Possible Involvement of PTEN Signaling Pathway in the Anti-apoptotic Effect of Electroacupuncture Following Ischemic Stroke in Rats

Drug pairs of Huangqi and Dnggui alleviates pyroptosis by promoting autophagy activity via AMPK/mTOR signaling pathway in middle-cerebral artery occlusion/reperfusion in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cerebral ischemia-reperfusion (I/R) injury is a common complication of ischemic stroke, with autophagy and pyroptosis playing key roles. Huangqi and Danggui (HQDG) are a commonly used drug pair of Chinese traditional medicine for clinical treatment of ischemic stroke.

AIM OF THE STUDY

The study aims to investigate the interaction between autophagy and pyroptosis regulated by HQDG through the AMPK/mTOR signaling pathway during cerebral I/R injury.

MATERIALS AND METHODS

Model of middle-cerebral artery occlusion/reperfusion (MCAO/R) in SD rats was established using the Longa suture method. The components of traditional Chinese medicine were detected by liquid chromatography coupled to quadrupole orbitrap high resolution mass spectrometry (LC/MS). Neurological deficits were evaluated by neurological function score. Changes of cerebral blood flow were detected by a laser speckle blood flow imaging instrument. The volume of cerebral infarction was observed by 2,3,5-Chlorotriphenyltetrazolium (TTC) staining. The permeability of the blood-brain barrier was measured by Evans blue test. Neurovascular unit and autophagosomes in brain tissue were assessed by transmission electron microscopy. Neuronal pyroptosis was detected by terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL)/Caspase-1 staining. The expression of autophagy related proteins, pyroptosis related proteins, and AMPK/mTOR pathway related proteins were detected by Western blot.

RESULTS

After cerebral I/R injury, autophagy and pyroptosis, were characterized by increased number of autophagosomes and pyroptosis cells, upregulated expression of Beclin 1, LC3-II/LC3-I, NLRP3, cleaved Caspase-1, IL-1beta, IL-18 proteins, and downregulated expression of P62 proteins. HQDG significantly improved neurological function, reduced the volume of cerebral infarction, increased cerebral blood flow, improved blood-brain barrier permeability and the function of neurovascular units. Autophagy was further activated and pyroptosis was significantly inhibited by HQDG, which promoted increased number of autophagosomes, enhanced expression of Beclin 1, LC3-II/LC3-I proteins, reduced expression of P62, NLRP3, cleaved Caspase-1, IL-1beta, and IL-18 proteins, and downregulated the number of pyroptosis cells. On the other hand, after administering 3-Methyladenine (3-MA) to inhibit autophagy, the above effects of HQDG were significantly inhibited. Besides, HQDG promoted AMPK phosphorylation, and weakened mTOR phosphorylation. However, after the administration of AMPK inhibitor Compound C, HQDG caused increase in Beclin 1 and LC3-II/LC3-I, reduced P62 and NLRP3, and cleaved Caspase-1 protein expression, whereas cerebral blood flow decreased.

CONCLUSION

HQDG alleviated pyroptosis by promoting autophagy via AMPK/mTOR signaling pathway after middle-cerebral artery occlusion/reperfusion in rats, showing its potential for treatment of cerebral I/R injury in humans.

Targeting PTEN in ischemic stroke: From molecular mechanisms to therapeutic potentials

Ischemic stroke remains a leading cause of mortality and disability worldwide, driven by complex pathophysiological mechanisms, including excitotoxicity, oxidative stress, apoptosis, and neuroinflammation. PTEN (Phosphatase and tensin homolog deleted on chromosome 10) plays a crucial role in these processes, influencing key signaling pathways such as PI3K/Akt and mTOR. This review aims to explore PTEN's multifaceted functions in ischemic stroke, examining its interactions with non-coding RNAs, involvement in mitophagy and immune suppression, and overall impact on cellular homeostasis. We will investigate various therapeutic strategies targeting PTEN, including synthetic drugs, natural products, and exosome-based therapies enriched with specific miRNAs. Additionally, we will assess the potential of non-pharmaceutical interventions such as electroacupuncture, exercise, transcranial direct current stimulation (tDCS), and therapeutic hypothermia in modulating PTEN activity to enhance cererbroprotection and functional recovery. By elucidating these aspects, this review aims to inspire and motivate the audience in their research and clinical practice, highlighting PTEN as a promising therapeutic target and paving the way for developing effective treatments for ischemic stroke.

Electroacupuncture alleviates acute myocardial ischemic injury in mice by regulating the β1 adrenergic receptor and post-receptor protein kinase A signaling pathway

OBJECTIVE

To determine the effect of electroacupuncture (EA) on β1-adrenergic receptor (β1-AR) and post-receptor protein kinase A (PKA) signaling pathway after acute myocardial ischemia (MI).

METHODS

An MI model was established by ligating the left anterior descending coronary artery of wild-type (WT) C57/BL and β1-AR+/- mice (heterozygous for β1-AR gene deletion). EA treatment was administered at HT5-HT7 or LU9-LU8. We evaluated cardiac function by measuring ST segment displacement, ischemic area and serum levels of creatine kinase (CK)-MB and lactate dehydrogenase (LDH). Pathological morphology/apoptosis of myocardial tissue were examined using hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Norepinephrine (NE) levels in myocardial tissue were detected by ELISA. Levels of β1 and post-receptor PKA signaling components were evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting.

RESULTS

EA stimulation at HT7-HT5 could better regulate the level of β1-AR in myocardial tissue than that at LU9-LU8. Following EA, the ST segment, serum CK-MB/ LDH and area of myocardial infarction were decreased in WT mice, and the degree of myocardial pathology/apoptosis and expression of cleaved caspase-3 were decreased. Myocardial levels of Gs protein (Gs), adenylate cyclase (AC), cyclic adenosine monophosphate (cAMP), phosphorylated protein kinase A (p-PKA), L-type voltage-gated calcium channel α1C (Cav1.2), serine phosphate 16-phospholamban (p-PLBs16) and sarcoplasmic reticulum Ca2+-adenosine triphosphate (ATP)ase 2a (SERCA2a) increased after EA. However, these effects of EA were not replicated in β1-AR+/- mice. Interestingly, myocardial NE content decreased after EA in WT and β1-AR+/- mice.

CONCLUSION

EA may enhance cardiac function and reduced MI area/apoptosis by restoring the activity of β1-AR and post-receptor PKA signaling.

Modulation of Brain Activities in Healthy Individuals by Acupuncture at Quchi (LI11)

This research investigated the modulation of acupuncture at Quchi (LI11) on the brain activities in healthy individuals. Sub-bands power and EEG microstate analysis were carried out at pre-acupuncture, acupuncture, needle retaining and post-acupuncture periods in both the acupuncture group (n = 16) and control group (n = 18). Four microstate classes (A-D) were derived from the clustering procedure. Regression analysis was conducted, together with a two-way repeated measures ANOVA, which was then followed by Bonferroni correction. In the acupuncture group, we found the beta power during the acupuncture periods was significantly reduced. The channel-by-channel analysis revealed that acupuncture at LI11 mainly altered the power of delta, theta, and alpha waves in specific brain regions. The delta power increased predominantly in parietal, occipital, and central lobes, while theta and alpha power decreased predominantly in temporal, frontal, parietal, and occipital lobes. During the acupuncture period, participants in the acupuncture group showed a significant increase in both duration and contribution of microstate A, as well as the bidirectional transition probabilities A and B/D. Microstate analysis showed that acupuncture at LI11 significantly enhances the activity of microstate A and potentially strengthens the functional connectivity between the auditory network and either the visual network or the dorsal attention network. These correlational results indicate that acupuncture at LI11 mainly affects activities of the frontal, temporal, parietal, and occipital lobes. These findings highlight the potential of microstate as neuroimaging evidence and a specific index for elucidating the neuromodulatory effects of acupuncture at LI11.

Identification and analysis of key immunity-related genes in experimental ischemic stroke

The regulation of the immune system and the occurrence of inflammation are vital factors in the pathophysiology of ischemic stroke. This study aims to screen target molecules which play key roles in alleviating the brain injury following ischemic stroke via regulating neuroinflammation. Several bioinformatics methods were used to identify immune-related genes in ischemic stroke. A total of 218 genes were identified as differentially expressed genes within the GSE97537 dataset. By performing GO, KEGG, and GSEA analyses, DEGs were mainly enriched in pathways related to immunity and inflammation. By utilizing the MCODE plugin in conjunction with Cytoscape software, a total of six crucial genes were identified, including C1qb, C1qc, Fcer1g, Fcgr3a, Tyrobp, and CD14. Based on the above crucial genes, 13 miRNAs were predicted. Furthermore, 71 potential drugs with therapeutic properties that target the crucial genes were screened, including lovastatin, ASPIRIN, and PREDNISOLONE. Moreover, the results of RT-qPCR showed that compared with Sham group, the expressions of C1qb, C1qc, Fcer1g, Fcgr3a, Tyrobp, and CD14 in MCAO group were significantly increased, which was consistent with the expression trend of validation dataset and training dataset. In conclusion, immune-related genes may play a key role in ischemic stroke. In addition, six crucial genes were identified as potential biomarkers and 71 promising drugs were screened to treat ischemic stroke patients.

Electroacupuncture attenuates cerebral ischemia/reperfusion injury by regulating oxidative stress, neuronal death and neuroinflammation via stimulation of PPAR-γ

BACKGROUND

Oxidative stress and inflammatory responses play essential roles in cerebral ischemia/reperfusion (I/R) injury. Electroacupuncture (EA) is widely used as a rehabilitation method for stroke in China; however, the underlying mechanism of action remains unclear. Peroxisome proliferator-activated receptor gamma (PPAR-γ) has been reported to impact anti-inflammatory and anti-oxidative effects.

OBJECTIVE

This study investigated the role of PPAR-γ in EA-mediated effects and aimed to illuminate its possible mechanisms in cerebral I/R.

METHODS

In this study, male Sprague-Dawley (SD) rats with middle cerebral artery occlusion/reperfusion (MCAO/R) injury were treated with EA at LI11 and ST36 for 30 min daily after MCAO/R for seven consecutive days. The neuroprotective effects of EA were measured by neurobehavioral evaluation, triphenyltetrazolium chloride staining, hematoxylin-eosin staining and transmission electron microscopy. Oxidative stress, inflammatory factors, neural apoptosis and microglial activation were examined by enzyme-linked immunosorbent assay, immunofluorescence and reverse transcriptase polymerase chain reaction. Western blotting was used to assess PPAR-γ-mediated signaling.

RESULTS

We found that EA significantly alleviated cerebral I/R-induced infarct volume, decreased neurological scores and inhibited I/R-induced oxidative stress, inflammatory responses and microglial activation. EA also increased PPAR-γ protein expression. Furthermore, the protective effects of EA were reversed by injection of the PPAR-γ antagonist T0070907.

CONCLUSION

EA attenuates cerebral I/R injury by regulating oxidative stress, neuronal death and neuroinflammation via stimulation of PPAR-γ.

Electroacupuncture regulates histone acetylation of Bcl-2 and Caspase-3 genes to improve ischemic stroke injury

Background

Imbalances between Bcl-2 and caspase-3 are significant evidence of apoptosis, which is considered an influential factor in rapidly occurring neuronal cell death and the decline of neurological function after stroke. Studies have shown that acupuncture can reduce poststroke brain cell damage via either an increase in Bcl-2 or a reduction in caspase-3 exposure. The current study aimed to investigate whether acupuncture could modulate Bcl-2 and caspase-3 expression through histone acetylation modifications, which could potentially serve as a neuroprotective mechanism.

Methods

This study used TTC staining, Nissl staining, Clark neurological system score, and Evans Blue (EB) extravasation to evaluate neurological damage following stroke. The expression of Bcl-2/caspase-3 mRNA was detected by real-time fluorescence quantification of PCR (real-time PCR), whereas the protein expression levels of Bcl-2, Bax, caspase-3, and cleaved caspase-3 were assessed using western blotting. TUNEL staining of the ischemic cortical neurons determined apoptosis in the ischemic cortex. Histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities, along with the protein performance of AceH3, H3K9ace, and H3K27ace, were detected to evaluate the degree of histone acetylation. The acetylation enrichment levels of H3K9 and K3K27 in the Bcl-2/caspase-3 gene were assessed using Chromatin Immunoprecipitation (ChIP) assay.

Results

Our data demonstrated that electroacupuncture (EA) exerts a significant neuroprotective effect in middle cerebral artery occlusion (MCAO) rats, as evidenced by a reduction in infarct volume, neuronal damage, Blood-Brain Barrier (BBB) disruption, and decreased apoptosis of ischemic cortical neurons. EA treatment can promote the mRNA and protein expression of the Bcl-2 gene in the ischemic brain while reducing the mRNA and protein expression levels of caspase-3 and effectively decreasing the protein expression levels of Bax and cleaved caspase-3. More importantly, EA treatment enhanced the level of histone acetylation, including Ace-H3, H3K9ace, and H3K27ace, significantly enhanced the occupancy of H3K9ace/H3K27ace at the Bcl-2 promoter, and reduced the enrichment of H3K9ace and H3K27ace at the caspase-3 promoter. However, the Histone Acetyltransferase inhibitor (HATi) treatment reversed these effects.

Conclusions

Our data demonstrated that EA mediated the expression levels of Bcl-2 and caspase-3 in MCAO rats by regulating the occupancy of acetylated H3K9/H3K27 at the promoters of these two genes, thus exerting a cerebral protective effect in ischemic reperfusion (I/R) injury.

Transcutaneous electrical acupoint stimulation attenuated neuroinflammation and oxidative stress by activating SIRT1-induced signaling pathway in MCAO/R rat models

BACKGROUND

Silent information regulator 1 (SIRT1) plays a beneficial role in cerebral ischemic injury. Previous reports have demonstrated that transcutaneous electrical acupoint stimulation (TEAS) exerts a beneficial effect on ischemic stroke; however, whether SIRT1 participates in the underlying mechanism for the neuroprotective effects of TEAS against ischemic brain damage has not been confirmed.

METHODS

The rat models of middle cerebral artery occlusion/reperfusion (MCAO/R) were utilized in the current experiment. After MCAO/R surgery, rats in TEAS, EC and EX group received TEAS intervention with or without the injection of EX527, the SIRT1 inhibitor. Neurological deficit scores, infarct volume, hematoxylin eosin (HE) staining and apoptotic cell number were measured. The results of RNA sequencing were analyzed to determine the differential expression changes of genes among sham, MCAO and TEAS groups, in order to investigate the possible pathological processes involved in cerebral ischemia and explore the protective mechanisms of TEAS. Moreover, oxidative stress markers including MDA, SOD, GSH and GSH-Px were measured with assay kits. The levels of the proinflammatory cytokines, such as IL-6, IL-1β and TNF-α, were detected by ELISA assay, and Iba-1 (the microglia marker protein) positive cells was measured by immunofluorescence (IF). Western blot and IF were utilized to examine the levels of key molecules in SIRT1/FOXO3a and SIRT1/BRCC3/NLRP3 signaling pathways.

RESULTS

TEAS significantly decreased brain infarcted size and apoptotic neuronal number, and alleviated neurological deficit scores and morphological injury by activating SIRT1. The results of RNA-seq and bioinformatic analysis revealed that oxidative stress and inflammation were the key pathological mechanisms, and TEAS alleviated oxidative injury and inflammatory reactions following ischemic stroke. Then, further investigation indicated that TEAS notably attenuated neuronal apoptosis, neuroinflammation and oxidative stress damage in the hippocampus of rats with MCAO/R surgery. Moreover, TEAS intervention in the MCAO/R model significantly elevated the expressions of SIRT1, FOXO3a, CAT, BRCC3, NLRP3 in the hippocampus. Furthermore, EX527, as the inhibitor of SIRT1, obviously abolished the anti-oxidative stress and anti-neuroinflammatory roles of TEAS, as well as reversed the TEAS-mediated elevation of SIRT1, FOXO3a, CAT and reduction of BRCC3 and NLRP3 mediated by following MCAO/R surgery.

CONCLUSIONS

In summary, these findings clearly suggested that TEAS attenuated brain damage by suppressing apoptosis, oxidative stress and neuroinflammation through modulating SIRT1/FOXO3a and SIRT1/BRCC3/NLRP3 signaling pathways following ischemic stroke, which can be a promising treatment for stroke patients.

The role and therapeutic potential of nuclear factor κB (NF-κB) in ischemic stroke

Stroke is a prevalent cerebrovascular condition with a global impact, causing significant rates of illness and death. Despite extensive research, the available treatment options for stroke remain restricted. Hence, it is crucial to gain a deeper understanding of the molecular mechanisms associated with the onset and advancement of stroke in order to establish a theoretical foundation for novel preventive and therapeutic approaches. NF-κB, also known as nuclear factor κB, is a transcription factor responsible for controlling the expression of numerous genes and plays a crucial role in diverse physiological processes. NF-κB is triggered and regulates neuroinflammation and other processes after stroke, promoting the generation of cytokine storms and contributing to the advancement of ischemic stroke (IS). Therefore, NF-κB could potentially play a vital role in stroke by regulating diverse pathophysiological processes. This review provides an overview of the functions of NF-κB in stroke and its governing mechanisms. In addition, our attention is directed towards various potential therapies that aim to inhibit the NF-κB signaling pathway in order to offer valuable insights for the advancement of innovative treatment approaches for stroke.

Global trends and development of acupuncture for stroke: A review and bibliometric analysis

The objective of this review is to elaborate on the status, hotspots, and trends of researches on acupuncture for stroke over the past 26 years. Publications about acupuncture for stroke were downloaded from the Web of Science Core Collection, and these papers were published up to December 31, 2022. A bibliometric analysis of acupuncture for stroke was conducted by CiteSpace (6.2.R4) and VOSviewer (1.6.17). In this study, VOSviewer was used for visual analysis of countries, institutions, authors, journals, keywords, and co-cited references. CiteSpace was used to draw a keyword burst map and a co-cited reference burst map. A total of 534 papers were obtained from the Web of Science Core Collection. The number of papers per year showed a rapid upward trend. The most productive country and institution in this field were China (452) and the Fujian University of Traditional Chinese Medicine (43), respectively. Tao Jing had the highest number of articles (34), and EZ Longa was the most popular author (129 co-citations). Neural Regeneration Research (51) was the most productive journal, and Stroke (1346) was the most co-cited journal. An paper written by EZ Longa was the most influential reference, with the highest citation count. The hotspots and frontiers of this area of research were focused on the mechanisms of acupuncture, especially its neural regenerative or neuroprotective effects. This study used CiteSpace and VOSviewer for bibliometric analysis to provide researchers with information on the research status, hotspots, and trends in acupuncture for stroke research over the past 26 years.

Transcutaneous electrical acupoint stimulation alleviates cerebral ischemic injury through the TLR4/MyD88/NF-κ B pathway

This study was to explore whether transcutaneous electrical acupoint stimulation (TEAS) treatment could mediate inflammation, apoptosis, and pyroptosis of neuronal cells and microglia activation through the TLR4/MyD88/NF-κB pathway in the early stage of ischemic stroke. TEAS treatment at Baihui (GV20) and Hegu (LI4) acupoints of the affected limb was administered at 24, 48, and 72 h following middle cerebral artery occlusion/reperfusion (MCAO/R), with lasting for 30 min each time. Neurological impairment scores were assessed 2 h and 72 h after ischemia/reperfusion (I/R). TTC staining was used to evaluate the volume of brain infarction. The histopathologic changes of hippocampus were detected by H&E staining. WB analysis was performed to assess the levels of TLR4, MyD88, p-NF-κB p65/NF-κB p65, and inflammation, apoptosis, pyroptosis-related proteins. TLR4 expression was measured using immunohistochemistry. The expression of inflammation-related proteins was also measured using ELISA. Immunofluorescence was used to detect the expression level of Iba1. Our findings demonstrated that TEAS intervention after I/R improved neurological function, reduced the volume of brain infarction, and mitigated pathological damage. Moreover, TEAS reduced the levels of TLR4, MyD88, p-NF-κB p65/NF-κB p65, TNF-α, IL-6, Bax, NLRP3, cleaved caspase-1/pro caspase-1, IL-1β, IL-18, GSDMD, and Iba1 while enhancing Bcl-2 expression. Moreover, the protective effects of TEAS could be counteracted by lipopolysaccharide (LPS, a TLR4 agonist). In conclusion, TEAS can reduce cerebral damage and suppress inflammation, cell death, and microglia activation after ischemic stroke via inhibiting the TLR4/MyD88/NF-κB pathway.

Signaling pathways in brain ischemia: Mechanisms and therapeutic implications

Ischemic stroke occurs when the arteries supplying blood to the brain are narrowed or blocked, inducing damage to brain tissue due to a lack of blood supply. One effective way to reduce brain damage and alleviate symptoms is to reopen blocked blood vessels in a timely manner and reduce neuronal damage. To achieve this, researchers have focused on identifying key cellular signaling pathways that can be targeted with drugs. These pathways include oxidative/nitrosative stress, excitatory amino acids and their receptors, inflammatory signaling molecules, metabolic pathways, ion channels, and other molecular events involved in stroke pathology. However, evidence suggests that solely focusing on protecting neurons may not yield satisfactory clinical results. Instead, researchers should consider the multifactorial and complex mechanisms underlying stroke pathology, including the interactions between different components of the neurovascular unit. Such an approach is more representative of the actual pathological process observed in clinical settings. This review summarizes recent research on the multiple molecular mechanisms and drug targets in ischemic stroke, as well as recent advances in novel therapeutic strategies. Finally, we discuss the challenges and future prospects of new strategies based on the biological characteristics of stroke.

Transcutaneous Electrical Nerve Stimulation (TENS) Alleviates Brain Ischemic Injury by Regulating Neuronal Oxidative Stress, Pyroptosis, and Mitophagy

Background

As a noninvasive treatment, transcutaneous electrical nerve stimulation (TENS) has been utilized to treat various diseases in clinic. However, whether TENS can be an effective intervention in the acute stage of ischemic stroke still remains unclear. In the present study, we aimed to explore whether TENS could alleviate brain infarct volume, reduce oxidative stress and neuronal pyroptosis, and activate mitophagy following ischemic stroke.

Methods

TENS was performed at 24 h after middle cerebral artery occlusion/reperfusion (MCAO/R) in rats for 3 consecutive days. Neurological scores, the volume of infarction, and the activity of SOD, MDA, GSH, and GSH-px were measured. Moreover, western blot was performed to detect the related protein expression, including Bcl-2, Bax, TXNIP, GSDMD, caspase-1, NLRP3, BRCC3, HIF-1α, BNIP3, LC3, and P62. Real-time PCR was performed to detect NLRP3 expression. Immunofluorescence was performed to detect the levels of LC3.

Results

There was no significant difference of neurological deficit scores between the MCAO group and the TENS group at 2 h after MCAO/R operation (P > 0.05), while the neurological deficit scores of TENS group significantly decreased in comparison with MCAO group at 72 h following MACO/R injury (P < 0.05). Similarly, TENS treatment significantly reduced the brain infarct volume compared with the MCAO group (P < 0.05). Moreover, TENS decreased the expression of Bax, TXNIP, GSDMD, caspase-1, BRCC3, NLRP3, and P62 and the activity of MDA as well as increasing the level of Bcl-2, HIF-1α, BNIP3, and LC3 and the activity of SOD, GSH, and GSH-px (P < 0.05).

Conclusions

In conclusion, our results indicated that TENS alleviated brain damage following ischemic stroke via inhibiting neuronal oxidative stress and pyroptosis and activating mitophagy, possibly via the regulation of TXNIP, BRCC3/NLRP3, and HIF-1α/BNIP3 pathways.

Electroacupuncture of Baihui and Shenting ameliorates cognitive deficits via Pten/Akt pathway in a rat cerebral ischemia injury model

Cerebral ischemic stroke is a huge threat to the health and life of many people. Electroacupuncture (EA) at Baihui (GV20) and Shenting (GV24) acupoints can notably alleviate cerebral ischemia/reperfusion injury (CIRI). However, the molecular basis underlying the effectiveness of EA at the GV20 and GV24 acupoints for CIRI remains largely unknown. Our present study demonstrated that EA treatment at the GV20 and GV24 acupoints markedly alleviated middle cerebral artery occlusion/reperfusion (MCAO/R)-induced cognitive deficits and cerebral infarction in rats. Proteomics analysis revealed that 195 and 218 proteins were dysregulated in rat hippocampal tissues in the MCAO/R vs. sham group and thhhe EA vs. MCAO/R group, respectively. Moreover, 62 proteins with converse alteration trends in MCAO/R vs. sham and EA vs. MCAO/R groups were identified. These proteins might be implicated in the EA-mediated protective effect against MCAO/R-induced cerebral injury. GO enrichment analysis showed that 39 dysregulated proteins in the MCAO/R vs. sham group and 40 dysregulated proteins in the EA vs. MCAO/R group were related to brain and nerve development. Protein–protein interaction analysis of the abovementioned dysregulated proteins associated with brain and nerve development suggested that Pten/Akt pathway-related proteins might play major roles in regulating EA-mediated protective effects against MCAO/R-induced brain and nerve injury. Western blot assays demonstrated that Pak4, Akt3, and Efnb2 were expressed at low levels in the MCAO/R group vs. the sham group but at high levels in the EA group vs. the MCAO/R group. In conclusion, multiple proteins related to the protective effect of EA at the GV20 and GV24 acupoints against CIRI were identified in our study.

Visualization and Analysis of the Mapping Knowledge Domain of Acupuncture and Central Nervous System Cell Apoptosis

Chinese acupuncture therapy has demonstrated good clinical effects on neurological diseases and is widely used internationally. In the past 20 years, an increasing number of researchers around the world have devoted themselves to the study of the effect and mechanism of acupuncture for the treatment of central nervous system cell apoptosis. To discover the current research status of acupuncture-induced antiapoptosis in the central nervous system, we used the method of scientometric research and data visualization software to visually analyse 155 articles. The findings are as follows. First, the antiapoptosis effects of acupuncture in the central nervous system have received increasing attention overseas and domestically. China and the United States have leading positions in this research field. Second, 5 stable and high-yielding research teams have been formed in the field of acupuncture-induced antiapoptosis. The main research directions of these teams are electroacupuncture (EA) pretreatment for the central nervous system cell apoptosis, acupuncture for antineuronal apoptosis in vascular dementia, EA regulation of related signalling pathways, EA regulation of nerve cell apoptosis and autophagy after stroke, and EA regulation of the MAPK signalling pathway. Researchers on teams with more extensive cooperation have more research results and better research continuity. Third, there are diversified research hotspots. The original research hotspots are still receiving attention, and new hotspots have emerged in recent years.

The Impact of Electroacupuncture Early Intervention on the Brain Lipidome in a Mouse Model of Post-traumatic Stress Disorder

The neuroprotective effect of electroacupuncture (EA) treatment has been well studied; growing evidence suggests that changes in lipid composition may be involved in the pathogenesis of post-traumatic stress disorder (PTSD) and may be a target for treatment. However, the influence of early EA intervention on brain lipid composition in patients with PTSD has never been investigated. Using a modified single prolonged stress (mSPS) model in mice, we assessed the anti-PTSD-like effects of early intervention using EA and evaluated changes in lipid composition in the hippocampus and prefrontal cortex (PFC) using a mass spectrometry-based lipidomic approach. mSPS induced changes in lipid composition in the hippocampus, notably in the content of sphingolipids, glycerolipids, and fatty acyls. These lipid changes were more robust than those observed in the PFC. Early intervention with EA after mSPS ameliorated PTSD-like behaviors and partly normalized mSPS-induced lipid changes, notably in the hippocampus. Cumulatively, our data suggest that EA may reverse mSPS-induced PTSD-like behaviors due to region-specific regulation of the brain lipidome, providing new insights into the therapeutic mechanism of EA.

Knockdown of circular RNA tousled-like kinase 1 relieves ischemic stroke in middle cerebral artery occlusion mice and oxygen-glucose deprivation and reoxygenation-induced N2a cell damage

Ischemic stroke (IS) is an essential contributor to the neurological morbidity and mortality throughout the world. The significance of circular RNA tousled-like kinase 1 (circTLK1) in IS has been documented. This study set out to explore the mechanism of circTLK1 in IS. Middle cerebral artery occlusion (MCAO) mouse models in vivo and oxygen-glucose deprivation and reoxygenation (OGD/R) cell models in vitro were first established, followed by evaluation of infarct volume and neurological impairment, and cell viability and apoptosis. The expression patterns of circTLK1, miR-26a-5p, phosphatase and tensin homolog (PTEN), insulin-like growth factor type 1 receptor (IGF-1 R), and glucose transporter type 1 (GLUT1) were detected by RT-qPCR and Western blotting. Co-localization of circTLK1 and miR-26a-5p in N2a cells was tested by fluorescence in situ hybridization assay. The binding relationships among circTLK1, PTEN, and miR-26a-5p were verified by dual-luciferase assay and RNA pull-down. circTLK1 and PTEN were highly expressed while miR-26a-5p was under-expressed in IS models. circTLK1 knockdown decreased infarct volume and neurological impairment in MCAO mouse models and relieved OGD/R-induced neuronal injury in vitro. circTLK1 and miR-26a-5p were co-located in the N2a cell cytoplasm. circTLK1 regulated PTEN as a sponge of miR-26a-5p. PTEN positively regulated IGF-1 R and GLUT1 expressions. miR-26a-5p inhibitor annulled the repressive effects of circTLK1 silencing on OGD/R-induced neuronal injury. sh-PTEN partially annulled the effects of the miR-26a-5p inhibitor on OGD/R-induced neuronal injury. In conclusion, circTLK1 knockdown relieved IS via the miR-26a-5p/PTEN/IGF-1 R/GLUT1 axis. These results may provide a new direction to IS potential therapeutic targets.

Targeting autophagy in ischemic stroke: From molecular mechanisms to clinical therapeutics

Stroke constitutes the second leading cause of death and a major cause of disability worldwide. Stroke is normally classified as either ischemic or hemorrhagic stroke (HS) although 87% of cases belong to ischemic nature. Approximately 700,000 individuals suffer an ischemic stroke (IS) in the US each year. Recent evidence has denoted a rather pivotal role for defective macroautophagy/autophagy in the pathogenesis of IS. Cellular response to stroke includes autophagy as an adaptive mechanism that alleviates cellular stresses by removing long-lived or damaged organelles, protein aggregates, and surplus cellular components via the autophagosome-lysosomal degradation process. In this context, autophagy functions as an essential cellular process to maintain cellular homeostasis and organismal survival. However, unchecked or excessive induction of autophagy has been perceived to be detrimental and its contribution to neuronal cell death remains largely unknown. In this review, we will summarize the role of autophagy in IS, and discuss potential strategies, particularly, employment of natural compounds for IS treatment through manipulation of autophagy.

Melatonin Protects Against Ischemic Brain Injury by Modulating PI3K/AKT Signaling Pathway via Suppression of PTEN Activity

Stroke is one of the leading causes of death and disability worldwide with limited therapeutic options. Melatonin can attenuate ischemic brain damage with improved functional outcomes. However, the cellular mechanisms of melatonin-driven neuroprotection against post-stroke neuronal death remain unknown. Here, distal middle cerebral artery occlusion (dMCAO) was performed in C57BL/6j mice to develop an ischemic stroke in vivo model. Melatonin was injected intraperitoneally immediately after ischemia, and 24 and 48 hours later. Melatonin treatment, with 5 to 20 mg/kg, elicited a dose-dependent decrease in infarct volume and concomitant increase in sensorimotor function. At the molecular level, phosphorylation of PTEN and Akt were increased, whereas PTEN activity was decreased in melatonin treated animals 72 hours after dMCAO. At the cellular level, oxygenglucose deprivation (OGD) challenge of neuronal cell line Neuro-2a (N2a) and primary neurons supported melatonin’s direct protection against neuronal cell death. Melatonin treatment reduced LDH release and neuronal apoptosis at various time points, markedly increased Akt phosphorylation in neuronal membrane, but significantly suppressed it in the cytoplasm of post-OGD neurons. Mechanistically, melatonin-induced Akt phosphorylation and neuronal survival was blocked by Wortmannin, a potent PIP3 inhibitor, exposing increased PI3K/Akt activation as a central player in melatonin-driven neuroprotection. Finally, PTEN knock-down through siRNA significantly inhibited PI3K/Akt activation and cell survival following melatonin treatment, suggesting that melatonin protection against ischemic brain damage, is at least partially, dependent on modulation of the PTEN/PI3K/Akt signaling axis.

Combination of Electroacupuncture and Constraint-Induced Movement Therapy Enhances Functional Recovery After Ischemic Stroke in Rats

Both electroacupuncture and constraint-induced movement therapy have been reported to produce therapeutic effects on the recovery of ischemic stroke. The combined use of these two therapies is not rare clinically, although its effectiveness is not yet clear. We aimed to evaluate the efficacy of the combination of electroacupuncture and constraint-induced movement therapy in ischemic stroke rats, and to explore the potential molecular mechanisms. Ischemic stroke rat models were established by middle cerebral artery occlusion. Then, the rats were assigned to receive one of the following interventions: sole electroacupuncture, sole constraint-induced movement therapy, the combination of both therapies, and no treatment. Functional recovery was assessed with the beam balance test and rotarod test. The infarct volume of the brain and the expression of the molecules Nogo-A, P75^NTR, NGF, BDNF, and VEGF in the brain tissue were investigated. The results demonstrated that the combination of the two therapies significantly improved neurological functional recovery in ischemic stroke rats compared to each therapy alone (P < 0.01). We also observed a significant decrease in infarct volume in rats receiving the combined treatment. Nogo-A and P75^NTR were downregulated and NGF, BDNF, and VEGF were upregulated in the combined treatment rats compared to the control rats. In conclusion, the combination of electroacupuncture and constraint-induced movement therapy enhanced functional recovery after ischemic stroke in rats, and it is a promising treatment strategy in the rehabilitation of stroke. The anti-Nogo-A effect of electroacupuncture may explain its good compatibility with CIMT in ischemic stroke rats.

Electroacupuncture Attenuates Ischemic Brain Injury and Cellular Apoptosis via Mitochondrial Translocation of Cofilin

OBJECTIVE

To investigate the potential mechanisms of electroacupuncture (EA) to prevent ischemic stroke.

METHODS

The method of middle cerebral artery occlusion (MCAO) was employed to establish a rat model of ischemic stroke. Seventy-eight Sprague-Dawley rats were divided into the sham group, MCAO + EA control (EC) group, and MCAO + EA (EA) group according to a random number table (n=26 per group). EA was applied to the acupoints of Baihui (DU 20) and Shenting (DU 24) 5 min and 6 h, respectively after the onset of MCAO. Rats in the sham and EC groups received only light isoflurane anesthesia for 30 min after MCAO. The neuroprotective effects of EA were evaluated by rota-rod test, neurological deficit scores and infarct volumes. Additionally, Nissl staining and immunostaining were performed to examine brain damage, rod formation, cellular apoptosis, and neuronal loss induced by ischemia. The activities of caspase-3, and expression levels of cofilin and p-cofilin in mitochondria and cytoplasm after ischemic injury were determined by Western blot.

RESULTS

Compared with the EC group, EA significantly improved neuromotor function and cognitive ability after ischemic stroke (P<0.05 or P<0.01). Therapeutic use of EA also resulted in a significant decrease of cofilin rod formation and microtubule-associated protein-2 (MAP2) degradation in the cortical penumbra area compared with the EC rats (P<0.01). Furthermore, Western blot analysis showed that EA stimulation significantly inhibited mitochondrial translocation of cofilin and caspase-3 cleavage (P<0.05 or P<0.01). Additionally, brain damage (infarct volume and neuropathy), cellular apoptosis and neuronal loss induced by ischemia were remarkably suppressed by EA in the cortical penumbra of rats (P<0.05 or P<0.01).

CONCLUSION

EA treatment after ischemic stroke may attenuate ischemic brain injury and cellular apoptosis through the regulation of mitochondrial translocation of cofilin, a novel mechanism of EA therapy.

LC-MS/MS assay for the determination of tat-K13, a novel interfering peptide for the treatment of ischemic stroke, in human plasma and its application to a pharmacokinetics study

A sensitive and robust method has been developed using an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) assay to quantify Tat-K13, a novel interfering peptide for the treatment of ischemic stroke, in human plasma. Automated solid-phase extraction on a Waters Oasis WCX (30 μm, 10 mg) 96-well plate was used to extract Tat-K13 from human plasma and the extracts were separated on a Waters Acquity CSH column (2.1 × 50 mm i.d., 1.7 μm) with a gradient elution method by mobile phase A (nonafluoropentanoic acid-acetic acid-water, 1:2:1000, v/v/v) and B (nonafluoropentanoic acid-acetic acid-water-acetonitrile, 1:2:100:900, v/v/v/v). The method was fully validated following international bioanalytical guidelines and showed good linearity from 2.10 to 1,050 ng/ml. The method was successfully applied to investigate the clinical pharmacokinetics of Tat-K13 in health volunteers. Rapid elimination of Tat-K13 from the body was observed, with half-life ranging from 0.26 to 0.78 h across different dose levels. The exposure of Tat-K13 was approximately dose-dependent in terms of the area under the concentration-time curve and peak concentration.

Detrimental and Beneficial Effect of Autophagy and a Potential Therapeutic Target after Ischemic Stroke

Autophagy, a physiologic mechanism that promotes energy recycling and orderly degradation through self-regulated disassembly of cellular components, helps maintain homeostasis. A series of evidences suggest that autophagy is activated as a response to ischemia and has been well-characterized as a therapeutic target. However, the role of autophagy after ischemia remains controversial. Activated-autophagy can remove necrotic substances against ischemic injury to promote cell survival. On the contrary, activation of autophagy may further aggravate ischemic injury, causing cell death. Therefore, the present review will examine the current understanding of the precise mechanism and role of autophagy in ischemia and recent neuroprotective therapies on autophagy, drug therapies, and nondrug therapies, including electroacupuncture (EA).

miR‑183‑5p attenuates cerebral ischemia injury by negatively regulating PTEN

Cerebral ischemia is a common cerebrovascular disease caused by the occlusion of a cerebral blood vessel. MicroRNAs (miRNAs/miRs) are emerging regulators of various human diseases, including cerebral ischemia. Upregulation of miR‑183‑5p has been reported to alleviate liver injury induced by ischemia‑reperfusion (I/R). However, the effect of miR‑183‑5p on cerebral ischemia injury remains unknown. The present study evaluated the effects of miR‑183‑5p on ischemia injury using ischemic models of mouse brains exposed to transient middle cerebral artery occlusion and Neuro‑2A (N2A) neuroblastoma cells exposed to oxygen‑glucose‑deprivation (OGD) and subsequently reoxygenated. Ischemia was evaluated in mice using neurological function scores, cerebral edema, 2,3,5‑triphenyltetrazoliumchloride, Nissl and Fluoro‑Jade B staining assays. In addition, miR‑183‑5p expression, N2A cell viability and the expression levels of apoptosis‑associated proteins were detected by quantitative PCR, Cell Counting Kit‑8 assay, flow cytometry and western blotting. The association between miR‑183‑5p and phosphatase and tensin homolog (PTEN) was also confirmed by a luciferase reporter assay. The results revealed that miR‑183‑5p expression was decreased and brain damage was increased in ischemic mice compared with the sham group. Additionally, miR‑183‑5p levels were reduced, and apoptosis was increased in N2A cells exposed to ischemia compared with the control group. Following transfection with agomiR‑183‑5p, cerebral ischemic injury and apoptosis levels were reduced in the in vivo I/R stroke model and OGD‑induced N2A cells. In addition, PTEN was determined to be a target of miR‑183‑5p following elucidation of a direct binding site. Overexpression of PTEN reversed the miR‑183‑5p‑induced N2A cell apoptosis inhibition and survival after OGD. The results of the present study suggested that miR‑183‑5p reduced ischemic injury by negatively regulating PTEN, which may aid the development of a novel therapeutic strategy for cerebral ischemia.

Levosimendan Protects against Doxorubicin-Induced Cardiotoxicity by Regulating the PTEN/Akt Pathway

BACKGROUND AND AIMS

Myocyte apoptosis plays a critical role in the development of doxorubicin- (DOX-) induced cardiotoxicity. In addition to its cardiotonic effect, laboratory evidence indicates that levosimendan can inhibit apoptosis, but its role in DOX-induced cardiac injury remains unclear. Therefore, the present study is aimed at exploring whether levosimendan could attenuate DOX-induced cardiotoxicity.

METHODS

Levosimendan (1 mg/kg) was administered to mice through oral gavage once daily for 4 weeks, and the mice were also subjected to an intraperitoneal injection of DOX (5 mg/kg) or saline, once a week for 4 weeks, to create a chronic model of DOX-induced cardiotoxicity. A morphological examination and biochemical analysis were used to evaluate the effects of levosimendan. H9C2 cells were used to verify the protective role of levosimendan in vitro. And an Akt inhibitor was utilized to verify the cardioprotection of levosimendan.

RESULTS

Levosimendan reduced the cardiac dysfunction and attenuated the myocardial apoptosis induced by DOX in vivo and in vitro. Levosimendan also inhibited the activation of phosphatase and tensin homolog (PTEN) and upregulated P-Akt expression both in vivo and in vitro. And inhibition of Akt abolished the cardioprotection of levosimendan in vitro.

CONCLUSION

Levosimendan may protect against DOX-induced cardiotoxicity via modulation of the PTEN/Akt signaling pathway.

Electroacupuncture Inhibits Neuronal Autophagy and Apoptosis via the PI3K/AKT Pathway Following Ischemic Stroke

Electroacupuncture (EA) is a safe and effective therapy for ischemic stroke in both clinical and laboratory settings. However, the underlying mechanism behind EA treatment for stroke remains unclear. Here, we aimed to evaluate whether EA treatment at the acupoints of Zusanli (ST36) and Quchi (LI11) exerted a neuroprotective effect on ischemic stroke rats by modulating autophagy and apoptosis via the PI3K/AKT/mTOR signaling pathway. EA was performed at 24 h following brain ischemia/reperfusion (I/R) for 30 min per day for 3 days. Our results indicated that EA treatment significantly decreased neurological deficits and cerebral infarct volume in ischemic stroke rats. Also, EA intervention markedly reduced neuronal apoptosis by suppressing the activation of cleaved caspase-3 (CCAS3) at 72 h following I/R, as shown by a Western blot analysis. Furthermore, EA treatment after ischemic stroke suppressed the ischemia activated expression level of LC3II/I and Atg7 and increased the ischemia inhibited expression level of PI3K, phosphorylation of mTOR, phosphorylation of AKT, P62 and LAMP1, hence mediating the autophagy level of the neurocyte, which was reversed by the PI3K inhibitor Dactolisib. In summary, our results indicate that the protective effects of EA treatment at points of Quchi (LI11) and Zusanli (ST36) in rats following cerebral I/R injury was associated with the inhibition of neuronal apoptosis and autophagy via activating the PI3K/AKT/mTOR signaling pathway.

The Role of Astragaloside IV against Cerebral Ischemia/Reperfusion Injury: Suppression of Apoptosis via Promotion of P62-LC3-Autophagy

Background: Ischemia/reperfusion (I/R) caused by ischemic stroke treatments leads to brain injury, and autophagy plays a role in the pathology. Astragaloside IV is a potential neuroprotectant, but its underlying mechanism on cerebral I/R injury needs to be explored. The objective of this study is to investigate the neuroprotective mechanism of Astragaloside IV against cerebral I/R injury. Methods: Middle cerebral artery occlusion method (MCAO) and oxygen and glucose deprivation/reoxygenation (OGD/R) method were used to simulate cerebral I/R injury in Sprague-Dawley (SD) rats and HT22 cells, respectively. The neurological score, 2,3,5-Triphe-nyltetrazolium chloride (TTC) staining, and transmission electron microscope were used to detect cerebral damage in SD rats. Cell viability and cytotoxicity assay were tested in vitro. Fluorescent staining and flow cytometry were applied to detect the level of apoptosis. Western blotting was conducted to examine the expression of proteins associated with autophagy. Results: This study found that Astragaloside IV could decrease the neurological score, reduce the infarct volume in the brain, and alleviate cerebral I/R injury in MCAO rats. Astragaloside IV promoted cell viability and balanced Bcl-2 and Bax expression in vitro, reduced the rate of apoptosis, decreased the expression of P62, and increased the expression of LC3II/LC3I in HT22 cells after OGD/R. Conclusions: These data suggested that Astragaloside IV plays a neuroprotective role by down-regulating apoptosis by promoting the degree of autophagy.