Electroacupuncture promotes neural stem cell proliferation and neurogenesis in the dentate gyrus of rats following stroke via upregulation of Notch1 expression

Acupuncture for stroke: A bibliometric analysis of global research from 2000 to 2022

Objective

This study aimed to explore the global and future research trends in acupuncture interventions for stroke between 2000 and 2022 using bibliometric analysis.

Method

A bibliometric analysis of literature from 2000 to 2022 in the Web of Science Core Collection was conducted in this study. The analysis utilized CiteSpace, VOSviewer, and Scimago Graphica software to identify the major contributors to publications, including authors, countries, institutions, journals, references, and keywords.

Results

The bibliometric analysis yielded a total of 860 publications. There was a gradual increase in the number of publications over the study period. China published the most articles. Evidence-Based Complementary and Alternative Medicine was the journal with the greatest number of publications. The most frequently used keywords were "acupuncture," "stroke," and "electroacupuncture."

Conclusion

These analysis uncovers the research trends in acupuncture for stroke spanning 2000 to 2022 and points to prospective research frontiers. This study provides a deeper and more thorough understanding of the connotations of acupuncture for stroke and guidance and support for future research in this field.

Pin1 Downregulation Is Involved in Excess Retinoic Acid-Induced Failure of Neural Tube Closure

Neural tube defects (NTDs), which are caused by impaired embryonic neural tube closure, are one of the most serious and common birth defects. Peptidyl-prolyl cis/trans isomerase 1 (Pin1) is a prolyl isomerase that uniquely regulates cell signaling by manipulating protein conformation following phosphorylation, although its involvement in neuronal development remains unknown. In this study, we explored the involvement of Pin1 in NTDs and its potential mechanisms both in vitro and in vivo. The levels of Pin1 expression were reduced in NTD models induced by all-trans retinoic acid (Atra). Pin1 plays a significant role in regulating the apoptosis, proliferation, differentiation, and migration of neurons. Moreover, Pin1 knockdown significantly was found to exacerbate oxidative stress (OS) and endoplasmic reticulum stress (ERs) in neuronal cells. Further studies showed that the Notch1-Nrf2 signaling pathway may participate in Pin1 regulation of NTDs, as evidenced by the inhibition and overexpression of the Notch1-Nrf2 pathway. In addition, immunofluorescence (IF), co-immunoprecipitation (Co-IP), and GST pull-down experiments also showed that Pin1 interacts directly with Notch1 and Nrf2. Thus, our study suggested that the knocking down of Pin1 promotes NTD progression by inhibiting the activation of the Notch1-Nrf2 signaling pathway, and it is possible that this effect is achieved by disrupting the interaction of Pin1 with Notch1 and Nrf2, affecting their proteostasis. Our research identified that the regulation of Pin1 by retinoic acid (RA) and its involvement in the development of NTDs through the Notch1-Nrf2 axis could enhance our comprehension of the mechanism behind RA-induced brain abnormalities.

Effect and mechanism of acupuncture on endogenous and exogenous stem cells in disease treatment: A therapeutic review

Acupuncture is effective intervention, particularly in nerve, endocrine diseases and immune diseases. The potential mechanisms mediating the effects of acupuncture include anti-inflammatory and oxidative stress, inhibition of cell apoptosis, and stimulation of the proliferation and differentiation of endogenous stem cells. Traditional Chinese medicine combined with stem cell transplantation have a synergistic effect in the treatment of diseases. Increasing studies have found that acupuncture can promote the proliferation, differentiation, homing and survival of exogenous stem cells. This article reviews the mechanism of acupuncture and Chinese herbs on endogenous stem cells and exogenous stem cells in the combined intervention of diverse disorders and the major problems in past 15 years, which will provide a reference for future clinical research.

Disorders of the central nervous system: Insights from Notch and Nrf2 signaling

The functional complexity of the central nervous system (CNS) is unparalleled in living organisms. It arises from neural crest-derived cells that migrate by the exact route, leading to the formation of a complex network of neurons and glial cells. Recent studies have shown that novel crosstalk exists between the Notch1 and Nrf2 pathways and is associated with many neurological diseases. The Notch1-Nrf2 axis may act on nervous system development, and the molecular mechanism has recently been reported. In this review, we summarize the essential structure and function of the CNS. The significance of interactions between signaling pathways and between developmental processes like proliferation, apoptosis and migration in ensuring the correct development of the CNS is also presented. We primarily focus on research concerning possible mechanism of interaction between Notch1 and Nrf2 and the functions of Notch1-Nrf2 in neurons. There may be a direct interaction between Notch1 and NRF2, which is closely related to the crosstalk that occurs between them. The significance and potential applications of the Notch1-Nrf2 axis in abnormal development of the nervous system are been highlighten. We also discuss the molecular mechanisms by which the Notch1-Nrf2 axis controls the apoptosis, antioxidant pathway and differentiation of neurons to modulate the development of the nervous system. This information will lead to a better understanding of Notch1-Nrf2 axis signaling pathways in the nervous system and may facilitate the development of new therapeutic strategies.

Electroacupuncture reverses endothelial cell death and promotes angiogenesis through the VEGF/Notch signaling pathway after focal cerebral ischemia-reperfusion injury

BACKGROUND

Angiogenesis is an important mechanism of recovery from ischemic stroke. Recent studies have found that there is a close relationship between the VEGF/Notch pathway and angiogenesis. It is unknown whether EA can exert a brain protection effect and promote angiogenesis by acting on the VEGF/Notch signaling pathway after focal cerebral ischemia-reperfusion injury (CIRI).

METHODS

The Middle Cerebral Artery occlusion/Reperfusion (MCAo/R) model was established, in which rats were subjected to occlusion with ischemic intervention for 30 min, followed by reperfusion for 8 h, 1 day, 3 days, and 7 days. The first EA treatment was performed 90 min after the animal model was successfully established, and then EA treatments were performed once a day for 7 days. The 2,3,5-triphenyltetrazolium chloride staining and neurological deficit examination were performed to assess the level of CIRI and neuroprotection by EA. Expression levels of VEGFA, Notch1, and Hes1 proteins were measured via western blotting, while the morphological changes of ECs and microvasculature in the cortex were determined using an ultrastructural observation method.

RESULTS

EA treatment of PC6, GV26, and SP6 can significantly improve the neurological function of MCAO/R rats, reduce the volume of cerebral infarction, and modulate the ultrastructure of ECs and microvessels in pathological states. Western blotting revealed that EA increased VEGFA protein expression at 8 h and 3 days after CIRI, as well as Notch1 protein expression at 1 and 7 days. Subsequently, EA activated the VEGF/Notch pathway, increasing the expression of the downstream target protein Hes1, reversing EC death, and promoting angiogenesis.

CONCLUSION

Our findings showed that EA plays a role in promoting angiogenesis following focal CIRI, and we hypothesized that this was due to the regulation of ECs by the EA-activated VEGF/Notch signaling pathway.

The impact of acupuncture on neuroplasticity after ischemic stroke: a literature review and perspectives

Ischemic stroke is common in the elderly, and is one of the main causes of long-term disability worldwide. After ischemic stroke, spontaneous recovery and functional reconstruction take place. These processes are possible thanks to neuroplasticity, which involves neurogenesis, synaptogenesis, and angiogenesis. However, the repair of ischemic damage is not complete, and neurological deficits develop eventually. The WHO recommends acupuncture as an alternative and complementary method for the treatment of stroke. Moreover, clinical and experimental evidence has documented the potential of acupuncture to ameliorate ischemic stroke-induced neurological deficits, particularly sequelae such as dyskinesia, spasticity, cognitive impairment, and dysphagia. These effects are related to the ability of acupuncture to promote spontaneous neuroplasticity after ischemic stroke. Specifically, acupuncture can stimulate neurogenesis, activate axonal regeneration and sprouting, and improve the structure and function of synapses. These processes modify the neural network and function of the damaged brain area, producing the improvement of various skills and adaptability. Astrocytes and microglia may be involved in the regulation of neuroplasticity by acupuncture, such as by the production and release of a variety of neurotrophic factors, including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Moreover, the evidence presented indicates that acupuncture promotes neuroplasticity by modulating the functional reconstruction of the whole brain after ischemia. Therefore, the promotion of neuroplasticity is expected to become a new target for acupuncture in the treatment of neurological deficits after ischemic stroke, and research into the mechanisms responsible for these actions will be of significant clinical value.

Mechanism Underlying Acupuncture Therapy in Spinal Cord Injury: A Narrative Overview of Preclinical Studies

Spinal cord injury (SCI) results from various pathogenic factors that destroy the normal structure and function of the spinal cord, subsequently causing sensory, motor, and autonomic nerve dysfunction. SCI is one of the most common causes of disability and death globally. It leads to severe physical and mental injury to patients and causes a substantial economic burden on families and the society. The pathological changes and underlying mechanisms within SCI involve oxidative stress, apoptosis, inflammation, etc. As a traditional therapy, acupuncture has a positive effect promoting the recovery of SCI. Acupuncture-induced neuroprotection includes several mechanisms such as reducing oxidative stress, inhibiting the inflammatory response and neuronal apoptosis, alleviating glial scar formation, promoting neural stem cell differentiation, and improving microcirculation within the injured area. Therefore, the recent studies exploring the mechanism of acupuncture therapy in SCI will help provide a theoretical basis for applying acupuncture and seeking a better treatment target and acupuncture approach for SCI patients.

Targeting the Erk1/2 and autophagy signaling easily improved the neurobalst differentiation and cognitive function after young transient forebrain ischemia compared to old gerbils

The hippocampal neurogenesis occurs constitutively throughout adulthood in mammalian species, but declines with age. In this study, we overtly found that the neuroblast proliferation and differentiation in the subgranular zone and the maturation into fully functional and integrated neurons in the granule-cell layer in young gerbils following cerebral ischemia/reperfusion was much more than those in old gerbils. The neurological function and cognitive and memory-function rehabilitation in the young gerbils improved faster than those in the old one. These results demonstrated that, during long term after cerebral ischemia/reperfusion, the ability of neurogenesis and recovery of nerve function in young animals were significantly higher than that in the old animals. We found that, after 14- and 28-day cerebral ischemia/reperfusion, the phosphorylation of MEK1/2, ERK1/2, p90RSK, and MSK1/2 protein levels in the hippocampus of young gerbils was significantly much higher than that of old gerbils. The levels of autophagy-related proteins, including Beclin-1, Atg3, Atg5, and LC3 in the hippocampus were effectively maintained and elevated at 28 days after cerebral ischemia/reperfusion in the young gerbils compared with those in the old gerbils. These results indicated that an increase or maintenance of the phosphorylation of ERK1/2 signal pathway and autophagy-related proteins was closely associated with the neuroblast proliferation and differentiation and the process of maturation into neurons. Further, we proved that neuroblast proliferation and differentiation in the dentate gyrus and cognitive function were significantly reversed in young cerebral ischemic gerbils by administering the ERK inhibitor (U0126) and autophagy inhibitor (3MA). In brief, following experimental young ischemic stroke, the long-term promotion of the neurogenesis in the young gerbil’s hippocampal dentate gyrus by upregulating the phosphorylation of ERK signaling pathway and maintaining autophagy-related protein levels, it overtly improved the neurological function and cognitive and memory function.

Silencing of lncRNA XLOC_035088 Protects Middle Cerebral Artery Occlusion-Induced Ischemic Stroke by Notch1 Signaling

Ischemic stroke represents one of the leading causes of mortality worldwide and especially in developing countries. It is crucial for finding effective therapeutic targets that protect the brain against ischemic injury. Long noncoding RNAs (lncRNAs) have emerged as major regulators of neurological diseases, and clarifying their roles in cerebral ischemic injury may provide novel targets for the treatment of ischemic stroke. We aimed to investigate the role of lncRNA-XLOC_035088 in middle cerebral artery occlusion (MCAO)-induced rat brain injury and oxygen-glucose deprivation (OGD)-reperfusion treated hippocampal neurons. In our findings, we found that XLOC_035088 expression was significantly upregulated in OGD-reperfusion treated hippocampal neurons and in different brain regions of MCAO-treated rats. XLOC_035088 silencing protected against MCAO-induced ischemic brain injury in vivo and OGD-induced hippocampal neuronal apoptosis in vitro. Intrahippocampal silencing of XLOC_035088 significantly decreased brain XLOC_035088 expression, reduced brain infarct size, and improved neurological function through inhibiting NOTCH1 following derepression of presenilin 2 (PSEN2). Taken together, this study provides evidence that the lncRNA XLOC_035088/PSEN2/Notch1 axis is involved in the pathogenesis of ischemic brain injury, and presents a promising therapeutic route for ischemic stroke.

Intracerebral hemorrhage influences hippocampal neurogenesis and neurological function recovery via Notch1 signaling

Intracerebral hemorrhage (ICH) is associated with high rate of mortality and morbidity, but lacks effective therapies. Accumulating studies indicated that the hippocampal neurogenesis plays an essential role in the recovery of neurological function after ICH. The Notch1 signaling pathway shows important roles in neurogenesis. However, the effects of Notch1 on the recovery of neurological function after ICH remain unclear. Here, we used ICH mice model to investigate whether Notch1 signaling was involved in the hippocampal neurogenesis and the recovery of neurological function post-ICH. Our results showed that the rate of symmetric division pattern of hippocampal neural stem cells (NSCs) decreased significantly at 3 days after ICH. Meanwhile, the expression of Notch1 in the hippocampus also was reduced significantly. However, Notch1 activator treatment enhanced the expression of Notch1 and increased the number of Sox2+GFAP+ cells. Further, the rate of symmetric division pattern of NSCs also increased after Notch1 activator treatment in mice with ICH. Importantly, the number of DCX+ cells and BrdU+NeuN+ in hippocampus were increased on 28 days post-ICH as the Notch1 expression was upregulated. The motor function and spatial memory ability in post-ICH mice following Notch1 activator treatment also were improved. Taken together, our results suggested that Notch1 signaling could influence the recovery of long-term neurological function by regulating the proliferation and differentiation of the hippocampal NSCs in mice after ICH. Our study may provide ideas for the improvement of neurological function and spatial memory defects after ICH.

Mechanism underlying treatment of ischemic stroke using acupuncture: transmission and regulation

The inflammatory response after cerebral ischemia/reperfusion is an important cause of neurological damage and repair. After cerebral ischemia/reperfusion, microglia are activated, and a large number of circulating inflammatory cells infiltrate the affected area. This leads to the secretion of inflammatory mediators and an inflammatory cascade that eventually causes secondary brain damage, including neuron necrosis, blood-brain barrier destruction, cerebral edema, and an oxidative stress response. Activation of inflammatory signaling pathways plays a key role in the pathological process of ischemic stroke. Increasing evidence suggests that acupuncture can reduce the inflammatory response after cerebral ischemia/reperfusion and promote repair of the injured nervous system. Acupuncture can not only inhibit the activation and infiltration of inflammatory cells, but can also regulate the expression of inflammation-related cytokines, balance the effects of pro-inflammatory and anti-inflammatory factors, and interfere with inflammatory signaling pathways. Therefore, it is important to study the transmission and regulatory mechanism of inflammatory signaling pathways after acupuncture treatment for cerebral ischemia/reperfusion injury to provide a theoretical basis for clinical treatment of this type of injury using acupuncture. Our review summarizes the overall conditions of inflammatory cells, mediators, and pathways after cerebral ischemia/reperfusion, and discusses the possible synergistic intervention of acupuncture in the inflammatory signaling pathway network to provide a foundation to explore the multiple molecular mechanisms by which acupuncture promotes nerve function restoration.

Electro-Acupuncture Promotes the Differentiation of Endogenous Neural Stem Cells via Exosomal microRNA 146b After Ischemic Stroke

Background: Evidences indicate that exosomes-mediated delivery of microRNAs (miRNAs or miRs) is involved in the neurogenesis of stroke. This study was to investigate the role of exosomal miRNAs in non-drug therapy of electro-acupuncture (EA) regulating endogenous neural stem cells for stroke recovery.

Methods: The model of focal cerebral ischemia and reperfusion in rats were established by middle cerebral artery occlusion (MCAO) and treated by EA. The exosomes were extracted from peri-ischemic striatum and identified by exosomal biomarkers, and detected differentially expressed miRNAs with microarray chip. Primary stem cells were cultured, and oxygen–glucose deprivation and reperfusion (OGD/R) was used to mimic vitro ischemic injury.

Results: The levels of exosomal biomarkers TSG101 and CD81 were increased in peri-ischemic striatum after EA treatment, and we revealed 25 differentially expressed miRNAs in isolated exosomes, of which miR-146b was selected for further analysis, and demonstrated that EA increased miR-146b expression and its inhibitors could block the effects. Subsequently, we confirmed that EA upregulated miR-146b expression to promote neural stem cells differentiation into neurons in peri-ischemic striatum. In vitro, it was verified that OGD/R hindered neural stem cells differentiation, and miR-146b inhibitors furtherly suppressed its differentiation, simultaneously NeuroD1 was involved in neural stem cells differentiation into neurons. Moreover, in vivo we found EA promoted NeuroD1-mediated neural stem cells differentiation via miR-146b. In addition, EA also could improve neurological deficits through miR-146b after ischemic stroke.

Conclusion: EA promotes the differentiation of endogenous neural stem cells via exosomal miR-146b to improve neurological injury after ischemic stroke.

Modulation of hippocampal dopamine and synapse-related proteins by electroacupuncture improves memory deficit caused by sleep deprivation

BACKGROUND

Sleep is crucial for proper functioning of the brain, whereas lack of sleep is very common in modern society and can cause memory impairment. Hence, it is of great significance to find effective methods to intervene in the pathogenesis of memory impairment.

OBJECTIVE

We designed this study to explore the mechanism underlying the therapeutic effects of electroacupuncture (EA) on the deficits caused by sleep deprivation (SD).

METHODS

In this study, we first utilized the modified multiple platform method (MMPM) to establish a rat model of SD, which was followed by use of the Y-maze and Morris water maze (MWM) to assess the performance of rats following EA treatment.

RESULTS

We found that EA at GV20 and ST36 significantly decreased the number of error reactions, increased the number of active avoidance responses in the Y-maze and shortened the latency of finding the platform in the MWM test in SD + EA versus untreated SD groups. Moreover, EA treatment partially restored SD-induced reductions in hippocampal dopamine (DA) content and significantly increased the levels of phosphorylated (p) synapsin I, calcium/calmodulin-dependent protein kinase (CaMK) II, and tyrosine hydroxylase, which are related to the synthesis and release of DA.

CONCLUSIONS

In summary, we it appears that EA at GV20 and ST36 may improve SD-induced memory deficits by restoring the quantity of DA in the hippocampus, which is related to activation of CaMK II, synapsin I, and tyrosine hydroxylase. EA may have potential as an alternative therapy for SD and could improve learning and memory deficits among those suffering from sleep deficiency, although this needs verification by prospective clinical studies.

The Effects of Electroacupuncture in a Rat Model of Cerebral Ischemia-Reperfusion Injury Following Middle Cerebral Artery Occlusion Involves MicroRNA-223 and the PTEN Signaling Pathway

Background

In China, electroacupuncture (EA) is used to treat the symptoms of ischemic stroke. However, the mechanisms involved in the effects of EA in cerebral ischemia remain to be investigated. This study aimed to investigate the molecular mechanism underlying the effects of EA in a rat model of cerebral ischemia-reperfusion injury (CIRI) induced by middle cerebral artery occlusion (MCAO).

Material/Methods

Seventy-five male Sprague-Dawley rats were divided into five groups: the sham group (with sham surgery), the model group (the MCAO model), the EA group (treated with EA), the EA control group, and the EA+antagomir-223-3p group. Rats in the model of CIRI underwent MCAO for 90 minutes. EA was performed on the second postoperative day and was performed at the Waiguan (TE5) and Zusanli (ST36) acupoints. The rat brains were evaluated for structural and molecular markers.

Results

EA treatment significantly upregulated the expression of microRNA-223 (miR-223), NESTIN, and NOTCH1, and downregulated the expression of PTEN in the subventricular zone (SVZ) and hippocampus. The luciferase reporter assay supported that PTEN was a direct target of miR-223, and antagomiR-223-3p reversed the effects of EA and reduced the increase in NESTIN and inhibition of PTEN expression associated with EA treatment. There was a negative correlation between PTEN expression and the number of neural stem cells (NSCs).

Conclusions

In a rat model of CIRI following MCAO, EA activated the NOTCH pathway, promoted the expression of miR-223, increased the number of NSCs, and reduced the expression of PTEN.

The reporting quality of acupuncture for neurogenesis in experimental ischemic stroke study

Background

There is increasing evidence demonstrating the highly inadequate reporting of preclinical research in multiple scientific publications. The purpose of this study is to systematically investigate the reporting quality of acupuncture for neurogenesis in animal models of acute ischemic stroke.

Methods

We searched eight databases, including PubMed, EMBASE, CINAHL, AMED, Chinese National Knowledge Infrastructure, VIP information database, Wanfang data Information Site, and Chinese Biomedical Literature Database. The methodological quality of included studies was assessed by using the CAMARADES 10-item checklist. The STRICTA statement was modified to gear to animal acupuncture research. The reporting quality was assessed according to the ARRIVE guidelines and the modified STRICTA statement. Data were analyzed with descriptive statistics.

Results

Ultimately, 44 studies containing 2,411 subjects were identified. The overall compliance with the CAMARADES 10-item checklist has a mean of 4.3. The reporting quality indicated that the overall compliance with ARRIVE guidelines has a mean of 59.9% and with the modified STRICTA statement a mean of 71.8%. The findings suggest that the reporting quality of acupuncture for preclinical stroke was generally poor.

Conclusions

Full compliance with ARRIVE guidelines and/or modified STRICTA statement in designing, conducting and reporting preclinical acupuncture research is urgently needed in the future.

Mechanisms Involved in the Neuroprotection of Electroacupuncture Therapy for Ischemic Stroke

Stroke is one of the main causes of death all over the world. As the combination of acupuncture and electric stimulation, electroacupuncutre is a safe and effective therapy, which is commonly applied in ischemic stroke therapy in both experimental studies and clinical settings. The review was performed via searching for related articles in the databases of OVID, PUBMED, and ISI Web of Science from their respective inceptions to May 2018. In this review, we summarized the mechanism of EA for ischemic stroke via a series of factors, consisting of apoptosis related-factors, inflammatory factors, autophagy-related factors, growth factors, transcriptional factors, cannabinoid CB1 receptors, and other factors. In summary, EA stimulation may effectively alleviate ischemic brain injury via a series of signal pathways and various other factors.

Combined Effects of Electroacupuncture and Behavioral Training on Learning-Memory Ability and Event-Related Potential P300 in Rats with Mid/Advanced Cerebral Infarction

Background:

The effectiveness of the combination of electroacupuncture (EA) and behavioral training (BT) for mid/advanced cerebral infarction (M/ACI) and related mechanisms remains unclear. This study aimed to investigate the combined effects on the learning-memory ability and event-related potential P300 in rats with M/ACI.

Methods:

Eighty rats with M/ACI were divided into Group Model (M), Group EA, Group BT, and Group EA-BT (n = 20) according to the random number with five healthy rats in Group Control (CON). On the 6^th week after modeling, EA, BT, and EA-BT were given to Group EA, Group BT, and Group EA-BT, respectively, whereas Group M and Group CON were not given any intervention. Y-maze test and P300 were recorded before and after the intervention.

Results:

After intervention, the P300 latency was lower and the amplitude was higher in the Group EA-BT, Group EA, and Group BT than before (for latency, t = −7.638, −4.334, and −5.916; for amplitude, t = 8.125, 3.846, and 5.238; P < 0.01), with Group EA-BT superior to Group EA (for latency, t = −3.708; for amplitude, t = 3.653; P < 0.01) and Group BT (for latency, t = −2.067; for amplitude, t = 2.816; P < 0.05), with no significant difference between Group BT and EA (for latency, t = −1.439; for amplitude, t = 1.075; P > 0.05). While the performances of Y-maze tests in the Group EA-BT, Group EA, and Group BT were all better than before (t = 10.359, 4.520, and 7.791, P < 0.01), with Group EA-BT better than Group EA (t = 5.627, P < 0.01) and Group BT (t = 2.913, P < 0.01) respectively, and Group BT better than Group EA (t = 2.912, P < 0.01).

Conclusion:

EA or BT can affect P300 in rats with M/ACI, and the combination of these two methods can significantly improve the learning-memory ability.

Electroacupuncture stimulates the proliferation and differentiation of endogenous neural stem cells in a rat model of ischemic stroke

Electroacupuncture (EA) may stimulate neurogenesis in animal models of ischemic stroke; however, the associated mechanisms are not clear. The present study aimed to evaluate the neurogenesis efficacy of EA on ischemic stroke and the underlying associated mechanisms. A model of middle cerebral artery occlusion (MCAO) was employed as the rat model of brain ischemia and reperfusion. EA treatment at the GV20 (Baihui) and GV14 (Dazhui) acupoints was conducted for 30 min daily following MCAO. Immunofluorescence was performed to measure the number of bromodeoxyuridine (BrdU)/nestin- or BrdU/doublecortin (DCX)-positive cells in the sham, MCAO and MCAO + EA groups. Results indicated that EA stimulation significantly decreased the neurological score and neuronal loss in rats in the MCAO group (both P<0.05). Furthermore, immunostaining assays indicated that BrdU/nestin- and BrdU/DCX-positive cells in EA-treated rats were significantly increased (P<0.05) when compared with the rats in the MCAO group, indicating EA may induce the proliferation and differentiation of endogenous neural stem cells (eNSCs) during cerebral ischemia-reperfusion. In addition, EA treatment significantly enhanced the protein expression levels of plasticity-related gene 5 (PRG5), a critical neurogenesis factor, and significantly decreased the protein expression levels of three neurogenesis inhibiting molecules, NogoA, lysophosphatidic acid and RhoA (all P<0.05). These results suggested that EA promotes the proliferation and differentiation of eNSCs, likely through modulating PRG5/RhoA signaling.

Applications of Acupuncture Therapy in Modulating Plasticity of Central Nervous System

OBJECTIVE

Acupuncture is widely applied for treatment of various neurological disorders. This manuscript will review the preclinical evidence of acupuncture in mediating neural plasticity, the mechanisms involved.

MATERIALS AND METHODS

We searched acupuncture, plasticity, and other potential related words at the following sites: PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and VIP information data base. The following keywords were used: acupuncture, electroacupuncture, plasticity, neural plasticity, neuroplasticity, neurogenesis, neuroblast, stem cell, progenitor cell, BrdU, synapse, synapse structure, synaptogenesis, axon, axon regeneration, synaptic plasticity, LTP, LTD, neurotrophin, neurotrophic factor, BDNF, GDNF, VEGF, bFGF, EGF, NT-3, NT-4, NT-5, p75NTR, neurotransmitter, acetylcholine, norepinephrine, noradrenaline, dopamine, monamine. We assessed the effects of acupuncture on plasticity under pathological conditions in this review.

RESULTS

Relevant references were reviewed and presented to reflect the effects of acupuncture on neural plasticity. The acquired literatures mainly focused on neurogenesis, alterations of synapses, neurotrophins (NTs), and neurotranimitters. Acupuncture methods mentioned in this article include manual acupuncture and electroacupuncture.

CONCLUSIONS

The cumulative evidences demonstrated that acupuncture could induce neural plasticity in rodents exposed to cerebral ischemia. Neural plasticity mediated by acupuncture in other neural disorders, such as Alzheimer's disease, Parkinson's disease, and depression, were also investigated and there is evidence of positive role of acupuncture induced plasticity in these disorders as well. Mediation of neural plasticity by acupuncture is likely associated with its modulation on NTs and neurotransmitters. The exact mechanisms underlying acupuncture's effects on neural plasticity remain to be elucidated. Neural plasticity may be the potential bridge between acupuncture and the treatment of various neurological diseases.

Electroacupuncture Improved Hippocampal Neurogenesis following Traumatic Brain Injury in Mice through Inhibition of TLR4 Signaling Pathway

The protective role of electroacupuncture (EA) treatment in diverse neurological diseases such as ischemic stroke is well acknowledged. However, whether and how EA act on hippocampal neurogenesis following traumatic brain injury (TBI) remains poorly understood. This study aims to investigate the effect of EA on hippocampal neurogenesis and neurological functions, as well as its underlying association with toll-like receptor 4 (TLR4) signaling in TBI mice. BrdU/NeuN immunofluorescence was performed to label newborn neurons in the hippocampus after EA treatment. Water maze test and neurological severity score were used to evaluate neurological function posttrauma. The hippocampal level of TLR4 and downstream molecules and inflammatory cytokines were, respectively, detected by Western blot and enzyme-linked immunosorbent assay. EA enhanced hippocampal neurogenesis and inhibited TLR4 expression at 21, 28, and 35 days after TBI, but the beneficial effects of EA on posttraumatic neurogenesis and neurological functions were attenuated by lipopolysaccharide-induced TLR4 activation. In addition, EA exerted an inhibitory effect on both TLR4/Myd88/NF-κB and TLR4/TRIF/NF-κB pathways, as well as the inflammatory cytokine expression in the hippocampus following TBI. In conclusion, EA promoted hippocampal neurogenesis and neurological recovery through inhibition of TLR4 signaling pathway posttrauma, which may be a potential approach to improve the outcome of TBI.

Neuroprotective Effects of Stem Cells in Ischemic Stroke

Ischemic stroke, the most common subtype of stroke, has been one of the leading causes of mobility and mortality worldwide. However, it is still lacking of efficient agents. Stem cell therapy, with its vigorous advantages, has attracted researchers around the world. Numerous experimental researches in animal models of stroke have demonstrated the promising efficacy in treating ischemic stroke. The underlying mechanism involved antiapoptosis, anti-inflammation, promotion of angiogenesis and neurogenesis, formation of new neural cells and neuronal circuitry, antioxidation, and blood-brain barrier (BBB) protection. This review would focus on the types and neuroprotective actions of stem cells and its potential mechanisms for ischemic stroke.

Phosphofructokinase-1 Negatively Regulates Neurogenesis from Neural Stem Cells

Phosphofructokinase-1 (PFK-1), a major regulatory glycolytic enzyme, has been implicated in the functions of astrocytes and neurons. Here, we report that PFK-1 negatively regulates neurogenesis from neural stem cells (NSCs) by targeting pro-neural transcriptional factors. Using in vitro assays, we found that PFK-1 knockdown enhanced, and PFK-1 overexpression inhibited the neuronal differentiation of NSCs, which was consistent with the findings from NSCs subjected to 5 h of hypoxia. Meanwhile, the neurogenesis induced by PFK-1 knockdown was attributed to the increased proliferation of neural progenitors and the commitment of NSCs to the neuronal lineage. Similarly, in vivo knockdown of PFK-1 also increased neurogenesis in the dentate gyrus of the hippocampus. Finally, we demonstrated that the neurogenesis mediated by PFK-1 was likely achieved by targeting mammalian achaete-scute homologue-1 (Mash 1), neuronal differentiation factor (NeuroD), and sex-determining region Y (SRY)-related HMG box 2 (Sox2). All together, our results reveal PFK-1 as an important regulator of neurogenesis.