A human neural stem cell line provides neuroprotection and improves neurological performance by early intervention of neuroinflammatory system

A taurine-based hydrogel with the neuroprotective effect and the ability to promote neural stem cell proliferation

Ischemic stroke, a cerebrovascular disease caused by arterial occlusion in the brain, can lead to brain impairment and even death. Stem cell therapies have shown positive advantages to treat ischemic stroke because of their extended time window, but the cell viability is poor when transplanted into the brain directly. Therefore, a new hydrogel GelMA-T was developed by introducing taurine on GelMA to transplant neural stem cells. The GelMA-T displayed the desired photocuring ability, micropore structure, and cytocompatibility. Its compressive modulus was more similar to neural tissue compared to that of GelMA. The GelMA-T could protect SH-SY5Y cells from injury induced by OGD/R. Furthermore, the NE-4C cells showed better proliferation performance in GelMA-T than that in GelMA during both 2D and 3D cultures. All results demonstrate that GelMA-T possesses a neuroprotective effect for ischemia/reperfusion injury against ischemic stroke and plays a positive role in promoting NSC proliferation. The novel hydrogel is anticipated to function as cell vehicles for the transplantation of neural stem cells into the stroke cavity, aiming to treat ischemic stroke.

The Role of Stem Cells as Therapeutics for Ischaemic Stroke

Stroke remains one of the leading causes of death and disability worldwide. Current reperfusion treatments for ischaemic stroke are limited due to their narrow therapeutic window in rescuing ischaemic penumbra. Stem cell therapy offers a promising alternative. As a regenerative medicine, stem cells offer a wider range of treatment strategies, including long-term intervention for chronic patients, through the reparation and replacement of injured cells via mechanisms of differentiation and proliferation. The purpose of this review is to evaluate the therapeutic role of stem cells for ischaemic stroke. This paper discusses the pathology during acute, subacute, and chronic phases of cerebral ischaemic injury, highlights the mechanisms involved in mesenchymal, endothelial, haematopoietic, and neural stem cell-mediated cerebrovascular regeneration, and evaluates the pre-clinical and clinical data concerning the safety and efficacy of stem cell-based treatments. The treatment of stroke patients with different types of stem cells appears to be safe and efficacious even at relatively higher concentrations irrespective of the route and timing of administration. The priming or pre-conditioning of cells prior to administration appears to help augment their therapeutic impact. However, larger patient cohorts and later-phase trials are required to consolidate these findings.

Comparative study of the efficacy of intra-arterial and intravenous transplantation of human induced pluripotent stem cells-derived neural progenitor cells in experimental stroke

Background

Cell therapy using neural progenitor cells (NPCs) is a promising approach for ischemic stroke treatment according to the results of multiple preclinical studies in animal stroke models. In the vast majority of conducted animal studies, the therapeutic efficacy of NPCs was estimated after intracerebral transplantation, while the information of the effectiveness of systemic administration is limited. Nowadays, several clinical trials aimed to estimate the safety and efficacy of NPCs transplantation in stroke patients were also conducted. In these studies, NPCs were transplanted intracerebrally in the subacute/chronic phase of stroke. The results of clinical trials confirmed the safety of the approach, however, the degree of functional improvement (the primary efficacy endpoint) was not sufficient in the majority of the studies. Therefore, more studies are needed in order to investigate the optimal transplantation parameters, especially the timing of cell transplantation after the stroke onset. This study aimed to evaluate the therapeutic effects of intra-arterial (IA) and intravenous (IV) administration of NPCs derived from induced pluripotent stem cells (iNPCs) in the acute phase of experimental stroke in rats. Induced pluripotent stem cells were chosen as the source of NPCs as this technology is perspective, has no ethical concerns and provides the access to personalized medicine.

Methods

Human iNPCs were transplanted IA or IV into male Wistar rats 24 h after the middle cerebral artery occlusion stroke modeling. Therapeutic efficacy was monitored for 14 days and evaluated in comparison with the cell transplantation-free control group. Additionally, cell distribution in the brain was assessed.

Results

The obtained results show that both routes of systemic transplantation (IV and IA) significantly reduced the mortality and improved the neurological deficit of experimental animals compared to the control group. At the same time, according to the MRI data, only IA administration led to faster and prominent reduction of the stroke volume. After IA administration, iNPCs transiently trapped in the brain and were not detected on day 7 after the transplantation. In case of IV injection, transplanted cells were not visualized in the brain. The obtained data demonstrated that the systemic transplantation of human iNPCs in the acute phase of ischemic stroke can be a promising therapeutic strategy.

Enhancing structural plasticity of PC12 neurons during differentiation and neurite regeneration with a catalytically inactive mutant version of the zRICH protein

BACKGROUND

Studies of the molecular mechanisms of nerve regeneration have led to the discovery of several proteins that are induced during successful nerve regeneration. RICH proteins were identified as proteins induced during the regeneration of the optic nerve of teleost fish. These proteins are 2',3'-cyclic nucleotide, 3'-phosphodiesterases that can bind to cellular membranes through a carboxy-terminal membrane localization domain. They interact with the tubulin cytoskeleton and are able to enhance neuronal structural plasticity by promoting the formation of neurite branches.

RESULTS

PC12 stable transfectant cells expressing a fusion protein combining a red fluorescent protein with a catalytically inactive mutant version of zebrafish RICH protein were generated. These cells were used as a model to analyze effects of the protein on neuritogenesis. Differentiation experiments showed a 2.9 fold increase in formation of secondary neurites and a 2.4 fold increase in branching points. A 2.2 fold increase in formation of secondary neurites was observed in neurite regeneration assays.

CONCLUSIONS

The use of a fluorescent fusion protein facilitated detection of expression levels. Two computer-assisted morphometric analysis methods indicated that the catalytically inactive RICH protein induced the formation of branching points and secondary neurites both during differentiation and neurite regeneration. A procedure based on analysis of random field images provided comparable results to classic neurite tracing methods.

The Implications of Microglial Regulation in Neuroplasticity-Dependent Stroke Recovery

Stroke causes varying degrees of neurological deficits, leading to corresponding dysfunctions. There are different therapeutic principles for each stage of pathological development. Neuroprotection is the main treatment in the acute phase, and functional recovery becomes primary in the subacute and chronic phases. Neuroplasticity is considered the basis of functional restoration and neurological rehabilitation after stroke, including the remodeling of dendrites and dendritic spines, axonal sprouting, myelin regeneration, synapse shaping, and neurogenesis. Spatiotemporal development affects the spontaneous rewiring of neural circuits and brain networks. Microglia are resident immune cells in the brain that contribute to homeostasis under physiological conditions. Microglia are activated immediately after stroke, and phenotypic polarization changes and phagocytic function are crucial for regulating focal and global brain inflammation and neurological recovery. We have previously shown that the development of neuroplasticity is spatiotemporally consistent with microglial activation, suggesting that microglia may have a profound impact on neuroplasticity after stroke and may be a key therapeutic target for post-stroke rehabilitation. In this review, we explore the impact of neuroplasticity on post-stroke restoration as well as the functions and mechanisms of microglial activation, polarization, and phagocytosis. This is followed by a summary of microglia-targeted rehabilitative interventions that influence neuroplasticity and promote stroke recovery.

Dying transplanted neural stem cells mediate survival bystander effects in the injured brain

Neural stem and progenitor cell (NSPC) transplants provide neuroprotection in models of acute brain injury, but the underlying mechanisms are not fully understood. Here, we provide evidence that caspase-dependent apoptotic cell death of NSPCs is required for sending survival signals to the injured brain. The secretome of dying NSPCs contains heat-stable proteins, which protect neurons against glutamate-induced toxicity and trophic factor withdrawal in vitro, and from ischemic brain damage in vivo. Our findings support a new concept suggesting a bystander effect of apoptotic NSPCs, which actively promote neuronal survival through the release of a protective "farewell" secretome. Similar protective effects by the secretome of apoptotic NSPC were also confirmed in human neural progenitor cells and neural stem cells but not in mouse embryonic fibroblasts (MEF) or human dopaminergic neurons, suggesting that the observed effects are cell type specific and exist for neural progenitor/stem cells across species.

Rho-Kinase inhibition decreases focal cerebral ischemia-induced glial activation in rats

Background

Rho-kinase inhibition in a rat middle cerebral artery occlusion (MCAO) model is reported to improve neurological functions and decrease infarction size.

Objective

The objective of this study is to investigate the underlying mechanisms of such improvement by evaluating the effects of Rho-kinase inhibition on astrocytes and microglial accumulation and activation in this condition.

Methods

Adult male Sprague-Dawley (SD) rats were used to generate the MCAO model, which received an I.P injection of a chemical Rho-kinase inhibitor (Fasudil- 5 mg/kg/day) or vehicle (PBS) for 2 and 4 days.

Results

Fasudil treatment significantly decreased the stroke volumes and water content in the lesion areas, as revealed by MRI. Immunostaining and Western blotting results demonstrated that Fasudil significantly decreased the levels of Aquaporin-4, a water channel protein. The number of GFAP⁺ astrocytes and Iba-1⁺ macrophage/microglia was decreased in the lesion areas. Proinflammatory transcription factor NF-κB protein levels were decreased in the Fasudil group 2 days after MCAO. Also, proinflammatory mediators including TNF-α, IL-1β, and iNOS levels were decreased. In vitro migration study using a human microglial cell line (HMO6) confirmed the inhibitory effects of Fasudil on the process. Fasudil also decreased combined IL-1β and IFNγ-induced NF-κB nuclear translocation in HMO6. Moreover, Fasudil transiently decreased combined IL-1β and IFNγ-induced iNOS, TNFα, and IL-1β mRNA levels in HMO6.

Conclusion

Our study demonstrates the inhibitory effects of Rho-kinase on NF-κB-mediated glial activation and cerebral edema, which might be a promising therapeutic target in acute cerebral ischemia conditions.

Berberine Ameliorates Cognitive Impairment by Regulating Microglial Polarization and Increasing Expression of Anti-inflammatory Factors following Permanent Bilateral Common Carotid Artery Occlusion in Rats

BACKGROUND

Chronic cerebral hypoperfusion is associated with vascular cognitive impairment, and there are no specific therapeutic agents for use in clinical practice. Berberine has demonstrated good neuroprotective effects in models of acute cerebral ischemia; however, whether it can alleviate cognitive impairment caused by chronic cerebral hypoperfusion has rarely been investigated.

OBJECTIVE

The present study aimed to explore the mechanism by which berberine alleviates cognitive impairment resulting from chronic cerebral hypoperfusion.

METHODS

Forty-two male Sprague-Dawley rats were randomly divided into three groups: sham, model, and berberine. The models of chronic cerebral hypoperfusion were established via permanent bilateral common carotid artery occlusion (BCCAO). Cognitive function was evaluated using the Morris water maze, while neuronal damage and microglial activation and polarization were evaluated using western blotting and immunofluorescence, respectively. Enzyme-linked immunosorbent assays were used to detect the expression of anti-inflammatory factors including interleukin- 4 (IL-4) and interleukin-10 (IL-10).

RESULTS

Rats exhibited cognitive dysfunction after BCCAO, which was significantly attenuated following the berberine intervention. Levels of synaptophysin and NeuN were decreased in states of chronic cerebral hypoperfusion, during which microglial activation and a transition from the M2 to M1 phenotype were observed. Berberine treatment also significantly reversed these features. Moreover, levels of IL-4 and IL-10 expression increased significantly after berberine treatment.

CONCLUSION

Berberine may mitigate vascular cognitive dysfunction by promoting neuronal plasticity, inhibiting microglial activation, promoting transformation from an M1 to an M2 phenotype, and increasing levels of IL-4 and IL-10 expression.

Identification of a Four-Gene Signature Associated with the Prognosis Prediction of Lung Adenocarcinoma Based on Integrated Bioinformatics Analysis

Lung adenocarcinoma (LUAD) is often diagnosed at an advanced stage, so it is necessary to identify potential biomarkers for the early diagnosis and prognosis of LUAD. In our study, a gene co-expression network was constructed using weighted gene co-expression network analysis (WGCNA) in order to obtain the key modules and genes correlated with LUAD prognosis. Four hub genes (HLF, CHRDL1, SELENBP1, and TMEM163) were screened out using least absolute shrinkage and selection operator (LASSO)–Cox regression analysis; then, a prognostic model was established for predicting overall survival (OS) based on these four hub genes..Furthermore, the prognostic values of this four-gene signature were verified in four validation sets (GSE26939, GSE31210, GSE72094, and TCGA-LUAD) as well as in the GEPIA database. To assess the prognostic values of hub genes, receiver operating characteristic (ROC) curves were constructed and a nomogram was created. We found that a higher expression of four hub genes was associated with a lower risk of patient death. In a training set, it was demonstrated that this four-gene signature was a better prognostic factor than clinical factors such as age and stage of disease. Moreover, our results revealed that these four genes were suppressor factors of LUAD and that their high expression was associated with a lower risk of death. In summary, we demonstrated that this four-gene signature could be a potential prognostic factor for LUAD patients. These findings provide a theoretical basis for exploring potential biomarkers for LUAD prognosis prediction in the future.

Understanding neural stem cell regulation in vivo and applying the insights to cell therapy for strokes

The use of neural stem cell (NSC) therapy for the treatment of stroke patients is successfully paving its way into advanced phases of large-scale clinical trials. To understand how to optimize NSC therapeutic approaches, it is fundamental to decipher the crosstalk between NSC and other cells that comprise the NSC microenvironment (niche) and regulate their function, in vivo; namely, the endothelial cells of the microvasculature. In this mini review, we first provide a concise summary of preclinical findings describing the signaling mechanisms between NSC and vascular endothelial cells and vice versa. Second, we describe the progress made in the development of NSC therapy for the treatment of strokes.

Potential Mechanisms and Perspectives in Ischemic Stroke Treatment Using Stem Cell Therapies

Ischemic stroke (IS) remains one of the major causes of death and disability due to the limited ability of central nervous system cells to regenerate and differentiate. Although several advances have been made in stroke therapies in the last decades, there are only a few approaches available to improve IS outcome. In the acute phase of IS, mechanical thrombectomy and the administration of tissue plasminogen activator have been widely used, while aspirin or clopidogrel represents the main therapy used in the subacute or chronic phase. However, in most cases, stroke patients fail to achieve satisfactory functional recovery under the treatments mentioned above. Recently, cell therapy, especially stem cell therapy, has been considered as a novel and potential therapeutic strategy to improve stroke outcome through mechanisms, including cell differentiation, cell replacement, immunomodulation, neural circuit reconstruction, and protective factor release. Different stem cell types, such as mesenchymal stem cells, marrow mononuclear cells, and neural stem cells, have also been considered for stroke therapy. In recent years, many clinical and preclinical studies on cell therapy have been carried out, and numerous results have shown that cell therapy has bright prospects in the treatment of stroke. However, some cell therapy issues are not yet fully understood, such as its optimal parameters including cell type choice, cell doses, and injection routes; therefore, a closer relationship between basic and clinical research is needed. In this review, the role of cell therapy in stroke treatment and its mechanisms was summarized, as well as the function of different stem cell types in stroke treatment and the clinical trials using stem cell therapy to cure stroke, to reveal future insights on stroke-related cell therapy, and to guide further studies.

Huoluo Yinao decoction mitigates cognitive impairments after chronic cerebral hypoperfusion in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Huoluo Yinao decoction (HLYND) has been used to ameliorate cognitive impairment induced by chronic cerebral hypoperfusion in clinical for years. However, the exact mechanisms remain unknown.

AIM OF THE STUDY

To investigate the effects and mechanisms underlying HLYND-mediated improvement in cognitive deficits associated with chronic cerebral hypoperfusion.

MATERIALS AND METHODS

Thirty-six Sprague-Dawley rats were randomly allocated to three groups: sham, model, and HLYND. Daily administration of HLYND or volume-matched vehicle by gavage was initiated 1 day after bilateral carotid artery stenosis (BCAS) and continued for 42 days. The Morris water maze (MWM) test was used to assess cognitive functions from days 36-42. Via western blot and immunofluorescent staining, restoration of neuronal plasticity and remyelination of white matter were evaluated by analyzing the expression profiles of MAP-2, synaptophysin and MBP. In addition, macrophage/microglial activation was assessed by quantifying changes in Iba1, and macrophage/microglial polarization was assessed by changes in iNOS and CD16 (M1 markers), as well as Arg1 and CD206 (M2 markers).

RESULTS

In the MWM test, BCAS rats showed significantly extended escape latency and reduced platform crossing times, while those in the HLYND group had shortened escape latency and increased frequency of platform crossing. In addition, rats in the model group showed decreased levels and abnormal morphological changes of MAP-2, synaptophysin and MBP, whereas HLYND administration reversed these effects. As expected, Iba1 levels were elevated in both the model and HLYND groups but rats in the model group showed increased levels of the M1 markers, iNOS and CD16, and a correspondent decrease in the M2 marker, Arg1. In contrast, in the HLYND group, iNOS and CD16 levels were suppressed, while Arg1 levels were elevated.

CONCLUSIONS

Our findings demonstrate that HLYND mitigates cognitive impairment after chronic cerebral hypoperfusion in rats through mechanisms involving increased neuronal plasticity and white matter remyelination, with a subtile modulation of macrophage/microglial polarization toward the M2 phenotype.

Neural stem cell therapy for stroke: A multimechanistic approach to restoring neurological function

INTRODUCTION

Neural stem cells (NSCs) have demonstrated multimodal therapeutic function for stroke, which is the leading cause of long-term disability and the second leading cause of death worldwide. In preclinical stroke models, NSCs have been shown to modulate inflammation, foster neuroplasticity and neural reorganization, promote angiogenesis, and act as a cellular replacement by differentiating into mature neural cell types. However, there are several key technical questions to address before NSC therapy can be applied to the clinical setting on a large scale.

PURPOSE OF REVIEW

In this review, we will discuss the various sources of NSCs, their therapeutic modes of action to enhance stroke recovery, and considerations for the clinical translation of NSC therapies. Understanding the key factors involved in NSC-mediated tissue recovery and addressing the current translational barriers may lead to clinical success of NSC therapy and a first-in-class restorative therapy for stroke patients.

Review of the Current Knowledge on the Role of Stem Cell Transplantation in Neurorehabilitation

The management involving stem cell (SC) therapy along with physiotherapy offers tremendous chance for patients after spinal cord injury (SCI), traumatic brain injury (TBI), stroke, etc. However, there are still only a limited number of reports assessing the impact of stem cells (SCs) on the rehabilitation process and/or the results of the simultaneous use of SC and rehabilitation. Additionally, since there is still not enough convincing evidence about the effect of SCT on humans, e.g., in stroke, there have been no studies conducted concerning rehabilitation program formation and expected outcomes. It has been shown that bone marrow-derived mesenchymal stem cell (BMSCs) transplantation in rats combined with hyperbaric oxygen therapy (HBO) can promote the functional recovery of hind limbs after SCI. An anti-inflammatory effect has been shown. One case study showed that, after the simultaneous use of SCT and rehabilitation, an SCI patient progressed from ASIA Grade A to ASIA Grade C. Such promising data in the case of complete tetraplegia could be a breakthrough in the treatment of neurologic disorders in humans. Although SCT appears as a promising method for the treatment of neurological conditions, e.g., complete tetraplegia, much work should be done towards the development of rehabilitation protocols.

Exogenous neural stem cell transplantation for cerebral ischemia

Cerebral ischemic injury is the main manifestation of stroke, and its incidence in stroke patients is 70–80%. Although ischemic stroke can be treated with tissue-type plasminogen activator, its time window of effectiveness is narrow. Therefore, the incidence of paralysis, hypoesthesia, aphasia, dysphagia, and cognitive impairment caused by cerebral ischemia is high. Nerve tissue regeneration can promote the recovery of the aforementioned dysfunction. Neural stem cells can participate in the reconstruction of the damaged nervous system and promote the recovery of nervous function during self-repair of damaged brain tissue. Neural stem cell transplantation for ischemic stroke has been a hot topic for more than 10 years. This review discusses the treatment of ischemic stroke with neural stem cells, as well as the mechanisms of their involvement in stroke treatment.

Repetitive transcranial magnetic stimulation promotes functional recovery and differentiation of human neural stem cells in rats after ischemic stroke

Stem cells hold great promise as a regenerative therapy for ischemic stroke by improving functional outcomes in animal models. However, there are some limitations regarding the cell transplantation, including low rate of survival and differentiation. Repetitive transcranial magnetic stimulation (rTMS) has been widely used in clinical trials as post-stroke rehabilitation in ischemic stroke and has shown to alleviate functional deficits following stroke. The present study was designed to evaluate the therapeutic effects and mechanisms of combined human neural stem cells (hNSCs) with rTMS in a middle cerebral artery occlusion (MCAO) rat model. The results showed that human embryonic stem cells (hESCs) were successfully differentiated into forebrain hNSCs for transplantation and hNSCs transplantation combined with rTMS could accelerate the functional recovery after ischemic stroke in rats. Furthermore, this combination not only significantly enhanced neurogenesis and the protein levels of brain-derived neurotrophic factor (BDNF), but also rTMS promoted the neural differentiation of hNSCs. Our findings are presented for the first time to evaluate therapeutic benefits of combined hNSCs and rTMS for functional recovery after ischemic stroke, and indicated that the combination of hNSCs with rTMS might be a potential novel therapeutic target for the treatment of stroke.

Neural stem cell therapy-Brief review

Adult mammalian neural stem cells are unique because of their properties, such as differentiation capacity, self-renewal, quiescence, and also because they exist in specific niches, which are the subventricular zone (SVZ) and subgranular zone (SGZ) - the dentate gyrus of the hippocampus. SVZ is situated along the ependymal cell layer, dividing the ventricular area and subventricular zone. There are several sources of neural stem cells such as human embryonic stem cells, human fetal brain-derived neural stem/progenitor cells, human induced pluripotent stem cells, direct reprogrammed astrocytes. Stem cell sciences are a promising tool for research purposes as well as therapy. Induced pluripotent stem cells appear to be very useful for human neuron studies, allowing the creation of defined neuron populations, particularly for neurodevelopmental and neurodegenerative diseases as well as ischemic events. Neural stem cell sciences have a promising future in terms of stem cell therapy as well as research. There is, however, still a great need for further research to overcome obstacles.

A novel scoring system for gastric cancer risk assessment based on the expression of three CLIP4 DNA methylation-associated genes

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-associated mortality worldwide. In the current study, comprehensive bioinformatic analyses were performed to develop a novel scoring system for GC risk assessment based on CAP-Gly domain containing linker protein family member 4 (CLIP4) DNA methylation status. Two GC datasets with methylation sequencing information and mRNA expression profiling were downloaded from the The Cancer Genome Atlas and Gene Expression Omnibus databases. Differentially expressed genes (DEGs) between the CLIP4 hypermethylation and CLIP4 hypomethylation groups were screened using the limma package in R 3.3.1, and survival analysis of these DEGs was performed using the survival package. A risk scoring system was established via regression factor-weighted gene expression based on linear combination to screen the most important genes associated with CLIP4 methylation and prognosis. Genes associated with high/low-risk value were selected using the limma package. Functional enrichment analysis of the top 500 DEGs that positively and negatively associated with risk values was performed using DAVID 6.8 online and the gene set enrichment analysis (GSEA) software. In total, 35 genes were identified to be that significantly associated with prognosis and CLIP4 DNA methylation, and three prognostic signature genes, claudin-11 (CLDN11), apolipoprotein D (APOD), and chordin like 1 (CHRDL1), were used to establish a risk assessment system. The prognostic scoring system exhibited efficiency in classifying patients with different prognoses, where the low-risk groups had significantly longer overall survival times than those in the high-risk groups. CLDN11, APOD and CHRDL1 exhibited reduced expression in the hypermethylation and low-risk groups compare with the hypomethylation and high-risk groups, respectively. Multivariate Cox analysis indicated that risk value could be used as an independent prognostic factor. In functional analysis, six functional gene ontology terms and five GSEA pathways were associated with CLDN11, APOD and CHRDL1. The results established the credibility of the scoring system in this study. Additionally, these three genes, which were significantly associated with CLIP4 DNA methylation and GC risk assessment, were identified as potential prognostic biomarkers.

Enhancing endogenous capacity to repair a stroke-damaged brain: An evolving field for stroke research

Stroke represents a severe medical condition that causes stroke survivors to suffer from long-term and even lifelong disability. Over the past several decades, a vast majority of stroke research targets neuroprotection in the acute phase, while little work has been done to enhance stroke recovery at the later stage. Through reviewing current understanding of brain plasticity, stroke pathology, and emerging preclinical and clinical restorative approaches, this review aims to provide new insights to advance the research field for stroke recovery. Lifelong brain plasticity offers the long-lasting possibility to repair a stroke-damaged brain. Stroke impairs the structural and functional integrity of entire brain networks; the restorative approaches containing multi-components have great potential to maximize stroke recovery by rebuilding and normalizing the stroke-disrupted entire brain networks and brain functioning. The restorative window for stroke recovery is much longer than previously thought. The optimal time for brain repair appears to be at later stage of stroke rather than the earlier stage. It is expected that these new insights will advance our understanding of stroke recovery and assist in developing the next generation of restorative approaches for enhancing brain repair after stroke.

Ginkgolide B promotes the proliferation and differentiation of neural stem cells following cerebral ischemia/reperfusion injury, both in vivo and in vitro

Neural stem cells have great potential for the development of novel therapies for nervous system diseases. However, the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central nervous system self-repair. Ginkgolide B has a robust neuroprotective effect. In this study, we investigated the cell and molecular mechanisms underlying the neuroprotective effect of ginkgolide B on focal cerebral ischemia/reperfusion injury in vitro and in vivo. Neural stem cells were treated with 20, 40 and 60 mg/L ginkgolide B in vitro. Immunofluorescence staining was used to assess cellular expression of neuron-specific enolase, glial fibrillary acid protein and suppressor of cytokine signaling 2. After treatment with 40 and 60 mg/L ginkgolide B, cells were large, with long processes. Moreover, the proportions of neuron-specific enolase-, glial fibrillary acid protein- and suppressor of cytokine signaling 2-positive cells increased. A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion. Six hours after ischemia, ginkgolide B (20 mg/kg) was intraperitoneally injected, once a day. Zea Longa’s method was used to assess neurological function. Immunohistochemistry was performed to evaluate the proportion of nestin-, neuron-specific enolase- and glial fibrillary acid protein-positive cells. Real-time quantitative polymerase chain reaction was used to measure mRNA expression of brain-derived neurotrophic factor and epidermal growth factor. Western blot assay was used to analyze the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2. Ginkgolide B decreased the neurological deficit score, increased the proportion of nestin-, neuron-specific enolase- and glial fibrillary acid protein-positive cells, increased the mRNA expression of brain-derived neurotrophic factor and epidermal growth factor, and increased the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2 in the ischemic penumbra. Together, the in vivo and in vitro findings suggest that ginkgolide B improves neurological function by promoting the proliferation and differentiation of neural stem cells in rats with cerebral ischemia/reperfusion injury.

Hypermethylation of the CHRDL1 promoter induces proliferation and metastasis by activating Akt and Erk in gastric cancer

CHRDL1 (Chordin-like 1) is a secreted protein that acts as an antagonist of bone morphogenetic protein (BMP). BMP plays a role as an activator of BMP receptor II (BMPR II), which mediates extracellular to intracellular signal transmission and is involved in carcinogenesis and metastasis. Herein, we report that CHRDL1 expression was significantly down-regulated in gastric cancer tissues and associated with poor survival. Clinic-pathological parameters demonstrated a close relationship between low CHRDL1 expression and metastasis. In vitro, CHRDL1 knockdown promoted tumor cell proliferation and migration through BMPR II by activating Akt, Erk and β-catenin. Furthermore, we observed the hypermethylation of the CHRDL1 promoter in gastric cancer, which induced low expression of CHRDL1 and decreased its secretion to the supernatant. Finally, in vivo experiments confirmed that CHRDL1 acted as a tumor suppressor gene in suppressing tumor growth and metastasis.

Induced Pluripotent Stem Cell-Derived Neural Stem Cell Therapy Enhances Recovery in an Ischemic Stroke Pig Model

Induced pluripotent stem cell-derived neural stem cells (iNSCs) have significant potential as an autologous, multifunctional cell therapy for stroke, which is the primary cause of long term disability in the United States and the second leading cause of death worldwide. Here we show that iNSC transplantation improves recovery through neuroprotective, regenerative, and cell replacement mechanisms in a novel ischemic pig stroke model. Longitudinal multiparametric magnetic resonance imaging (MRI) following iNSC therapy demonstrated reduced changes in white matter integrity, cerebral blood perfusion, and brain metabolism in the infarcted tissue. The observed tissue level recovery strongly correlated with decreased immune response, enhanced neuronal protection, and increased neurogenesis. iNSCs differentiated into neurons and oligodendrocytes with indication of long term integration. The robust recovery response to iNSC therapy in a translational pig stroke model with increased predictive potential strongly supports that iNSCs may be the critically needed therapeutic for human stroke patients.

Roles of electro-acupuncture in glucose metabolism as assessed by 18F-FDG/PET imaging and AMPKα phosphorylation in rats with ischemic stroke

Targeted energy metabolism balance contributes to neural survival during ischemic stroke. Herein, we tested the hypothesis that electro‑acupuncture (EA) can enhance cerebral glucose metabolism assessed by 18F‑fluorodeoxyglucose/positron emission tomography (18F‑FDG/PET) imaging to prevent propagation of tissue damage and improve neurological outcome in rats subjected to ischemia and reperfusion injury. Rats underwent middle cerebral artery occlusion (MCAO) and received EA treatment at the LI11 and ST36 acupoints or non‑acupoint treatment once a day for 7 days. After EA treatment, a significant reduction in the infarct volume was determined by T2‑weighted imaging, accompanied by the functional recovery in CatWalk and Rota-rod performance. Moreover, EA promoted higher glucose metabolism in the caudate putamen (CPu), motor cortex (MCTX), somatosensory cortex (SCTX) regions as assessed by animal 18F‑FDG/PET imaging, suggesting that three‑brain regional neural activity was enhanced by EA. In addition, the AMP‑activated protein kinase α (AMPKα) in the CPu, MCTX and SCTX regions was phosphorylated at threonine 172 (Thr172) after ischemic injury; however, phosphorylation of AMPK was further increased by EA. These results indicate that EA could promote AMPKα phosphorylation of the CPu, MCTX and SCTX regions to enhance neural activity and motor functional recovery after ischemic stroke.

Endoplasmic reticulum stress eIF2α-ATF4 pathway-mediated cyclooxygenase-2 induction regulates cadmium-induced autophagy in kidney

The heavy metal cadmium (Cd) is nephrotoxic. Recent studies show that autophagy plays an essential role in Cd-induced kidney injury. However, the mechanisms of Cd-induced kidney injury accompanied by autophagy are still obscure. In the present study, we first confirmed that Cd induced kidney damage and dysfunction, along with autophagy, both in vivo and in vitro. Then, we observed that cyclooxygenase-2 (COX-2) and the eIF2α-ATF4 pathway of endoplasmic reticulum (ER) stress were induced by Cd in both kidney tissues and cultured cells. Further studies showed that inhibition of COX-2 with celecoxib or RNA interference (RNAi) inhibited the Cd-induced autophagy in kidney cells. In addition, blocking ER stress with 4-phenylbutyrate or RNAi partially counteracted COX-2 overexpression and autophagy induced by Cd, which suggested that ER stress was required for Cd-induced kidney autophagy. Significantly, our results showed that Cd activated ATF4 and induced its translocation to the nucleus. Knockdown of ATF4 inhibited Cd-induced COX-2 overexpression. While COX-2 overexpression is involved in renal dysfunction, there is no prior report on the role of COX-2 in autophagy regulation. The results of the current study suggest a novel molecular mechanism that the ER stress eIF2α-ATF4 pathway-mediated COX-2 overexpression contributes to Cd-induced kidney autophagy and injury. The present study implies that COX-2 may be a potential target for therapy against Cd-induced nephrotoxicity.