observed in intervention group compared to controls (Risk Ratio 0.84, 95% CI 0.43 to 1.66) among acute or sub-acute, as well as in the chronic stroke group (Risk Ratio 0.47, 95% CI 0.20 to 1.09).

Conclusion:

Our meta-analysis provides no clinically important evidence for efficacy of stem cells in reducing neurological deficit compared to control group. Well-designed large randomized controlled trials are required to provide more information on the efficacy of stem cell therapy in patients with IS.

Stem Cell Therapies for Ischemic Stroke: A Systematic Review

Stroke is one of the leading causes of death and disability worldwide. It is associated with a high economic burden, causing an increasing demand for highly effective, curative, and long-lasting therapies. Stem cells are unique human cells that have the capacity for developing into specialized cell types with the potential for facilitating regeneration and repair of damaged tissues. Therefore, many preclinical studies have shown the feasibility, safety, and efficacy of stem cell-based therapies; however, the evidence is still inadequate for their therapeutic use in humans. We employed a systematic approach to search published data from 2000 to 2020 on five main databases: PubMed, PubMed Central, Google Scholar, ScienceDirect, and Medline. Two research registries were also searched: the Cochrane Registry and clinicaltrial.gov. Data was collected after applying inclusion and exclusion criteria and studies were appraised critically. Both Medical Subject Headings (MeSH) and regular keyword search strategies were employed. The findings of this study are in line with previously reported studies in which stem cell-based therapies were found to be relatively safe, feasible, and effective.

Protective effects of mesenchymal stem cells on ischemic brain injury: therapeutic perspectives of regenerative medicine

Cerebral ischemic injury as the main manifestation of stroke can occur in stroke patients (70-80%). Nowadays, the main therapeutic strategy used for ischemic brain injury treatment aims to achieve reperfusion, neuroprotection, and neurorecovery. Also, angiogenesis as a therapeutic approach maybe represents a promising tool to enhance the prognosis of cerebral ischemic stroke. Unfortunately, although many therapeutic approaches as a life-saving gateway for cerebral ischemic injuries like pharmacotherapy and surgical treatments are widely used, they all fail to restore or regenerate damaged neurons in the brain. So, the suitable therapeutic approach would focus on regenerating the lost cells and restore the normal function of the brain. Currently, stem cell-based regenerative medicine introduced a new paradigm approach in cerebral ischemic injuries treatment. Today, in experimental researches, different types of stem cells such as mesenchymal stem cells have been applied. Therefore, stem cell-based regenerative medicine provides the opportunity to inquire and develop a more effective and safer therapeutic approach with the capability to produce and regenerate new neurons in damaged tissues.

Enhancing Brain Plasticity to Promote Stroke Recovery

Stroke disturbs both the structural and functional integrity of the brain. The understanding of stroke pathophysiology has improved greatly in the past several decades. However, effective therapy is still limited, especially for patients who are in the subacute or chronic phase. Multiple novel therapies have been developed to improve clinical outcomes by improving brain plasticity. These approaches either focus on improving brain remodeling and restoration or on constructing a neural bypass to avoid brain injury. This review describes emerging therapies, including modern rehabilitation, brain stimulation, cell therapy, brain-computer interfaces, and peripheral nervous transfer, and highlights treatment-induced plasticity. Key evidence from basic studies on the underlying mechanisms is also briefly discussed. These insights should lead to a deeper understanding of the overall neural circuit changes, the clinical relevance of these changes in stroke, and stroke treatment progress, which will assist in the development of future approaches to enhance brain function after stroke.

Olfactory Mucosa Mesenchymal Stem Cells Alleviate Cerebral Ischemia/Reperfusion Injury Via Golgi Apparatus Secretory Pathway Ca2+ -ATPase Isoform1

Olfactory mucosa mesenchymal stem cells (OM-MSCs) have exhibited their effectiveness in central nervous system diseases and provided an appealing candidate for the treatment of ischemic stroke. Previous evidence have shown that Golgi apparatus (GA) secretory pathway Ca²⁺-ATPase isoform1 (SPCA1) was a potential therapeutic target for ischemic stroke. In this study, we explored the neuroprotective mechanism of OM-MSCs and its effect on the expression and function of SPCA1 during cerebral ischemia/reperfusion. Based on in vitro and in vivo experiments, we discovered that OM-MSCs attenuated apoptosis and oxidative stress in ischemic stroke models, reduced the cerebral infarction volume, and improved the neurologic deficits of rats. OM-MSCs also upregulated SPCA1 expression and alleviated Ca²⁺ overload and decreased the edema and dissolution of the GA in neurons. Moreover, we discovered that SPCA1 depletion in oxygen and glucose deprivation/reoxygenation (OGD/R)-treated N2a cells mitigated the protective effects of OM-MSCs. Altogether, OM-MSCs exerted neuroprotective effects in ischemic stroke probably via modulating SPCA1 and reducing the edema and dissolution of the GA in neurons.

Mesenchymal Stem Cell-Mediated Mitochondrial Transfer: a Therapeutic Approach for Ischemic Stroke

Stroke is the leading cause of death and adult disability worldwide. Mitochondrial dysfunction is one of the hallmarks of stroke-induced neuronal death, and maintaining mitochondrial function is essential in cell survival and neurological progress following ischemic stroke. Stem cell-mediated mitochondrial transfer represents an emerging therapeutic approach for ischemic stroke. Accumulating evidence suggests that mesenchymal stem cells (MSCs) can directly transfer healthy mitochondria to damaged cells, and rescue mitochondrial damage-provoked tissue degeneration. This review summarizes the research on MSCs-mediated mitochondrial transfer as a therapeutic strategy against ischemic stroke.

Outcomes of bone marrow mononuclear cell transplantation combined with interventional education for autism spectrum disorder

The aim of this study was to evaluate the safety and efficacy of autologous bone marrow mononuclear cell transplantation combined with educational intervention for children with autism spectrum disorder. An open‐label clinical trial was performed from July 2017 to August 2019 at Vinmec International Hospital, Hanoi, Vietnam. Thirty children who fulfilled the autism criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and had Childhood Autism Rating Scale (CARS) scores >37 were selected. Bone marrow was harvested by anterior iliac crest puncture under general anesthesia. The volume collected was as follows: 8 mL/kg for patients under 10 kg (80 mL + [body weight in kg − 10] × 7 mL) for patients above 10 kg. Mononuclear cells were isolated with a Ficoll gradient and then infused intrathecally. The same procedure was repeated 6 months later. After the first transplantation, all patients underwent 8 weeks of educational intervention based on the Early Start Denver Model. There were no severe adverse events associated with transplantation. The severity of autism spectrum disorder (ASD) was significantly reduced, with the median CARS score decreasing from 50 (range 40‐55.5) to 46.5 (range 33.5‐53.5) (P < .05). Adaptive capacity increased, with the median Vineland Adaptive Behavior Scales score rising from 53.5 to 60.5. Social communication, language, and daily skills improved markedly within 18 months after transplantation. Conversely, repetitive behaviors and hyperactivity decreased remarkably. Autologous bone marrow mononuclear cell transplantation in combination with behavioral intervention was safe and well tolerated in children with ASD (Trial registration: ClinicalTrials.gov identifier: NCT03225651).

New directions in necrotizing enterocolitis with early-stage investigators

The 2019 Necrotizing Enterocolitis (NEC) Symposium expanded upon the NEC Society's goals of bringing stakeholders together to discuss cutting-edge science, potential therapeutics and preventative measures, as well as the patient-family perspectives of NEC. The Symposium facilitated discussions and shared knowledge with the overarching goal of creating "A World Without NEC." To accomplish this goal, new research to advance the state of the science is necessary. Over the last decade, several established investigators have significantly improved our understanding of the pathophysiology of NEC and they have paved the way for the next generation of clinician-scientists funded to perform NEC research. This article will serve to highlight the contributions of these young clinician-scientists that seek to elucidate how immune, microbial and nervous system dysregulation contributes to the pathophysiology of NEC.

Cerebrolysin for acute ischaemic stroke

BACKGROUND

Cerebrolysin is a mixture of low-molecular-weight peptides and amino acids derived from porcine brain that has potential neuroprotective properties. It is widely used in the treatment of acute ischaemic stroke in Russia, Eastern Europe, China, and other Asian and post-Soviet countries. This is an update of a review first published in 2010 and last updated in 2017.

OBJECTIVES

To assess the benefits and harms of Cerebrolysin for treating acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE, Embase, Web of Science Core Collection, with Science Citation Index, LILACS, OpenGrey, and a number of Russian databases in October 2019. We also searched reference lists, ongoing trials registers, and conference proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing Cerebrolysin, started within 48 hours of stroke onset and continued for any length of time, with placebo or no treatment in people with acute ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality and risk of bias, extracted data, and applied GRADE criteria to the evidence.

MAIN RESULTS

Seven RCTs (1601 participants) met the inclusion criteria of the review. In this update we re-evaluated risk of bias through identification, examination, and evaluation of study protocols and judged it to be low, unclear, or high across studies: unclear for all domains in one study, and unclear for selective outcome reporting across all studies; low for blinding of participants and personnel in four studies and unclear in the remaining three; low for blinding of outcome assessors in three studies and unclear in four studies. We judged risk of bias to be low in two studies and unclear in the remaining five studies for generation of allocation sequence; low in one study and unclear in six studies for allocation concealment; and low in one study, unclear in one study, and high in the remaining five studies for incomplete outcome data. The manufacturer of Cerebrolysin supported four multicentre studies, either totally, or by providing Cerebrolysin and placebo, randomisation codes, research grants, or statisticians. We judged three studies to be at high risk of other bias and the remaining four studies to be at unclear risk of other bias. All-cause death: we extracted data from six trials (1517 participants). Cerebrolysin probably results in little to no difference in all-cause death: risk ratio (RR) 0.90, 95% confidence interval (CI) 0.61 to 1.32 (6 trials, 1517 participants, moderate-quality evidence). None of the included trials reported on poor functional outcome defined as death or dependence at the end of the follow-up period or early death (within two weeks of stroke onset), or time to restoration of capacity for work and quality of life. Only one trial clearly reported on the cause of death: cerebral infarct (four in the Cerebrolysin and two in the placebo group), heart failure (two in the Cerebrolysin and one in the placebo group), pulmonary embolism (two in the placebo group), and pneumonia (one in the placebo group). Serious adverse events (SAEs): Cerebrolysin probably results in little to no difference in the total number of people with SAEs (RR 1.15, 95% CI 0.81 to 1.65, 4 RCTs, 1435 participants, moderate-quality evidence). This comprised fatal SAEs (RR 0.90, 95% CI 0.59 to 1.38) and an increase in the total number of people with non-fatal SAEs (RR 2.15, 95% CI 1.01 to 4.55, P = 0.047, 4 trials, 1435 participants, moderate-quality evidence). In the subgroup of dosing schedule 30 mL for 10 days (cumulative dose 300 mL), the increase was more prominent: RR 2.86, 95% CI 1.23 to 6.66, P = 0.01 (2 trials, 1189 participants). Total number of people with adverse events: four trials reported on this outcome. Cerebrolysin may result in little to no difference in the total number of people with adverse events: RR 0.97, 95% CI 0.85 to 1.10, P = 0.90, 4 trials, 1435 participants, low-quality evidence. Non-death attrition: evidence from six trials involving 1517 participants suggests that Cerebrolysin results in little to no difference in non-death attrition, with 96 out of 764 Cerebrolysin-treated participants and 117 out of 753 placebo-treated participants being lost to follow-up for reasons other than death (very low-quality evidence).

AUTHORS' CONCLUSIONS

Moderate-quality evidence indicates that Cerebrolysin probably has little or no beneficial effect on preventing all-cause death in acute ischaemic stroke, or on the total number of people with serious adverse events. Moderate-quality evidence also indicates a potential increase in non-fatal serious adverse events with Cerebrolysin use.

Stem cell-based therapies for ischemic stroke: a systematic review and meta-analysis of clinical trials

Recently, extensive researches about stem cell-based therapies for ischemic stroke have been published; our review evaluated the efficacy and safety of stem cell-based therapies for ischemic stroke. Our review was registered on PROSPERO (http://www.crd.york.ac.uk/PROSPERO), registration number CRD42019135805. Two independent observers searched PubMed, EMBASE, Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials), and Web of Science (Science Citation Index Expanded) for relevant studies up to 31 May 2019. We included clinical trials which compared efficacy outcomes (measured by National Institutes of Health Stroke Scale (NIHSS), modified Rankin scale (mRS), or Barthel index (BI)) and safety outcomes (such as death and adverse effects) between the stem cell-based therapies and control in ischemic stroke. We performed random effect meta-analysis using Review Manager 5.3. Our review included nine randomized controlled trials (RCTs) and seven non-randomized studies (NRSs), involving 740 participants. Stem cell-based therapies were associated with better outcomes measured by NIHSS (mean difference (MD) − 1.63, 95% confidence intervals (CI) − 2.73 to − 0.53, I² =60%) and BI (MD 14.68, 95% CI 1.12 to 28.24, I² = 68%) in RCTs, and by BI (MD 6.40, 95% CI 3.14 to 9.65, I² = 0%) in NRSs. However, the risk of bias was high and the efficacy outcomes of RCTs were high heterogeneity. There was no significant difference in mortality between the stem cell group and the control group. Fever, headache, and recurrent stroke were the most frequently reported adverse effects. Our review shows that stem cell-based therapies can improve the neurological deficits and activities of daily living in patients with ischemic stroke.

Stem cell homing, tracking and therapeutic efficiency evaluation for stroke treatment using nanoparticles: A systematic review

BACKGROUND

Stroke is the second leading cause of death worldwide. There is a real need to develop treatment strategies for reducing neurological deficits in stroke survivors, and stem cell (SC) therapeutics appear to be a promising alternative for stroke therapy that can be used in combination with approved thrombolytic or thrombectomy approaches. However, the efficacy of SC therapy depends on the SC homing ability and engraftment into the injury site over a long period of time. Nonetheless, tracking SCs from their niche to the target tissues is a complex process.

AIM

To evaluate SC migration homing, tracking and therapeutic efficacy in the treatment of stroke using nanoparticles

METHODS

A systematic literature search was performed to identify articles published prior to November 2019 that were indexed in PubMed and Scopus. The following inclusion criteria were used: (1) Studies that used in vivo models of stroke or ischemic brain lesions; (2) Studies of SCs labeled with some type of contrast agent for cell migration detection; and (3) Studies that involved in vivo cellular homing and tracking analysis.

RESULTS

A total of 82 articles were identified by indexing in Scopus and PubMed. After the inclusion criteria were applied, 35 studies were selected, and the articles were assessed for eligibility; ultimately, only 25 studies were included. Most of the selected studies used SCs from human and mouse bone marrow labeled with magnetic nanoparticles alone or combined with fluorophore dyes. These cells were administered in the stroke model (to treat middle cerebral artery occlusion in 74% of studies and for photothrombotic induction in 26% of studies). Fifty-three percent of studies used xenogeneic grafts for cell therapy, and the migration homing and tracking evaluation was performed by magnetic resonance imaging as well as other techniques, such as near-infrared fluorescence imaging (12%) or bioluminescence assays (12%).

CONCLUSION

Our systematic review provided an up-to-date evaluation of SC migration homing and the efficacy of cellular therapy for stroke treatment in terms of functional and structural improvements in the late stage.

The effectiveness of various cytotherapeutic strategies for the treatment of ischemic stroke: a Bayesian network meta-analysis of randomized controlled trials

BACKGROUND

Cytotherapy is a potential treatment for ischemic stroke (IS) patients but lacks uniform procedures. We aimed to assess the impact of the time of intervention, cell type, dose, and route of administration on the clinical effects by network meta-analysis.

METHODS

We searched public electronic databases through July 7, 2019. Bayesian network meta-analyses were performed to compare differences among different cytotherapeutic strategies.

RESULTS

Cytotherapy can significantly improve patients' activity of daily living according to the modified Rankin Scale (standard mean difference (SMD) - 0.81; 95% confidence interval (CI) - 1.58, - 0.03; p = 0.0417) and Barthel Index (SMD 0.67; 95% CI 0.05, 1.30; p = 0.036) results as well as improve neurological recovery (SMD - 0.93; 95% CI - 1.29, - 0.57; p < 0.001). Network meta-analysis showed that the intra-arterial injection of large amounts of mononuclear cells (NCs) or aldehyde dehydrogenase (ALDH)-positive cells was beneficial for improving patients' activity of daily living, while CD34⁺ cells through intracerebral injection had an advantage in the recovery of injured nerve function. Intravenous injection of mesenchymal stem cells (MSCs) or endothelial progenitor cells (EPCs) was beneficial in reducing mortality and serious adverse event (SAE) onset.

CONCLUSIONS

In the subacute stage, the intra-arterial injection of NCs or ALDH cells improves patients' activity of daily living. Additionally, CD34⁺ cells through intracerebral injection had an advantage in the recovery of injured nerve function even in the chronic stage. Intravenous injection of MSCs or EPCs is a safety delivery route that can reduce mortality and SAE onset. However, further clinical studies are still needed to confirm these results.