The immunomodulatory effect of bone marrow stromal cells (BMSCs) on interleukin (IL)-23/IL-17-mediated ischemic stroke in mice

Therapeutic Efficacy and Migration of Mesenchymal Stem Cells after Intracerebral Transplantation in Rats with Experimental Ischemic Stroke

We studied therapeutic efficacy and migration characteristics of mesenchymal stem cells isolated from the human placenta after their intracerebral (stereotactic) administration to rats with the experimental ischemic stroke. It was shown that cell therapy significantly improved animal survival rate and reduced the severity of neurological deficit. New data on the migration pathways of transplanted cells in the brain were obtained.

Dynamic MRI of the Mesenchymal Stem Cells Distribution during Intravenous Transplantation in a Rat Model of Ischemic Stroke

Systemic transplantation of mesenchymal stem cells (MSCs) is a promising approach for the treatment of ischemia-associated disorders, including stroke. However, exact mechanisms underlying its beneficial effects are still debated. In this respect, studies of the transplanted cells distribution and homing are indispensable. We proposed an MRI protocol which allowed us to estimate the dynamic distribution of single superparamagnetic iron oxide labeled MSCs in live ischemic rat brain during intravenous transplantation after the transient middle cerebral artery occlusion. Additionally, we evaluated therapeutic efficacy of cell therapy in this rat stroke model. According to the dynamic MRI data, limited numbers of MSCs accumulated diffusely in the brain vessels starting at the 7th minute from the onset of infusion, reached its maximum by 29 min, and gradually eliminated from cerebral circulation during 24 h. Despite low numbers of cells entering brain blood flow and their short-term engraftment, MSCs transplantation induced long lasting improvement of the neurological deficit, but without acceleration of the stroke volume reduction compared to the control animals during 14 post-transplantation days. Taken together, these findings indicate that MSCs convey their positive action by triggering certain paracrine mechanisms or cell-cell interactions or invoking direct long-lasting effects on brain vessels.

Therapeutic strategies targeting inflammation and immunity in atherosclerosis: how to proceed?

Atherosclerosis is a chronic inflammatory disease of the arterial wall, characterized by the formation of plaques containing lipid, connective tissue and immune cells in the intima of large and medium-sized arteries. Over the past three decades, a substantial reduction in cardiovascular mortality has been achieved largely through LDL-cholesterol-lowering regimes and therapies targeting other traditional risk factors for cardiovascular disease, such as hypertension, smoking, diabetes mellitus and obesity. However, the overall benefits of targeting these risk factors have stagnated, and a huge global burden of cardiovascular disease remains. The indispensable role of immunological components in the establishment and chronicity of atherosclerosis has come to the forefront as a clinical target, with proof-of-principle studies demonstrating the benefit and challenges of targeting inflammation and the immune system in cardiovascular disease. In this Review, we provide an overview of the role of the immune system in atherosclerosis by discussing findings from preclinical research and clinical trials. We also identify important challenges that need to be addressed to advance the field and for successful clinical translation, including patient selection, identification of responders and non-responders to immunotherapies, implementation of patient immunophenotyping and potential surrogate end points for vascular inflammation. Finally, we provide strategic guidance for the translation of novel targets of immunotherapy into improvements in patient outcomes.

In this Review, the authors provide an overview of the immune cells involved in atherosclerosis, discuss preclinical research and published and ongoing clinical trials assessing the therapeutic potential of targeting the immune system in atherosclerosis, highlight emerging therapeutic targets from preclinical studies and identify challenges for successful clinical translation.

Inflammation is an important component of the pathophysiology of cardiovascular disease; an imbalance between pro-inflammatory and anti-inflammatory processes drives chronic inflammation and the formation of atherosclerotic plaques in the vessel wall.

Clinical trials assessing canakinumab and colchicine therapies in atherosclerotic cardiovascular disease have provided proof-of-principle of the benefits associated with therapeutic targeting of the immune system in atherosclerosis.

The immunosuppressive adverse effects associated with the systemic use of anti-inflammatory drugs can be minimized through targeted delivery of anti-inflammatory drugs to the atherosclerotic plaque, defining the window of opportunity for treatment and identifying more specific targets for cardiovascular inflammation.

Implementing immunophenotyping in clinical trials in patients with atherosclerotic cardiovascular disease will allow the identification of immune signatures and the selection of patients with the highest probability of deriving benefit from a specific therapy.

Clinical stratification via novel risk factors and discovery of new surrogate markers of vascular inflammation are crucial for identifying new immunotherapeutic targets and their successful translation into the clinic.

Strategies to Improve the Efficiency of Transplantation with Mesenchymal Stem Cells for the Treatment of Ischemic Stroke: A Review of Recent Progress

Cerebral ischemia is a common global disease that is characterized by a loss of neurological function and a poor prognosis in many patients. However, only a limited number of treatments are available for this condition at present. Given that the efficacies of these treatments tend to be poor, cerebral ischemia can create a significant burden on patients, families, and society. Mesenchymal stem cell (MSC) transplantation treatment has shown significant potential in animal models of ischemic stroke; however, the specific mechanisms underlying this effect have yet to be elucidated. Furthermore, clinical trials have yet to yield promising results. Consequently, there is an urgent need to identify new methods to improve the efficiency of MSC transplantation as an optimal treatment for ischemic stroke. In this review, we provide an overview of recent scientific reports concerning novel strategies that promote MSC transplantation as an effective therapeutic approach, including physical approaches, chemical agents, traditional Chinese medicines and extracts, and genetic modification. Our analyses showed that two key factors need to be considered if we are to improve the efficacy of MSC transplantation treatments: survival ability and homing ability. We also highlight the importance of other significant mechanisms, including the enhanced activation of MSCs to promote neurogenesis and angiogenesis, and the regulation of permeability in the blood-brain barrier. Further in-depth investigations of the specific mechanisms underlying MSC transplantation treatment will help us to identify effective methods that improve the efficiency of MSC transplantation for ischemic stroke. The development of safer and more effective methods will facilitate the application of MSC transplantation as a promising adjuvant therapy for the treatment of poststroke brain damage.

Progress in Mesenchymal Stem Cell Therapy for Ischemic Stroke

Ischemic stroke (IS) is a serious cerebrovascular disease with high morbidity and disability worldwide. Despite the great efforts that have been made, the prognosis of patients with IS remains unsatisfactory. Notably, recent studies indicated that mesenchymal stem cell (MSCs) therapy is becoming a novel research hotspot with large potential in treating multiple human diseases including IS. The current article is aimed at reviewing the progress of MSC treatment on IS. The mechanism of MSCs in the treatment of IS involved with immune regulation, neuroprotection, angiogenesis, and neural circuit reconstruction. In addition, nutritional cytokines, mitochondria, and extracellular vesicles (EVs) may be the main mediators of the therapeutic effect of MSCs. Transplantation of MSCs-derived EVs (MSCs-EVs) affords a better neuroprotective against IS when compared with transplantation of MSCs alone. MSC therapy can prolong the treatment time window of ischemic stroke, and early administration within 7 days after stroke may be the best treatment opportunity. The deliver routine consists of intraventricular, intravascular, intranasal, and intraperitoneal. Furthermore, several methods such as hypoxic preconditioning and gene technology could increase the homing and survival ability of MSCs after transplantation. In addition, MSCs combined with some drugs or physical therapy measures also show better neurological improvement. These data supported the notion that MSC therapy might be a promising therapeutic strategy for IS. And the application of new technology will promote MSC therapy of IS.

Psoriasis: Comorbidities

Psoriasis has long been known as a disease with many complications, but was attributed to diet and obesity. However, in recent years, psoriasis itself has been recognized as a series of systemic inflammatory diseases, and that the cytokines involved can induce a variety of other diseases. Individuals with psoriasis were also found to have higher incidences of cerebral and cardiovascular diseases and a younger age at death compared to healthy individuals. However, no clear guidelines have been defined regarding how much vascular lesion testing should be performed in patients with psoriasis. In this report, I attempt to unravel the objective data on psoriasis and its complications from various reviews and reports, and introduce the impact of biologics, which are currently the main treatment for psoriasis, on cardiac vascular disease.

Intra-Arterial Stem Cell Transplantation in Experimental Stroke in Rats: Real-Time MR Visualization of Transplanted Cells Starting With Their First Pass Through the Brain With Regard to the Therapeutic Action

Cell therapy is an emerging approach to stroke treatment with a potential to limit brain damage and enhance its restoration after the acute phase of the disease. In this study we tested directly reprogrammed neural precursor cells (drNPC) derived from adult human bone marrow cells in the rat middle cerebral artery occlusion (MCAO) model of acute ischemic stroke using human placenta mesenchymal stem cells (pMSC) as a positive control with previously confirmed efficacy. Cells were infused into the ipsilateral (right) internal carotid artery of male Wistar rats 24 h after MCAO. The main goal of this work was to evaluate real-time distribution and subsequent homing of transplanted cells in the brain. This was achieved by performing intra-arterial infusion directly inside the MRI scanner and allowed transplanted cells tracing starting from their first pass through the brain vessels. Immediately after transplantation, cells were observed in the periphery of the infarct zone and in the brain stem, 15 min later small numbers of cells could be discovered deep in the infarct core and in the contralateral hemisphere, where drNPC were seen earlier and in greater numbers than pMSC. Transplanted cells in both groups could no longer be detected in the rat brain 48-72 h after infusion. Histological and histochemical analysis demonstrated that both the drNPC and pMSC were localized inside blood vessels in close contact with the vascular wall. No passage of labeled cells through the blood brain barrier was observed. Additionally, the therapeutic effects of drNPC and pMSC were compared. Both drNPC and pMSC induced substantial attenuation of neurological deficits evaluated at the 7th and 14th day after transplantation using the modified neurological severity score (mNSS). Some of the effects of drNPC and pMSC, such as the influence on the infarct volume and the survival rate of animals, differed. The results suggest a paracrine mechanism of the positive therapeutic effects of IA drNPC and pMSC infusion, potentially enhanced by the cell-cell interactions. Our data also indicate that the long-term homing of transplanted cells in the brain is not necessary for the brain's functional recovery.

Evaluating the effect of transplanting umbilical cord matrix stem cells on ischemic tolerance in an animal model of stroke

OBJECTIVE

Stroke, a cerebrovascular disease, has been introduced as the second cause of death and physical disability in the world. Recently, cell-based therapy has been considered by the scientific community as a promising strategy for reducing ischemic damages. The stem cells of the umbilical cord release growth and neurotrophic factors. The remarkable properties of these cells are the reason why they were selected as a potential candidate in the present research.

METHODS

In this study, the impact of transplanting umbilical cord stem cells on injuries resulting from ischemia was investigated. The male rats were categorized into three major. Using stereotaxic surgery, stem cells were injected to the right striatum of the brain. One week after transplantation, cerebral ischemic induction surgery was performed. The rats in the transplantation + ischemia group were separately divided into distinct sub-groups to explore the score of the neurological deficits, infarction volume, integrity of the blood-brain barrier, and brain edema.

RESULTS

In this study, a significant decrease was observed in the neurological deficits of the transplantation + ischemia group compared with those of the control group. Similarly, the volume of infarction, the permeability of the blood-brain barrier, and edema were significantly reduced in the transplantation + ischemia group in comparison with those of the control group.

CONCLUSION

The pretreatment of the transplanted umbilical cord stem cells in the striatum of ischemic rats possibly leads to restorative events, exerting a decreasing effect on cell death. Subsequently, these events may improve the motor ability and reduce ischemic injuries.

Interleukin-17 and ischaemic stroke

Interleukin-17 (IL-17) is a cytokine family that includes 6 members, IL-17A through IL-17F, most of them are reported to have pro-inflammatory role. Through binding to their receptors (IL-17Rs), IL-17 activates the intracellular signalling pathways to play an important role in autoimmune diseases, including rheumatoid arthritis (RA) and multiple sclerosis (MS). Ischaemic stroke is a complex pathophysiological process mainly caused by regional cerebral ischaemia. Inflammatory factors contribute to the physiological process of stroke that leads to poor prognosis. IL-17 plays a crucial role in promoting inflammatory response and inducing secondary injury in post-stroke. Though immune cells and inflammatory factors have been reported to be involved in the damage of stroke, the functions of IL-17 in this process need to be elucidated. This review focuses on the pathological modulation and the mechanism of IL-17 family in ischaemic stroke and seeking to provide new insights for future therapies.

The role of the interleukin-23/Th17 pathway in cardiometabolic comorbidity associated with psoriasis

Alterations in the innate and adaptive immunity underpin psoriasis pathophysiology, with the Th17 cells subset now recognized as the fundamental cells in the key controlling pathway involved in its pathogenesis. Since psoriasis is a systemic disease with important comorbidity, further knowledge on the interleukin (IL)‐23/Th17 axis led to the hypothesis that there may be shared pathogenic pathways between primary skin disease and comorbidity. Psoriasis has been identified as a risk factor for cardiovascular and metabolic disease, and increasing evidence gives support to this epidemiological observation from the clinical‐pathologically field. As an example, increased levels of IL‐23 and IL‐23R have been found in human atherosclerotic plaque, and levels correlated with symptom duration and mortality. Also, upregulation of IL‐23/IL‐17 seems to play an important role in both myocardial damage and stroke, with interesting reports on deleterious effect neutralization after administration of related anti‐bodies in both associated conditions. In diabetic patients, increased levels of IL‐23/IL‐17 have also been observed and available data support a synergistic role of IL‐23/IL‐17 in β‐cells damage. In obesity, signs of an expansion of Th17 subset in adipose tissue have been reported, as well as elevated concentrations of IL‐23 in obese patients. In non‐alcoholic fatty liver disease, closely related to metabolic syndrome, but also in other mentioned cardiometabolic disorders, a predominance of IL‐23 and other related pro‐inflammatory factors has been identified as participating in their pathogenesis. Thus, the involvement of the IL‐23/Th17 axis in these shared psoriasis‐cardiometabolic pathogenic mechanisms is reviewed and discussed in the light of the existing preclinical and clinical evidence, including that from comorbid psoriasis patients.

The association between IL-17A and IL-23R polymorphisms and coronary artery disease risk in a Middle Eastern Chinese population

Background

Polymorphisms in IL‐17A and IL‐23R may affect the expression of these genes and could contribute to a patient's susceptibility to coronary artery disease (CAD). Although this association was investigated by previous studies, the relationship remains unclear.

Method

We conducted this hospital‐based case‐control study to determine whether polymorphisms in these two genes could be associated with a risk of CAD. A total of 191 patients and 131 controls, as determined by SXscore, were enrolled in this study. The genotyping was performed with the Sequenom MassARRAY platform.

Results

The results showed that that the FPG and HbA1C levels were higher in patients with CAD than in the controls. In addition, the HDL and ApoA1 levels were significantly higher in the controls than in the cases. In contrast, the Lp(a) level was significantly lower in the controls than in the patients. The IL‐17A rs2275913 and IL‐23R rs6682925 polymorphisms were associated with an increased risk of CAD (rs2275913: AA vs GG: crude OR = 2.16, 95% CI = 1.08‐4.30; AG/AA vs GG: crude OR = 1.81, 95% CI = 1.04‐3.15; rs6682925 CC vs TT: crude OR = 1.91, 95% CI = 1.00‐3.63). The subgroup analysis by SXscore revealed that the IL‐23R rs6682925 polymorphism (CT/CC vs TT: crude OR = 3.72, 95% CI = 1.19‐11.66) was associated with an increased risk of CAD in patients with a high SXscore.

Conclusion

This study suggested that T2DM, Lp(a), HDL‐c, and ApoA1 were risk factors of CAD and that the IL‐17A rs2275913 and IL‐23R rs6682925 polymorphisms may contribute to susceptibility to CAD.

Neutrophil-mediated and low density lipoprotein receptor-mediated dual-targeting nanoformulation enhances brain accumulation of scutellarin and exerts neuroprotective effects against ischemic stroke

Delivery of poorly permeable drugs across the blood-brain barrier (BBB) is a great challenge in the treatment of ischemic stroke.

Transplanting Mesenchymal Stem Cells for Treatment of Ischemic Stroke

Stroke is a major disease that leads to high mortality and morbidity. Given the ageing population and the potential risk factors, the prevalence of stroke and socioeconomic burden associated with stroke are expected to increase. During the past decade, both prophylactic and therapeutic strategies for stroke have made significant progress. However, current therapies still cannot adequately improve the outcomes of stroke and may not apply to all patients. One of the significant advances in modern medicine is cell-derived neurovascular regeneration and neuronal repair. Progress in stem cell biology has greatly contributed to ameliorating stroke-related brain injuries in preclinical studies and demonstrated clinical potential in stroke treatment. Mesenchymal stem cells (MSCs) have the differentiating potential of chondrocytes, adipocytes, and osteoblasts, and they have the ability to transdifferentiate into endothelial cells, glial cells, and neurons. Due to their great plasticity, MSCs have drawn much attention from the scientific community. This review will focus on MSCs, stem cells widely utilized in current medical research, and evaluate their effect and potential of improving outcomes in ischemic stroke.

Inflammatory cytokines and cells are potential markers for patients with cerebral apoplexy in intensive care unit

Cerebral apoplexy is a disease caused by obstruction of the blood circulation in the brain. Evidence has indicated that inflammatory cytokines are implicated in ischaemic cerebral apoplexy and are regarded as a general cardiovascular risk factor, which may be a possible immediate trigger, a component of the response to tissue injury and a therapeutic target. The present study investigated changes of inflammatory cytokines and cells in patients with cerebral apoplexy at the intensive care unit (ICU). The plasma concentrations of inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-8, IL-10, IL-1β and IL-17A were evaluated using ELISA. Changes in the plasma concentrations of inflammatory cells were detected by using flow cytometry. The results indicated that serum levels of TNF-α, IL-4, IL-8, IL-1β and IL-17A were upregulated in patients with cerebral apoplexy compared with those in healthy individuals, while those of IL-6 and IL-10 were downregulated. Furthermore, it was demonstrated that the plasma concentration of lymphocytes, granulocytes and mononuclear cells was decreased in patients with cerebral apoplexy in the ICU compared with that in healthy individuals. Of note, humoral as well as cellular inflammatory cytokines were evidently increased in patients with cerebral apoplexy in ICU. In conclusion, the present study provided evidence that inflammatory cytokines and inflammatory cells are upregulated, while anti-inflammatory cytokines are downregulated in patients with cerebral apoplexy in an ICU setting. These results suggest that anti-inflammatory interventions may be beneficial either in the prevention or acute treatment of patients with cerebral apoplexy.

Neutrophil affinity for PGP and HAIYPRH (T7) peptide dual-ligand functionalized nanoformulation enhances the brain delivery of tanshinone IIA and exerts neuroprotective effects against ischemic stroke by inhibiting proinflammatory signaling pathways

A great challenge to the therapy of ischemic stroke is the poor physicochemical properties and inability of the drug to cross the blood–brain barrier (BBB).

Human Neural Stem Cells for Ischemic Stroke Treatment

Ischemic stroke is the second most common cause of death worldwide and a major cause of disability. It takes place when the brain does not receive sufficient blood supply due to the blood clot in the vessels or narrowing of vessels' inner space due to accumulation of fat products. Apart from thrombolysis (dissolving of blood clot) and thrombectomy (surgical removal of blood clot or widening of vessel inner area) during the first hours after an ischemic stroke, no effective treatment to improve functional recovery exists in the post-ischemic phase. Due to their narrow therapeutic time window, thrombolysis and thrombectomy are unavailable to more than 80% of stroke patients.Many experimental studies carried out in animal models of stroke have demonstrated that stem cell transplantation may become a new therapeutic strategy in stroke. Transplantation of stem cells of different origin and stage of development has been shown to lead to improvement in experimental models of stroke through several mechanisms including neuronal replacement, modulation of cellular and synaptic plasticity and inflammation, neuroprotection and stimulation of angiogenesis. Several clinical studies and trials based on stem cell delivery in stroke patients are in progress with goal of improvements of functional recovery through mechanisms other than neuronal replacement. These approaches may provide therapeutic benefit, but generation of specific neurons for reconstruction of stroke-injured neural circuitry remains ultimate challenge. For this purpose, neural stem cells could be developed from multiple sources and fated to adopt required neuronal phenotype.

Comparisons of the therapeutic effects of three different routes of bone marrow mesenchymal stem cell transplantation in cerebral ischemic rats

Bone marrow mesenchymal stem cells (BMSCs) are mainly administered via three routes: intra-arterial, intravenous and intracerebral. It has been reported that BMSC administration via each route ameliorates the functional deficits after cerebral ischemia. However, there have been no comparisons of the therapeutic benefits of BMSC administration through different delivery routes. In this study, we injected BMSCs into a rat model of transient middle cerebral artery occlusion (MCAO) through the intra-arterial, intravenous, or intracerebral route at day 7 after MCAO. Control animals received only the vehicle. Neurological function was assessed at post-ischemic days (PIDs) 1, 7, 14, 21, 28 and 35 using behavioral tests (modified Neurological Severity Score (mNSS) and the adhesive removal test). At PID 35, the rat brain tissues were processed for histochemical and immunohistochemical staining. Our results showed that BMSC transplantation via the intra-arterial, intravenous, and intracerebral routes induced greater improvement in neurological functions than the control treatments; furthermore, the intra-arterial route showed the greatest degree and speed of neurological functional recovery. Moreover, BMSCs treatment through each route enhanced reconstruction of axonal myelination in the area of the corpus callosum on the infarct side of the cerebral hemisphere, increased the expression of SYN and Ki-67, and decreased the expression of Nogo-A in the brain. These effects were more apparent in the intra-arterial group than in the intravenous and intracerebral groups. These data suggest that BMSCs transplantation, especially through intra-arterial delivery, can effectively improve neurological function intra-arterial. The underlying mechanism may include the promotion of synaptogenesis, endogenous cell proliferation, and axonal regeneration.

Aneurysmal subarachnoid hemorrhage lead to systemic upregulation of IL-23/IL-17 inflammatory axis

IL-23 and IL-17 are pro-inflammatory cytokines. IL-23 is secreted by activated macrophages and dendritic cells, while IL-17 by Th17 cells. Serum IL-23 and IL-17 are known to be elevated in numerous inflammatory diseases including neurodegenerative diseases. The role of serum IL-23 and IL-17 in aneurysmal subarachnoid hemorrhage (aSAH) has still not been investigated. The present work investigates the serum IL-23 and IL-17 levels and their association with post hemorrhagic complications and clinical outcome in patients with aSAH.

METHODS

In this study, 80 patients with aSAH (Hunt and Hess grade I-V) were prospectively recruited. We enrolled 24 control patients with lumbar spinal stenosis. Peripheral venous blood was withdrawn from controls and from aSAH patients at day 1 and day 7, allowed to clot and centrifuged to obtain serum. Enzyme linked immunoassay kits were employed to quantify the serum levels of IL-23 and IL-17 by applying 50µL of serum samples. Post hemorrhagic complications and clinical outcome were documented prospectively from patient's hospital record.

RESULTS

Serum IL-23 and IL-17 levels were significantly elevated in aSAH patients at day 1 and day 7 (n=80) as compared to control patients (n=24). Further analysis after dichotomy of patients who suffered from post hemorrhagic complications including cerebral vasospasm, chronic hydrocephalus, seizures, cerebral ischemia, delayed neurological deficits showed differential correlations with different post hemorrhagic complications (Table 1). Serum IL-23 and IL-17 levels did not correlate with clinical outcome.

CONCLUSION

Serum IL-23 and IL-17 levels were elevated in patients with aSAH showing upregulation of IL-23/IL-17 inflammatory axis after aSAH. Serum IL-23 and IL-17 showed differential correlations with post hemorrhagic complications and no correlation with clinical outcome.

Effect of human mesenchymal stem cell transplantation on cerebral ischemic volume-controlled photothrombotic mouse model

Various animal models of stroke have been developed to simulate the human stroke with the development of the ischemic method facilitates preclinical stroke research. The photothrombotic ischemia model, based on the intravascular photochemical reaction, is widely used for in vivo studies. However, this study has limitations, which generated a relatively small‐sized infarction model on superficial cortex compared to that of the MCAO stroke model. In this study, the photothorombosis mouse model is adapted and the optimum conditions for generation of cell death and deficits with high reproducibility is determined. The extent of damage within the cortex was assessed by infarct volume and cellular/behavioral analyses. In this model, the neural cell death and inflammatory responses is detected; moreover, the degree of behavioral impairment is correlated with the brain infarct volume. Further, to enhance the understanding of neural repair, the effect of neural differentiation by transplantation of human bone marrow‐derived mesenchymal stem cells (BM‐MSCs) is analyzed. The authors demonstrated that transplantation of BM‐MSCs promoted the neural differentiation and behavioral performance in their photothrombosis model. Therefore, this research was meaningful to provide a stable animal model of stroke with low variability. Moreover, this model will facilitate development of novel MSC‐based therapeutics for stroke.

The effect of ultrasound for increasing neural differentiation in hBM-MSCs and inducing neurogenesis in ischemic stroke model

AIMS

This study's purpose was to evaluate the effect of ultrasound in air at a frequency of 0.04MHz and an intensity of 50mW/cm² on neural differentiation of hBM-MSCs in vitro and on neurogenesis in an ischemic stroke model.

MATERIALS AND METHODS

hBM-MSCs were exposed to 0.04MHz ultrasound and then compared with no exposed one in cell morphology, lactate dehydrogenase (LDH) activity, RT-PCR, and Western blot. In addition, we made stroke model mice by means of the photothrombosis (PT) method and these models were exposed to 0.04MHz ultrasound after hBM-MSCs injection. We compared with sham group in histological and immunohistochemical analysis and western blot.

KEY FINDINGS

Ultrasound induced neural differentiation without cell death. In stroke models, inflammatory cells were observed around the infarct area in the Cell, Cell/Ultrasound group and the brain infarct volume in the Cell/Ultrasound group was smaller than in the sham group. Further, the expression of neural proteins in the Cell/Ultrasound group was increased relative to the sham group.

SIGNIFICANCE

The present study showed that ultrasound promotes neural differentiation of hBM-MSC and neurogenesis in a mouse stroke model. This may be applicable as a therapeutic device with the aim of inducing neurogenesis following stroke.

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.

Stem Cell Ophthalmology Treatment Study (SCOTS): improvement in serpiginous choroidopathy following autologous bone marrow derived stem cell treatment

We report results in a 77-year-old male patient with visual loss from long-standing serpiginous choroidopathy treated with bone marrow derived stem cells (BMSC) within the Stem Cell Ophthalmology Treatment Study (SCOTS). SCOTS is an Institutional Review Board approved clinical trial and the largest ophthalmology stem cell study registered at the National Institutes of Health to date (ClinicalTrials.gov Identifier: NCT01920867). Eight months after treatment by a combination of retrobulbar, subtenon, intravitreal and intravenous injection of BMSC, the patient's best corrected Snellen acuity improved from 20/80^– to 20/60⁺¹ in the right eye and from 20/50^– to 20/20^–3 in the left eye. The Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity continued to improve over the succeeding 8 months and the optical coherence tomography macular volume increased. The increases in visual acuity and macular volume are encouraging and suggest that the use of BMSC as provided in SCOTS may be a viable approach to treating serpiginous choroidopathy.

Rational modulation of the innate immune system for neuroprotection in ischemic stroke

The innate immune system plays a dualistic role in the evolution of ischemic brain damage and has also been implicated in ischemic tolerance produced by different conditioning stimuli. Early after ischemia, perivascular astrocytes release cytokines and activate metalloproteases (MMPs) that contribute to blood–brain barrier (BBB) disruption and vasogenic oedema; whereas at later stages, they provide extracellular glutamate uptake, BBB regeneration and neurotrophic factors release. Similarly, early activation of microglia contributes to ischemic brain injury via the production of inflammatory cytokines, including tumor necrosis factor (TNF) and interleukin (IL)-1, reactive oxygen and nitrogen species and proteases. Nevertheless, microglia also contributes to the resolution of inflammation, by releasing IL-10 and tumor growth factor (TGF)-β, and to the late reparative processes by phagocytic activity and growth factors production. Indeed, after ischemia, microglia/macrophages differentiate toward several phenotypes: the M1 pro-inflammatory phenotype is classically activated via toll-like receptors or interferon-γ, whereas M2 phenotypes are alternatively activated by regulatory mediators, such as ILs 4, 10, 13, or TGF-β. Thus, immune cells exert a dualistic role on the evolution of ischemic brain damage, since the classic phenotypes promote injury, whereas alternatively activated M2 macrophages or N2 neutrophils prompt tissue remodeling and repair. Moreover, a subdued activation of the immune system has been involved in ischemic tolerance, since different preconditioning stimuli act via modulation of inflammatory mediators, including toll-like receptors and cytokine signaling pathways. This further underscores that the immuno-modulatory approach for the treatment of ischemic stroke should be aimed at blocking the detrimental effects, while promoting the beneficial responses of the immune reaction.

The potential use of mesenchymal stem cells in stroke therapy--From bench to bedside

Stroke is the second main cause of morbidity and mortality worldwide. The rationale for the use of mesenchymal stem cells (MSCs) in stroke is based on the capacity of MSCs to secrete a large variety of bioactive molecules such as growth factors, cytokines and chemokines leading to reduction of inflammation, increased neurogenesis from the germinative niches of central nervous system, increased angiogenesis, effects on astrocytes, oligodendrocytes and axons. This review presents the data derived from experimental studies and the evidence available from clinical trials about the use of MSCs in stroke therapy.

Interleukin 23 levels are increased in carotid atherosclerosis: possible role for the interleukin 23/interleukin 17 axis

BACKGROUND AND PURPOSE

Interleukin (IL)-23 is a cytokine in the IL-12 family, mainly produced by antigen-presenting cells with a central role in inflammation. We hypothesize that IL-23 is also important in atherogenesis and investigate this in a population with carotid atherosclerosis.

METHODS

Plasma levels of IL-23 were measured in patients with carotid artery stenosis and in healthy controls. The mRNA levels of IL-23 and its receptor, IL-23R, were measured in atherosclerotic plaques, nonatherosclerotic vessels, peripheral blood mononuclear cells, and plasmacytoid dendritic cells.

RESULTS

Our findings were as follows: (1) patients with carotid atherosclerosis (n=177) had significantly raised plasma levels of IL-23 when compared with healthy controls (n=24) with particularly high levels in those with the most recent symptoms. (2) mRNA levels of IL-23 and IL-23R were markedly increased in carotid plaques (n=68) when compared with nonatherosclerotic vessels (n=8-10). Immunostaining showed colocalization to plaque macrophages. (3) Patients with carotid atherosclerosis had increased mRNA levels of both IL-23 and IL-23R in plasmacytoid dendritic cells, but not in peripheral blood mononuclear cells. (4) IL-23 increased IL-17 release in monocytes and particularly in peripheral blood mononuclear cells from patients with carotid atherosclerosis, but not in cells from healthy controls. (5) IL-23 gave a prominent tumor necrosis factor release in monocytes from patients with carotid atherosclerosis but not in cells from healthy controls. (6) High plasma levels of IL-23 were associated with increased mortality during follow-up.

CONCLUSIONS

We have shown an association between IL-23 and disease progression in patients with carotid atherosclerosis, potentially involving IL-17-related mechanisms.

Pivotal role of cerebral interleukin-23 during immunologic injury in delayed cerebral ischemia in mice

BACKGROUND

Interleukin-23 (IL-23) is required for T helper 17 (Th17) cell responses and IL-17 production in ischemic stroke. We previously showed that the IL-23/IL-17 axis aggravates immune injury after cerebral infarction in mice. However, IL-23 might activate other cytokines and transcription factor forkhead box P3 (Foxp3) production in cerebral ischemia. We aimed to determine whether IL-23p19 knockdown prevents cerebral ischemic injury by reducing ischemic-induced inflammation.

METHODS

Ischemic stroke models were established by permanent middle cerebral arterial occlusion (pMCAO) in male C57BL/6 mice. In vivo gene knockdown was achieved by intravenous delivery of lentiviral vectors (LVs) encoding IL-23p19 short hairpin RNA (LV-IL-23p19 shRNA). Enzyme-linked immunoassay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR) confirmed inhibitory efficiency. Behavioral deficits were evaluated by adhesive-removal somatic-sensory test. Brain infarct volume was measured at day 5 after pMCAO by 2,3,5-triphenyltetrazolium chloride (TTC) staining. Expression of IL-17, IL-4, interferon (IFN)-γ and Foxp3 in ischemic brain tissues were detected by qRT-PCR and Western blotting, respectively. Additionally, immunohistochemical staining located cytokines in ischemic brain tissues.

RESULTS

RNA interference knockdown of IL-23p19 resulted in improved neurological function and reduced infarct volume. IL-23p19 knockdown suppressed IL-17 gene and protein expression. Moreover, IL-23p19 deficiency enhanced IFN-γ and Foxp3 expressions in delayed cerebral ischemic mice, and did not impact IL-4 expression. Immunohistochemical staining showed that IL-17, IL-4, IFN-γ and Foxp3-positive cells were located around ischemic lesions of the ipsilateral hemisphere.

CONCLUSIONS

IL-23p19 knockdown prevents delayed cerebral ischemic injury by dampening the ischemia-induced inflammation, and is a promising approach for clinically managing ischemic stroke.

Damage effect of interleukin (IL)-23 on oxygen-glucose-deprived cells of the neurovascular unit via IL-23 receptor

Interleukin-23/interleukin-23 receptor (IL-23/IL-23R) has been implicated in many inflammatory diseases. Previous research mainly focused on its ability to induce IL-17 production from T cells. However, few studies have investigated its role in cerebral ischemic injury. The aim of our study was to explore the potential effect of IL-23 on cells of the neurovascular unit (NVU) under an oxygen-glucose deprivation (OGD) condition and the role of IL-23R in IL-23-mediated effect. OGD of primary cells of the NVU and permanent middle cerebral artery occlusion (pMCAO) were used to produce experimental stroke in vitro and in vivo, respectively. IL-23 and IL-23R were detected by immunohistochemistry and western blot in pMCAO mice. Metabolic viability of cultured cells was assessed by MTT assay. The cell-associated proteins (Bcl-2, AQP4 and ET-1) were determined by western blot and enzyme-linked immunosorbent assay (ELISA). Immunofluorescence staining and western blot were used to detect the IL-23R expression. The results showed that the expression of IL-23/IL-23R was elevated in pMCAO mice. IL-23 could aggravate neuron damage, astrocyte swelling, and further impair the integrity of blood-brain barrier induced by OGD. In addition, the effect of IL-23 on cells of the NVU is mediated by IL-23R and is likely IL-23R-expression-level dependent. However, there are no such biological properties for the IL-23p19 subunit alone. Our study provides the first evidence that IL-23 has a toxic effect on cells of the NVU under OGD stress, which is mediated by IL-23R. These results not only help us better understand the role of IL-23/IL-23R in brain ischemia, but also provide a potential therapeutic target in stroke.

Immunomodulatory characteristics of mesenchymal stem cells and their role in the treatment of multiple sclerosis

Multiple Sclerosis (MS) is a chronic inflammatory neurodegenerative disease of central nervous system (CNS). Although the main cause of MS is not clear, studies suggest that MS is an autoimmune disease which attacks myelin sheath of neurons. There are different therapeutic regimens for MS patients including interferon (IFN)-β, glatiramer acetate (GA), and natalizumab. However, such therapies are not quite effective and are associated with some side effects. So which, there is no complete therapeutic method for MS patients. Regarding the potent immunomodulatory effects of mesenchymal stem cells (MSCs) and their ameliorative effects in experimental autoimmune encephalopathy (EAE), it seems that MSCs may be a new therapeutic method in MS therapy. MSC transplantation is an approach to regulate the immune system in the region of CNS lesions. In this review, we have tried to discuss about the immunomodulatory properties of MSCs and their therapeutic mechanisms in MS patients.

Multipotent stromal cells for arthritic joint pain therapy and beyond

Multipotent stromal cells (MSCs) have been studied as a candidate for cell-based therapy for a variety of conditions including joint diseases. Clinical studies have used MSCs to treat arthritis and related joint diseases and generated encouraging results. There is improved joint cartilage tissues and functional activity, along with reduction of pain. MSCs may also possess intrinsic analgesic properties. Studies have shown MSC-induced pain relief in animal models and the opioids are involved in this effect. Beyond tissue repair, MSCs may not need to be grafted to the injury site to produce an effect. It is hypothesized that MSCs interact with the host immune cells and the relayed signal helps to produce and maintain a long-lasting therapeutic effect including pain relief.

Activation of innate immune-response genes in little brown bats (Myotis lucifugus) infected with the fungus Pseudogymnoascus destructans

Recently bats have been associated with the emergence of diseases, both as reservoirs for several new viral diseases in humans and other animals and, in the northern Americas, as hosts for a devastating fungal disease that threatens to drive several bat species to regional extinction. However, despite these catastrophic events little Information is available on bat defences or how they interact with their pathogens. Even less is known about the response of bats to infection during torpor or long-term hibernation. Using tissue samples collected at the termination of an experiment to explore the pathogenesis of White Nose Syndrome in Little Brown Bats, we determined if hibernating bats infected with the fungus Pseudogymnoascus destructans could respond to infection by activating genes responsible for innate immune and stress responses. Lesions due to fungal infection and, in some cases, secondary bacterial infections, were restricted to the skin. However, we were unable to obtain sufficient amounts of RNA from these sites. We therefore examined lungs for response at an epithelial surface not linked to the primary site of infection. We found that bats responded to infection with a significant increase in lungs of transcripts for Cathelicidin (an anti-microbial peptide) as well as the immune modulators tumor necrosis factor alpha and interleukins 10 and 23. In conclusion, hibernating bats can respond to experimental P. destructans infection by activating expression of innate immune response genes.