Does acupuncture ameliorate motor impairment after stroke? An assessment using the CatWalk gait system

Icaritin promotes brain functional rehabilitation in ischemic stroke rats by regulating astrocyte activation and polarization via GPER

BACKGROUND

Cerebral ischemic injury induces the polarization of astrocytes toward two different phenotypes, i.e., the proinflammatory A1 phenotype and the protective, anti-inflammatory A2 phenotype, affects the prognosis of cerebral ischemia. To explore the neuroprotective effect of phytoestrogens ICT on cerebral ischemic rehabilitation and the preliminary mechanism of regulating astrocyte polarization.

METHODS

Transient middle cerebral artery occlusion (tMCAO)/reperfusion was performed on rats and then treated with ICT (i.p.) once daily for 28 days. Intervention of GPER specific inhibitor G15 was repeated. The body weight, Garcia JH scale, right/left brain weight ratio, CatWalk gait test and Y maze test to assess overall neural function in rats. Inflammatory factors in ischemic cortical were detected by Western blotting. The number of newborn neurons was observed by BrdU staining, and the double immunofluorescence staining and Western blotting to evaluated the activation and A1 and A2 polarization of astrocytes.

RESULTS

The results showed that ICT treatment markedly perfected functional outcomes on a long-term basis after ischemic stroke, it also improved learning and memory and gait. ICT inhibited the polarization of A1 type astrocytes and promoted the polarization of A2 type astrocytes, promote neuron regeneration in hippocampus DG region. G15 removes some of the protective effects of ICT.

CONCLUSIONS

The experimental results show that ICT exerts neuroprotective effects and regulates astrocyte polarization through GPER, suggesting that it may be a potential therapeutic agent for ischemic stroke during the recovery period.

Genistein-3'-sodium sulfonate promotes brain functional rehabilitation in ischemic stroke rats by regulating astrocytes polarization through NF-κB signaling pathway

The activation and polarization of astrocytes are involved in neuroinflammation and brain functional rehabilitation after ischemic stroke. Our previous studies display the neuroprotective effect of genistein-3'-sodium sulfonate (GSS) in the acute phase of cerebral ischemia-reperfusion injury (CI/RI). This study aimed to investigate the brain function improvement of GSS during the recovery period after CI/RI in rats and to explore the potential mechanism from the perspective of astrocyte activation and polarization. The transient middle cerebral artery occlusion (tMCAO) rats were treated with GSS (1 mg/kg) continuously for 28 days. The behavior tests were measured to assess neurological function. The mRNA and protein expression in affected cerebral cortex were detected on day 29 after tMCAO. Our results demonstrated that GSS treatment significantly improved the spatial and temporal gait parameters in the Catwalk gait test, prolonged the time on the stick and increased the rotation speed in the rotarod test, and decreased the time to find the hidden platform and increased the time in the target quadrant in the Morris water maze test. In addition, GFAP, GBP2, C3, IL-1β protein expressions and Nos2A mRNA level were decreased, while Nrf2, BDNF, IL-10 protein expressions and Sphk1 and Nef2l2 mRNA levels increased after GSS treatment. Interestingly, GSS presented a strong binding affinity to TLR4 and suppressed the activation of NF-κB signaling. In conclusion, GSS can promote brain function recovery by inhibiting astrocyte activation and polarization to A1 phenotype, and enhancing astrocyte polarization to A2 phenotype via inactivating TLR4/NF-κB signaling, which provide a candidate compound for clinical rehabilitation therapy in the recovery period after ischemic stroke.

Extracellular Vesicles Maintain Blood-Brain Barrier Integrity by the Suppression of Caveolin-1/CD147/VEGFR2/MMP Pathway After Ischemic Stroke

Background

Ischemic stroke (IS) causes tragic death and disability worldwide. However, effective therapeutic interventions are finite. After IS, blood-brain barrier (BBB) integrity is disrupted, resulting in deteriorating neurological function. As a novel therapeutic, extracellular vesicles (EVs) have shown ideal restorative effects on BBB integrity post-stroke; however, the definite mechanisms remain ambiguous. In the present study, we investigated the curative effects and the mechanisms of EVs derived from bone marrow mesenchymal stem cells and brain endothelial cells (BMSC-EVs and BEC-EVs) on BBB integrity after acute IS.

Methods

EVs were isolated from BMSCs and BECs, and we investigated the therapeutic effect in vitro oxygen-glucose deprivation (OGD) insulted BECs model and in vivo rat middle cerebral artery occlusion (MCAo) model. The cell monolayer leakage, tight junction expression, and metalloproteinase (MMP) activity were evaluated, and rat brain infarct volume and neurological function were also analyzed.

Results

The administration of two kinds of EVs not only enhanced ZO-1 and Occludin expressions but also reduced the permeability and the activity of MMP-2/9 in OGD-insulted BECs. The amelioration of the cerebral infarction, BBB leakage, neurological function deficits, and the increasing ZO-1 and Occludin levels, as well as MMP activity inhibition was observed in MCAo rats. Additionally, the increased levels of Caveolin-1, CD147, vascular endothelial growth factor receptor 2 (VEGFR2), and vascular endothelial growth factor A (VEGFA) in isolated brain microvessels were downregulated after EVs treatment. In vitro, the employment of Caveolin-1 and CD147 siRNA partly suppressed the expressions of VEGFR2, VEGFA and MMP-2/9 activity and reduced the leakage of OGD insulted BECs and enhanced ZO-1 and Occludin expressions.

Conclusion

Our study firstly demonstrates that BEC and BMSC-EVs administrations maintain BBB integrity via the suppression of Caveolin-1/CD147/VEGFR2/MMP pathway after IS, and the efficacy of BMSC-EVs is superior to that of BEC-EVs.

Mechanisms of microRNA-132 in central neurodegenerative diseases: A comprehensive review

MicroRNA-132 (miR-132) is a highly conserved molecule that plays a crucial regulatory role in central nervous system (CNS) disorders. The expression levels of miR-132 exhibit variability in various neurological disorders and have been closely linked to disease onset and progression. The expression level of miR-132 in the CNS is regulated by a diverse range of stimuli and signaling pathways, including neuronal migration and integration, dendritic outgrowth, and complexity, synaptogenesis, synaptic plasticity, as well as inflammation and apoptosis activation. The aberrant expression of miR-132 in various central neurodegenerative diseases has garnered widespread attention. Clinical studies have revealed altered miR-132 expression levels in both chronic and acute CNS diseases, positioning miR-132 as a potential biomarker or therapeutic target. An in-depth exploration of miR-132 holds the promise of enhancing our understanding of the mechanisms underlying CNS diseases, thereby offering novel insights and strategies for disease diagnosis and treatment. It is anticipated that this review will assist researchers in recognizing the potential value of miR-132 and in generating innovative ideas for clinical trials related to CNS degenerative diseases.

Influence of Acupuncture and Other Clinical Factors on the Recovery of Limb Motor Function in Patients After Stroke: A Retrospective Study

Background

Limb motor disorders after stroke are very common, and the clinical related factors of improving limb motor function are still unclear. As a part of comprehensive rehabilitation strategy, acupuncture has been widely used in rehabilitation after stroke in China. But more evidence is needed for the influence of acupuncture and some other clinical factors on post-stroke motor disorders.

Patients and Methods

A retrospective study was conducted using the database of patients with post-stroke motor disorders admitted to the Neurological Rehabilitation Unit of the First Teaching Hospital of Tianjin University of Traditional Chinese Medicine. The included patients were grouped according to whether NIHSS improved or muscle strength improved. The positive logistic regression was used to analyze the influencing factors of possible NIHSS improvement. Combined with the influencing factors of NIHSS improvement and muscle strength improvement, the influencing factors of limb motor function recovery after stroke were obtained.

Results

When analyzing the baseline of the included patients, it was found that patients with NIHSS improvement had earlier acupuncture intervention time (M, (IQR):13.5 (14), OR=0.716, 95% CI [0.591-0.869], p=0.001), more cumulative acupuncture treatment times (M,(IQR):29 (12), OR=0.744, 95% CI [0.608-0.910], p=0.004), and less hypertension history (OR=0.256, 95% CI [0.082-0.801], p=0.019). Smoking history only has positive significance in univariate and multivariate analysis of NIHSS, not muscle strength (OR=0.274, 95% CI [0.097-0.779], p=0.015).

Conclusion

The earlier acupuncture intervention and the more cumulative acupuncture treatment times are, the more beneficial the limb function of stroke patients with motor disorders will be. The previous history of hypertension is the influencing factor of limb motor function not improving in patients with limb motor disorder after a stroke. The effect of smoking history on limb movement function of patients with limb motor disorder after stroke needs further study.

Intermittent hypoxia promotes the recovery of motor function in rats with cerebral ischemia by regulating mitochondrial function

Hypoxia preconditioning is neuroprotective, but the therapeutic effects of intermittent hypoxia were not fully considered. The present study investigated the neuroprotective effect and mechanism of intermittent hypoxia on motor function after cerebral ischemia and explored alternative clinical treatment options. In total, 36 8-week-old male Sprague-Dawley rats were subjected to 60 min of transient middle cerebral artery occlusion (tMCAO) and then randomly divided into a sham-operated group (SHAM), tMCAO-sedentary group (SED), and tMCAO-intermittent hypoxia group (IH). The intervention was performed 1 week after tMCAO and lasted 4 weeks. Rats in the IH group were placed in an animal hypoxic chamber (altitude 5000 m and oxygen concentration of 13%) for 4 h/day and 7 days/week, and rats in the SED group were placed in a normoxic environment for 4 weeks. Body weights, neurological deficit scores, cerebral infarction volume ratios, gait analyses, mitochondrial structure, adenosine triphosphate (ATP) content and AMO-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α), and silencing regulatory protein 3 (Sirt3) expression in the peri-ischemic region brain tissues were detected during the intervention. Compared with the SED group, the body weight of the IH group gradually recovered, and the neurological deficit scores were significantly reduced (P < 0.05). The gait analysis results showed that the pressure of the affected paw and the maximum content area, swing speed, stride length, and other parameters were significantly restored (P < 0.05). The cerebral infarction volume ratio was significantly reduced (P < 0.01). Mitochondrial morphological structure damage in the peri-ischemic region brain tissues recovered, the number was significantly increased (P < 0.05), and the expression of AMPK, PGC-1α, and Sirt3 proteins (P < 0.05), and ATP content were significantly increased (P < 0.05). Intermittent hypoxia may activate the AMPK-PGC-1α-Sirt3 signaling pathway, promote mitochondrial biogenesis, repair mitochondrial ultrastructural damage, and improve mitochondrial function to reduce brain damage and promote motor function recovery in rats with cerebral ischemia.

Prunus cerasoides Extract and Its Component Compounds Upregulate Neuronal Neuroglobin Levels, Mediate Antioxidant Effects, and Ameliorate Functional Losses in the Mouse Model of Cerebral Ischemia

Prunus cerasoides (PC) has been reported to have antimicrobial and anti-inflammatory properties, but its potential as a neuroprotective agent in a mouse model of cerebral ischemia has not been explored. Considering neuroglobin (Ngb), an endogenous neuroprotective factor, as a novel approach to neuroprotection, in this study, Ngb promoter activity, Ngb expression changes, and antioxidant protection by PC extract (PCE) and PC component compounds (PCCs) were analyzed in oxygen-glucose deprivation (OGD)-treated neurons. In vivo analysis involved transient middle cerebral artery occlusion (tMCAO) in mice with pre- and post-treatment exposure to PCE. Following ischemic stroke induction, neurological behavior scores were obtained, and cellular function-related signals were evaluated in the ischemic infarct areas. In addition to PCE, certain component compounds from PCE also significantly increased Ngb levels and attenuated the intracellular ROS production and cytotoxicity seen with OGD in primary neurons. Administration of PCE reduced the infarct volume and improved neurological deficit scores in ischemic stroke mice compared with the vehicle treatment. Increased Ngb levels in infarct penumbra with PCE treatment were also accompanied by decreased markers of apoptosis (activated p38 and cleaved caspase-3). Our findings point to the benefits of Ngb-mediated neuroprotection via PCE and its antioxidant activity in an ischemic stroke model.

Exercise-induced neuroprotection against cerebral ischemia/reperfusion injury is mediated via alleviating inflammasome-induced pyroptosis

As a primary nonpharmacological tool, exercise training is neuroprotective after experimental ischemic stroke by relieving neuroinflammation. However, the specific mechanism of which and anti-inflammatory effect of exercise at different intensities require in-depth investigations. To explore the issue, middle cerebral artery occlusion-reperfusion (MCAO-r) in mice were utilized, with subsequent exercise training at different intensities (high-intensity interval training versus moderate-intensity continuous training, i.e. HIIT vs. MICT) during an early phase post-modeling. The neurobehavioral assessment showed that MICT improved the performance of neurological deficit scores and rotarod test earlier, while HIIT appeared to be more efficacious to meliorate locomotor impairments and aerobic fitness at the end of intervention. Both exercise regimens inhibited the expressions of NLRP3 inflammasome components (NLRP3, ASC, and Cl.caspase-1) and pyroptosis-associated proteins (GSDMD, Cl.IL-1β, and Cl.IL-18) as indicated by western blot and immunofluorescence co-staining. Multiplex assay panel revealed that both exercise regimens reduced the levels of pro-inflammatory cytokines and upregulated anti-inflammatory cytokine. Furthermore, an increased proportion of M2-like microglia and a diminished proportion of M1-like microglia in the peri-infarct zone were observed by colocalization analysis, which was jointly validated by western blot. Here, for the first time, our study demonstrated that HIIT elicited better improvements at functional and cardiovascular levels than MICT after ischemic stroke, and anti-inflammatory effect of exercise might result from suppression in inflammasome-mediated pyroptosis by shifting microglial polarization toward neuroprotective M2 phenotype.

Acute effects of acupuncture in balance and gait of Parkinson disease patients - A preliminary study

INTRODUCTION

Balance and gait disorders are relevant symptoms in the quality of life of Parkinson's patients. Currently, there is no therapy to reverse or treat this condition. Acupuncture treatment is believed to improve motor ability through the cortico-basal-thalamus-cortical-ganglia.

AIM

To investigate qualitatively the acute effect of acupuncture on balance and gait in Parkinson's disease in 7 patients.

METHODS

This is a randomized and controlled crossover study. The same individual patient was part of both, experimental (real acupuncture) and control group (false acupuncture/sham), and the sequence was randomized. Balance and gait parameters were measured at two different moments, before and after treatment, using four force platforms as well as the collection of 3D markers positions taken by 11 cameras. Images were analyzed using Qualisys Track Manager software that let us extract data related to the quality of gait and balance.

RESULTS

Statistically significant differences were found in gait speed (p = 0.016), gait cadence (p = 0.006), support base width (p = 0.0001), medio-lateral oscillation (p = 0.017), left-right step length (p = 0.0002), and stride length: right-right (p = 0.0000) and left-left (p = 0.0018), time of left support phase (p = 0.029), right support phase (p = 0.025) and double support phase (p = 0.015), between the initial and final moments for the experimental group. Differences in right-left stride length were found for both groups.

CONCLUSION

Our results suggest that the acupuncture protocol used objectively could improve gait in Parkinson disease patients. A deep research involving a statistical evaluation supported on a larger number of voluntaries should be accomplished to confirming these promising preliminary results.

Dynamics of T Lymphocyte between the Periphery and the Brain from the Acute to the Chronic Phase Following Ischemic Stroke in Mice

Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4^-CD8^-CD3⁺ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10⁺Foxp3⁺ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10⁺Foxp3⁺ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.

Comparative functional analysis of mice after local injection with botulinum neurotoxin A1, A2, A6, and B1 by catwalk analysis

Botulinum neurotoxins (BoNTs) are potent neurotoxins and are the causative agent of botulism, as well as valuable pharmaceuticals. BoNTs are divided into seven serotypes that comprise over 40 reported subtypes. BoNT/A1 and BoNT/B1 are currently the only subtypes approved for pharmaceutical use in the USA. While several other BoNT subtypes including BoNT/A2 and/A6 have been proposed as promising pharmaceuticals, detailed characterization using in vivo assays are essential to determine their pharmaceutical characteristics compared to the currently used BoNT/A1 and/B1. Several methods for studying BoNTs in mice are being used, but no objective and quantitative assay for assessment of functional outcomes after injection has been described. Here we describe the use of CatWalk XT as a new analytical tool for the objective and quantitative analysis of the paralytic effect after local intramuscular injection of BoNT subtypes A1, A2, A6, and B1. Catwalk is a sophisticated gait and locomotion analysis system that quantitatively analyzes a rodent's paw print dimensions and footfall patterns while traversing a glass plate during unforced walk. Significant changes were observed in several gait parameters in mice after local intramuscular injection of all tested BoNT subtypes, however, no changes were observed in mice injected intraperitoneally with the same BoNTs. While a clear difference in time to peak paralysis was observed between BoNT/A1 and/B1, injection of all four toxins resulted in a deficit in the injected limb with the other limbs functionally compensating and with no qualitative differences between the four BoNT subtypes. The presented data demonstrate the utility of CatWalk as a tool for functional outcomes after local BoNT injection through its ability to collect large amounts of quantitative data and objectively analyze sensitive changes in static and dynamic gait parameters.

Acupuncture Enhances Communication between Cortices with Damaged White Matters in Poststroke Motor Impairment

Stroke is a leading cause of motor disability. Acupuncture is an effective therapeutic strategy for poststroke motor impairment. However, its mechanism is still elusive. Twenty-two stroke patients having a right-hemispheric subcortical infarct and 22 matched healthy controls were recruited to undergo diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) scanning. The resting-state fMRI was implemented before and after needling at GB34 (Yanglingquan). The stroke patients presented a substantially reduced fractional anisotropy value in the right superior longitudinal fasciculus (SLF), corticospinal tract, and corpus callosum. The structural integrity of the frontoparietal part of the SLF (SLF-FP) correlated with the motor scores of lower limbs in stroke patients. This corticocortical association bundle originated from the premotor cortex (PM) and the adjacent supplementary motor area (SMA), known as secondary motor areas, and terminated in the supramarginal gyrus (SMG). After acupuncture intervention, the corresponding functional connectivity between the PM/SMA and SMG was enhanced in stroke patients compared with healthy controls. These findings suggested that the integrity of the SLF is a potential neuroimaging biomarker for motor disability of lower limbs following a stroke. Acupuncture could increase the communication between the cortices connected by the impaired white matter tracts, implying the neural mechanism underlying the acupuncture intervention.

Electroacupuncture Improves Neurobehavioral Function Through Targeting of SOX2-Mediated Axonal Regeneration by MicroRNA-132 After Ischemic Stroke

Our previous studies have shown that electroacupuncture (EA) enhances neurobehavioral functional recovery after ischemic stroke, however, the underlying regulatory mechanisms remain unclear. MicroRNAs (miRNAs) are abundant in the brain and are involved in post-transcriptional gene regulation. During cerebral ischemia reperfusion, miRNAs perform numerous biological functions in the central nervous system related to regeneration and repair of damaged nerves. Our previous studies also have shown that the expression of miRNA-132 (miR-132) is obviously down-regulated after stroke by middle cerebral artery occlusion (MCAO), which can be up-regulated by EA. This study aimed to identify whether up-regulation of miR-132 by EA improved the damaged nerves after stroke and to screen the potential target of miR-132. The results showed that EA up-regulated miR-132 thus suppressing SOX2 expression in vivo after MCAO, which obviously ameliorated neurobehavioral functional recovery. Moreover, our results also suggested that up-regulated miR-132 suppressed SOX2 in primary neurons after oxygen-glucose deprivation (OGD), which promoted neurite outgrowth. In conclusion, EA enhances neurobehavioral functional recovery against ischemic stroke through targeting of SOX2-mediated axonal regeneration by miR-132.

The extent of intrauterine growth restriction determines the severity of cerebral injury and neurobehavioural deficits in rodents

Background

Cerebral Palsy (CP) is the most common physical pediatric neurodevelopmental disorder and spastic diplegic injury is its most frequent subtype. CP results in substantial neuromotor and cognitive impairments that have significant socioeconomic impact. Despite this, its underlying pathophysiological mechanisms and etiology remain incompletely understood. Furthermore, there is a need for clinically relevant injury models, which a) reflect the heterogeneity of the condition and b) can be used to evaluate new translational therapies. To address these key knowledge gaps, we characterized a chronic placental insufficiency (PI) model, using bilateral uterine artery ligation (BUAL) of dams. This injury model results in intrauterine growth restriction (IUGR) in pups, and animals recapitulate the human phenotype both in terms of neurobehavioural and anatomical deficits.

Methods

Effects of BUAL were studied using luxol fast blue (LFB)/hematoxylin & eosin (H&E) staining, immunohistochemistry, quantitative Magnetic Resonance Imaging (MRI), and Catwalk neurobehavioural tests.

Results

Neuroanatomical analysis revealed regional ventricular enlargement and corpus callosum thinning in IUGR animals, which was correlated with the extent of growth restriction. Olig2 staining revealed reductions in oligodendrocyte density in white and grey matter structures, including the corpus callosum, optic chiasm, and nucleus accumbens. The caudate nucleus, along with other brain structures such as the optic chiasm, internal capsule, septofimbrial and lateral septal nuclei, exhibited reduced size in animals with IUGR. The size of the pretectal nucleus was reduced only in moderately injured animals. MAG/NF200 staining demonstrated reduced myelination and axonal counts in the corpus callosum of IUGR animals. NeuN staining revealed changes in neuronal density in the hippocampus and in the thickness of hippocampal CA2 and CA3 regions. Diffusion weighted imaging (DWI) revealed regional white and grey matter changes at 3 weeks of age. Furthermore, neurobehavioural testing demonstrated neuromotor impairments in animals with IUGR in paw intensities, swing speed, relative print positions, and phase dispersions.

Conclusions

We have characterized a rodent model of IUGR and have demonstrated that the neuroanatomical and neurobehavioural deficits mirror the severity of the IUGR injury. This model has the potential to be applied to examine the pathobiology of and potential therapeutic strategies for IUGR-related brain injury. Thus, this work has potential translational relevance for the study of CP.

Stroke and other cerebrovascular diseases

To achieve success in developing more effective treatments for stroke, we need a better understanding in all aspects of stroke including prevention, diagnosis, treatment, and post-stroke recovery and complications. The objective of this special issue is to bring to the readership of Neurochemistry International the latest developments and knowledge in a broad spectrum of areas of stroke research in both review and original research articles. Topics include neuroprotective diets, biomarkers used to aid clinical management, neurodegenerative as well as neuroprotective effects of the immune system, potential therapeutic targets, engineered growth factors that promote endogenous neuroregeneration, mechanisms of cerebral small vessel disease, and post stroke epilepsy.