Cerebral Ischemia In Rats Research Articles

Nattokinase Attenuated Excitatory Amino Acids and Cytokines Release and Restored Cerebral Blood Flow in a Thrombolytic Focal Cerebral Ischemic Rat Model.

Nattokinase (NK), a protease enzyme present in traditional fermented Japanese food, has shown fibrinolytic properties in vitro as well as in cardiac ischemia. In the present study, the Neuroprotective effect of standardized NK was evaluated in the thrombolytic focal cerebral ischemic model. The parameters of behavioural assessment, cerebral blood flow, inflammatory mediators, excitatory amino acids, and immunohistochemistry were measured to support the NK effect. NK was administered at 150 and 300 mg/kg, and its effects were compared with streptokinase (STK) (100μl/rat). Each mg of NK contains 5.5 Units of the enzyme, which can cause lysis of the fibrin. The results indicate that 7 days of treatment of 300 mg NK restored the cerebral blood flow and prevented the release of cytokine and excitatory amino acids. Similarly, neurological scores were reduced, and grip strength increased significantly with NK treatment. The GFAP and synaptophysin staining of the hippocampus (CA1) and cerebrum have shown recovery of neurons from ischemic damage in comparison to vehicle-treated ischemic-reperfused rats. The NK (300 mg/kg) fibrinolytic effect is comparable to STK treatment. To conclude, NK, a serine protease, protects the brain from ischemic degeneration in thrombolytic cerebral ischemia. Consumption of this Japanese food might exhibit prophylactic activity.

Microglia-mediated endothelial protection: the role of SHPL-49 in ischemic stroke

It was previously shown that SHPL-49, a glycoside derivative of salidroside formed through structural modification, exhibited neuroprotective effects in a rat cerebral ischemia model of permanent middle cerebral artery occlusion (pMCAO). Additionally, SHPL-49 enhanced the mRNA expression of vascular endothelial growth factor-a (Vegf-a) in macrophages. Microglia, functioning as resident macrophages within the brain, promptly respond to cerebral ischemia and engage in interactions with the cells of the Glial-Vascular Unit to orchestrate nerve injury responses. We postulated that the neuroprotective effects of SHPL-49 were mediated through microglia-dependent amelioration of endothelial dysfunction following cerebral ischemia. The present study demonstrates that SHPL-49 effectively mitigated microglia-dependent endothelial dysfunction in the pMCAO model by upregulating the expression of VEGF and suppressing the release of MMP-9 from microglia. Further MRI analyses confirmed that SHPL-49 significantly reduced nerve and endothelial function when microglia were depleted in the brains of pMCAO rats. The above phenomenon was also confirmed in the in vitro experiment investigating microglia-mediated brain endothelial cell function. Furthermore, we discovered that SHPL-49 activates the VEGFR2/Akt/eNOS pathways in endothelial cells and suppresses the p38 MAPK/MMP-9 pathways in microglia cells, thereby facilitating brain endothelial cell protection. Altogether, we have demonstrated that SHPL-49 effectively ameliorates endothelial dysfunction induced by cerebral ischemia through a microglia-dependent mechanism, thereby providing more valuable insights and references for the clinical evaluation of SHPL-49 injection for ischemic stroke.

Zhongfeng decoction attenuates cerebral ischemia-reperfusion injury by inhibiting autophagy via regulating the AGE-RAGE signaling pathway

Ethnopharmacological relevanceTackling phlegm and improving blood circulation is vital in the treatment of ischemic stroke (IS), culminating in the development of Zhongfeng Decoction (ZFD), a method grounded in this approach and serving as an effective therapy for IS. Nonetheless, the defensive mechanism of the ZFD in preventing cerebral ischemia-reperfusion damage remains ambiguous. Aim of the studyDetermine the active ingredients in ZFD that have neuroprotective effects, and identify its mechanism of action against IS. Materials and methodsA cerebral ischemia model in rats was developed, utilizing TTC, Nissl staining, and an oxidative stress kit to evaluate the neuroprotective impact of ZFD on this rat model. Following this, an amalgamation of LC-MS and network pharmacology techniques was employed to pinpoint potential active components, primary targets, and crucial action mechanisms of ZFD in treating IS. Finally, key targets and signaling pathways were detected using qRT-PCR, ELISA, Western blotting, electron microscopy, and other methods. ResultsThrough LC-MS and network analysis, 15 active ingredients and 6 hub targets were identified from ZFD. Analysis of pathway enrichment revealed that ZFD predominantly engages in the AGE-RAGE signaling route. Kaempferol, quercetin, luteolin, baicalein, and nobiletin in ZFD are the main active ingredients for treating IS. In vivo validation showed that ZFD can improve nerve damage in cerebral ischemic rats, reduce the mRNA expression of IL6, SERPINE1, CCL2, and TGFB1 related to inflammation. Furthermore, we also confirmed that ZFD can inhibit the protein expression of AGEs, RAGE, p-IKBα/IKBα, p-NF-κB p65/NF-κB p65, reduce autophagy levels, and thus decrease neuronal apoptosis. ConclusionsThe mechanism of action of ZFD in treating IS primarily includes inflammation suppression, oxidative stress response alleviation, post-stroke cell autophagy and apoptosis regulation, and potential mediation of the AGE-RAGE signaling pathway. This study elucidates how ZFD functions in treating IS, establishing a theoretical basis for its clinical application.

A Novel Biomarker in Experimental Cerebral Ischemia: Junctional Adhesion Molecule-A

Objectives: To investigate the role of blood brain barrier biomarkers for the detection of experimental cerebral ischemia in rats. Methods: Forty adult male Wistar albino rats with a mean age of 4–6 months and an average weight of 350–400 g were used in the study. The rats were divided into five ischemia groups (control, 1.5 h of ischemia, 4.5 h of ischemia, 6 h of ischemia, and 24 h of ischemia). Cerebral ischemia was achieved by unilateral ligating of CCA and ECA at the same time. After surgical preparation and awaiting for appropriate ischemia time we collected blood and brain tissue samples. Then we investigated serum occludin, claudin-5 and JAM-A levels from blood samples and the apoptotic index and percentages of pycnotic nucleus from brain tissues histologically. The obtained data were analyzed using IBM SPSS Statistics software package version 18 and the Jamovi software package. Results: Serum JAM-A level showed a statistically significant difference in all ischemia groups compared with the control group (p

Melittin protects against neural cell damage in rats following ischemic stroke

ObjectiveIn this study, we explored the neuroprotective effect of melittin (MEL) after brain ischemia using a rat model. MethodsThe rats underwent middle cerebral artery occlusion (MCAO) for 60 min and were randomly divided into the control group, saline group, and MEL group. Rats in each group were injected intraperitoneally with MEL one day before MCAO until sacrificed. Morris water maze and rotation test were used to assess locomotor function and cognitive ability. The 9.4 Tesla MRI was used to scan and assess the infarct volume of the rat brains. Immunohistochemistry was used to detect the sites of action of MEL on microglia. Western blot and ELISA were used to measure the effect of MEL on the production of pro-inflammatory cytokines. The effect of MEL on neuronal cell apoptosis was observed by flow cytometry. ResultsCompared with the saline group, MEL treatment significantly increased the density of neurons in the cerebral cortical and reduced the cerebral infarct size after MCAO (33.9 ± 8.8% vs. 15.8 ± 3.9%, P < 0.05). Meanwhile, the time for MEL-treated rats to complete the water maze task on the 11th day after MCAO was significantly shorter than that of rats in the saline group (P < 0.05). MEL treatment also prolonged the rotarod retention time on day 14 after MCAO. Immunohistochemistry analysis showed that MEL inhibited the activation of microglia and suppressed the expression of TNF-α, IL-6, and IL-1β in the brain after ischemia. MEL treatment resulted in a significant decrease in TLR4, MyD88, and NF-κB p65 levels in extracts from the ischemic cerebral cortex. Finally, MEL reduced neuronal apoptosis induced by ischemic stroke (P < 0.05). ConclusionMEL treatment promotes neurological function recovery after cerebral ischemia in rats. These effects are potentially mediated through anti-inflammatory and anti-apoptotic mechanisms.

Burst-Suppression EEG Reactivity to Photic Stimulation-A Translational Biomarker in Hypoxic-Ischemic Brain Injury.

The reactivity of an electroencephalogram (EEG) to external stimuli is impaired in comatose patients showing burst-suppression (BS) patterns following hypoxic-ischemic brain injury (HIBI). We explored the reactivity of BS induced by isoflurane in rat models of HIBI and controls using intermittent photic stimulation (IPS) delivered to one eye. The relative time spent in suppression referred to as the suppression ratio (SR) was measured on the contralateral fronto-occipital cortical EEG channel. The BS reactivity (BSR) was defined as the decrease in the SR during IPS from the baseline before stimulation (SRPRE). We found that BSR increased with SRPRE. To standardize by anesthetic depth, we derived the BSR index (BSRi) as BSR divided by SRPRE. We found that the BSRi was decreased at 3 days after transient global cerebral ischemia in rats, which is a model of brain injury after cardiac arrest. The BSRi was also reduced 2 months after experimental perinatal asphyxia in rats, a model of birth asphyxia, which is a frequent neonatal complication in humans. Furthermore, Oxytocin attenuated BSRi impairment, consistent with a neuroprotective effect in this model. Our data suggest that the BSRi is a promising translational marker in HIBI which should be considered in future neuroprotection studies.

Gastrodin combined with electroacupuncture prevents the development of cerebral ischemia via rebalance of brain-derived neurotrophic factor and interleukin-6 in stroke model rats.

Traditional Chinese medicine (TCM) has long been used to treat various diseases, including cerebral ischemia. The specific molecular mechanism of TCM in the treatment of cerebral ischemia, however, is still unclear. This study investigated the effects of gastrodin, electroacupuncture and their combination on cerebral ischemic rats. We used Nissl staining, immunohistochemical staining and immunoblotting to detect the expression changes of brain-derived neurotrophic factor (BDNF) and interleukin-6 (IL-6) in the frontal cortex. The results showed that the combination therapy of gastrodin and electroacupuncture significantly increased the number of Nissl-positive neurons and improved cell morphology compared with other groups. Mechanistically, we found that the combination of gastrodin and electroacupuncture treatment group can restore the abnormal morphology of neuronal cells caused by cerebral ischemia by rebalancing the expression levels of BDNF and IL-6. Our research indicates that gastrodin combined with electroacupuncture has a significant protective effect on cerebral ischemic injury in rats, possibly by regulating the expression of BDNF and IL-6. This combination therapy is superior to single-drug or electroacupuncture therapy.

Solid lipid nanoparticle: A potent vehicle of the kaempferol for brain delivery through the blood-brain barrier in the focal cerebral ischemic rat

Kaempferol is major flavonoid present in Convolvulus pluricaulis. This phytochemical protects the brain against oxidative stress, neuro-inflammation, neurotoxicity, neurodegeneration and cerebral ischemia induced neuronal destruction. Kaempferol is poorly water soluble. Our study proved that solid lipid nanoparticles (SLNs) were efficient carrier of kaempferol through blood-brain barrier (BBB). Kaempferol was incorporated into SLNs prepared from stearic acid with polysorbate 80 by the process of ultrasonication. Mean particle size and zeta potential of kaempferol loaded solid lipid nanoparticles (K-SLNs) were 451.2 nm and −15.0 mV. Atomic force microscopy showed that K-SLNs were spherical in shape. Fourier transformed infrared microscopy (FTIR) showed that both stearic acid and kaempferol were present in K-SLNs. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) revealed that the matrices of K-SLNs were in untidy crystalline state. Entraptment efficiency of K-SLNs was 84.92%. In-vitro drug release percentage was 93.24%. Kaempferol loaded solid lipid nanoparticles (K-SLNs) showed controlled release profile. In-vitro uptake study showed significant efficiency of K-SLNs to cross blood-brain barrier (BBB). After oral administration into the focal cerebral ischemic rat, accumulation of fluorescent labeled K-SLNs was observed in the brain cortex which confirmed its penetrability into the brain. It significantly decreased the neurological deficit, infarct volume and level of reactive oxygen species (ROS) and decreased the level of pro-inflammatory mediators like NF-κB and p-STAT3. Damaged neurons and brain texture were improved. This study indicated increased bioavailability of kaempferol into the brain tissue through SLNs formulation.

MORPHOLOGICAL CHANGES IN THE HIPPOCAMPUS OF THE RAT BRAIN IN ISCHEMIA AND IN CONDITIONS OF COMBINED PRECONDITIONING

BACKGROUND: Preconditioning is an effective method of increasing the body's resistance to hypoxia/ischemia.&#x0D; AIM: The aim is to evaluate morphological changes in the most hypoxia-sensitive fields of the hippocampus CA1 and CA3 in cerebral ischemia in rats and under conditions of combined preconditioning.&#x0D; MATERIALS AND METHODS. Cerebral ischemia was simulated in rats under anesthesia (8% chloral hydrate solution 400 mg/kg) by bilateral ligation of the common carotid arteries. The combined preconditioning method (CPreC) included the alternate use of two preconditional factors – pharmacological (amtisol at a dose of 25 mg /kg) and hypoxic (hypobaric hypoxia, 410 mmHg, exposure time 60 min). Morphometric assessment of brain damage was performed a day after modeling ischemia in the CA1 and CA3 fields of the hippocampus.&#x0D; RESULTS. KPreK has a positive effect on the morphometric parameters of the brain during its ischemia, increasing the survival of neurons in the early and late periods of ischemia modeling, preventing the formation of necrotically and apoptotically altered neurons, hyperactivation of microglial cells and contributing to the preservation of endotheliocytes. &#x0D; CONCLUSION. KPreK (amtisol + hypobaric hypoxia) has a neuroprotective effect in cerebral ischemia.

Green synthesis, chemical characterization, and protective potentials of silver nanoparticles on the development of cerebrovascular diseases in rat cerebral ischemia reperfusion injury

Thrombolysis or mechanical recanalization are two methods that can be used to restore blood flow after an ischemic stroke. However, it is important to note that in certain situations, reperfusion can actually exacerbate the initial damage caused by ischemia, leading to a condition known as “cerebral reperfusion injury.” This injury involves several pathological processes, including the infiltration of leukocytes, activation of platelets and complement, postischemic hyperperfusion, and disruption of the blood–brain barrier. The main objective of research conducted globally is to create a novel therapeutic medication for stroke. In light of the nano revolution, it is imperative to merge nanoscience and medicine. Knowledge acquired from nature has paved the path for the development of biogenic technologies, facilitating the production of cutting-edge nanomaterials. We have recently conducted a study to evaluate the neuroprotective properties of a blend of Mellisa officinalis leaf extract and green-mediated silver nanoparticles on the development of cerebrovascular diseases in rat cerebral ischemia reperfusion injury. The silver nanoparticles were thoroughly examined using UV–Vis, FE-SEM, and EDX analyses to ensure comprehensive characterization. The Ag NPs were observed to have various polymorphic shapes and were found to be aggregated. Also, the particles average size was measured by ImageJ software and it is about 29.15 nm. The UV–Vis measurements showed that the spectra displayed the highest absorption at around 432 nm. The stroke occurred as a result of the occlusion of the middle cerebral artery for 1.5 h, followed by reperfusion for 2 days. Before the ischemia reperfusion, the rats received an intravenous injection of AgNPs at doses of 40, 80 and 160 µg/kg once daily for a consecutive period of 3 days. The evaluation of the cell damage index involved assessing various factors such as immunoglobulin G (IgG) extravasation into the cerebral parenchyma, lactate dehydrogenase efficacy, serum MDA level, infarct volume, and learning and memory function. The results of the study showed that pretreatment with AgNPs had a protective effect on stroke in animals. Moreover, AgNPs effectively alleviated the memory and learning impairments caused by stroke. Additionally, AgNPs significantly reduced infarct volume, IgG extravasation, serum MDA level, and lactate dehydrogenase efficacy.

Enriched environment treatment promotes neural functional recovery together with microglia polarization and remyelination after cerebral ischemia in rats

BackgroundMicroglia activation and oligodendrocyte maturation are critical for remyelination after cerebral ischemia. Studies have shown that enriched environment (EE) can effectively alleviate stroke-induced neurological deficits. However, little is known about the mechanism associated with glial cells underlying the neuroprotection of EE. Therefore, this study focuses on investigating the effect of EE on activated microglia polarization as well as oligodendrogenesis in the progress of remyelination following cerebral ischemia. MethodsThe ischemia/reperfusion (I/R) injury model was established by middle cerebral artery occlusion (MCAO) in rats. Animals executed 4 weeks of environmental intervention after performing MCAO or sham surgery and were divided into sham, MCAO, and MCAO+EE groups. Cognitive function, myelin damage, microglia activation and polarization, inflammation, oligodendrogenesis, remyelination, and protein expression of the PI3K/AKT/GSK3β signaling pathway were determined. ResultsThe staining of NeuN indicated that the infarct size of MCAO rats was decreased under EE. EE intervention improved animal performance in the Morris water maze test and novel object recognition test, promoting the recovery of cognitive function after I/R injury. EE treatment alleviated myelin damage in MCAO rats, as evidenced by the lower fluorescence intensity ratio of SMI-32/MBP in MCAO+EE group. EE increased the fluorescence intensity ratio of NG2+/Ki67+/Olig2+, MBP, and MOG, enhancing the proliferation and differentiation of OPCs and oligodendrogenesis after MCAO. In terms of remyelination, more myelinated axons and lower G/ratio were detected in MCAO+EE rats compared with MCAO group. Moreover, EE treatment decreased the number of Iba1+/CD86+ M1 microglia, increased the number of Iba1+/CD206+ M2 microglia, and suppressed the inflammation response after I/R injury, which could be attributed to the augmented expression of PI3K/AKT/GSK3β axis. ConclusionEE improved long‑term recovery of cognitive function after cerebral I/R injury, at least in part by promoting M2 microglia transformation through activation of the PI3K/AKT/GSK3β signaling pathway, inhibiting inflammation to provide a favorable microenvironment for oligodendrocyte maturation and remyelination. The effect of the EE on myelin and inflammation could account for the neuroprotection provided by EE.

Abstract WP307: Combinatory Therapy With a PAF-Receptor Antagonist Plus a Lipid Mediator Provides Long-Lasting Protection in Experimental Stroke

Objective: Neuroprotective efficacy observed during short survival periods may not necessarily apply to more extended survival periods, and some stroke-impaired behaviors recover naturally in rodent models 1-2 weeks after stroke. The objective of the present study was to test the hypothesis that acute LAU-0901 plus NPD1-induced neuroprotection endures in animals allowed to survive for several weeks after focal ischemic insult. Two small bioactive molecules were investigated: LAU-0901, a PAF-R antagonist that blocks pro-inflammatory signaling, and neuroprotectin D1 (NPD1), which activates cell-survival pathways, and their combination exerts potent anti-inflammatory activity in the brain. Methods: Male SD rats (290-360g) were subjected to 2h of middle cerebral artery occlusion (MCAo) by the intraluminal filament and treated with vehicle, LAU-0901 (60 mg/kg, IP), NPD1 (222 μg/kg, IV), LAU-0901+NPD1 at 3 h after onset of MCAo. Rats received neurobehavioral examinations during MCAo (60 min) and then on days 1, 2, 3, 7, and weekly during eight weeks survival period, followed by ex vivo MRI on weeks 4 and 8. Results: Physiological variables showed no significant differences among groups. No adverse behavioral side effects were observed after administering LAU-0901, NPD1, or LAU-0901+NPD1. LAU-0901 and NPD1 treatments alone significantly improved the behavior compared to the vehicle group on day 1 (by 32 and 33%), day 7 (38 and 40%), week 4 (38 and 39%), and persisting throughout eight weeks of survival period (by 58 and 44%, respectively). Combinatory treatment with LAU-0901+NPD1 dramatically improved behavior on days 1 (by 37), 2 (by 37%), 3 (by 36%), 7 (40%), and on weeks 4 (by 40%), 5 (44%), 6 (44%), 7 (44%) and 8 (41%) compared to vehicle group. Treatments with LAU-0901, NPD1, and NPD1+RvD1 reduced T2WI lesion volumes on week 4 by 32, 41, and 50% and tissue loss on week 8 by 83, 51, and 50%, respectively, compared to vehicles. Conclusion: These data suggest that LAU-0901 and NPD1 alone provide high-grade neuroprotection in the MCAo model. Combinatory therapy with LAU-0901 plus NPD1 is more effective than the single therapy affording synergistic neuroprotection with improved neurological recovery when administered at 3h after focal cerebral ischemia in rats.

Effect of pretreatment with Devil's Claw on locomotor activity, infarct volume, and neuronal density in focal cerebral ischemia in rats.

Stroke is a highly prevalent and devastating condition affecting millions worldwide. The Devil's Claw (DCW) plant is a native African plant whose anti-inflammatory, antioxidant, and neuroprotective properties have been investigated. We postulated that DCW could protect the brain injury caused by cerebral ischemia. The rats were randomly divided into four groups. The sham and control (Ctrl) groups received pretreatment with a distilled water vehicle. Doses of 200 and 400 mg/kg were selected for pretreatment with DCW. The filament or intravascular occlusion method was used for middle cerebral artery occlusion (MCAO). The Triphenyl tetrazolium chloride (TTC) staining method was used to investigate the infarct zone and penumbra volume. The neuroprotective effect of DCW was measured by hematoxylin staining. Movement performance was evaluated from neurological deficit score, rotarod performance, and open field tests. TTC staining showed that the DCW/400 group could maintain the penumbra's structure and reduce the infarct volume compared to the Ctrl group (p<0.001). Histological studies confirmed the neuroprotective properties of DCW at doses of 200 and 400 mg/kg compared to the Ctrl group (p<0.01 and p<0.0001, respectively). The results of behavioral tests showed an improvement in behavioral performance in pretreatment 400 mg/kg doses compare to Ctrl group (p<0.0001). The study showed that pretreatment with DCW with its neuron protection potential reduces the infarct area and restores motor function after MCAO.

Comparative prototypes and metabolites of Du-zhi pill in normal and cerebral ischemia rats by UHPLC-Q-TOF-MS/MS method

Du-Zhi pill (DZP) is widely used as a Chinese medicine in treating cerebral ischemia. UHPLC-Q-TOF-MS/MS techniques were used to detect and identify the metabolites in rat brain samples of normal and middle cerebral artery occlusion (MCAO) model rats administered with DZP. It was tentatively found that 43 prototypes and 93 metabolites could be identified in rat brain samples. Normal and MCAO model rat brain samples contained 19 prototype components. Eight prototype components were only detected in normal rat brain samples, while 16 were found only in MCAO model rat brain samples. It was determined that 47 metabolites had been identified in the normal rats, while 86 had been placed in MCAO model rats. There were 40 common metabolites in both normal and MCAO model rat brain samples. Seven metabolites were only detected in normal rat brain samples, while 46 were found only in MCAO rat brain samples. The comparison of metabolites in brain samples of normal and MCAO rats showed apparent differences. It was discovered that glucuronidation, methylation, acetylation, and sulfation are phase II metabolic routes of DZP, while hydrogenation, hydroxylation, and dehydroxylation are phase I metabolic routes. Moreover, hydrogenation, glucuronidation, hydroxylation, and methylation were the main metabolic pathways because of the number of metabolites identified in these metabolic pathways. The results provide a valuable reference for further research into effective substances of DZP for treating cerebral ischemia.

Protein inhibitor of activated STAT1 (PIAS1) alleviates cerebral infarction and inflammation after cerebral ischemia in rats

BackgroundIschemic stroke is a severe disorder with high incidence, disability rate and mortality. Multiple pathogenesis mechanisms are involved in ischemic stroke, such as inflammation and neuronal cell apoptosis. Protein inhibitor of activated signal transducer and activators of transcription 1 (PIAS1) plays a crucial role in various biological processes, including inflammation. PIAS1 is also downregulated in ischemia-reperfusion injury and involved in the disease processes. However, the role of PIAS1 in cerebral ischemia is unclear. MethodsSprague-Dawley (SD) rats were induced with middle cerebral artery occlusion (MCAO). The role and mechanisms of PIAS1 in ischemic cerebral infarction were explored by Longa test, 2,3,5-triphenyltetrazolium chloride (TTC) staining, Morris water maze (MWM) test, hematoxylin-eosin (HE) staining, quantification of brain water content, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), Western blot and immunofluorescence assays. ResultsThe expression of PIAS1 in MCAO-induced rat was declined compared to sham rats. Overexpression of PIAS1 reduced the Longa neurological scores, the percent of infarction area, the pathological abnormality, the escape latency of swimming and the percent of brain water content, and increased the number of platform crossings and time in the target quadrant in the MCAO-induced rats. Besides, overexpression of PIAS1 decreased the MCAO-induced the contents of IL-1β, IL-6 and TNF-α, but further elevated the concentrations of IL-10 in both sera and brain tissues. Moreover, overexpression of PIAS1 reversed the MCAO-induced apoptosis rate and the relative protein level of Bax, cleaved caspase3 and Bcl-2. Overexpression of PIAS1 also reversed the level of proteins involved in NF-κB pathway. ConclusionPIAS1 reduced inflammation and apoptosis, thereby alleviating ischemic cerebral infarction in MCAO-induced rats through regulation NF-κB pathway.

Engineered Basic Fibroblast Growth Factor Specifically Bonded with Injectable Extracellular Matrix Hydrogel for the Functional Restoration of Cerebral Ischemia in Rats.

Cerebral ischemia was one of the leading causes of mortality and disability worldwide. Extracellular matrix (ECM) hydrogel held great potential to replace volumetric brain tissue loss following ischemic injury but with limited regenerative effect for functional restoration when implanted alone. In the present study, an engineered basic fibroblast growth factor (EBP-bFGF) was constructed, which fused a specific ECM-binding peptide (EBP peptide) with bFGF. The recombinant EBP-bFGF showed typical binding capacity with ECM without affecting the bioactivity of bFGF both invitro and invivo. Furthermore, the EBP-bFGF was used for bioactive modification of ECM hydrogel to repair cerebral ischemia. The combination of EBP-bFGF and ECM hydrogels could realize the sustained release of bFGF in the ischemic brain and improve the regenerative effect of ECM, which protected the survival of neurons, enhanced angiogenesis, and decreased the permeability of blood-brain barrier, ultimately promoted the recovery of motor function. In addition, transcriptome analysis revealed neuregulin-1/AKT pathway involved in this process. Therefore, EBP-bFGF/ECM hydrogel would be a promising therapeutic strategy for cerebral ischemia.

Synthesis and biological evaluations of 8-biaryl-2,2-dimethylbenzopyranamide derivatives against Alzheimer's disease and ischemic stroke

Alzheimer's disease, the commonest cause of dementia, is a growing global health concern with huge implications for individuals and society. Stroke has still been a significant challenge in clinics for a long time, which is the second leading cause of death in the world, especially ischemic stroke. Both Alzheimer's disease and stroke are closely related to oxidative stress and HIF-1 signaling pathways in nerve cells. Herein, we describe our structure-based design, synthesis, and biological evaluation of a new class of 8-biaryl-2,2-dimethylbenzopyranamide derivatives as natural product derivatives. Our efforts have resulted in the discovery of highly potent neuroprotective agents, as exemplified by compound D13 as a HIF-1α inhibitor, which significant improvement in the behavior of Alzheimer's disease mice and shows great potential improvement of brain infarct volume in pMCAO model rats, improves the increase of blood–brain barrier permeability after cerebral ischemia in rats, neuroprotective effect, reduce the level of apoptotic cells in rats after cerebral ischemia, better than Edaravone.

Rehabilitation facilitates functional improvement following intravenous infusion of mesenchymal stem cells in the chronic phase of cerebral ischemia in rats

The primary objective of this study was to investigate the potential facilitating effects of daily rehabilitation for chronic cerebral ischemia following the intravenous infusion of mesenchymal stem cells (MSC) in rats. The middle cerebral artery (MCA) was occluded by intraluminal occlusion using a microfilament (MCAO). Eight weeks after MCAO induction, the rats were used as a chronic cerebral ischemia model. Four experimental groups were studied: Vehicle group (medium only, no cells); Rehab group (vehicle + rehabilitation), MSC group (MSC only); and Combined group (MSC + rehabilitation). Rat MSCs were intravenously infused eight weeks after MCAO induction, and the rats received daily rehabilitation through treadmill exercise for 20 min. Behavioral testing, lesion volume assessment using magnetic resonance imaging (MRI), and histological analysis were performed during the observation period until 16 weeks after MCAO induction. All treated animals showed functional improvement compared with the Vehicle group; however, the therapeutic efficacy was greatest in the Combined group. The combination therapy is associated with enhanced neural plasticity shown with histological analysis and MRI diffusion tensor imaging. These findings provide behavioral evidence for enhanced recovery by combined therapy with rehabilitation and intravenous infusion of MSCs, and may form the basis for the development of clinical protocols in the future.

Tangeretin confers neuroprotection, cognitive and memory enhancement in global cerebral ischemia in rats.

Global cerebral ischemia is commonly associated with neurological deficits, including cognitive and memory impairments. The present study aims to investigate the neuroprotective, cognitive, and memory enhancement effects of Tangeretin, a flavonoid against global cerebral ischemia in rats. Bilateral common carotid artery occlusion (BCCAO) and reperfusion injury method was used to induce global cerebral ischemia in rats. Motor, cognitive, and memory functions were evaluated using rotarod, grip strength, Y-maze, and Morris water maze. Further, acetylcholine esterase (AchE) enzyme activity, acetylcholine (Ach), oxidative stress markers (ROS, SOD, MDA, and CAT), inflammation (IL-6 and TNF-α), and apoptotic markers (cytochrome C, caspase 9, and caspase 3) in BCCAO rats were measured following Tangeretin (5,10, and 20mg/kg, oral) treatment. Our findings show that Tangeretin treatment significantly improved cognition and memory by enhancing Ach levels through the amelioration of AchE enzyme activity in BCCAO rats. Moreover, Tangeretin exhibited neuroprotective effects through the mitigation of oxidative stress, inflammation, and apoptosis in the BCCAO rats. In summary, the current findings suggested that Tangeretin exhibited neuroprotection, cognitive and memory enhancement against global cerebral ischemia.

Co-activation of NMDAR and mGluRs controls protein nanoparticle-induced osmotic pressure in neurotoxic edema

BackgroundGlutamate stimuli and hyperactivation of its receptor are predominant determinants of ischemia-induced cytotoxic cerebral edema, which is closely associated with protein nanoparticle (PN)-induced increases in osmotic pressure. Herein, we investigated the electrochemical and mechanical mechanisms underlying the neuron swelling induced by PNs via the co-activation of N-methyl-D-aspartate receptor subunit (NMDAR) and excitatory metabotropic glutamate receptors (mGluRs). ResultsWe observed that co-activation of ionic glutamate receptor NMDAR and Group I metabotropic mGluRs promoted alteration of PN-induced membrane potential and increased intracellular osmosis, which was closely associated with calcium and voltage-dependent ion channels. In addition, activation of NMDAR-induced calmodulin (CaM) and mGluR downstream diacylglycerol (DAG)/protein kinase C α (PKCα) were observed to play crucial roles in cytotoxic hyperosmosis. The crosstalk between CaM and PKCα could upregulate the sensitivity and sustained opening of sulfonylurea receptor 1 (SUR1)-transient receptor potential cation channel subfamily M member 4 (TRPM4) and transmembrane protein 16 A (TMEM16A) channels, respectively, maintaining the massive Na+/Cl- influx, and the resultant neuron hyperosmosis and swelling. Intracellular PNs and Na+/Cl- influx were found to be as potential targets for cerebral edema treatment, using the neurocyte osmosis system and a cerebral ischemic rat model. ConclusionsThis study highlights PNs as a key factor in “electrochemistry-tension” signal transduction controlling Na+/Cl- ion channels and increased osmotic pressure in ischemia-induced cytotoxic edema. Moreover, enhanced sensitivity in both Na+ and Cl- ion channels also has a crucial role in cerebral edema.