Combination of electroacupuncture and grafted mesenchymal stem cells overexpressing TrkC improves remyelination and function in demyelinated spinal cord of rats

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.

Dopamine relieves inflammatory responses through the D2 receptor after electroacupuncture at ST36 in a mouse model of chronic obstructive pulmonary disease

OBJECTIVE

To detect the role of dopamine in the anti-inflammatory effect of electroacupuncture (EA) at ST36 in a mouse model of chronic obstructive pulmonary disease (COPD).

METHODS

Twenty-eight male BALB/c mice were randomly divided into the control group, model group, sham EA (sham) group or ST36 EA (ST36) group in a 1:1:1:1 ratio (n = 7 each). The COPD mouse model was established through cigarette smoke (CS) exposure for 12 weeks. During the last 2 weeks, EA was applied at a sham point location or ST36 before CS exposure. Lung function, histopathological changes, inflammatory cell counts in bronchoalveolar lavage fluid (BALF), inflammatory cytokines in BALF, plasma, lung tissue homogenate (LTH), and plasma dopamine levels were detected in the different groups. Furthermore, the role of different dopamine receptors was explored through intraperitoneal injections of non-specific dopamine receptor antagonist chlorpromazine, specific dopamine D1 receptor antagonist SCH 23390 and specific dopamine D2 receptor antagonist eticlopride hydrochloride prior to ST36 EA and CS exposure.

RESULTS

EA at ST36 improved lung function, alleviated lung and systemic inflammatory responses by reducing inflammatory cells and cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-8 and IL-1β in BALF, plasma and lung tissue in this COPD mouse model. Plasma dopamine was greatly increased after EA at ST36, negatively correlated with lung histological lesions and inflammatory cytokine levels, and positively correlated with mice body weight and lung function indicators. Chlorpromazine and eticlopride hydrochloride inhibited the anti-inflammatory effect of EA at ST36, while SCH 23390 showed no neutralizing effect.

CONCLUSION

EA at ST36 could alleviate inflammation in this mouse model of COPD through the dopamine D2 receptor pathway.

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.

Electro-acupuncture and its combination with adult stem cell transplantation for spinal cord injury treatment: A summary of current laboratory findings and a review of literature

The incidence and disability rate of spinal cord injury (SCI) worldwide are high, imposing a heavy burden on patients. Considerable research efforts have been directed toward identifying new strategies to effectively treat SCI. Governor Vessel electro‐acupuncture (GV‐EA), used in traditional Chinese medicine, combines acupuncture with modern electrical stimulation. It has been shown to improve the microenvironment of injured spinal cord (SC) by increasing levels of endogenous neurotrophic factors and reducing inflammation, thereby protecting injured neurons and promoting myelination. In addition, axons extending from transplanted stem cell‐derived neurons can potentially bridge the two severed ends of tissues in a transected SC to rebuild neuronal circuits and restore motor and sensory functions. However, every single treatment approach to severe SCI has proven unsatisfactory. Combining different treatments—for example, electro‐acupuncture (EA) with adult stem cell transplantation—appears to be a more promising strategy. In this review, we have summarized the recent progress over the past two decades by our team especially in the use of GV‐EA for the repair of SCI. By this strategy, we have shown that EA can stimulate the nerve endings of the meningeal branch. This would elicit the dorsal root ganglion neurons to secrete excess amounts of calcitonin gene‐related peptide centrally in the SC. The neuropeptide then activates the local cells to secrete neurotrophin‐3 (NT‐3), which mediates the survival and differentiation of donor stem cells overexpressing the NT‐3 receptor, at the injury/graft site of the SC. Increased local production of NT‐3 facilitates reconstruction of host neural tissue such as nerve fiber regeneration and myelination. All this events in sequence would ultimately strengthen the cortical motor‐evoked potentials and restore the motor function of paralyzed limbs. The information presented herein provides a basis for future studies on the clinical application of GV‐EA and adult stem cell transplantation for the treatment of SCI.

Electroacupuncture facilitates the integration of a grafted TrkC-modified mesenchymal stem cell-derived neural network into transected spinal cord in rats via increasing neurotrophin-3

Aims

This study was aimed to investigate whether electroacupuncture (EA) would increase the secretion of neurotrophin‐3 (NT‐3) from injured spinal cord tissue, and, if so, whether the increased NT‐3 would promote the survival, differentiation, and migration of grafted tyrosine kinase C (TrkC)‐modified mesenchymal stem cell (MSC)‐derived neural network cells. We next sought to determine if the latter would integrate with the host spinal cord neural circuit to improve the neurological function of injured spinal cord.

Methods

After NT‐3‐modified Schwann cells (SCs) and TrkC‐modified MSCs were co‐cultured in a gelatin sponge scaffold for 14 days, the MSCs differentiated into neuron‐like cells that formed a MSC‐derived neural network (MN) implant. On this basis, we combined the MN implantation with EA in a rat model of spinal cord injury (SCI) and performed immunohistochemical staining, neural tracing, electrophysiology, and behavioral testing after 8 weeks.

Results

Electroacupuncture application enhanced the production of endogenous NT‐3 in damaged spinal cord tissues. The increase in local NT‐3 production promoted the survival, migration, and maintenance of the grafted MN, which expressed NT‐3 high‐affinity TrkC. The combination of MN implantation and EA application improved cortical motor‐evoked potential relay and facilitated the locomotor performance of the paralyzed hindlimb compared with those of controls. These results suggest that the MN was better integrated into the host spinal cord neural network after EA treatment compared with control treatment.

Conclusions

Electroacupuncture as an adjuvant therapy for TrkC‐modified MSC‐derived MN, acted by increasing the local production of NT‐3, which accelerated neural network reconstruction and restoration of spinal cord function following SCI.

Electroacupuncture Enhance Therapeutic Efficacy of Mesenchymal Stem Cells Transplantation in Rats With Intracerebral Hemorrhage

BACKGROUND

Previous studies have showed the beneficial effects of mesenchymal stem cells (MSCs) on experimental intracerebral hemorrhage (ICH) animal. Enhancement of the treatment efficacy of MSCs in ICH is essential, considering the diseases association with high rates of disability and mortality. Some auxiliary methods to enhance the beneficial efficacy of MSCs have been introduced. However, the effect of electroacupuncture (EA) on the therapeutic efficacy of MSCs transplantation in hemorrhagic stroke and its potential mechanism is not explored.

METHODS

ICH rat models were established using collagenase and heparin. 48 h after ICH induction, the rats were randomly divided into model control (MC), MSCs transplantation (MSCs), EA stimulation (EA) and MSCs transplantation combined with EA stimulation (MSCs + EA) groups. We used mNSS test and gait analysis to assess neurological function of rats, and PET/CT to evaluate the volume of hemorrhage focus and level of glucose uptake. The concentrations of MDA, SOD, NSE, S100B and MBP in serum or plasma were examined with ELISA. Neural differentiation of MSCs, and the expressions of Bcl-2, Bax, Arg-1 and iNOS proteins around hematoma were detected by immunofluorescence and immunohistochemistry staining respectively. Western blot was carried out to analyze the expression levels of COX4, OGDH, PDH-E1α, Bcl-2 and Bax proteins. TUNEL staining was used to estimate cell apoptosis and transmission electron microscopy (TEM) was used to observe the ultrastructure and number of mitochondria.

RESULTS

Our data showed that EA promoted neuron-like differentiation of transplanted MSCs and the expressions of BDNF and NGF proteins in ICH rats. The score of mNSS and the gait analysis showed that the recovery of the neurological function in the MSCs + EA group was better than that in the MSCs and EA groups. EA improved the structure of brain tissue, and alleviated brain injury further after MSCs transplantation in ICH rats. When compared with the MSCs and EA groups, the level of glucose uptake and numbers of mitochondria and Arg-1 positive cells in MSCs + EA group increased significantly, but the numbers of apoptotic cells and iNOS positive cells and volume of hemorrhage focus reduced. The expressional levels of COX4, OGDH, PDH-E1α and Bcl-2 proteins increased, while the expressional level of Bax protein decreased compared with those in the MSCs and EA groups.

CONCLUSIONS

Our results reveal that EA improve therapeutic efficacy of MSCs transplantation in ICH rats.

Decellularized optic nerve functional scaffold transplant facilitates directional axon regeneration and remyelination in the injured white matter of the rat spinal cord

Axon regeneration and remyelination of the damaged region is the most common repair strategy for spinal cord injury. However, achieving good outcome remains difficult. Our previous study showed that porcine decellularized optic nerve better mimics the extracellular matrix of the embryonic porcine optic nerve and promotes the directional growth of dorsal root ganglion neurites. However, it has not been reported whether this material promotes axonal regeneration in vivo. In the present study, a porcine decellularized optic nerve was seeded with neurotrophin-3-overexpressing Schwann cells. This functional scaffold promoted the directional growth and remyelination of regenerating axons. In vitro, the porcine decellularized optic nerve contained many straight, longitudinal channels with a uniform distribution, and microscopic pores were present in the channel wall. The spatial micro topological structure and extracellular matrix were conducive to the adhesion, survival and migration of neural stem cells. The scaffold promoted the directional growth of dorsal root ganglion neurites, and showed strong potential for myelin regeneration. Furthermore, we transplanted the porcine decellularized optic nerve containing neurotrophin-3-overexpressing Schwann cells in a rat model of T10 spinal cord defect in vivo. Four weeks later, the regenerating axons grew straight, the myelin sheath in the injured/transplanted area recovered its structure, and simultaneously, the number of inflammatory cells and the expression of chondroitin sulfate proteoglycans were reduced. Together, these findings suggest that porcine decellularized optic nerve loaded with Schwann cells overexpressing neurotrophin-3 promotes the directional growth of regenerating spinal cord axons as well as myelin regeneration. All procedures involving animals were conducted in accordance with the ethical standards of the Institutional Animal Care and Use Committee of Sun Yat-sen University (approval No. SYSU-IACUC-2019-B034) on February 28, 2019.

Electroacupuncture Alleviates Diabetic Peripheral Neuropathy by Regulating Glycolipid-Related GLO/AGEs/RAGE Axis

Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus (DM) and affects over one-third of all patients. Neuropathic pain and nerve dysfunction induced by DM is related to the increase of advanced glycation end products (AGEs) produced by reactive dicarbonyl compounds in a hyperglycemia environment. AGEs induce the expression of pro-inflammatory cytokines via the main receptor (RAGE), which has been documented to play a crucial role in the pathogenesis of diabetic peripheral neuropathy. Electroacupuncture (EA) has been reported to have a positive effect on paralgesia caused by various diseases, but the mechanism is unclear. In this study, we used high-fat-fed low-dose streptozotocin-induced rats as a model of type 2 diabetes (T2DM). Persistent metabolic disorder led to mechanical and thermal hyperalgesia, as well as intraepidermal nerve fiber density reduction and nerve demyelination. EA improved neurological hyperalgesia, decreased the pro-inflammatory cytokines, reduced the generation of AGEs and RAGE, and regulated the glyoxalase system in the EA group. Taken together, our study suggested that EA plays a role in the treatment of T2DM-induced DPN, and is probably related to the regulation of metabolism and the secondary influence on the GLO/AGE/RAGE axis.

Governor Vessel Electro-Acupuncture Promotes the Intrinsic Growth Ability of Spinal Neurons through Activating Calcitonin Gene-Related Peptide/α-Calcium/Calmodulin-Dependent Protein Kinase/Neurotrophin-3 Pathway after Spinal Cord Injury

Spinal cord injury (SCI) invariably results in neuronal death and failure of axonal regeneration. This is attributed mainly to the hostile microenvironment and the poor intrinsic regrowth capacity of the injured spinal neurons. We have reported previously that electro-acupuncture on Governor Vessel acupoints (GV-EA) can promote neuronal survival and axonal regeneration of injured spinal cord. However, the underlying mechanism for this has remained uncertain. The present study aimed to explore the neural afferent pathway of GV-EA stimulation and the possible mechanism by which GV-EA can activate the intrinsic growth ability of injured spinal neurons. By cholera toxin B (CTB) retrograde labeling, immunostaining, and enzyme-linked immunosorbent assay (ELISA), we showed here that GV-EA could stimulate the spinal nerve branches of the dorsal root ganglion cells. This would then increase the release of calcitonin gene-related peptide (CGRP) from the afferent terminals in the spinal cord. It is of note that the effect was abrogated after dorsal rhizotomy. Additionally, both in vivo and in vitro results showed that CGRP would act on the post-synaptic spinal cord neurons and triggered the synthesis and secretion of neurotrophin-3 (NT-3) by activating the calcitonin gene-related peptide (CGRP)/ receptor activity-modifying protein (RAMP)1/calcium/calmodulin-dependent protein kinase (αCaMKII) pathway. Remarkably, the observed effect was prevented by the dorsal rhizotomy and the blockers of the CGRP/RAMP1/αCaMKII pathway. More importantly, increase in NT-3 promoted the survival, axonal regrowth, and synaptic maintenance of spinal cord neurons in the injured spinal cord. Therefore, it is concluded that increase in NT-3 production is one of the mechanisms by which GV-EA can activate the intrinsic growth ability of spinal neurons after SCI. The experimental results have reinforced the theoretical basis of GV-EA for its clinical efficacy in patients with SCI.

Effects and Mechanisms of Acupuncture Combined with Mesenchymal Stem Cell Transplantation on Neural Recovery after Spinal Cord Injury: Progress and Prospects

Spinal cord injury (SCI) is a structural event with devastating consequences worldwide. Due to the limited intrinsic regenerative capacity of the spinal cord in adults, the neural restoration after SCI is difficult. Acupuncture is effective for SCI-induced neurologic deficits, and the potential mechanisms responsible for its effects involve neural protection by the inhibition of inflammation, oxidation, and apoptosis. Moreover, acupuncture promotes neural regeneration and axon sprouting by activating multiple cellular signal transduction pathways, such as the Wnt, Notch, and Rho/Rho kinase (ROCK) pathways. Several studies have demonstrated that the efficacy of combining acupuncture with mesenchymal stem cells (MSCs) transplantation is superior to either procedure alone. The advantage of the combined treatment is dependent on the ability of acupuncture to enhance the survival of MSCs, promote their differentiation into neurons, and facilitate targeted migration of MSCs to the spinal cord. Additionally, the differentiation of MSCs into neurons overcomes the problem of the shortage of endogenous neural stem cells (NSCs) in the acupuncture-treated SCI patients. Therefore, the combination of acupuncture and MSCs transplantation could become a novel and effective strategy for the treatment of SCI. Such a possibility needs to be verified by basic and clinical research.

Genetic Engineering as a Strategy to Improve the Therapeutic Efficacy of Mesenchymal Stem/Stromal Cells in Regenerative Medicine

Mesenchymal stem/stromal cells (MSCs) have been widely studied in the field of regenerative medicine for applications in the treatment of several disease settings. The therapeutic potential of MSCs has been evaluated in studies in vitro and in vivo, especially based on their anti-inflammatory and pro-regenerative action, through the secretion of soluble mediators. In many cases, however, insufficient engraftment and limited beneficial effects of MSCs indicate the need of approaches to enhance their survival, migration and therapeutic potential. Genetic engineering emerges as a means to induce the expression of different proteins and soluble factors with a wide range of applications, such as growth factors, cytokines, chemokines, transcription factors, enzymes and microRNAs. Distinct strategies have been applied to induce genetic modifications with the goal to enhance the potential of MCSs. This review aims to contribute to the update of the different genetically engineered tools employed for MSCs modification, as well as the factors investigated in different fields in which genetically engineered MSCs have been tested.

Subarachnoid transplantation of human umbilical cord mesenchymal stem cell in rodent model with subacute incomplete spinal cord injury: Preclinical safety and efficacy study

Functional multipotency renders human umbilical cord mesenchymal stem cell (hUC-MSC) a promising candidate for the treatment of spinal cord injury (SCI). However, its safety and efficacy have not been fully understood for clinical translation. In this study, we performed cellular, kinematic, physiological, and anatomical analyses, either in vitro or in vivo, to comprehensively evaluate the safety and efficacy associated with subarachnoid transplantation of hUC-MSCs in rats with subacute incomplete SCI. Concerning safety, hUC-MSCs were shown to have normal morphology, excellent viability, steady proliferation, typical biomarkers, stable karyotype in vitro, and no tumorigenicity both in vitro and in vivo. Following subarachnoid transplantation of hUC-MSCs in the subject rodents, the biodistribution of hUC-MSCs was restricted to the spinal cord, and no toxicity to immune system or organ function was observed. Body weight, organ weight, and the ratio of the latter upon the former between stem cell-transplanted rats and placebo-injected rats revealed no statistical differences. Regarding efficacy, hUC-MSCs could differentiate into osteoblasts, chondrocytes, adipocytes and neural progenitor cells in vitro. While in vivo studies revealed that subarachnoid transplantation of stem cells resulted in significant improvement in locomotion, earlier automatic micturition recovery and reduced lesion size, which correlated with increased regeneration of tracking fiber and reduced parenchymal inflammation. In vivo luminescence imaging showed that a few of the transplanted luciferase-labeled hUC-MSCs tended to migrate towards the lesion epicenter. Shortened latency and enhanced amplitude were also observed in both motor and sensory evoked potentials, indicating improved signal conduction in the damaged site. Immunofluorescent staining confirmed that a few of the administrated hUC-MSCs integrated into the spinal cord parenchyma and differentiated into astrocytes and oligodendrocytes, but not neurons. Moreover, decreased astrogliosis, increased remyelination, and neuron regeneration could be observed. To the best of our knowledge, this preclinical study provides detailed safety and efficacy evidence regarding intrathecal transplantation of hUC-MSCs in treating SCI for the first time and thus, supports its initiation in the following clinical trial.

Upregulation of microRNA-200a in bone marrow mesenchymal stem cells enhances the repair of spinal cord injury in rats by reducing oxidative stress and regulating Keap1/Nrf2 pathway

Spinal cord injury (SCI) is a common disease with high incidence, disability rate and treatment cost. microRNA (miR)-200a is reported to inhibit Keap1 to activate Nrf2 signaling. This study aimed to explore the effects of lentivirus-mediated miR-200a gene-modified bone marrow mesenchymal stem cells (BMSCs) transplantation on the repair of SCI in a rat model. BMSCs were isolated from the bone marrow of Sprague-Dawley rats. MiR-200a targeting to Keap1 was identified by luciferase reporter gene assay. The expressions of Keap1, nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H-dependent quinone oxidoreductase 1 (NQO-1), heme oxygenase-1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC) were detected by Western blotting in SCI rats. The locomotor capacity of the rats was evaluated using the Basso, Beattie, and Bresnahan scale. The levels of malondialdehyde (MDA), activities of superoxide dismutase (SOD), and catalase (CAT) were measured. miR-200a inhibited Keap-1 3' UTR activity in BMSCs. Transplantation of BMSCs with overexpression of miR-200a or si-Keap1 increased locomotor function recovery of rats after SCI, while decreased MDA level, increased SOD, CAT activities, and Nrf2 expression together with its downstream HO-1, NQO1, GCLC protein expressions in SCI rat. These results indicated that overexpressed miR-200a in BMSCs promoted SCI repair, which may be through regulating antioxidative signaling pathway.

Electroacupuncture Facilitates the Integration of Neural Stem Cell-Derived Neural Network with Transected Rat Spinal Cord

The hostile environment of an injured spinal cord makes it challenging to achieve higher viability in a grafted tissue-engineered neural network used to reconstruct the spinal cord circuit. Here, we investigate whether cell survival and synaptic transmission within an NT-3 and TRKC gene-overexpressing neural stem cell-derived neural network scaffold (NN) transplanted into transected spinal cord could be promoted by electroacupuncture (EA) through improving the microenvironment. Our results showed that EA facilitated the cell survival, neuronal differentiation, and synapse formation of a transplanted NN. Pseudorabies virus tracing demonstrated that EA strengthened synaptic integration of the transplanted NN with the host neural circuit. The combination therapy also promoted axonal regeneration, spinal conductivity, and functional recovery. The findings highlight EA as a potential and safe supplementary therapeutic strategy to reinforce the survival and synaptogenesis of a transplanted NN as a neuronal relay to bridge the two severed ends of an injured spinal cord.

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EA promotes the survival and synapse formation of NSC-derived neurons in grafted NN

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EA strengthens synaptic integration of grafted NN with the spinal cord neural circuit

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EA enhances NT-3 level and activates NT-3/TRKC/AKT pathway in the injury/graft site

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The combination therapy increases axonal regeneration and spinal functional recovery

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.

Improved therapeutic potential of MSCs by genetic modification

Mesenchymal stem cells (MSCs), well-studied adult stem cells in various tissues, possess multi-lineage differentiation potential and anti-inflammatory properties. MSCs have been approved to regenerate lineage-specific cells to replace injured cells in tissues. MSCs are approved to treat inflammatory diseases. With the discovery of genes important for the repair of damaged tissues, MSCs genetically modified by such genes hold improved therapeutic potential. In this review, we summarised the uses of genetically modified MSCs to treat different diseases, including bone diseases, cardiovascular diseases, autoimmune diseases, central nervous system disorders, and cancer. To better understand the exact role of genetically modified MSCs, key mechanisms determining, which genes are selected to be used for modifying MSCs and improvements in post-genetic modification are discussed. Therapeutic benefits enhanced by genetic modifications are to be documented by further clinical studies.

Therapeutic Potential of a Combination of Electroacupuncture and TrkB-Expressing Mesenchymal Stem Cells for Ischemic Stroke

We prepared and grafted tropomyosin receptor kinase B (TrkB) gene-transfected mesenchymal stem cells (TrkB-MSCs) into the ischemic penumbra and investigated whether electroacupuncture (EA) treatment could promote functional recovery from ischemic stroke. For the behavioral test, TrkB-MSCs+EA resulted in significantly improved motor function compared to that obtained with MSCs+EA or TrkB-MSCs alone. At 30 days after middle cerebral artery occlusion (MCAO), the largest number of grafted MSCs was detected in the TrkB-MSC+EA group. Some differentiation into immature neuroblasts and astrocytes was detected; however, only a few mature neuron-like cells were found. Compared to other treatments, TrkB-MSCs+EA upregulated the expression of mature brain-derived neurotrophic factor (BDNF) and neurotrophin-4/5 (NT4) and induced the activation of TrkB receptor and its transcription factor cAMP response element-binding protein (CREB). At 60 days after MCAO, EA highly promoted the differentiation of TrkB-MSCs into mature neuron-like cells compared to the effect in MSCs. A selective TrkB antagonist, ANA-12, reverted the effect of TrkB-MSCs+EA in motor function recovery and survival of grafted MSCs. Our results suggest that EA combined with grafted TrkB-MSCs promotes the expression of BDNF and NT4, induces the differentiation of TrkB-MSCs, and improves motor function. TrkB-MSCs could serve as effective therapeutic agents for ischemic stroke if used in combination with BDNF/NT4-inducing therapeutic approaches.

Potential benefits of mesenchymal stem cells and electroacupuncture on the trophic factors associated with neurogenesis in mice with ischemic stroke

The beneficial effects of mesenchymal stem cells (MSCs) and electroacupuncture (EA) on neurogenesis and related trophic factors remain unclear. Bone marrow MSCs (mBMSC) were transplanted into the striatum of mice with middle cerebral artery occlusion (MCAO), and EA stimulation was applied at two acupoints, Baihui and Dazhui. EA treatment significantly improved motor function, and a synergistic effect of combined mBMSC and EA treatment was observed. Combined mBMSC and EA treatment reduced prominent atrophic changes in the striatum and led to proliferation of neural progenitor cells in the subventricular zone (SVZ) and the surrounding areas of the striatum (SVZ + striatum) of MCAO mice. The mBMSC and EA treatment markedly enhanced mature brain-derived neurotrophic factor (mBDNF) expression in the SVZ + striatum and hippocampus of mice with MCAO, and combined treatment enhanced neurotrophin-4 (NT4) expression. The number of mBDNF- and NT4-positive neurons in the SVZ + striatum and hippocampus increased following EA treatment. Combined treatment led to an increase in the expression levels of phosphorylated cAMP response element binding protein in the neuroblasts of the striatum. Our results indicate that combined MSC and EA treatment may lead to a better therapeutic effect via co-regulation of neurotrophic factors in the brain, by regulating neurogenesis more than single therapy.

Electroacupuncture Restores Locomotor Functions After Mouse Spinal Cord Injury in Correlation With Reduction of PTEN and p53 Expression

Background: We previously showed that electroacupuncture (EA) at Jiaji points promotes expression of adhesion molecule L1 in spinal cord tissue after mouse spinal cord injury (SCI) and contributes to recovery of neural functions. Objective: We investigated the effects of EA on downstream signaling molecules of L1 and molecules relevant to apoptosis with the aim to understand the underlying molecular mechanisms. Methods: Female C57BL/6 mice were divided into a sham group, injury group, injury+acupuncture (AP) group and injury+EA group. We investigated the changes in cognate L1-triggered signaling molecules after SCI by immunofluorescence staining and immunoblot analysis. Results: Protein levels of phosphatase and tensin homolog (PTEN) and p53 were decreased by EA at different time points after injury, whereas the levels of phosphorylated mammalian target of rapamycin (pmTOR), p-Akt and phosphorylated extracellular signal-regulatedkinase (p-Erk) were increased. Also, levels of myelin basic protein (MBP) were increased by EA. AP alone showed less pronounced changes in expression of the investigated molecules, when compared to EA. Conclusion: We propose that EA contributes to neuroprotection by inhibiting PTEN and p53 expression and by increasing the levels of pmTOR/Akt/Erk and of MBP after SCI. These observations allow novel insights into the beneficial effects of EA via L1-triggered signaling molecules after injury.

Combined therapy involving electroacupuncture and treadmill exercise attenuates demyelination in the corpus callosum by stimulating oligodendrogenesis in a rat model of neonatal hypoxia-ischemia

We investigated whether electroacupuncture (EA) and treadmill (TM) exercise improve behaviors related to motor and memory dysfunction in a cerebral palsy-like rat model via activation of oligodendrogenesis. A neonatal hypoxia-ischemia model was created using Sprague-Dawley rats (P7), and these underwent EA stimulation and treadmill training from 3 to 5weeks after hypoxia-ischemia induction. EA treatment was delivered via electrical stimulation (2Hz, 1mA) at two acupoints, Baihui (GV20) and Zusanli (ST36). Behavioral tests showed that EA alleviated motor dysfunction caused by hypoxia-ischemia on a rotarod test, and TM exercise alleviated motor and memory dysfunction seen on cylinder and passive avoidance tests. Combined therapy with EA and TM exercise showed synergistic effects on the cylinder, rotarod, and catwalk tests. TM exercise significantly restored corpus callosum thickness, and combined therapy with EA and TM restored myelin basic protein (MBP) levels in this region. While EA stimulation only increased activation of cAMP-response element binging protein (CREB) in oligodendrocytes of the corpus callosum, TM exercise increased newly generated oligodendrocyte progenitor cells or oligodendrocytes via activation of CREB. Synergistic effects on oligodendrogenesis were also observed by the combined therapy. Furthermore, the combined therapy induced mature brain-derived neurotrophic factor (BDNF) expression in the cerebral cortex. These results demonstrate that combined therapy with EA and TM exercise may restore myelin components following neonatal hypoxia-ischemia via upregulation of oligodendrogenesis involving CREB/BDNF signaling, which subsequently improves motor and memory function. Therefore, combined therapy with EA and TM exercise offers another treatment option for functional recovery from injuries caused by neonatal hypoxia-ischemia, such as cerebral palsy.

Tail Nerve Electrical Stimulation and Electro-Acupuncture Can Protect Spinal Motor Neurons and Alleviate Muscle Atrophy after Spinal Cord Transection in Rats

Spinal cord injury (SCI) often results in death of spinal neurons and atrophy of muscles which they govern. Thus, following SCI, reorganizing the lumbar spinal sensorimotor pathways is crucial to alleviate muscle atrophy. Tail nerve electrical stimulation (TANES) has been shown to activate the central pattern generator (CPG) and improve the locomotion recovery of spinal contused rats. Electroacupuncture (EA) is a traditional Chinese medical practice which has been proven to have a neural protective effect. Here, we examined the effects of TANES and EA on lumbar motor neurons and hindlimb muscle in spinal transected rats, respectively. From the third day postsurgery, rats in the TANES group were treated 5 times a week and those in the EA group were treated once every other day. Four weeks later, both TANES and EA showed a significant impact in promoting survival of lumbar motor neurons and expression of choline acetyltransferase (ChAT) and ameliorating atrophy of hindlimb muscle after SCI. Meanwhile, the expression of neurotrophin-3 (NT-3) in the same spinal cord segment was significantly increased. These findings suggest that TANES and EA can augment the expression of NT-3 in the lumbar spinal cord that appears to protect the motor neurons as well as alleviate muscle atrophy.

Comparative analysis of the beneficial effects of treadmill training and electroacupuncture in a rat model of neonatal hypoxia-ischemia

In the present study, we investigated whether treadmill training and electroacupuncture (EA) have autonomous or synergistic beneficial effects on deficits caused by neonatal hypoxia-ischemia in Sprague-Dawley rats. For this purpose, rats subjected to hypoxia-ischemia underwent treadmill training and EA stimulation from 4 to 8 weeks of age. Conventional EA (CEA) and scalp EA (SEA) were delivered by electrical stimulation (2 Hz, 1 mA) at traditional acupoints and at the scalp to the primary motor area, respectively. In the behavioral examination, markedly improved performances in the rotarod test were observed in the rats that underwent treadmill exercise, and in the rats that underwent treadmill exercise and CEA compared to the untreated rats subjected to hypoxia-ischemia. An improvement was also observed in the passive avoidance test in the rats that underwent treadmill training and EA. As shown by western blot analysis, the expression levels of neuronal nuclei (NeuN), 2′,3′-cyclic-nucleotide 3′-phosphodiesterase and myelin basic protein (MBP) exhibited a significant decrease in the contralateral subventricular zone (SVZ) of the rats subjected to hypoxia-ischemia compared to the controls; however, these expression levels increased following treadmill exercise and EA stimulation. As shown by immunohistochemical analyses, the thickness of the corpus callosum and the integrated optical density (IOD) of MBP were significantly increased in the rats subjected to treadmill exercise and EA compared to the untreated rats subjected to hypoxiaa-ischemia. The synergistic effects of treadmill training and EA were also observed in the protein levels and IOD of MBP. A marked increase in the number of bromodeoxyuridine (BrdU)- and BrdU/NeuN-positive cells in the contralateral SVZ was also observed in the rats that underwent treadmill training and EA; the number of BrdU-positive cells was synergistically affected by treadmill training and EA. These results suggest that treadmill training and EA stimulation contribute to the enhancement of behavioral recovery following hypoxia-ischemia via the upregulation of myelin components and neurogenesis. Thus, treatment with EA stimulation, as well as treadmill training offers another treatment option to promote functional recovery in cerebral palsy.

Effects of Electroacupuncture at Governor Vessel Acupoints on Neurotrophin-3 in Rats with Experimental Spinal Cord Injury

In an effort to explore new, noninvasive treatment options for spinal cord injuries (SCI), this study investigated the effects of electroacupuncture (EA) for SCI rat models. SCI was induced by a modified Allen's weight-drop method. We investigated the response of EA at Dazhui (GV 14) and Mingmen (GV 4) acupoints to understand the effects and mechanisms of EA in neuroprotection and neuronal function recovery after SCI. BBB testing was used to detect motor function of rats' hind limbs among groups, and EA was shown to promote the recovery of SCI rats' motor function. Nissl staining showed a restored neural morphology and an increase in the quantity of neurons after EA. Also, the antiapoptosis role was exposed by TUNEL staining. Western blotting analysis was used to determine the protein expression of neurotrophin-3 (NT-3) in spinal cord tissue. Compared to the sham group, the expression levels of NT-3 were significantly decreased and EA was shown to upregulate the expression of NT-3. The present study suggests that the role of EA in neuroprotection and dorsal neuronal function recovery after SCI in rats, especially EA stimulation at GV 14 and GV 4, can greatly promote neuronal function recovery, which may result from upregulating the expression of NT-3.

Electroacupuncture ameliorates memory impairments by enhancing oligodendrocyte regeneration in a mouse model of prolonged cerebral hypoperfusion

We modeled prolonged cerebral hypoperfusion in mice using bilateral common carotid artery stenosis (BCAS) and electroacupuncture (EA) stimulation was applied at two acupoints, Baihui (GV20) and Dazhui (GV14). In behavioral tests of memory, BCAS produced impairments in spatial and short-term memory in mice that were attenuated by therapeutic EA stimulation. Therapeutic use of EA in BCAS also enhanced oligodendrocyte (OL) differentiation from oligodendrocyte precursor cells (OPCs), in association with white matter improvements in the corpus callosum (CC). In PCR analyses of growth factor gene expression, significant positive changes in 3 genes were observed following EA stimulation in BCAS, and here we highlight alterations in neurotrophin-4/5 (NT4/5). We confirmed EA-mediated positive changes in the expression of NT4/5 and its receptor, tyrosine receptor kinase B (TrkB). Treatment of naïve and BCAS + EA animals with a selective TrkB antagonist, ANA-12, produced losses of myelin and cognitive function that were ameliorated by EA therapy. Moreover, following BCAS we observed an EA-dependent increase in phospho-activated CREB (a downstream mediator of NT4/5-TrkB signaling) in OPCs and OLs of the CC. Our results suggest that EA stimulation promotes the recovery of memory function following white matter injury via a mechanism that promotes oligodendrocyte regeneration and involves NT4/5-TrkB signaling.

Electroacupuncture at Dazhui (GV14) and Mingmen (GV4) protects against spinal cord injury: the role of the Wnt/β-catenin signaling pathway

Electroacupuncture at Dazhui (GV14) and Mingmen (GV4) on the Governor Vessel has been shown to exhibit curative effects on spinal cord injury; however, the underlying mechanism remains poorly understood. In this study, we established rat models of spinal cord injury using a modified Allen's weight-drop method. Ninety-nine male Sprague-Dawley rats were randomly divided into three equal groups: sham (only laminectomy), SCI (induction of spinal cord injury at T₁₀), and EA (induction of spinal cord injury at T₁₀ and electroacupuncture intervention at GV14 and GV4 for 20 minutes once a day). Rats in the SCI and EA groups were further randomly divided into the following subgroups: 1-day (n = 11), 7-day (n = 11), and 14-day (n = 11). At 1, 7, and 14 days after electroacupuncture treatment, the Basso, Beattie and Bresnahan locomotor rating scale showed obvious improvement in rat hind limb locomotor function, hematoxylin-eosin staining showed that the histological change of injured spinal cord tissue was obviously alleviated, and immunohistochemistry and western blot analysis showed that Wnt1, Wnt3a, β-catenin immunoreactivity and protein expression in the injured spinal cord tissue were greatly increased compared with the sham and SCI groups. These findings suggest that electroacupuncture at GV14 and GV4 upregulates Wnt1, Wnt3a, and β-catenin expression in the Wnt/β-catenin signaling pathway, exhibiting neuroprotective effects against spinal cord injury.

Transdifferentiation of differentiated stem cells contributes to remyelination

Evidence suggests that transdifferentiation of mesenchymal stem cells (MSCs) into various neuronal cells contributes to functional recovery after experimental spinal cord injury. Qiu et al. have recently published an exciting article in Stem Cell Research & Therapy demonstrating the transdifferentiation of already differentiated MSCs that contributes to remyelination of injured/regenerating axons, and thereby to functional recovery of spinal cord injured animals. The authors highlight the importance of interaction between neurotrophin-3 and tropomyosin receptor kinase C for the observed effects. This study provided important evidence that manipulation of rat bone marrow-derived MSCs before transplantation could enhance the therapeutic benefit of cell-based treatment.