Therapeutic applications of bone marrow-derived stem cells in ischemic stroke

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.

GATA3 improves the protective effects of bone marrow-derived mesenchymal stem cells against ischemic stroke induced injury by regulating autophagy through CREG

BACKGROUND

Bone marrow-derived mesenchymal stem cells (BMSCs) transplantation has been demonstrated to benefit functional recovery after ischemic stroke, however, the low survival rate of BMSCs in ischemic microenvironment largely limits its use.

METHODS

Rat BMSCs (rBMSCs) were isolated from SD rats and treated with oxygen glucose deprivation/reoxygenation (OGD) to mimic ischemic microenvironment in vitro. Expression of mRNAs and proteins were assessed by qRT-PCR and western blot, respectively. Cell viability was detected using MTT. ROS level was evaluated by DCFH-DA Assay Kit. TUNEL and flow cytometry analysis were adopted to detect cell apoptosis. Immunofluorescence analysis was used to examine LC3 expression. Dual-luciferase reporter and ChIP assays were employed to determine the interaction between CREG and GATA3. Middle cerebral artery occlusion (MCAO) model was established to mimic ischemic stroke in vivo. TTC staining was used to measure the infarcts area in the brain of MCAO rats. Nissl staining was used to examine the quantity of neurons, and mNSS test was applied to compare behavioral functions of animals.

RESULTS

The rBMSCs were successfully isolated from SD rats. OGD exposure decreased the expression of GATA3 in rBMSCs, GATA3 overexpression alleviated OGD-induced cell injury and enhanced autophagy. Treatment with autophagy inhibitor (3-MA) abolished the protective effects of GATA3 against OGD-induced cell injury. GATA3 targeted the promoter of CREG and positively regulated its expression. The protective effect of GATA3 overexpression on autophagy during OGD exposure was reversed by CREG knockdown. Moreover, GATA3 overexpression improved the therapeutic effects of BMSCs transplantation on ischemic stroke in vivo.

CONCLUSION

Our results indicated that GATA3 overexpression improved the therapeutic effects of rBMSCs transplantation against ischemic stroke induced injury by regulating autophagy through CREG.

Research progress on the therapeutic effect of olfactory ensheathing cell transplantation on ischemic stroke

Olfactory ensheathing cells (OECs) are a special type of glial cell in the olfactory system, which exhibit neuroprotective, immunomodulatory, and angiogenic effects. Although many studies have focused on the reversal of demyelination and axonal degeneration (during spinal cord injury) by OECs, few reports have focused on the ability of OECs to repair ischemic nerve injury. This article reviews the protective effects of OEC transplantation in ischemic stroke and provides a theoretical basis and new strategy for OEC transplantation in the treatment of ischemic stroke.

Treatment of the bone marrow stromal stem cell supernatant by nasal administration-a new approach to EAE therapy

Introduction

Multiple sclerosis (MS) is one of the most common autoimmune diseases of the central nervous system (CNS). CNS has its own unique structural and functional features, while the lack of precision regulatory element with high specificity as therapeutic targets makes the development of disease treatment in the bottleneck. Recently, the immunomodulation and neuroprotection capabilities of bone marrow stromal stem cells (BMSCs) were shown in experimental autoimmune encephalomyelitis (EAE). However, the administration route and the safety evaluation limit the application of BMSC. In this study, we investigated the therapeutic effect of BMSC supernatant by nasal administration.

Methods

In the basis of the establishment of the EAE model, the BMSC supernatant were treated by nasal administration. The clinical score and weight were used to determine the therapeutic effect. The demyelination of the spinal cord was detected by LFB staining. ELISA was used to detect the expression of inflammatory factors in serum of peripheral blood. Flow cytometry was performed to detect pro-inflammatory cells in the spleen and draining lymph nodes.

Results

BMSC supernatant by nasal administration can alleviate B cell-mediated clinical symptoms of EAE, decrease the degree of demyelination, and reduce the inflammatory cells infiltrated into the central nervous system; lessen the antibody titer in peripheral bloods; and significantly lower the expression of inflammatory factors. As a new, non-invasive treatment, there are no differences in the therapeutic effects between BMSC supernatant treated by nasal route and the conventional applications, i.e. intraperitoneal or intravenous injection.

Conclusions

BMSC supernatant administered via the nasal cavity provide new sights and new ways for the EAE therapy.

Promoting therapeutic angiogenesis of focal cerebral ischemia using thrombospondin-4 (TSP4) gene-modified bone marrow stromal cells (BMSCs) in a rat model

Background

A stroke caused by angiostenosis always has a poor prognosis. Bone marrow stromal cells (BMSC) are widely applied in vascular regeneration. Recently, thrombospondin-4 (TSP4) was reported to promote the regeneration of blood vessels and enhance the function of endothelial cells in angiogenesis. In this work, we observed the therapeutic effect of TSP4-overexpressing BMSCs on angiogenesis post-stroke.

Methods

We subcloned the tsp4 gene into a lentivirus expression vector system and harvested the tsp4 lentivirus using 293FT cells. Primary BMSCs were then successfully infected by the tsp4 virus, and overexpression of GFP-fused TSP4 was confirmed by both western blot and immunofluorescence. In vitro, TSP4-overexpressing BMSCs and wild-type BMSCs were co-cultured with human umbilical vein endothelial cells (HUVECs). The expression level of TSP4, vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β) in the supernatant were detected by enzyme-linked immunosorbent assay (ELISA). Wound healing, tube formation and an arterial ring test were performed to estimate the ability of TSP4-overexpressing BMSCs to promote the angiogenesis of endothelial cells. Using a rat permanent middle cerebral artery occlusion (MCAO) model, the effect of TSP4-overexpressing BMSCs on the regeneration of blood vessels was systematically tested by the neurological function score, immunohistochemistry and immunofluorescence staining assays.

Results

Our results demonstrated that TSP4-overexpressing BMSCs largely increased the expression of VEGF, angiopoietin-1 (Ang-1), matrix metalloprotein 9 (MMP9), matrix metalloprotein 2 (MMP2) and p-Cdc42/Rac1 in endothelial cells. TSP4-BMSC treatment notably up-regulated the TGF-β/Smad2/3 signalling pathway in HUVECs. In vivo, the TSP4-BMSC infusion improved the neurological function score of MCAO rats and expanded the expression of the von Willebrand factor (vWF), Ang-1, MMP2 and MMP9 proteins in cerebral ischemic penumbra.

Conclusions

Our data illustrate that TSP4-BMSCs can promote the proliferation and migration of endothelial cells and tube formation. We found that TSP4-BMSC infusion can promote the recovery of neural function post-stroke. The tsp4 gene-modified BMSCs provides a better therapeutic effect than that of wild-type BMSCs.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1845-z) contains supplementary material, which is available to authorized users.

CGRP gene-modified rBMSCs show better osteogenic differentiation capacity in vitro

Calcitonin gene-related peptide (CGRP) is a marked and important neuropeptide expressed in nerve fibers during bone repair. This study investigated the role of CGRP overexpression on osteogenic differentiation of rat bone mesenchymal stem cells (rBMSCs). rBMSCs were infected with viral stocks of pLenO-DCE-CGRP (CGRP group) or pLenO-DCE (Vector group), while normal rBMSCs were used as a control. Transfection efficiency of rBMSCs was analyzed by flow cytometry. Cell proliferation was examined using a Cell Counting Kit-8 and flow cytometry. Expressions of alkaline phosphatase(ALP), bone sialoprotein (BSP) and Runt-related transcription factor 2(Runx2) in rBMSCs were detected at 1 and 2 weeks after mineral induction by real-time PCR and western blotting. Alizarin Red staining was applied at 28 days. The ratio of osteoprotegerin (OPG) to receptor activator of nuclear factor kappa B ligand (RANKL) was also detected to determine the underlying mechanism. pLenO-DCE-CGRP-induced rBMSCs stably overexpressing CGRP were successfully established. Overexpression of the CGRP gene significantly promoted rBMSC proliferation (p < 0.05). In addition, expressions of osteogenesis-related indexes were upregulated in the CGRP group (p < 0.05) compared with vector and control groups, and more mineralization nodules were observed in the CGRP group (p < 0.05). CGRP gene increased OPG and reduced RANKL in rBMSCs. Hence, the OPG/ RANKL ratio was increased in the CGRP group compared with the other two groups. CGRP gene-modified rBMSCs show better osteogenic differentiation capacity compared with rBMSCs in vitro.

Implantation of bone mesenchymal stem cells overexpressing miRNA‑705 mitigated ischemic brain injury

Ischemic brain damage remains the major cause of death and disability worldwide. Bone mesenchymal stem cell (BMSC) transplantation has been identified to serve important roles in cerebral infarction due to its multi‑directional differentiation and proliferative ability. However, the function of miR‑705 combined with BMSCs on ischemic brain injury remains to be fully elucidated. In the present study, an ischemic brain injury mouse model was constructed, and the mice were injected with BMSCs infected by lentiviral particles expressing miR‑705 (BMSCs‑Ad‑miR‑705) to explore the mechanism by which BMSCs‑Ad‑miR‑705 mitigates neurological deficits in ischemic brain damage. In the sham group, no significant neurological injury evaluated via neurological deficit scores was identified, the morphological structure of brain stained with HE was almost normal, and few apoptotic cells were detected by TUNEL assay. However, the PBS group exhibited significant brain damage (P<0.05). BMSCs‑Ad (BMSCs infected with control lentiviral particles) and BMSCs‑Ad‑miR‑705 markedly mitigated neurological injury, suppressed morphological damage and inhibited neuronal apoptosis, however promoted the mRNA levels of brain‑derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) examined by reverse transcription‑quantitative polymerase chain reaction and western blotting. Notably, BMSCs‑Ad‑miR‑705 improved the outcome of BMSCs‑Ad transplantation. These data indicated that BMSCs‑Ad‑miR‑705 promoted the secretion of VEGF and BDNF, suppressed neuronal apoptosis, and stimulated neuronal regeneration, in turn mitigating the impairment of ischemic brain damage.

Intravenous infusion of human bone marrow mesenchymal stromal cells promotes functional recovery and neuroplasticity after ischemic stroke in mice

Transplantation of human bone marrow mesenchymal stromal cells (hBM-MSC) promotes functional recovery after stroke in animal models, but the mechanisms underlying these effects remain incompletely understood. We tested the efficacy of Good Manufacturing Practices (GMP) compliant hBM-MSC, injected intravenously 3.5 hours after injury in mice subjected to transient middle cerebral artery occlusion (tMCAo). We addressed whether hBM-MSC are efficacious and if this efficacy is associated with cortical circuit reorganization using neuroanatomical analysis of GABAergic neurons (parvalbumin; PV-positive cells) and perineuronal nets (PNN), a specialized extracellular matrix structure which acts as an inhibitor of neural plasticity. tMCAo mice receiving hBM-MSC, showed early and lasting improvement of sensorimotor and cognitive functions compared to control tMCAo mice. Furthermore, 5 weeks post-tMCAo, hBM-MSC induced a significant rescue of ipsilateral cortical neurons; an increased proportion of PV-positive neurons in the perilesional cortex, suggesting GABAergic interneurons preservation; and a lower percentage of PV-positive cells surrounded by PNN, indicating an enhanced plastic potential of the perilesional cortex. These results show that hBM-MSC improve functional recovery and stimulate neuroprotection after stroke. Moreover, the downregulation of “plasticity brakes” such as PNN suggests that hBM-MSC treatment stimulates plasticity and formation of new connections in the perilesional cortex.

Modification of Bone Marrow Stem Cells for Homing and Survival During Cerebral Ischemia

Over the last decade, major advances have been made in stem cell-based therapy for ischemic stroke, which is one of the leading causes of death and disability worldwide. Various stem cells from bone marrow, such as mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), and endothelial progenitor cells (EPCs), have shown therapeutic potential for stroke. Concomitant with these exciting findings are some fundamental bottlenecks that must be overcome in order to accelerate their clinical translation, including the low survival and engraftment caused by the harsh microenvironment after transplantation. In this chapter, strategies such as gene modification, hypoxia/growth factor preconditioning, and biomaterial-based methods to improve cell survival and homing are summarized, and the potential strategies for their future application are also discussed.

Bone marrow mesenchymal stem cell therapy in ischemic stroke: mechanisms of action and treatment optimization strategies

Animal and clinical studies have confirmed the therapeutic effect of bone marrow mesenchymal stem cells on cerebral ischemia, but their mechanisms of action remain poorly understood. Here, we summarize the transplantation approaches, directional migration, differentiation, replacement, neural circuit reconstruction, angiogenesis, neurotrophic factor secretion, apoptosis, immunomodulation, multiple mechanisms of action, and optimization strategies for bone marrow mesenchymal stem cells in the treatment of ischemic stroke. We also explore the safety of bone marrow mesenchymal stem cell transplantation and conclude that bone marrow mesenchymal stem cell transplantation is an important direction for future treatment of cerebral ischemia. Determining the optimal timing and dose for the transplantation are important directions for future research.

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

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Research progress in rehabilitation treatment of stroke patients: A bibliometric analysis

Background:

Stroke presents as a transient or chronic brain dysfunction and is associated with high morbidity and high mortality. The doctors and scientists would like to argue how to enhance the validity of the rehabilitation treatment and how to further improve the level of treatment on stroke.

Objective:

The aim of this study was to quantitatively analyze the current worldwide progress in research on stroke rehabilitation treatment based on Web of Science database and ClinicalTrial.gov in the past 10 years.

Methods:

We conducted a quantitative analysis of clinical trial articles regarding stroke rehabilitation published in English from 2003 to 2013 and indexed in the National Institutes of Health Clinical Trials registry and Web of Science databases. Data were downloaded on March 15, 2013.

Results:

(1) From 2003 to 2013, 2 654 clinical trials investigating stroke were indexed in ClinicalTrials.gov. There were only 58 clinical trials registered in 2003, and there was a marked increase from 2005. A total of 605 clinical trials on the rehabilitation of stroke were conducted in the past 10 years. (2) The analysis showed that most of the trials in the field were registered by North American institutions. With respect to the Asian countries, China and Taiwan area of China also published a reasonable proportion of the trials, but comparatively speaking, the number of trials is really rare. Most of the interventions were drugs, followed by the devices, and behavioral interventions were ranked third. (3) In the past 10 years, there were 4 052 studies on stroke indexed by Web of Science database.

Conclusion:

From perspective of research progress, we found that the number of clinical trials and papers on stroke rehabilitation has increased significantly in the past 10 years, between them a remarkable positive correlation exists.

Multipotent neural crest stem cell-like cells from rat vibrissa dermal papilla induce neuronal differentiation of PC12 cells

Bone marrow mesenchymal stem cells (BMSCs) transplants have been approved for treating central nervous system (CNS) injuries and diseases; however, their clinical applications are limited. Here, we model the therapeutic potential of dermal papilla cells (DPCs) in vitro. DPCs were isolated from rat vibrissae and characterized by immunocytofluorescence, RT-PCR, and multidifferentiation assays. We examined whether these cells could secrete neurotrophic factors (NTFs) by using cocultures of rat pheochromocytoma cells (PC12) with conditioned medium and ELISA assay. DPCs expressed Sox10, P75, Nestin, Sox9, and differentiated into adipocytes, osteoblasts, smooth muscle cells, and neurons under specific inducing conditions. The DPC-conditioned medium (DPC-CM) induced neuronal differentiation of PC12 cells and promoted neurite outgrowth. Results of ELISA assay showed that compared to BMSCs, DPCs secreted more brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF). Moreover, we observed that, compared with the total DPC population, sphere-forming DPCs expressed higher levels of Nestin and P75 and secreted greater amounts of GDNF. The DPCs from craniofacial hair follicle papilla may be a new and promising source for treating CNS injuries and diseases.

Stem cell-like dog placenta cells afford neuroprotection against ischemic stroke model via heat shock protein upregulation

In this study, we investigated the dog placenta as a viable source of stem cells for stroke therapy. Immunocytochemical evaluation of phenotypic markers of dog placenta cells (DPCs) cultured in proliferation and differentiation medium revealed that DPCs expressed both stem cell and neural cell markers, respectively. Co-culture with DPCs afforded neuroprotection of rat primary neural cells in a dose-dependent manner against oxygen-glucose deprivation. Subsequent in vivo experiments showed that transplantation of DPCs, in particular intravenous and intracerebral cell delivery, produced significant behavioral recovery and reduced histological deficits in ischemic stroke animals compared to those that received intra-arterial delivery of DPCs or control stroke animals. Furthermore, both in vitro and in vivo studies implicated elevated expression of heat shock protein 27 (Hsp27) as a potential mechanism of action underlying the observed therapeutic benefits of DPCs in stroke. This study supports the use of stem cells for stroke therapy and implicates a key role of Hsp27 signaling pathway in neuroprotection.

Update on therapeutic mechanism for bone marrow stromal cells in ischemic stroke

Cerebral ischemia is a major cause of morbidity and mortality in the aged population, as well as a tremendous burden on the healthcare system. Despite timely treatment with thrombolysis and percutaneous intravascular interventions, many patients are often left with irreversible neurological deficits. Bone marrow stromal cells (BMSCs), also referred to as mesenchymal stem cells (MSCs), are a type of nonhematopoietic stem cells which exists in bone marrow mesh, with the potential to self-renew. Unlike cells in the central nervous system, BMSCs differentiate not only into mesodermal cells, but also endodermal and ectodermal cells. Moreover, it has been reported that BMSCs develop into cells with neural and vascular markers and play a role in recovery from ischemic stroke. These findings have fuelled excitement in regenerative medicine for neurological diseases, especially for ischemic stroke. There is now preclinical evidence to suggest that BMSCs grafted into the brain of ischemic models abrogate neurological deficits. Based on the overwhelming evidence from animal studies as well as in clinical trials, BMSC transplantation is considered a promising strategy for treatment of ischemic stroke. The goal of this review is to present an integrated consideration of molecular mechanisms in a chronological fashion and discuss an optimal BMSC delivery route for ischemic stroke.