Cerebral Ischemia-reperfusion Injury Model Research Articles

Luteolin alleviates cerebral ischemia/reperfusion injury by regulating cell pyroptosis.

This study aimed to clarify the roles and underlying mechanisms of luteolin in the progression of cerebral ischemia/reperfusion injury (CIRI). A mouse model of CIRI was established using the middle cerebral artery occlusion (MCAO) method, after which luteolin was administered. Subsequently, neuronal apoptosis and pyroptosis were measured and the brain tissues of each group were subjected to RNA sequencing. Luteolin alleviated MCAO-induced brain infarction, apoptosis, and pyroptosis. RNA sequencing identified 3,379, 2,777, and 3,933 differentially expressed genes (DEGs) in the MCAO vs sham, MCAO vs MCAO + luteolin, and MCAO + luteolin vs sham groups, respectively. The identified DEGs showed enrichment in multiple processes, including pattern specification, forebrain development, anion transport, leukocyte migration, regulation of cell-cell adhesion, and positive regulation of the response to external stimuli, as well as the calcium, PI3K-AKT, JAK-STAT, NF-kappa B, IL-17, cAMP, cGMP-PKG, and Wnt signaling pathways. In addition, Ccl2 and Angpt2 interacted more with the other top 30 DEGs with high interaction weights. Finally, RT-qPCR results showed that MCAO induction significantly up-regulated the expression of Stoml3, Eomes, and Ms4a15 and down-regulated Nms, Ttr, and Avpr1a; however, luteolin could partially reverse the expression caused by MCAO. Luteolin can alleviate brain infarction, apoptosis, and pyroptosis in CIRI, and may improve MCAO-induced CIRI by targeting the identified DEGs and their enriched pathways.

Exploration the effective components of Gastrodia elata in improving cerebral ischemia reperfusion injury based on “Spectrum-effect” correlation and zebrafish verification experiment

BackgroundGastrodia elata (GE) has been widely used in clinical practice for many years with the functions of relieving stroke, suppressing liver Yang, dispelling wind and clearing collaterals. Our group's previous experimental studies have proved that GE has therapeutic effect on cerebral ischemia reperfusion injury (CIRI) (Ding et al., 2022). However, the active components of GE in treating CIRI remain unclear and require further research. PurposeThe purpose of this paper was to explore the potential effective components of GE improving CIRI based on the “Spectrum-effect” correlation. Zebrafish model was used for verification in vivo experimental. Materials and methodsFirst, the absorption components and metabolites of GE in rat serum were identified using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS). Second, pharmacodynamic indexes were determined by ELISA kit method, and the effect-time curve of each pharmacodynamic indexes was established. The potential compounds were screened using the statistical method of grey correlation between pharmacodynamic indicator and component response. Finally, the zebrafish CIRI model was successfully established, and the in vivo effect of the active components of GE was verified intuitively. Results45 chemical components were detected in GE. A total of 87 active components in serum of GE were identified including 25 prototype components and 62 metabolites. GE can improve CIRI by regulating the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α), MDA levels and SOD levels. It was found that p-hydroxy benzaldehyde (PHB), p-hydroxybenzyl alcohol (PHBA) and gastrodin (GA) of GE were the possibly main active components by grey correlation statistics. The in vivo experiments of zebrafish model showed that PHB, PHBA, and GA have the ability to ameliorate cerebral thrombosis by regulation of oxidative stress and apoptosis. ConclusionsThe potential active components of GE on CIRI were initially excavated using UHPLC-Q-TOF-MS/MS, pharmacodynamics, and in vivo experiments of zebrafish model. It makes up for the disadvantages of separate research on chemical components and pharmacodynamics, and reflects the material basis of pharmacodynamics more objectively. It has provided theoretical basis for further quality evaluation and scientific foundation for rational drug using of GE in clinical.

Effect of "Xingnao Kaiqiao" needling on expression of ferroptosis-related factors in rats with cerebral ischemia-reperfusion injury

To observe the effect of "Xingnao Kaiqiao" needling on the expression of ferroptosis-related proteins in neurons of rats with cerebral ischemia-reperfusion injury (CIRI), so as to explore its mechanism underlying improvement of CIRI. Male Wistar rats were randomly divided into sham operation, model, acupuncture and deferoxamine (DFO) groups, with 18 rats in each group. The CIRI model was established by occlusion of the middle cerebral artery. In the acupuncture group, "Xingnao Kaiqiao" needling was applied to "Shuigou" (GV26), "Neiguan" (PC6) and "Sanyinjiao"(SP6) for 20 min with electroacupuncture (2 Hz/15 Hz, 1 mA) at PC6 and SP6, twice daily for continuous 3 days. Rats of the DFO group received intraperitoneal injection of iron chelator DFO (0.1 g/kg, once daily). The severity of neurological impairment (neurological deficit score, 0-5 points, the lower the score, the severer is the neurological impairment) was evaluated by using Zausinger 6-poins scaling method. The cerebral infarct volume was measured after 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, and the histopathological changes of the ischemic brain tissue were observed after H.E. staining. The mitochondrial structure of the hippocampal neurons on the ischemic side of the brain was observed by using transmission electron microscope. The levels of iron deposition rate (%) in the ischemic penumbra of the brain tissue and hippocampus were observed after Prussian blue staining, and the reactive oxygen species (ROS) content of the cerebral ischemic penumbra was assayed using flow cytometry, and the content of glutathione (GSH) content in the ischemic penumbra was detected by using microplate method. The real-time quantitative PCR was used to detect the expression of glutathione peroxidase 4 (GPX4), divalent metal transporter 1 (DMT1), transferrin (TF), transferrin receptor 1 (TFR1), and ferroportin 1 (FPN1) mRNAs in the ischemic penumbra, and the Western blot was used to detect the expression of GPX4, DMT1, TF, TFR1, FPN1, and ferritin (FER) proteins in the ischemic penumbra. Compared with the sham operation group, the neurological deficit score, GSH content, expression of GPX4 and FPN1 mRNAs and proteins were significantly decreased (P<0.01), while the percentage of cerebral infarct volume, iron deposit rates of the cerebral ischemic penumbra and hippocampus, ROS content, and the expression levels of DMT1, TF, and TFR1 mRNAs and proteins and FER protein were considerably increased (P<0.01) in the model group. In comparison with the model group, the decrease of neurological deficit score, GSH content, expression of GPX4 and FPN1 mRNAs and proteins, and the increase of the percentage of cerebral infarct volume, iron deposit rates of the cerebral ischemic penumbra and hippocampus, ROS content, and the expression levels of DMT1, TF, and TFR1 mRNAs and proteins and FER protein were all reversed in both DFO and acupuncture groups (P<0.01, P<0.05). The effects of acupuncture were significantly superior to those of DFO in lowering the levels of cerebral cortical and hippocampal iron deposit rates, ROS content and in elevating the expression of GPX4 mRNA and protein (P<0.01, P<0.05). H.E. staining showed large necrotic cells, disordered arrangement of cells in the cerebral cortex and hippocampus, with hyperchromic nuclei, vacuole-like changes, widening of cellular space, and cell swelling in the model group, which was relatively milder in the cell damage in both acupuncture and DFO groups. In addition, the ultrastructure of cells in the hippocampus showed irregular cellular nuclear morphology, atrophy of some mitochondria in the cytoplasm, partial mitochondrial membrane rupture and edema, and loosening of the ridge structure in the model group, which was milder in the mitochondrial impairment (including reduced number of mitochondria, broken mitochondrial membrane and reduced ridge structure in fewer cells) in the acupuncture group. The "Xingnao Kaiqiao" needling intervention has a neuroprotective effect in CIRI rats, which may be related to its functions in regulating ferroptosis-related targets and iron metabolism in cerebral ischemic penumbra, reducing oxidative stress injury, and suppressing neuronal ferroptosis.

A coloaded liposome in situ gel as a novel therapeutic strategy to treat cerebral ischemia reperfusion injury

BackgroundIschemic stroke has become one of the leading causes of death and disability worldwide in individuals aged 60 and above. However, currently available drugs show limited efficacy. Therefore, research to find more effective and safer therapeutic strategies is an urgent requirement for the treatment of cerebral ischemia reperfusion injury (CIRI). MethodsFirst, the free radical scavenger Edaravone and a Ginseng active ingredient were coloaded into liposomes (aER@Lip), followed by optimization and characterization. Pluronic F127 and F68 at different concentrations were mixed and stored at 4 °C for more than 24 h to obtain gel solutions. Then, aER@Lip was added to the gel solutions to prepare the drug-loaded in situ gel, termed aER@Lip-TSG. ResultsIn vitro experiments showed that aER@Lip-TSG was taken up by cells and had a good protective effect on oxygen-glucose deprivation/reoxygenation in pheochromocytoma 12 cells. In a rat CIRI model, aER@Lip-TSG delivered by intranasal administration not only decreased the apoptosis in brain tissue induced by CIRI, but also decreased the resultant inflammatory response. Moreover, the results suggested that aER@Lip-TSG had good biosafety. ConclusionThis delivery system provides a promising multi-factor combination, synergistic effects, sustained-release capabilities, and is a non-invasive treatment strategy for CIRI. It thus meets the urgent need for effective treatments of central nervous system diseases.

Lithocarpus polystachyus Rehd. ameliorates cerebral ischemia/reperfusion injury through inhibiting PI3K/AKT/NF-κB pathway and regulating NLRP3-mediated pyroptosis.

Ischemic stroke (IS) is a serious threat to human life and health, and cerebral ischemia/reperfusion injury (CIRI) exacerbates IS by enhancing neuroinflammation and oxidative stress. Sweet tea (ST) comprises several bioactive components, such as phlorizin, trilobatin, and phloretin, with diverse pharmacological activities. However, it remains uncertain whether ST can confer protection against CIRI. In this study, we aimed to investigate the impact and potential underlying mechanism of ST in the context of CIRI. CIRI model were established in male sprague dawley (SD) rats. The neurobehavioral assessment, the volume of cerebral infarction and the morphology of neurons were measured to complete the preliminary pharmacodynamic study. The therapeutic targets and pathways of ST on IS were obtained by protein-protein interaction, molecular docking and Metascape database. The predicted results were further verified in vivo. Our results revealed that ST treatment significantly ameliorated brain damage in rats subjected to CIRI by mitigating mitochondrial oxidative stress and neuroinflammation. Additionally, we identified the PI3K/AKT/NF-κB pathway and the NLRP3-mediated pyroptosis axis as crucial processes, with molecular docking suggested direct interactions between the main compounds of ST and NLRP3. ST safeguards against CIRI-induced neuronal loss, neuroinflammation and oxidative stress through the inhibition of the PI3K/AKT/NF-κB pathway and the regulation of NLRP3-mediated pyroptosis.

A vascular endothelial growth factor-loaded chitosanhyaluronic acid hydrogel scaffold enhances the therapeutic effect of adipose-derived stem cells in the context of stroke.

Adipose-derived stem cell, one type of mesenchymal stem cells, is a promising approach in treating ischemia-reperfusion injury caused by occlusion of the middle cerebral artery. However, its application has been limited by the complexities of the ischemic microenvironment. Hydrogel scaffolds, which are composed of hyaluronic acid and chitosan, exhibit excellent biocompatibility and biodegradability, making them promising candidates as cell carriers. Vascular endothelial growth factor is a crucial regulatory factor for stem cells. Both hyaluronic acid and chitosan have the potential to make the microenvironment more hospitable to transplanted stem cells, thereby enhancing the therapeutic effect of mesenchymal stem cell transplantation in the context of stroke. Here, we found that vascular endothelial growth factor significantly improved the activity and paracrine function of adipose-derived stem cells. Subsequently, we developed a chitosan-hyaluronic acid hydrogel scaffold that incorporated vascular endothelial growth factor and first injected the scaffold into an animal model of cerebral ischemia-reperfusion injury. When loaded with adipose-derived stem cells, this vascular endothelial growth factor-loaded scaffold markedly reduced neuronal apoptosis caused by oxygen-glucose deprivation/reoxygenation and substantially restored mitochondrial membrane potential and axon morphology. Further in vivo experiments revealed that this vascular endothelial growth factor-loaded hydrogel scaffold facilitated the transplantation of adipose-derived stem cells, leading to a reduction in infarct volume and neuronal apoptosis in a rat model of stroke induced by transient middle cerebral artery occlusion. It also helped maintain mitochondrial integrity and axonal morphology, greatly improving rat motor function and angiogenesis. Therefore, utilizing a hydrogel scaffold loaded with vascular endothelial growth factor as a stem cell delivery system can mitigate the adverse effects of ischemic microenvironment on transplanted stem cells and enhance the therapeutic effect of stem cells in the context of stroke.

Sufentanil-induced Nrf2 protein ameliorates cerebral ischemia-reperfusion injury through suppressing neural ferroptosis

As an oxidative stress and inflammation-related disease, cerebral ischemia-reperfusion injury (CIRI) is a prevalent pathogenic factor of ischemic stroke (IS) and seriously degrades the life quality of human beings. As an opioid analgesic for anesthesia, Sufentanil (SUF) can activate the Nrf2 protein-induced anti-oxidant effects, which indicate that SUF may be used as alternative drug for CIRI therapy, but little is known regarding to its molecular mechanisms. Thus, this research aimed to examine whether SUF pre-treatment alleviated CIRI through the modulation of Nrf2 protein-mediated antioxidant activity. Our research revealed that middle cerebral artery occlusion/reperfusion (MCAO/R)-treated rats exhibited apparent CIRI-related symptoms and induced damages in rats' brain, which were all notably mitigated in the MCAO/R rats. The subsequent in vitro cellular experiments verified that oxygen-glucose deprivation/reoxygenation (OGD/R)-induced cytotoxicity were apparently reversed by SUF co-treatment in HT22 and BV2 cells, and it was also validated that SUF was capable of suppressing inflammation and ferroptosis in CIRI models by inhibiting oxidative stress-related damages. Mechanistically, the Akt/GSK-3β pathway was excessively activated by SUF to promote Nrf2 protein expressions and enhance Nrf2-meidated anti-oxidant effects, and it was found that SUF-induced protective effects during CIRI progression were all abrogated by co-treating cells with MK2206 (Akt inhibitor), NP-12 (GSK-3β inhibitor), or ML385 (Nrf2 inhibitor). In conclusion, SUF activated the Akt/GSK-3β pathway to initiate Nrf2 protein-mediated antioxidant effects, which further suppressed oxidative stress-related inflammation and ferroptosis to ameliorate CIRI progression, and SUF could potentially be used as novel therapeutic agent for CIRI treatment in clinic.

Exogenous leptin alleviates glutamate-excitotoxic injury caused by cerebral ischemia–reperfusion in mice by affecting the expression of glutamate transporters

Ischemic stroke is characterized by high morbidity and mortality and a lack of effective therapeutic interventions. Leptin plays an important role in regulating oxidative stress, angiogenesis, hematopoiesis, etc. Although recent studies have found a neuroprotective effect of leptin, little is known about its role in cerebral ischemia. This study explores the possible roles and potential preventative mechanisms of leptin in cerebral ischemia–reperfusion injury (CIRI). An in vivo middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was used to replicate the CIRI model, low (0.5 mg/kg), medium (1 mg/kg) and high (2 mg/kg) concentrations of leptin were injected intraperitoneally immediately after inserting the embolic line. After 1.5 h of ischemia and 24 h of reperfusion, we examined the neural function of the mice, collected brain tissue for histological examination, and screened for the optimal concentrations of leptin intervention. On this basis, we observed the changes of cortical apoptosis injury, intracellular calcium fluorescence intensity and astrocyte glial fibrillary acidic protein (GFAP) expression and morphological changes. In addition, we also tested the expression of transporters and metabolism-related enzymes (VGLUT-1, VGLUT-2, GLAST, GLT-1, GS, ATP1α1), the expression of inflammatory factors and the content of glutamate (Glu). Compared with the I/R group, we found that leptin improved neurological deficits, reduced the area of infarcts, maintained the normal morphology of astrocytes (AST), downregulated the expression of VGLUT-1, and upregulates the expression of GLT-1 and GLAST, thereby reducing the content of Glu in the synaptic cleft. Our studies suggest that leptin may have a neuroprotective effect by decreasing the excitotoxicity of glutamate.

Perioperative complications of middle cerebral artery occlusion in rats alleviated by human umbilical cord mesenchymal stem cells.

For acute ischemic stroke treatment, the limitations of treatment methods and the high incidence of perioperative complications seriously affect the survival rate and postoperative recovery of patients. Human umbilical cord mesenchymal stem cells (hucMSCs) have multi-directional differentiation potential and immune regulation function, which is a potential cell therapy. The present investigation involved developing a model of cerebral ischemia-reperfusion injury by thrombectomy after middle cerebral artery occlusion (MCAO) for 90min in rats and utilizing comprehensive multi-system evaluation methods, including the detection of brain tissue ischemia, postoperative survival rate, neurological score, anesthesia recovery monitoring, pain evaluation, stress response, and postoperative pulmonary complications, to elucidate the curative effect of tail vein injection of hucMSCs on MCAO's perioperative complications. Based on our research, it has been determined that hucMSCs treatment can reduce the volume of brain tissue ischemia, promote the recovery of neurological function, and improve the postoperative survival rate of MCAO in rats. At the same time, hucMSCs treatment can prolong the time of anesthesia recovery, relieve the occurrence of delirium during anesthesia recovery, and also have a good control effect on postoperative weight loss, facial pain expression, and lung injury. It can also reduce postoperative stress response by regulating blood glucose and serum levels of stress-related proteins including TNF-α, IL-6, CRP, NE, cortisol, β-endorphin, and IL-10, and ultimately promote the recovery of MCAO's perioperative complications.

The effects and mechanisms of AM1241 in alleviating cerebral ischemia-reperfusion injury

ObjectiveResearch has shown that cerebral ischemia-reperfusion injury (CIRI) involves a series of physiological and pathological mechanisms, including inflammation, oxidative stress, and cell apoptosis. The cannabinoid receptor 2 agonist AM1241 has been found to have anti-inflammatory and anti-oxidative stress effects. However, it is unclear whether AM1241 has a protective effect against brain ischemia-reperfusion injury, and its underlying mechanisms are not yet known. MethodsIn this study, we investigated the anti-inflammatory, anti-oxidative stress, and anti-apoptotic effects of AM1241 and its mechanisms in BV2 cells stimulated with H2O2 and in a C57BL/6 mouse model of CIRI in vitro and in vivo, respectively. ResultsIn vitro, AM1241 significantly inhibited the release of pro-inflammatory cytokines TNF-α and IL-6, reactive oxygen species (ROS), and the increase in Toll-like receptor 4/myeloid differentiation protein 2 (MD2/TLR4) complex induced by H2O2. Under H2O2 stimulation, MD2 overexpression resulted in increased levels of MD2/TLR4 complex, TNF-α, IL-6, NOX2, BAX, and Cleaved-Caspase3 (C-Caspase3), as well as the activation of the MAPK pathway and NF-κB, which were reversed by AM1241. In addition, molecular docking experiments showed that AM1241 directly interacted with MD2. Surface Plasmon Resonance (SPR) experiments further confirmed the binding of AM1241 to MD2. In vivo, AM1241 significantly attenuated neurofunctional impairment, brain edema, increased infarct volume, oxidative stress levels, and neuronal apoptosis in CIRI mice overexpressing MD2. ConclusionOur study demonstrates for the first time that AM1241 alleviates mouse CIRI by inhibiting the MD2/TLR4 complex, exerting anti-inflammatory, anti-oxidative stress and anti-apoptotic effects.

RNA sequencing reveals the potential mechanism of exercise preconditioning for cerebral ischemia reperfusion injury in rats.

Cerebral ischemia reperfusion injury (CIRI) often leads to deleterious complications after stroke patients receive reperfusion therapy. Exercise preconditioning (EP) has been reported to facilitate brain function recovery. We aim to explore the specific mechanism of EP in CIRI. Sprague-Dawley rats were randomized into Sham, middle cerebral artery occlusion (MCAO), and EP groups (n=11). The rats in the EP group received adaptive training for 3 days (10m/min, 20min/day, with a 0° incline) and formal training for 3 weeks (6 days/week, 25m/min, 30min/day, with a 0° incline). Then, rats underwent MCAO surgery to establish CIRI models. After 48h, neurological deficits and cerebral infarction of the rats were measured. Neuronal death and apoptosis in the cerebral cortices were detected. Furthermore, RNA sequencing was conducted to investigate the specific mechanism of EP on CIRI, and qPCR and Western blotting were further applied to confirm RNA sequencing results. EP improved neurological deficit scores and reduced cerebral infarction in MCAO rats. Additionally, pre-ischemic exercise also alleviated neuronal death and apoptosis of the cerebral cortices in MCAO rats. Importantly, 17 differentially expressed genes (DEGs) were identified through RNA sequencing, and these DEGs were mainly enriched in the HIF-1 pathway, cellular senescence, proteoglycans in cancer, and so on. qPCR and Western blotting further confirmed that EP could suppress TIMP1, SOCS3, ANGPTL4, CDO1, and SERPINE1 expressions in MCAO rats. EP can improve CIRI in vivo, the mechanism may relate to TIMP1 expression and HIF-1 pathway, which provided novel targets for CIRI treatment.

Targeting TNF-α: The therapeutic potential of certolizumab pegol in the early period of cerebral ischemia reperfusion injury in mice

The neuroinflammatory response triggered by cerebral ischemia–reperfusion injury (CIRI) is characterized by the upsurge of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, which promote leukocyte infiltration and subsequent accumulation in the ischemic zone. This accumulation further intensifies inflammation and aggravates ischemic damage. Certolizumab pegol (CZP), a monoclonal antibody targeting TNF-α, is widely used in treating various inflammatory diseases. This study explored the therapeutic potential of CZP in a mouse model of CIRI, induced by middle cerebral artery occlusion (MCAO), focusing on its influence on the microglial inflammatory response. In vitro analyses revealed that CZP markedly inhibits TNF-α-stimulated inflammation in primary microglia with an EC50 of 1.743 ng/mL. In vivo, MCAO mice treated with CZP (10 μg/mouse, i.p.) for 3 days showed reduced infarct volume, partially improved neurological function, and diminished blood–brain barrierdisruption. Additionally, CZP treatment curtailed microglial activation and the release of pro-inflammatory mediators in the early stages of stroke. It also favorably modulated microglial M1/M2 polarization, rebalanced Th17/Treg cells dynamics, and inhibited Caspase-8-mediated GSDMD cleavage, preventing microglial pyroptosis. Collectively, this study described that the treatment with CZP reversed damaging process caused by CIRI, offering a promising therapeutic strategy for the treatment of ischemic stroke.

Detection of miR-203 expression using a nanofluorescent probe to study the neuroprotective effect of sevoflurane in a neuroinflammatory injury rat model

Ischemic cerebrovascular disease has high disability and mortality rates that can result in related sequelae if not treated promptly and properly. Nanofluorescent probes are useful in the early diagnosis of the disease due to their high sensitivity and specificity, thus facilitating early therapeutic measures and observation of disease progression. Here, a novel nanostructure probe was designed to detect the expression of miR-203 in a cerebral ischemia-reperfusion injury (CIRI) model after sevoflurane treatment, and the effects of sevoflurane and neuroinflammatory injury were discussed. A CIRI rat model was established to study miR-203 expression, nerve injury, oxidative stress, and inflammatory factors in the brain tissue of rats treated with sevoflurane. The nanofluorescent probe showed high specificity and sensitivity for miR-203 detection. miR-203 was over-expressed in CIRI rats, which was decreased by sevoflurane treatment. In addition, sevoflurane treatment significantly improved neurological function, learning, and memory in CIRI rats; decreased malondialdehyde, lactate dehydrogenase, and superoxide dismutase levels; and inhibited the expression of tumor necrosis factor α and interleukins 1 and 6. Moreover, an inverse correlation was determined between miR-203 expression and the degree of neuroinflammation. This study demonstrated that miR-203 may be a useful diagnostic and prognostic index for neuroinflammatory injury.

The protective effect and mechanism of glycosides of cistanche deserticola on rats in middle cerebral artery occlusion (MCAO) model

ABSTRACT Cerebral ischemia-reperfusion injury (CIRI) occurs frequently clinically as a complication following cardiovascular resuscitation resulting in neuronal damage specifically to the hippocampal CA1 region with consequent cognitive impairment. Apoptosis and oxidative stress were proposed as major risk factors associated with CIRI development. Previously, glycosides obtained from Cistanche deserticola (CGs) were shown to play a key role in counteracting CIRI; however, the underlying mechanisms remain to be determined. This study aimed to investigate the neuroprotective effect of CGs on subsequent CIRI in rats. The model of CIRI was established for 2 hr and reperfusion for 24 hr by middle cerebral artery occlusion (MCAO) model. The MCAO rats were used to measure the antioxidant and anti-apoptotic effects of CGs on CIRI. Neurological function was evaluated by the Longa neurological function score test. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to detect the area of cerebral infarction. Nissl staining was employed to observe neuronal morphology. TUNEL staining was used to detect neuronal apoptosis, while Western blot determined protein expression levels of factors for apoptosis-related and PI3K/AKT/Nrf2 signaling pathway. Data demonstrated that CGs treatment improved behavioral performance, brain injury, and enhanced antioxidant and anti-apoptosis in CIRI rats. In addition, CGs induced activation of PI3K/AKT/Nrf2 signaling pathway accompanied by inhibition of the expression of apoptosis-related factors. Evidence indicates that CGs amelioration of CIRI involves activation of the PI3K/AKT/Nrf2 signaling pathway associated with increased cellular viability suggesting these glycosides may be considered as an alternative compound for CIRI treatment.

Dietary Supplementation with Nervonic Acid Ameliorates Cerebral Ischemia-Reperfusion Injury by Modulating of Gut Microbiota Composition-Fecal Metabolites Interaction.

Cerebral ischemia-reperfusion (IR) injury stands as a prominent global contributor to disability and mortality. Nervonic acid (NA), a bioactive elongated monounsaturated fatty acid, holds pivotal significance in human physiological well-being. This research aims to explore the prophylactic effects and fundamental mechanisms of NA in a rat model of cerebral IR injury. Through the induction of middle cerebral artery occlusion, this study establishes a rat model of cerebral IR injury and comprehensively assesses the pharmacodynamic impacts of NA pretreatment. This evaluation involves behavioral analyses, histopathological examinations, and quantification of serum markers. Detailed mechanisms of nervonic acid's prophylactic effects are revealed through fecal metabolomics and 16S rRNA sequencing analyses. Our findings robustly support nervonic acid's capacity to ameliorate neurological impairments in rats afflicted with cerebral IR injury. Beyond its neurological benefits, NA demonstrates its potential by rectifying metabolic perturbations across diverse pathways, particularly those pertinent to unsaturated fatty acid metabolism. Additionally, NA emerges as a modulator of gut microbiota composition, notably by selectively enhancing vital genera like Lactobacillus. These comprehensive findings highlight the potential of incorporating NA as a functional component in dietary interventions aimed at targeting cerebral IR injury.

Moxibustion preconditioning reduces inflammatory response in rats with cerebral ischemia-reperfusion injury by regulating PI3K / AKT / mTOR signaling pathway.

To observe the effect of moxibustion preconditioning on inflammatory response in rats with cerebral ischemia reperfusion injury (CIRI), so as to explore its mechanisms underlying improving CIRI. Seventy-five male SD rats were randomly divided into sham operation, model, moxibustion preconditioning 3 days (Moxi 1), moxibustion preconditioning 5 days (Moxi 2) and moxibustion preconditioning 7 days (Moxi 3) groups, with 15 rats in each group. Moxibustion was applied at "Baihui"(GV20), "Dazhui"(GV14) and "Zusanli"(ST36) for 20 min once a day, totally for 3, 5 or 7 days. Thirty minutes after the last moxibustion treatment, the CIRI model was established by occlusion of the middle cerebral artery. The neurological deficit score was assessed by using Longa's method. The infarct size of the brain assessed after staining with 2% triphenyltetrazolium chloride (TTC). The morphological changes of cortical neurons were observed by HE staining. The contents of inflammatory factors interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), S-100β protein (S-100β) and neuron-specific enolase (NSE) were detected by ELISA. The expression of phosphatidylinositol-3-kinase (PI3K), p-PI3K, protein kinase B (AKT) and mammalian target of rapamycin (mTOR) proteins in the ischemic cortex tissues were detected by immunohistochemistry and Western blot. Compared with the sham operation group, the neurological function score and the percentage of cerebral ischemic volume were increased (P<0.01). The contents of serum IL-1β, TNF-α, S-100β and NSE were significantly increased (P<0.01), while the protein expressions of PI3K, p-PI3K, AKT and mTOR in the cerebral cortex were significantly decreased (P<0.01) in the model group. Compared with the model group, the neurological function score and the percentage of cerebral ischemic volume were significantly decreased (P<0.01). The contents of serum IL-1β, TNF-α, S-100β and NSE were significantly decreased (P<0.01), and the expressions of PI3K, p-PI3K, AKT and mTOR proteins in the cerebral cortex were significantly increased (P<0.01) in three moxibustion groups. Compared with the Moxi 1 and Moxi 2 groups, the above indicators were significantly improved in rats of the Moxi 3 group (P<0.01, P<0.05). Moxibustion preconditioning can significantly improve the neurological function of rats after ischemia-reperfusion, inhibit serum inflammatory factors IL-1 β and TNF-α, inhibit brain tissue injury markers S-100β and NSE, which may be related to the activation of PI3K/AKT/mTOR signaling pathway. The protective effect of moxibustion preconditioning for 7 days on CIRI was better than that of 5 days and 3 days.

FDA compound library screening Baicalin upregulates TREM2 for the treatment of cerebral ischemia-reperfusion injury

Acute ischemic stroke (AIS) is a leading cause of global incidence and mortality rates. Oxidative stress and inflammation are key factors in the pathogenesis of AIS neuroinjury. Therefore, it is necessary to develop drugs that target neuroinflammation and oxidative stress in AIS. The Triggering Receptor Expressed on Myeloid Cells 2 (TREM2), primarily expressed on microglial cell membranes, plays a critical role in reducing inflammation and oxidative stress in AIS. In this study, we employed a high-throughput screening (HTS) strategy to evaluate 2625 compounds from the (Food and Drug Administration) FDA library in vitro to identify compounds that upregulate the TREM2 receptor on microglia. Through this screening, we identified Baicalin as a potential drug for AIS treatment. Baicalin, a flavonoid compound extracted and isolated from the root of Scutellaria baicalensis, demonstrated promising results. Next, we established an in vivo mouse model of cerebral ischemia-reperfusion injury (MCAO/R) and an in vitro microglia cell of oxygen-glucose deprivation reperfusion (OGD/R) to investigate the role of Baicalin in inflammation injury, oxidative stress, and neuronal apoptosis. Our results showed that baicalin effectively inhibited microglia activation, reactive oxygen species (ROS) production, and inflammatory responses in vitro. Additionally, baicalin suppressed neuronal cell apoptosis. In the in vivo experiments, baicalin not only improved neurological functional deficits and reduced infarct volume but also inhibited microglia activation and inflammatory responses. Overall, our findings demonstrate the efficacy of Baicalin in treating MCAO/R by upregulating TREM2 to reduce inflammatory responses and inhibit neuronal apoptosis.

Effect of Naotaifang on microglial polarization and glial scar following cerebral ischemia reperfusion injury

This study aims to investigate the effect of Naotaifang(NTF) on the proteins associated with microglial polarization and glial scar in the rat model of cerebral ischemia reperfusion injury(CIRI). The CIRI model was established by middle cerebral artery occlusion/reperfusion. The 48 successfully modeled rats were randomized into model 7 d, model 14 d, NTF 7 d, and NTF 14 d groups(n=12). In addition, 12 SD rats were selected as the sham group. The NTF group was administrated with NTF suspension at 27 g·kg~(-1)·d~(-1) by gavage, and the sham, model 7 d, and model 14 d groups were administrated with the same volume of normal saline every day by gavage for 7 and 14 days, respectively. After the intervention, Longa score was evaluated. The infarct volume was measured by 2,3,5-triphenyl-2H-tetrazolium chloride(TTC) staining. Morris water maze and open field tests were carried out to evaluate the spatial learning, memory, cognitive function, and anxiety degree of rats. Hematoxylin-eosin(HE) staining was employed to observe the morphological structure and damage of the brain tissue. The immunofluorescence assay was employed to measure the expression of glial fibrillary acidic protein(GFAP) and glial scar. Western blot was employed to determine the protein levels of GFAP, neurocan, phosphacan, CD206, arginase-1(Arg-1), interleukin(IL)-1β, IL-6, and IL-4. Compared with the sham, model 7 d and model 14 d groups showed cerebral infarction of different degrees, severe pathological injury of cerebral cortex and hippocampus, neurological impairment, reduced spatial learning and memory, cognitive dysfunction, severe anxiety, astrocyte hyperplasia, thickening penumbra glial scar, and up-regulated protein levels of IL-1β, IL-6, GFAP, neurocan, phosphacan, CD206, and Arg-1(P&lt;0.01). Compared with the model group, NTF 7 d and NTF 14 d groups improved spatial learning, memory, and cognitive function, reduced anxiety, improved nerve function, reduced cerebral infarction volume, reduced astrocyte hyperplasia, thinned penumbra glial scar, down-regulated the protein levels of GFAP, neurocan, phosphacan, IL-6, and IL-1β, and up-regulated the protein levels of IL-4, CD206, and Arg-1(P&lt;0.05 or P&lt;0.01). NTF exerts a neuroprotective effect on CIRI by inducing the M2 polarization of microglia, inhibiting inflammatory response, and reducing the formation of glial scar.

Mechanism of astragaloside Ⅳ combined with Panax notoginseng saponins in regulating angiogenesis to treat cerebral ischemia based on network pharmacology and experimental verification

Network pharmacology and animal and cell experiments were employed to explore the mechanism of astragaloside Ⅳ(AST Ⅳ) combined with Panax notoginseng saponins(PNS) in regulating angiogenesis to treat cerebral ischemia. The method of network pharmacology was used to predict the possible mechanisms of AST Ⅳ and PNS in treating cerebral ischemia by mediating angiogenesis. In vivo experiment: SD rats were randomized into sham, model, and AST Ⅳ(10 mg·kg~(-1)) + PNS(25 mg·kg~(-1)) groups, and the model of cerebral ischemia was established with middle cerebral artery occlusion(MCAO) method. AST Ⅳ and PNS were administered by gavage twice a day. the Longa method was employed to measure the neurological deficits. The brain tissue was stained with hematoxylin-eosin(HE) to reveal the pathological damage. Immunohistochemical assay was employed to measure the expression of von Willebrand factor(vWF), and immunofluorescence assay to measure the expression of vascular endothelial growth factor A(VEGFA). Western blot was employed to determine the protein levels of vascular endothelial growth factor receptor 2(VEGFR2), VEGFA, phosphorylated phosphatidylinositol 3-kinase(p-PI3K), and phosphorylated protein kinase B(p-AKT) in the brain tissue. In vitro experiment: the primary generation of rat brain microvascular endothelial cells(rBEMCs) was cultured and identified. The third-generation rBMECs were assigned into control, model, AST Ⅳ(50 μmol·L~(-1)) + PNS(30 μmol·L~(-1)), LY294002(PI3K/AKT signaling pathway inhibitor), 740Y-P(PI3K/AKT signaling pathway agonist), AST Ⅳ + PNS + LY294002, and AST Ⅳ + PNS + 740Y-P groups. Oxygen glucose deprivation/re-oxygenation(OGD/R) was employed to establish the cell model of cerebral ischemia-reperfusion injury. The cell counting kit-8(CCK-8) and scratch assay were employed to examine the survival and migration of rBEMCs, respectively. Matrigel was used to evaluate the tube formation from rBEMCs. The Transwell assay was employed to examine endothelial cell permeability. Western blot was employed to determine the expression of VEGFR2, VEGFA, p-PI3K, and p-AKT in rBEMCs. The results of network pharmacology analysis showed that AST Ⅳ and PNS regulated 21 targets including VEGFA and AKT1 of angiogenesis in cerebral infarction. Most of these 21 targets were involved in the PI3K/AKT signaling pathway. The in vivo experiments showed that compared with the model group, AST Ⅳ + PNS reduced the neurological deficit score(P&lt;0.05) and the cell damage rate in the brain tissue(P&lt;0.05), promoted the expression of vWF and VEGFA(P&lt;0.01) and angiogenesis, and up-regulated the expression of proteins in the PI3K/AKT pathway(P&lt;0.05, P&lt;0.01). The in vitro experiments showed that compared with the model group, the AST Ⅳ + PNS, 740Y-P, AST Ⅳ + PNS + LY294002, and AST Ⅳ + PNS + 740Y-P improved the survival of rBEMCs after OGD/R, enhanced the migration of rBEMCs, increased the tubes formed by rBEMCs, up-regulated the expression of proteins in the PI3K/AKT pathway, and reduced endothelial cell permeability(P&lt;0.05, P&lt;0.01). Compared with the LY294002 group, the AST Ⅳ + PNS + LY294002 group showed increased survival rate, migration rate, and number of tubes, up-regulated expression of proteins in the PI3K/AKT pathway, and decreased endothelial cell permeability(P&lt;0.05,P&lt;0.01). Compared with the AST Ⅳ + PNS and 740Y-P groups, the AST Ⅳ + PNS + 740Y-P group presented increased survival rate, migration rate, and number of tubes and up-regulated expression of proteins in the PI3K/AKT pathway, and reduced endothelial cell permeability(P&lt;0.01). This study indicates that AST Ⅳ and PNS can promote angiogenesis after cerebral ischemia by activating the PI3K/AKT signaling pathway.

Ozone-mediated cerebral protection: Unraveling the mechanism through ferroptosis and the NRF2/SLC7A11/GPX4 signaling pathway

BackgroundThe pathogenesis of brain ischemic/reperfusion (I/R) insult is characterized by neuronal loss due to excessive oxidative stress responses. Ferroptosis, a form of oxidative cell death, can be triggered when the balance between antioxidants and pro-oxidants in cells is disrupted. Ozone, a natural bioactive molecule with antioxidant/anti-apoptotic and pro-autophagic properties, has been shown to enhance the antioxidant system's capacity and ameliorate oxidative stress. However, its role in neuronal ferroptosis remains unclear. Therefore, we investigated the functions and possible mechanisms of ozone in cerebral I/R-induced ferroptotic neuronal death. MethodsA cerebral ischemia-reperfusion injury model was induced in Sprague-Dawley (SD) rats pre-treated with ozone. Intraperitoneal administration of the NRF2 inhibitor ML385, the SLC7A11 inhibitor Erastin, and the GPX4 inhibitor RSL3 was performed one hour prior to model establishment. ResultsOur results showed that ozone preconditioning mitigated neuronal damage caused by cerebral I/R, reduced the severity of neurological deficits, lowered cerebral infarct volume in middle cerebral artery occlusion (MCAO) rats, and decreased the volume of cerebral infarcts. Transmission electron microscopy, immunofluorescence, and Western blotting indicated ferroptosis following MCAO-induced brain damage. MCAO resulted in morphological damage to neuronal mitochondria, increased lipid peroxidation accumulation, and elevated malondialdehyde (MDA) production. Furthermore, MCAO decreased levels of FTH1 and GPX4 (negative regulators of ferroptosis) and increased ACSL4 levels (a positive regulator of ferroptosis). Ozone preconditioning demonstrated a neuroprotective effect by increasing NRF2 nuclear translocation and the expression of SLC7A11 and GPX4. Treatment with ML385, Erastin, and RSL3 significantly reversed ozone preconditioning's protective effect on neuronal ferroptosis. ConclusionOur findings demonstrated that ozone treatment attenuates ferroptosis in a cerebral ischemia/reperfusion injury rat model via the NRF2/SLC7A11/GPX4 pathway, providing a theoretical basis for ozone's potential use as a therapy to prevent ischemic stroke.