Early Post-Stroke Electroacupuncture Promotes Motor Function Recovery in Post-Ischemic Rats by Increasing the Blood and Brain Irisin

Effect of electroacupuncture on vascular remodeling in rats with cerebral ischemia by regulating irisin based on VEGF/Akt/eNOS signaling pathway

OBJECTIVE

This study aimed to explore the cumulative effects and expression patterns of electroacupuncture (EA) on irisin secretion, observe the effects of EA on the recovery of neurobehavioral function and vascular remodeling after cerebral ischemia, and elucidate the mechanism by which EA promotes vascular remodeling by regulating irisin expression.

METHODS

A rat model of left middle cerebral artery occlusion (MCAO) was prepared, and EA was performed. Tissue distribution and expression of irisin were determined by immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and Western blotting. Type III fibronectin domain protein 5-silenced adeno-associated virus (rAAV-shFNDC5) was injected into the lateral ventricle as a control. Neurobehavioral function was evaluated using 2,3,5-triphenyltetrazolium chloride (TTC) staining and behavioral experiments, while vascular remodeling was evaluated using laser speckle blood flow imaging, and the expressions of irisin and vascular remodeling-related factors were measured by ELISA and Western blotting.

RESULTS

The number of FNDC5-positive neurons, fluorescence intensity, and irisin expression reached their maximum increase after 7 days of EA treatment. In addition, the EA group exhibited a significant reduction in cerebral infarct volume and impairment of neurobehavioral function, an increase in cerebral blood flow and microvascular diameter on the ischemic side, and significantly higher expression levels of FNDC5, brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), protein kinase B (Akt), and endothelial nitric oxide synthase (eNOS). However, rAAV-shFNDC5 significantly weakened the therapeutic effects of EA.

CONCLUSIONS

EA upregulated irisin expression, reaching a peak after 7 days of EA and then stabilizing. EA facilitated vascular remodeling after cerebral ischemia, and this might be associated with the activation of the irisin-mediated VEGF/Akt/eNOS signaling pathway.

Electroacupuncture alleviated post-stroke cognitive impairment via the mTOR/NLRP3-mediated autophagy-inflammatory pathway

BACKGROUND

Post-stroke cognitive impairment (PSCI) severely reduces quality of life of patients with stroke. This study aimed to assess the effects of electroacupuncture (EA) on PSCI and the role of the mTOR/NLRP3-mediated autophagy-inflammatory pathway in this process.

METHODS

The rat focal cerebral ischemia model was established using middle cerebral artery occlusion (MCAO). Following successful induction of the model, EA was applied to the bilateral Fengchi, Fengfu, and Dazhui acupoints, and brain tissue samples were collected on day 15. Cognitive function was assessed using the Morris water maze test. Cerebral infarct volume was quantified by Triphenyltetrazolium chloride (TTC) staining. Hematoxylin-eosin and TUNEL staining were performed to evaluate pathological changes and apoptosis rates. Apoptosis-, inflammation-, and autophagy-related biomarkers were measured, and autophagosomes were visualized using transmission electron microscopy.

RESULTS

MCAO rats exhibited slower weight gain, reduced mobility, increased infarct size, pathological damage, and apoptosis, confirming successful establishment of the MCAO rat model. Following EA treatment, MCAO rats displayed faster weight gain, improved mobility, and shorter escape latency. EA also reduced the area of cerebral infarction and alleviated pathological damage and apoptosis in MCAO rats. Furthermore, EA downregulated IL-1β, IL-18, NLRP3, and LC3 II/LC3 I expression and upregulated p62, mTOR, and Beclin-1 expression in MCAO rats. EA treatment also decreased the number of autophagosomes in these rats.

CONCLUSIONS

EA effectively mitigates post-stroke cognitive impairment by reducing apoptosis, inflammation, and autophagy through the regulation of the mTOR/NLRP3-mediated autophagy-inflammatory pathway, offering valuable therapeutic insights for stroke rehabilitation.

Acupuncture and Electroacupuncture Effects of ST-36 (Zusanli) and SP-9 (Yinlingquan) on Motor Behavior in Ischemic Gerbils

Objective

Stroke is a leading cause of death and disability worldwide. To find ways to reduce behavioral disabilities, researchers study animal models. By targeting ST-36 (Zusanli) and SP-9 (Yinlingquan), this study investigated the effects of traditional acupuncture and electroacupuncture (EA) on motor behavior in gerbils following global cerebral ischemia.

Materials and Methods

Thirty-six male gerbils were randomly assigned to 6 groups (n = 6 in each): control (C); sham-surgical (S); ischemia (I); acupuncture (Ac); EA (Ea); and sham-EA (SEa). The animals were habituated in an activity cage (AC) 72 hours before surgery. After induction of global ischemia, the Ac, Ea, and SEa groups received bilateral stimulation at ST-36 and SP-9. In the Ea group, an alternating electrical current was used. The animals were tested in the AC 4 days after surgery, and the results were analyzed by Kruskal-Wallis, followed by Dunn's posthoc test.

Results

Statistical analysis revealed increased distance traveled and sensors triggered by the I, Ea, and SEa groups, compared to the C, Ac, and S groups. The animals' movement tracks had a similar pattern between the I and Ea groups, with increased exploration along the walls of the AC. Meanwhile, the Ac, S, and SEa groups explored the AC similarly to the C group.

Conclusions

These findings suggest that acupuncture may normalize motor behavior in gerbils with ischemia and could be a promising treatment for stroke-induced motor deficits.

Effects of combined electroacupuncture and medication therapy on the RhoA/ROCK-2 signaling pathway in the striatal region of rats afflicted by cerebral ischemia

OBJECTIVE

To investigate the effects of electroacupuncture(EA), gastrodin(Gas), and their combination on the signaling pathways involving Ras homologous gene family member A (RhoA) and Rho-associated frizzled helix protein kinase (ROCK-2) within the striatal region of rats subjected to cerebral ischemia. Additionally, we aim to elucidate the therapeutic effects and potential underlying mechanisms associated with the concurrent application of electroacupuncture and medication in the treatment of cerebral ischemia.

METHODS

Rats were randomly assigned to one of five groups, namely, the sham operation (Sham) group, model group, EA group, Gas group, and the EA combined with Gas group (referred to as the "EA+Gas group"). Each group consisted of ten rats. Following the induction of cerebral ischemia, the EA group and EA+Gas group received EA stimulation at the Baihui(GV20) and Zusanli(ST36) acupoints for 30 min per session, administered once daily for 14 consecutive days. The Gas group and EA+Gas group were intraperitoneally injected with Gas at a dosage of 10 mg/kg, also administered once daily for 14 consecutive days. Nissl staining was employed to observe morphological alterations in the striatal nerve cells of rats in each group. Immunohistochemistry and western blot techniques were employed to evaluate the expression levels of striatal RhoA and ROCK-2 proteins.

RESULTS

In comparison to the Sham group, the model group exhibited a substantial reduction in the number of striatal nerve cells on the ischemic side, accompanied by notable changes in cell morphology, characterized by reduced cytoplasm, defective and atrophied cytosol, solidified nuclei, loosely arranged cells, and enlarged intercellular spaces. Additionally, there was a notable increase in the positive expression of RhoA and ROCK-2. In contrast, when compared to the model group, the EA, Gas, and EA+Gas groups demonstrated an elevated number of normal nerve cells within the ischemic striatal region, with a significant improvement in cell count and morphology. Furthermore, positive expression levels of RhoA and ROCK-2 were notably reduced in these groups. Compared with the EA group or the GAS group, the number of normal nerve cells in the striatum on the ischemic side of the EA+GAS group was further increased, and the positive expression level of RhoA and ROCK-2 were both further reduced.

CONCLUSION

The protective mechanism underlying the therapeutic efficacy of EA combined with Gas against cerebral ischemic striatal injury in rats may be associated with the inhibition of the activation of the RhoA/ROCK-2 signaling pathway. Importantly, the therapeutic effects observed with the combination of electroacupuncture and medication were superior to those achieved with EA alone or the sole administration of Gas.

Global trends and hotspots in research on acupuncture for stroke: a bibliometric and visualization analysis

Acupuncture has been widely used in stroke and post-stroke rehabilitation (PSR), but there is no literature on the bibliometric analysis of acupuncture for stroke. This study aimed to characterize the global publications and analyze the trends of acupuncture for stroke in the past 40 years. We identified 1157 publications from the Web of Science Core Collection. The number of publications grew slowly in the first three decades from 1980 until it started to grow after 2010, with significant growth in 2011-2012 and 2019-2020. China, the USA, and South Korea are the top three countries in this field, and China has formed good internal cooperative relations. Early studies focused on the clinical efficacy of acupuncture for stroke. In the last five years, more emphasis has been placed on the effectiveness of acupuncture in treating sequelae and complications, combined with neuroimaging studies to explore the mechanisms of brain injury repair and neurological recovery. Acupuncture for stroke has a vast research potential, and researchers from different countries/regions and organizations still need to remove academic barriers to enhance communication and collaboration.

Electroacupuncture alleviates early brain injury via modulating microglia polarization and suppressing neuroinflammation in a rat model of subarachnoid hemorrhage

Subarachnoid hemorrhage refers to an uncommon but severe subtype of stroke leading to high mortality and disability rates. Electroacupuncture, a traditional Chinese medical therapy combined with modern technology, shows evident curative effects on cerebral vascular diseases. This study attempts to investigate the possible treatment effects and mechanisms of EA on early brain injury after SAH. Data were gathered among sham group, SAH-induced group, and EA-treated group of male SD rats, concerning mortality rates, weight loss, rotarod latencies, cerebral blood flow, cell apoptosis, pro-inflammatory cytokines releasing, apoptotic protein level, microglia activation and related signal pathway. All results were collected 24-72 h after SAH induction. EA treatment demonstrated significant improvement on motor function 24 h after SAH without significant changes in mortality rate, weight loss, and cerebral blood flow. Another important finding was that EA regulated Bax and Bcl-2 imbalance and reduced cleaved casepase-3 caused by SAH. Additionally, levels of TNF-α, IL-1β, IL-6 were suppressed. The neuron apoptosis was suppressed by EA. The M1 polarization of activated microglia decreased while M2 polarized phenotype increased after EA treatment. Furthermore, pSTAT3-NOX2 signal axis, the M1 phenotype related activation pathway, was depressed after EA treatment. These findings suggested that EA improved motor deficits and ameliorated early brain injury after SAH probably via decreasing neuron apoptosis and anti-inflammation, which may involve modulation of microglia polarization. Taken together, EA may be a potential therapy for SAH treatment.

Brain Activation Site of Laryngeal Elevation During Swallowing: An fMRI Study

The object of this study is to investigate dysphagia caused by reduced laryngeal elevation in patients poststroke. The central mechanism of laryngeal elevation during swallowing was explored by comparing the brain activation area before and after treatment with that of healthy subjects. The treatment group included patients diagnosed with dysphagia poststroke that showed reduced laryngeal elevation. They were treated with electrical stimulation at the motor points of the muscles related to laryngeal elevation. Functional magnetic resonance imaging (fMRI) using the blood oxygenation level-dependent (BOLD) was used to observe brain activation of the normal healthy control group and treatment group during voluntary swallowing. Independent sample t test and paired sample t test were used to analyze the differences in brain activation between and within the groups. Compared with the control group, no activation was observed in the brainstem and putamen regions of the experimental group before treatment. Statistics showed that the experimental group had a wider range of brain activation than the control group pretreatment, including the left supplementary motor area, the cingulate gyrus, the inferior frontal gyrus, the right thalamus, and the right putamen. After the electrical stimulation, the brain stem subregion, the left cerebellar lobule IV and V, and parts of the cerebral cortex were more active, while the left supplementary motor area, paracentral lobule, and occipital lobule were less active post-treatment. (1) The brainstem and putamen are the specific brain regions that control laryngeal movement. (2) The enhanced activation of the cortical-basal ganglia-thalamic circuit after stroke is a compensatory mechanism. (3) The improvement of hyoid bone elevation was related to the enhanced activation of the IV and V lobes of the cerebellar hemisphere. The over-activation of the supplementary motor area poststroke would subside once the motor function improved.

The treatment of post-stroke dysarthria with a combination of different acupuncture types and language rehabilitation training: a systematic review and network meta-analysis

Background

This study used a network meta-analysis to evaluate the efficacy of various different acupuncture types and language rehabilitation training on post-stroke dysarthria (PSD), and examined the possible mechanisms involved. There are often clinical studies comparing the effects of different acupuncture methods on dysarthria after stroke. The efficacy of these methods can be ranked by network meta-analysis. This is necessary for clinical acupoints selection. The results of this study illustrated the comparison of the therapeutic effects of 6 different acupuncture types, which can provide some reference for clinical acupoints selection and research.

Methods

A comprehensive search for clinical studies related to the use of acupuncture to treat PSD was conducted in eight English and Chinese databases. Patients were divided into six groups based on the acupoints selected, namely, tongue, neck, scalp, body, combination, and traditional acupuncture. The recovery of neurological function in the patients was assessed based on the curative impact and the National Institutes of Health Stroke Scale (NIHSS) score. The quality of the included studies was evaluated using the Cochrane risk bias assessment tool and the STandards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) criteria. A network meta-analysis was performed using the network-meta package of Stata 15.1 software based on frequency. The heterogeneity test, consistency test, head-to-head mixed comparison, efficacy ranking, and publication bias study were all performed.

Results

A total of 47 studies were finally included. There was a total of 4,197 patients in the eligible studies. The model for network meta-analysis proved robust, with minimal heterogeneity and high consistency. Combined acupuncture combined with language rehabilitation training was the most effective in treating dysarthria symptoms, followed by tongue acupuncture (TA) and nape acupuncture (NA). In addition, the combined effect of acupuncture and language training was superior to that of acupuncture alone. In terms of recovery of nerve function, traditional acupuncture and body acupuncture were more effective. To facilitate the recovery of nerve function, increasing the frequency of acupoints is necessary.

Conclusions

Combined acupuncture may have the most beneficial healing effect on PSD, followed by acupuncture of the tongue and the nape of the neck. In terms of recovery of nerve function, traditional acupuncture and body acupuncture may have more effective.

Alteration of brain functional networks induced by electroacupuncture stimulation in rats with ischemia–reperfusion: An independent component analysis

Motor dysfunction is the major sequela of ischemic stroke. Motor recovery after stroke has been shown to be associated with remodeling of large-scale brain networks, both functionally and structurally. Electroacupuncture (EA) is a traditional Chinese medicine application that has frequently been recommended as an alternative therapy for ischemic stroke and is reportedly effective for alleviating motor symptoms in patients. In the present study, the effect of EA on the alterations of functional resting state networks (RSNs) was explored after middle cerebral artery occlusion/reperfusion (MCAO/R) injury using resting-state functional MRI. Rats were randomly assigned to three groups, including the sham group, MCAO/R group and MCAO/R+EA group. The ladder rung walking test was conducted prior to and after modeling to assess behavioral changes. RSNs were identified based on the independent component analysis (ICA) performed on the fMRI data from groups. EA treatment effectively reduced the occurrence of contralateral forelimb foot faults. Furthermore, our results suggested the disrupted function of the whole-brain network following ischemic stroke and the modulatory effect of acupuncture. The sensorimotor network (SMN), interoceptive network (IN), default mode network (DMN) and salience network (SN) were related to the therapeutic effect of EA on stroke recovery. Collectively, our findings confirmed the effect of EA on motor function recovery after cerebral ischemia reperfusion and shed light on the assessment of EA intervention-induced effects on brain networks. This study provides neuroimaging evidence to explain the therapeutic effects of EA in ischemic stroke and will lay the groundwork for further studies.

Irisin: A promising treatment for neurodegenerative diseases

The beneficial effects of exercise on human brain function have been demonstrated in previous studies. Myokines secreted by muscle have attracted increasing attention because of their bridging role between exercise and brain health. Regulated by PPARγ coactivator 1α, fibronectin type III domain-containing protein 5 releases irisin after proteolytic cleavage. Irisin, a type of myokine, is secreted during exercise, which induces white adipose tissue browning and relates to energy metabolism. Recently, irisin has been shown to exert a protective effect on the central nervous system. Irisin secretion triggers an increase in brain-derived neurotrophic factor levels in the hippocampus, contributing to the amelioration of cognition impairments. Irisin also plays an important role in the survival, differentiation, growth, and development of neurons. This review summarizes the role of irisin in neurodegenerative diseases and other neurological disorders. As a novel positive mediator of exercise in the brain, irisin may effectively prevent or decelerate the progress of neurodegenerative diseases in models and also improve cognitive functions. We place emphasis herein on the potential of irisin for prevention rather than treatment in neurodegenerative diseases. In ischemic diseases, irisin can alleviate the pathophysiological processes associated with stroke. Meanwhile, irisin has anxiolytic and antidepressant effects. The potential therapeutic effects of irisin in epilepsy and pain have been initially revealed. Due to the pleiotropic and beneficial properties of irisin, the possibility of irisin treating other neurological diseases could be gradually explored in the future.

Electroacupuncture treatment improves motor function and neurological outcomes after cerebral ischemia/reperfusion injury

Electroacupuncture (EA) has been widely used for functional restoration after stroke. However, its role in post-stroke rehabilitation and the associated regulatory mechanisms remain poorly understood. In this study, we applied EA to the Zusanli (ST36) and Quchi (LI11) acupoints in rats with middle cerebral artery occlusion and reperfusion. We found that EA effectively increased the expression of brain-derived neurotrophic factor and its receptor tyrosine kinase B, synapsin-1, postsynaptic dense protein 95, and microtubule-associated protein 2 in the ischemic penumbra of rats with middle cerebral artery occlusion and reperfusion. Moreover, EA greatly reduced the expression of myelin-related inhibitors Nogo-A and NgR in the ischemic penumbra. Tyrosine kinase B inhibitor ANA-12 weakened the therapeutic effects of EA. These findings suggest that EA can improve neurological function after middle cerebral artery occlusion and reperfusion, possibly through regulating the activity of the brain-derived neurotrophic factor/tyrosine kinase B signal pathway. All procedures and experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine, China (approval No. PZSHUTCM200110002) on January 10, 2020.

Irisin-Associated Neuroprotective and Rehabilitative Strategies for Stroke

Irisin, a newly discovered protein hormone that is secreted in response to low frequency whole body vibration (LFV), could be a promising post-stroke rehabilitation therapy for patients who are frail and cannot comply with regular rehabilitation therapy. Irisin is generated from a membrane-bound precursor protein fibronectin type III domain-containing protein 5 (FNDC5). Aside from being highly expressed in muscle, FNDC5 is highly expressed in the brain. The cleaved form of FNDC5 was found in the cerebrospinal fluid as well as in various regions of the brain. Numerous studies suggest that irisin plays a key role in brain metabolism and inflammation regulation. Both the metabolism and inflammation govern stroke outcome, and in a published study, we demonstrated that LFV therapy following middle cerebral artery occlusion significantly reduced innate immune response, improved motor function and infarct volume in reproductively senescent female rats. The observed effect of LFV therapy could be working via irisin, therefore, the current review focuses to understand various aspects of irisin including its mechanism of action on the brain.