Ischemic Stroke In Rats Research Articles

Preclinical safety and efficacy evaluation of the intrathecal transplantation of GMP-grade human umbilical cord mesenchymal stem cells for ischemic stroke

Intrathecal administration of human umbilical cord mesenchymal stem cells may be a promising approach for the treatment of stroke, but its safety, effectiveness, and mechanism remain to be elucidated. In this study, good manufacturing practice–grade human umbilical cord mesenchymal stem cells (5 × 105 and 1 × 106 cells) and saline were administered by cerebellomedullary cistern injection 72 hours after stroke induced by middle cerebral artery occlusion in rats. The results showed (1) no significant difference in mortality or general conditions among the three groups. There was no abnormal differentiation or tumor formation in various organs of rats in any group. (2) Compared with saline-treated animals, those treated with human umbilical cord mesenchymal stem cells showed significant functional recovery and reduced infarct volume, with no significant differences between different human umbilical cord mesenchymal stem cell doses. (3) Human umbilical cord mesenchymal stem cells were found in the ischemic brain after 14 and 28 days of follow-up, and the number of positive cells significantly decreased over time. (4) Neuronal nuclei expression in the human umbilical cord mesenchymal stem cell group was greater than that in the saline group, while glial fibrillary acidic protein and ionized calcium binding adaptor molecule 1 expression levels decreased. (5) Human umbilical cord mesenchymal stem cell treatment increased the number of CD31+ microvessels and doublecortin-positive cells after ischemic stroke. Human umbilical cord mesenchymal stem cells also upregulated the expression of CD31+/Ki67+. (6) At 14 days after intrathecal administration, brain-derived neurotrophic factor expression in the peri-infarct area and the concentrations of brain-derived neurotrophic factor in the cerebrospinal fluid in both human umbilical cord mesenchymal stem cell groups were significantly greater than those in the saline group and persisted until the 28th day. Taken together, these results indicate that the intrathecal administration of human umbilical cord mesenchymal stem cells via cerebellomedullary cistern injection is safe and effective for the treatment of ischemic stroke in rats. The mechanisms may include alleviating the local inflammatory response in the peri-infarct region, promoting neurogenesis and angiogenesis, and enhancing the production of neurotrophic factors.

Minimally Invasive Syringe-Injectable Hydrogel with Angiogenic Factors for Ischemic Stroke Treatment.

Ischemic stroke (IS) accounts for most stroke incidents and causes intractable damage to brain tissue. This condition manifests as diverse aftereffects, such as motor impairment, emotional disturbances, and dementia. However, a fundamental approach to curing IS remains unclear. This study proposes a novel approach for treating IS by employing minimally invasive and injectable jammed gelatin-norbornene nanofibrous hydrogels (GNF) infused with growth factors (GFs). The developed GNF/GF hydrogels are administered to the motor cortex of a rat IS model to evaluate their therapeutic effects on IS-induced motor dysfunction. GNFs mimic a natural fibrous extracellular matrix architecture and can be precisely injected into a targeted brain area. The syringe-injectable jammed nanofibrous hydrogel system increased angiogenesis, inflammation, and sensorimotor function in the IS-affected brain. For clinical applications, the biocompatible GNF hydrogel has the potential to efficiently load disease-specific drugs, enabling targeted therapy for treating a wide range of neurological diseases.

LncRNA Taurine Up-Regulated 1 Knockout Provides Neuroprotection in Ischemic Stroke Rats by Inhibiting Nuclear-Cytoplasmic Shuttling of HuR

Background: Long non-coding RNA taurine-upregulated gene 1 (TUG1) is involved in various cellular processes, but its role in cerebral ischemia–reperfusion injury remains unclear. This study investigated TUG1’s role in regulating the nucleocytoplasmic shuttling of human antigen R (HuR), a key apoptosis regulator under ischemic conditions. Methods: CRISPR-Cas9 technology was used to generate TUG1 knockout Sprague Dawley rats to assess TUG1’s impact on ischemic injury. The infarct area and neuronal apoptosis were evaluated using TUNEL, hematoxylin and eosin (HE), and TTC staining, while behavioral functions were assessed. Immunofluorescence staining with confocal microscopy was employed to examine TUG1-mediated HuR translocation and expression changes in the apoptosis-related proteins COX-2 and Bax. Results: TUG1 knockout rats showed significantly reduced cerebral infarct areas, decreased neuronal apoptosis, and improved neurological functions compared to controls. Immunofluorescence staining revealed that HuR translocation from the nucleus to the cytoplasm was inhibited, leading to decreased COX-2 and Bax expression levels. Conclusions: TUG1 knockout reduces ischemic damage and neuronal apoptosis by inhibiting HuR nucleocytoplasmic shuttling, making TUG1 a potential therapeutic target for ischemic stroke.

Comparative study of the neuroprotective potential of semaglutide injectable preparations in experimental ischemic stroke

Introduction. Stroke remains one of the major causes of death in type diabetes mellitus (DM). Injectable form of glucagon-like peptide-1 receptor agonist semaglutide, Ozempic® decreases the stroke risk. In Russia there appeared a biosimilar Semavic® but its effects on the brain are not yet studied.Aim. To compare neuroprotective properties of Semavic® and Ozempic® while used before ischemic stroke in rats without DM.Materials and methods. The study was conducted in male Wistar rats that were divided into the following groups: “Control” (n = 10) – 0.9% NaCl, “MET” (n = 9) – metformin 200 mg/kg once daily per os, “Ozempic” (n = 10) – Ozempic® 0.012 mg/kg s.c. once daily, “Semavic” (n = 9) – Semavic® 0.012 mg/kg s.c. once daily. After 7 days ischemic stroke was modelled, after 48 hour of reperfusion neurological deficit and brain damage volume were evaluated. Glycemia was measured on the 3rd, 7th days as well as during and after ischemia.Results. None of the study drugs caused hypoglycemia including in poststroke period. Neurological deficit in “MET” group did not differ from that in the “Control” (11.00 [6.50; 12.50] and 10.0 [6.25; 12.00] scores). Both semaglutide drugs caused comparable improvement in neurological status (14.00 [12.00; 18.00] and 14.00 [11.00; 18.00] scores in “Ozempic” and “Semavic” groups). Brain necrosis volume in “Control” group was 16.60 [13.40; 28.58] %. All the study drugs had infarct-limiting effect but brain damage volume in “Ozempic” (6.00 [4.32; 8.44] %) and “Semavic” (7.69 [2.99; 11.33] %) was smaller than in “MET” group (13.07 [8.67; 29.94] %). There were no differences between semaglutide drugs.Conclusions. Biosimilar Semavic® and original Ozempic® demonstrate comparable neuroprotective effect while used in animals without DM prior to ischemic stroke modelling. This protective effect is not due to the drugs’ influence on glycemic profile.

Transcriptome Sequencing-Based Screening of Key Melatonin-Related Genes in Ischemic Stroke.

Ischemic stroke (IS) is a complex syndrome of neurological deficits due to stenosis or occlusion of the carotid and vertebral arteries for which there is still no effective treatment. Melatonin, a hormone secreted by the pineal gland, has multiple biological effects, such as antioxidant and anti-inflammatory properties, circadian rhythm regulation, and tissue regeneration, demonstrating potential applications in the treatment of IS. The aim of this study was to investigate key melatonin-regulated genes associated with IS using transcriptome sequencing and bioinformatics analyses and to explore their potential mechanisms of action in the disease process. We obtained gene expression data related to ischemic stroke (IS) from the Gene Expression Omnibus (GEO) database and identified candidate genes using machine learning algorithms. We then assessed the predictive power of these genes using PPI network analysis and diagnostic models. Finally, a series of enrichment analyses identified four key genes: ADM, PTGS2, MMP9, and VCAN. In addition, we determined the mRNA levels of these four key genes in an IS rat model using qPCR and found that all of these genes were significantly upregulated in the IS model compared to the control group, which is consistent with the results of previous analyses. Meanwhile, these genes have biological functions such as regulating vascular tone, participating in the inflammatory response, influencing tissue remodeling, and regulating cell adhesion and proliferation, playing key roles in the pathogenesis of IS. Therefore, we suggest that these four key genes may serve as prospective biomarkers for IS and help predict the risk of developing IS. In conclusion, this study elucidates for the first time the potential role of melatonin in the pathogenesis of IS and lays the foundation for in-depth studies on the functions of these key genes in the pathophysiology of IS and their potential applications in clinical diagnosis and treatment.

Illustrate the metabolic regulatory mechanism of Taohong Siwu decoction in ischemic stroke by mass spectrometry imaging.

Metabolic dysregulation in the ischemic region has been increasingly recognized as a contributing factor to ischemic stroke pathogenesis. Taohong Siwu decoction (THSWD), a traditional Chinese medicine preparation used to enhance blood circulation, is frequently employed in treating ischemic stroke. However, the metabolic regulatory mechanism underlying the therapeutic effects of THSWD in ischemic stroke remains largely unexplored. In this study, we employed desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to investigate the metabolic changes in the brain tissue of ischemic stroke rat model. Our investigation revealed that 30 metabolites exhibited significant dysregulation in the ischemic brain regions, specifically the cortex and striatum, following ischemic injury. Following the treatment of THSWD, almost all the dysregulated metabolites got different degrees of callback. Further pathway analysis indicated that THSWD might exert its therapeutic effects by restoring energy metabolism, improving neurotransmitter metabolism, recovering polyamine metabolism, and so on. DESI-MSI offers a favorable methodology for investigating the alterations in the spatial distribution and level within the ischemic brain region following treatment with THSWD in ischemic stroke. These findings provide a novel perspective on the underlying mechanisms of the efficacy of THSWD in ischemic stroke treatment.

Systematic review and Meta-analysis of brain plasticity associated with electroacupuncture in experimental ischemic stroke.

To systematically evaluate the role of electroacupuncture in maintaining brain plasticity in ischemic stroke mediated brain damage. We searched for all relevant trials published through Oct 7, 2022 from seven databases. Metho-dological quality was assessed using the CAMARADES Risk of Bias Tool. A Meta-analysis of comparative effects was performed using Review Manager v.5.3 software. A total of 101 studies involving 2148 animals were included. For most studies, primary outcomes results of the Meta-analysis indicate that EA significantly improved ischemic stroke rat's postsynaptic density thickness [Standardized Mean Difference (SMD) = 1.41, 95% confidence interval (CI) (0.59, 2.23), P = 0.0008], numerical density of synapses [SMD = 1.55, 95% CI (0.48, 2.63), P = 0.005] compared with non-EA-treated. Similarly, EA could improve parts of biomarkers of synapses, neurogenesis, angiogenesis and neurotrophin activity than the control group (P < 0.05). The existing evidence suggests EA regulating ischemic stroke may be through brain plasticity. More rigorous and high quality studies should be conducted in the future.

Neuroprotective effects of Gastrodia elata Blume on promoting M2 microglial polarization by inhibiting JNK/TLR4/T3JAM/NF-κB signaling after transient ischemic stroke in rats.

Gastrodia elata Blume, also called Tian Ma (TM), has been used to treat stroke for centuries. However, its effects on inflammation in acute cerebral ischemic injury and underlying mechanisms involved in microglial polarization remain unknown. The present study explored the effects of the TM extract on the modulation of microglial M1/M2 polarization 2days after transient cerebral ischemia. Male Sprague Dawley rats were intracerebroventricularly administered with 1% dimethyl sulfoxide 25min before cerebral ischemia and subsequently intraperitoneally administered 0.25g/kg (DO + TM-0.25g), 0.5g/kg (DO + TM-0.5g), or 1g/kg (DO + TM-1g) of the TM extract after cerebral ischemia onset. DO + TM-0.5g and DO + TM-1 g treatments downregulated the following: phospho-c-Jun N-terminal kinase (p-JNK)/JNK, tumor necrosis factor (TNF) receptor-associated factor 3 (TRAF3), TRAF3-interacting JNK-activating modulator (T3JAM), p-nuclear factor-kappa B p65 (p-NF-κB p65)/NF-κB p65, ionized calcium-binding adapter molecule 1 (Iba1), CD86, TNF-α, interleukin (IL)-1β, and IL-6 expression and toll-like receptor 4 (TLR4)/Iba1, CD86/Iba1, and p-NF-κB p65/Iba1 coexpression. These treatments also upregulated IL-10, nerve growth factor, and vascular endothelial growth factor A expression and YM-1/2/Iba1 and IL-10/neuronal nuclei coexpression in the cortical ischemic rim. The JNK inhibitor SP600125 exerted similar treatment effects as the DO + TM-0.5g and DO + TM-1 g treatments. DO + TM-0.5g and DO + TM-1 g/kg treatments attenuate cerebral infarction by inhibiting JNK-mediated signaling. TM likely exerts the neuroprotective effects of promoting M1 to M2 microglial polarization by inhibiting JNK/TLR4/T3JAM/NF-κB-mediated signaling in the cortical ischemic rim 2days after transient cerebral ischemia.

Therapeutic potential of mesenchymal stromal cells on morphological parameters in the hippocampus of rats with brain ischemia-reperfusion modeling

Ischemic stroke is an extremely important pathology with high mortality, in which more than 50 % of patients with occlusion of the main vessels remain disabled, despite early reperfusion therapy by thrombolysis or thrombectomy. As part of the regenerative strategy, stem cell transplantation in ischemic stroke became a new impetus. Cell therapy with the use of mesenchymal stromal cells demonstrated encouraging results regarding endogenous mechanisms of neuroregeneration in response to ischemic damage to brain structures. The aim of the research is to study the influence of mesenchymal stromal cells of various genesis, lysate of mesenchymal stromal cells obtained from Wharton’s jelly umbilical cord and citicoline on the dynamics of morphological changes in the hippocampal CA1 region of rats with acute cerebral ischemia-reperfusion according to light microscopy and micromorphometry data. The experiment was carried out using 200 male Wistar rats, which were subjected to ischemia-reperfusion by reversible 20-minute bilateral occlusion of the internal carotid arteries. Animals with modeled pathology were intravenously transplanted with mesenchymal stromal cells of various genesis (from Wharton’s jelly of the human umbilical cord, human and rat adipose tissue), and rat embryonic fibroblasts, lysate of mesenchymal stromal cells and citicoline were injected. Histological analysis of rat brain sections was performed on the 7th and 14th day of the experiment. Statistical analysis was performed using “Statistica 6.0” (StatSoft® Snc, USA). The significance of differences was assessed using the Student’s t-test and the nonparametric Mann-Whitney U test. During the study, it was found that modeled ischemia-reperfusion in rats caused almost complete degeneration of the structure of the pyramidal layer of hippocampal CA1 region, gave uniformity to the structure of the radiant layer, infiltration of microglia, contributed to the disruption of the arrangement of apical dendrite bundles and narrowing of blood vessels as a result of perivascular edema. Also, the modeled pathology reduced the total number of neuronal nuclei in the hippocampal CA1 area, the overwhelming majority of which had signs of pathological changes. Transplantation of mesenchymal stromal cells of various origins, lysate of mesenchymal stromal cells and citicoline contributed to a significant increase in the number of neuronal nuclei in the hippocampal CA1 zone and nuclei that did not undergo pathological changes. The most positive effect was found in the transplantation of mesenchymal stromal cells from human Wharton’s jelly-derived cells. Thus, both in the subacute and recovery periods of ischemic stroke in rats, the transplantation of human Wharton’s jelly-derived mesenchymal stromal cells was significantly surpassed the reference drug citicoline in its ability to reduce the number of pathologically changed nuclei by 1.5 times (p&lt;0.05). At the same time, the number of pathologically unchanged nuclei significantly exceeded the number of nuclei with signs of karyorrhexis and karyopyknosis, so it would be advisable to use mesenchymal stromal cells of various genesis, lysate or citicoline in conditions of acute cerebral ischemia-reperfusion, taking into account their ability to reduce the volume of the infarct. In the future, an injectable drug will be created from the most effective culture of mesenchymal stromal cells in terms of cerebroprotective properties for cell therapy of patients with acute ischemic stroke.

Buqi-Huoxue-Tongnao decoction drives gut microbiota-derived indole lactic acid to attenuate ischemic stroke via the gut-brain axis

BackgroundIschemic stroke belongs to “apoplexy” and its pathogenesis is characterized by qi deficiency and blood stasis combining with phlegm-damp clouding orifices. Buqi-Huoxue-Tongnao decoction (BHTD) is a traditional Chinese medicine formula for qi deficiency, blood stasis and phlegm obstruction syndrome. However, its efficacy and potential mechanism on ischemic stroke are still unclear. This study aims to investigate the protective effect and potential mechanism of BHTD against ischemic stroke.Materials and methodsMiddle cerebral artery occlusion (MCAO) surgery was carried out to establish an ischemic stroke model in rats. Subsequently, the rats were gavaged with different doses of BHTD (2.59, 5.175, 10.35 g/kg) for 14 days. The protective effects of BHTD on the brain and gut were evaluated by neurological function scores, cerebral infarction area, levels of brain injury markers (S-100B, NGB), indicators of gut permeability (FD-4) and bacterial translocation (DAO, LPS, D-lactate), and tight junction proteins (Occludin, Claudin-1, ZO-1) in brain and colon. 16S rRNA gene sequencing and metabolomic analysis were utilized to analyze the effects on gut microecology and screen for marker metabolites to explore potential mechanisms of BHTD protection against ischemic stroke.ResultsBHTD could effectively mitigate brain impairment, including reducing neurological damage, decreasing cerebral infarction and repairing the blood–brain barrier, and BHTD showed the best effect at the dose of 10.35 g/kg. Moreover, BHTD reversed gut injury induced by ischemic stroke, as evidenced by decreased intestinal permeability, reduced intestinal bacterial translocation, and enhanced intestinal barrier integrity. In addition, BHTD rescued gut microbiota dysbiosis by increasing the abundance of beneficial bacteria, including Turicibacter and Faecalibaculum. Transplantation of the gut microbiota remodeled by BHTD into ischemic stroke rats recapitulated the protective effects of BHTD. Especially, BHTD upregulated tryptophan metabolism, which promoted gut microbiota to produce more indole lactic acid (ILA). Notably, supplementation with ILA by gavage could alleviate stroke injury, which suggested that driving the production of ILA in the gut might be a novel treatment for ischemic stroke.ConclusionBHTD could increase gut microbiota-derived indole lactic acid to attenuate ischemic stroke via the gut-brain axis. Our current finding provides evidence that traditional Chinese medicine can ameliorate central diseases through regulating the gut microbiology.

Nadolol Attenuates Brain Cell Ferroptosis in Ischemic Stroke Rats by Targeting the HOIL-1/IRP2 Pathway.

Heme-oxidized iron regulatory protein 2 (IRP2) ubiquitin ligase-1 (HOIL-1) is believed to contribute to the ubiquitination of IRP2, which facilitates the transcription of transferrin receptor 1 (TfR1) while preventing the transcription of ferroportin-1 (FPN-1). Bioinformatics analysis predicts that nadolol (a β-blocker) interacts with the HOIL-1. The present study is intended to explore whether nadolol suppresses ferroptosis in the brains of rats suffering from ischemic stroke via targeting the HOIL-1/IRP2 pathway. A rat model of ischemic stroke was established by blocking the middle cerebral artery for 2 h plus 24 h reperfusion, and nadolol (2.5 or 5 mg/kg) was given at 1h after reperfusion. HT22 cells were subjected to 12 h of hypoxia, followed by 24 h of reoxygenation for simulating ischemic stroke, and nadolol (0.1 or 0.25 μM) was administered to the culture medium before reoxygenation. The stroke rats showed evident brain injury (increases in neurological deficit score and infarct volume) and ferroptosis, along with up-regulation of IRP2 and TfR1 while downregulation of HOIL-1 and FPN-1; these phenomena were reversed in the presence of nadolol. In the cultured HT22 cells, hypoxia/reoxygenation-induced LDH release, ferroptosis, and changes in the levels of relevant proteins (IRP2, TfR1, HOIL-1, and FPN-1) were also reversed by nadolol. In terms of these findings, it is concluded that nadolol can protect the ischemic rats' brains against ferroptosis by targeting the HOIL-1/IRP2 pathway, thereby preventing intracellular iron overload. Thus, nadolol may be a novel indication for treating patients with ischemic stroke.

Human neural stem cell-derived extracellular vesicles protect against ischemic stroke by activating the PI3K/AKT/mTOR pathway.

Human neural stem cell-derived extracellular vesicles exhibit analogous functions to their parental cells, and can thus be used as substitutes for stem cells in stem cell therapy, thereby mitigating the risks of stem cell therapy and advancing the frontiers of stem cell-derived treatments. This lays a foundation for the development of potentially potent new treatment modalities for ischemic stroke. However, the precise mechanisms underlying the efficacy and safety of human neural stem cell-derived extracellular vesicles remain unclear, presenting challenges for clinical translation. To promote the translation of therapy based on human neural stem cell-derived extracellular vesicles from the bench to the bedside, we conducted a comprehensive preclinical study to evaluate the efficacy and safety of human neural stem cell-derived extracellular vesicles in the treatment of ischemic stroke. We found that administration of human neural stem cell-derived extracellular vesicles to an ischemic stroke rat model reduced the volume of cerebral infarction and promoted functional recovery by alleviating neuronal apoptosis. The human neural stem cell-derived extracellular vesicles reduced neuronal apoptosis by enhancing phosphorylation of phosphoinositide 3-kinase, mammalian target of rapamycin, and protein kinase B, and these effects were reversed by treatment with a phosphoinositide 3-kinase inhibitor. These findings suggest that human neural stem cell-derived extracellular vesicles play a neuroprotective role in ischemic stroke through activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway. Finally, we showed that human neural stem cell-derived extracellular vesicles have a good in vivo safety profile. Therefore, human neural stem cell-derived extracellular vesicles are a promising potential agent for the treatment of ischemic stroke.

Electroacupuncture promotes angiogenesis by regulating miR-142-5p and activating ADAMTS1/PI3K/AKT pathway in ischemic stroke rats.

To observe the effect of electroacupuncture on miR-142-5p and ADAMTS1/PI3K/AKT pathway in rats with ischemic stroke, so as to explore the regulatory mechanism of electroacupuncture on angiogenesis after ischemic stroke. This study was divided into two parts. The first part of the experiment：SD rats were randomly divided into sham operation group, model group and electroacupuncture group. There were 20 rats in each group. The middle cerebral artery occlusion (MCAO) rat model was prepared using a modified Longa's method. In the electroacupuncture group, "Shuigou" (GV26) was selected for electroacupuncture intervention (4 Hz/20 Hz) for 30 min each time. The rats in the electroacupuncture group were given electroacupuncture immediately after successful modeling, once a day for 4 times. Hunter score and TTC staining were used to observe the neurological deficits and infarct volumes respectively；HE staining was used to observe the cortical pathological changes；immunohistochemistry was used to determine the changes of cerebral microvascular density. Real-time quantitative PCR and Western blot were used to observe the miR-142-5p expression, mRNA and protein expression levels of ADAMTS1, VEGF, PI3K, AKT, eNOS in ischemic cortex. The second part of the experiment：The rats were randomly divided into electroacupuncture+control group and electroacupuncture+miR-142-5p Antagomir group with 8 rats in each group. MCAO model was established after injection. Electroacupuncture+control group was given 0.9% sodium chloride solution injected into the right ventricle.The rats in the electroacupuncture+miR-142-5p Antagomir group were injected with miR-142-5p inhibitor into the right ventricle 30 min before modeling. Rats in electroacupuncture+control group and electroacupuncture+miR-142-5p Antagomir group were all given the same electroacupuncture treatment. Real-time fluorescence quantitative PCR was used to observe the effect of miR-142-5p Antagomir on the expression of miR-142-5p and ADAMTS1 mRNA. The effect of miR-142-5p Antagomir on ADAMTS1 protein was observed by Western blot. In the first part of the experiment, compared with the sham operation group, the Hunter score in the model group was significantly increased (P<0.01)；the volume of cerebral infarction in the model group was significantly increased (P<0.01)；the degree of brain edema and neuronal necrosis and the density of cerebral microvessels was increased；the cerebral microvascular density was significantly increased (P<0.01)；the expression levels of miR-142-5p and the mRNA expression levels of VEGF, AKT and eNOS were significantly decreased (P<0.01, P<0.05), and the protein expression levels of VEGF, p-AKT and eNOS were significantly down-regulated (P<0.01), while the mRNA expression levels of ADAMTS1 and PI3K, and the protein expression levels of ADAMTS1 and p-PI3K were all up-regulated (P<0.01, P<0.05) in the model group. Compared with the model group, after intervention, the Hunter score in the electroacupuncture group was decreased (P<0.01), the volume of cerebral infarction was significantly decreased (P<0.01)；the degree of brain edema and neuronal necrosis were alleviated；the cerebral microvascular density was significantly increased (P<0.01)；the expression of miR-142-5p and the mRNA expression of VEGF, PI3K, AKT and eNOS were increased (P<0.01), the protein expressions of VEGF, p-PI3K, p-AKT and eNOS were increased (P<0.01, P<0.05), while the mRNA and protein expression of ADAMTS1 were decreased (P<0.05, P<0.01). After injection of miR-142-5p inhibitor, compared with electroacupuncture+control group, the expression of miR-142-5p in electroacupuncture+miR-142-5p Antagomir group was decreased(P<0.05), while the mRNA and protein expression of ADAMTS1 were increased (P<0.01, P<0.05). Electroacupuncture at GV26 can improve the neurological damage of ischemic stroke rats, reduce the volume of cerebral infarction and promote angiogenesis. The mechanism may be associated with the function of electroacupuncture in promoting the expression of miR-142-5p, so as to inhibit the expression of its target gene ADAMTS1, mediate the up-regulation of VEGF expression, activate PI3K/AKT pathway, promote the release of eNOS, and participate in promoting angiogenesis in ischemic stroke rats.

Study on the Therapeutic Effects and Mechanisms of Human Mesenchymal Stem Cell-Derived Exosomes Carrying NGF Gene in Treating Ischemic Stroke in Rats

Study on the Therapeutic Effects and Mechanisms of Human Mesenchymal Stem Cell-Derived Exosomes Carrying NGF Gene in Treating Ischemic Stroke in Rats

Exosomal miR-486 derived from bone marrow mesenchymal stem cells promotes angiogenesis following cerebral ischemic injury by regulating the PTEN/Akt pathway

Bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) have been shown to promote angiogenesis after ischemic stroke, in which microRNAs (miRs) are believed to play an important role in exosome-mediated therapeutic effects, though the mechanism is still not clear. In this study, a series of molecular biological and cellular assays, both in vitro and in vivo, were performed to elucidate the role of exosomal miR-486 in angiogenesis following cerebral ischemic and its molecular mechanisms. Our results revealed that BMSC-Exos significantly improved neurological function and increased microvessel density in ischemic stroke rats. In vitro assays showed that BMSC-Exos promoted the proliferation, migration, and tube formation ability of oxygen–glucose deprivation/reoxygenation (OGD/R) injured rat brain microvascular endothelial cells (RBMECs). Importantly, BMSC-Exos increased the expression of miR-486 and phosphorylated protein kinase B (p-Akt) and down-regulated the protein level of phosphatase and tensin homolog (PTEN) in vivo and in vitro. Mechanistic studies demonstrated that transfection with miR-486 mimic enhanced RBMECs angiogenesis and increased p-Akt expression, while inhibited PTEN expression. On the other hand, the miR-486 inhibitor induced an opposite effect, which could be blocked by PTEN siRNA. It was thus concluded that exosomal miR-486 from BMSCs may enhance the functional recovery by promoting angiogenesis following cerebral ischemic injury, which might be related to its regulation of the PTEN/Akt pathway.

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.

Astragaloside IV promotes cerebral tissue restoration through activating AMPK- mediated microglia polarization in ischemic stroke rats

Ethnopharmacological relevanceAstragaloside IV (AS), a key active ingredient obtained from Chinese herb Astragalus mongholicus Bunge, exerts potent neuroprotective and anti-inflammatory effects for treating neurodegenerative diseases. However, mechanisms of AS on improvement of ischemic brain tissue repair remain unclear. Aim of the studyThis research aims at using magnetic resonance imaging (MRI) to noninvasively determine whether AS facilitates brain tissue repair, and investigating whether AS exerts brain remodeling through adenosine monophosphate-activated protein kinase (AMPK) metabolic signaling regulating key glycolytic enzymes and energy transporters, thereby impacting microglia polarization. Materials and methodsIschemic stroke model in male Sprague–Dawley rats were induced through permanent occlusion of the middle cerebral artery (MCAO). Infarct volume, the alterations of brain microstructure and nerve fibers reorganization were examined by multi-parametric MRI. The pathological damages of myelinated axons and microglia polarization surrounding infarct tissue were detected using pathological techniques. Furthermore, M1/M2 microglia polarization associated protein, glycolytic rate-limiting enzymes, energy transporters and AMPK/mammalian target of rapamycin (mTOR)/hypoxia inducible factor-1α (HIF-1α) signal were examined both in ischemic stroke rats and BV2 microglia treated with lipopolysaccharide (LPS) + interferon-γ (IFN-γ) by western blotting. ResultsMRI revealed that AS obviously decreased infarct volume, relieved brain microstructure damage and improved nerve fibers reorganization in ischemic stroke rats. Histological tests supported MRI findings. Notably, AS promoted microglia M2 and reduced M1 polarization, induced the AMPK activation accompanied with decreased levels of phosphorylated mTOR and HIF-1α. Moreover, AS suppressed the expression of glycolytic rate-limiting enzymes and energy transporters in ischemic stroke rats and BV2 microglia. In contrast, these beneficial effects were greatly blocked by AMPK inhibitor compound C. ConclusionOverall, these results collectively suggested that AS facilitated tissue remodeling that may be partially through modulating polarization of microglia in AMPK- dependent metabolic pathways after ischemic stroke.

Investigating the therapeutic effects of nimodipine on vasogenic cerebral edema and blood-brain barrier impairment in an ischemic stroke rat model

Vasogenic brain edema, a potentially life-threatening consequence following an acute ischemic stroke, is a major clinical problem. This research aims to explore the therapeutic benefits of nimodipine, a calcium channel blocker, in mitigating vasogenic cerebral edema and preserving blood-brain barrier (BBB) function in an ischemic stroke rat model. In this research, animals underwent the induction of ischemic stroke via a 60-min blockage of the middle cerebral artery and treated with a nonhypotensive dose of nimodipine (1 mg/kg/day) for a duration of five days. The wet/dry method was employed to identify cerebral edema, and the Evans blue dye extravasation technique was used to assess the permeability of the BBB. Furthermore, immunofluorescence staining was utilized to assess the protein expression levels of matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1). The study also examined mitochondrial function by evaluating mitochondrial swelling, succinate dehydrogenase (SDH) activity, the collapse of mitochondrial membrane potential (MMP), and the generation of reactive oxygen species (ROS). Post-stroke administration of nimodipine led to a significant decrease in cerebral edema and maintained the integrity of the BBB. The protective effects observed were associated with a reduction in cell apoptosis as well as decreased expression of MMP-9 and ICAM-1. Furthermore, nimodipine was observed to reduce mitochondrial swelling and ROS levels while simultaneously restoring MMP and SDH activity. These results suggest that nimodipine may reduce cerebral edema and BBB breakdown caused by ischemia/reperfusion. This effect is potentially mediated through the reduction of MMP-9 and ICAM-1 levels and the enhancement of mitochondrial function.

Overexpression of olfactory receptor 78 ameliorates brain injury in cerebral ischaemia-reperfusion rats by activating Prkaca-mediated cAMP/PKA-MAPK pathway.

Ischemic stroke is one of the main causes of disability and death. However, recanalization of occluded cerebral arteries is effective only within a very narrow time window. Therefore, it is particularly important to find neuroprotective biological targets for cerebral artery recanalization. Here, gene expression profiles of datasets GSE160500 and GSE97537 were downloaded from the GEO database, which were related to ischemic stroke in rats. Olfactory receptor 78 (Olfr78) was screened, and which highly associated with Calcium signalling pathway and MAPK pathway. Interacting protein of Olfr78, Prkaca, was predicted by STRING, and their interaction was validated by Co-IP analysis. Then, a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) and a neuronal cell model stimulated by oxygen-glucose deprivation/reoxygenation (OGD/R) were constructed, and the results showed that expression of Olfr78 and Prkaca was downregulated in MCAO rats and OGD/R-stimulated neurons. Overexpression of Olfr78 or Prkaca inhibited the secretion of inflammatory factors, Ca2+ overload, and OGD/R-induced neuronal apoptosis. Moreover, Overexpression of Prkaca increased protein levels of cAMP, PKA and phosphorylated p38 in OGD/R-stimulated neurons, while SB203580, a p38 inhibitor, treatment inhibited activation of the cAMP/PKA-MAPK pathway and counteracted the effect of Olfr78 overexpression on improvement of neuronal functions. Meanwhile, overexpression of Olfr78 or Prkaca markedly inhibited neuronal apoptosis and improved brain injury in MCAO/R rats. In conclusion, overexpression of Olfr78 inhibited Ca2+ overload and reduced neuronal apoptosis in MCAO/R rats by promoting Prkaca-mediated activation of the cAMP/PKA-MAPK pathway, thereby improving brain injury in cerebral ischaemia-reperfusion.

Cerebroprotective Effects of the TLR4-Binding DNA Aptamer ApTOLL in a Rat Model of Ischemic Stroke and Thrombectomy Recanalization.

ApTOLL, a TLR4 modulator aptamer, has demonstrated cerebroprotective effects in a permanent ischemic stroke mouse model, as well as safety and efficacy in early phase clinical trials. We carried out reverse translation research according to STAIR recommendations to further characterize the effects and mechanisms of ApTOLL after transient ischemic stroke in rats and to better inform the design of pivotal clinical trials. Adult male rats subjected to transient middle cerebral artery occlusion were treated either with ApTOLL or the vehicle intravenously at different doses and time-points. ApTOLL was compared with TAK-242 (a TLR4 inhibitor). Female rats were also studied. After neurofunctional evaluation, brains were removed for infarct/edema volume, hemorrhagic transformation, and histologic determinations. Peripheral leukocyte populations were assessed via flow cytometry. ApTOLL showed U-shaped dose-dependent cerebroprotective effects. The maximum effective dose (0.45 mg/kg) was cerebroprotective when given both before reperfusion and up to 12 h after reperfusion and reduced the hemorrhagic risk. Similar effects occurred in female rats. Both research and clinical ApTOLL batches induced slightly superior cerebroprotection when compared with TAK-242. Finally, ApTOLL modulated circulating leukocyte levels, reached the brain ischemic tissue to bind resident and infiltrated cell types, and reduced the neutrophil density. These results show the cerebroprotective effects of ApTOLL in ischemic stroke by reducing the infarct/edema volume, neurofunctional impairment, and hemorrhagic risk, as well as the peripheral and local immune response. They provide information about ApTOLL dose effects and its therapeutic time window and target population, as well as its mode of action, which should be considered in the design of pivotal clinical trials.