Cerebral Water Research Articles

Salidroside ameliorates cerebral ischemic injury and regulates the glutamate metabolism pathway in astrocytes.

Salidroside (SA) is the main active component of Rhodiola rosea L., with potential in treating cardiovascular and cerebrovascular diseases and cerebral ischemia. However, its efficacy and mechanism in cerebral ischemia remain unclear, particularly regarding its effect on glutamate (Glu) metabolism. In this paper, we aimed to investigate the efficacy of SA in treating cerebral ischemia and its pharmacological mechanism. We studied the effects of SA on SD rats with cerebral ischemia, evaluating neurobehavior, cerebral water content, infarct size, and brain microstructure. We also assessed its impact on glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), and glutamate transporter 1 (GLT-1) proteins using immunohistochemistry and Western blot. Additionally, we used SVGp12 cells to simulate cerebral ischemia and measured Glu levels and used Western blot to observe the level of GS and GLT-1. SA improved neural function, reduced infarct size, and regulated GSH and Glu levels in rats. In cell experiments, SA increased cell viability and decreased Glu concentration after ischemia induction. It also regulated the expression of GFAP, GS, and GLT-1. SA alleviates cerebral ischemia-induced injury by acting on astrocytes, possibly through regulating the glutamate metabolic pathway.

Sevoflurane regulates DICER1 expression by targeting miR-192-5p to protect cerebral ischemia-reperfusion injury in rats.

Sevoflurane is considered an effective neuroprotector in cerebral ischemia/reperfusion injury (CIRI). Sevoflurane preconditioning in CIRI, however, remains unknown precisely by its molecular mechanism. The middle cerebral artery occlusion reperfusion (MCAO/R) rat model was established, and neurological function was evaluated by Zea-Longa score. Cerebral water content was determined to assess cerebral edema. Brain pathological condition was observed by hematoxylin and eosin staining, the intact changes of rat neurons were observed by Nissl staining, and neuronal apoptosis was measured by TUNEL staining. In addition, miR-192-5p and DICER1 levels were detected by RT-qPCR or Western blot, and the targeting relationship between miR-192-5p and DICER1 was verified by bioinformatics analysis and luciferase reporting experiment. miR-192-5p was up-regulated and DICER1 was down-regulated in MCAO/R rats. Sevoflurane preconditioning could decrease miR-192-5p and promote DICER1 expression. Sevoflurane preconditioning could alleviate brain tissue injury and neuronal apoptosis in MCAO/R rats. DICER1 expression was negatively regulated by targeting miR-192-5p. Elevating miR-192-5p or suppressing DICER1 rescued the protective effect of sevoflurane preconditioning on MCAO/R rats. Sevoflurane alleviates brain injury in MCAO/R rats via miR-192-5p/DICER1 axis.

Nicotinamide riboside restores nicotinamide adenine dinucleotide levels and alleviates brain injury by inhibiting oxidative stress and neuroinflammation in a mouse model of intracerebral hemorrhage.

Hemorrhagic stroke is a global health problem owing to its high morbidity and mortality rates. Nicotinamide riboside is an important precursor of nicotinamide adenine dinucleotide characterized by a high bioavailability, safety profile, and robust effects on many cellular signaling processes. This study aimed to investigate the protective effects of nicotinamide riboside against collagenase-induced hemorrhagic stroke and its underlying mechanisms of action. An intracerebral hemorrhage model was constructed by stereotactically injecting collagenase into the right striatum of adult male Institute for Cancer Research mice. After 30 minutes, nicotinamide riboside was administered via the tail vein. The mice were sacrificed at different time points for assessments. Nicotinamide riboside reduced collagenase-induced hemorrhagic area, significantly reduced cerebral water content and histopathological damage, promoted neurological function recovery, and suppressed reactive oxygen species production and neuroinflammation. Nicotinamide riboside exerts neuroprotective effects against collagenase-induced intracerebral hemorrhage by inhibiting neuroinflammation and oxidative stress.

Naodesheng Pills Ameliorate Cerebral Ischemia Reperfusion-Induced Ferroptosis via Inhibition of the ERK1/2 Signaling Pathway.

Ferroptosis plays a crucial role in the occurrence and development of cerebral ischemia-reperfusion (I/R) injury and is regulated by mitogen-activated protein kinase 1/2 (ERK1/2). In China, Naodesheng Pills (NDSP) are prescribed to prevent and treat cerebrosclerosis and stroke. However, the protective effects and mechanism of action of NDSP against cerebral I/R-induced ferroptosis remain unclear. We investigated whether NDSP exerts its protective effects against I/R injury by regulating ferroptosis and aimed to elucidate the underlying mechanisms. The efficacy of NDSP was evaluated using a Sprague-Dawley rat model of middle cerebral artery occlusion and an in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) model. Brain injury was assessed using 2,3,5-triphenyltetrazolium chloride (TTC), hematoxylin and eosin staining, Nissl staining, and neurological scoring. Western blotting was performed to determine the expression levels of glutathione peroxidase 4 (GPX4), divalent metal-ion transporter-1 (DMT1), solute carrier family 7 member 11 (SLC7A11), and transferrin receptor 1 (TFR1). Iron levels, oxidative stress, and mitochondrial morphology were also evaluated. Network pharmacology was used to assess the associated mechanisms. NDSP (1.08 g/kg) significantly improved cerebral infarct area, cerebral water content, neurological scores, and cerebral tissue damage. Furthermore, NDSP inhibited I/R- and OGD/R-induced ferroptosis, as evidenced by the increased protein expression of GPX4 and SLC7A11, suppression of TFR1 and DMT1, and an overall reduction in oxidative stress and Fe2+ levels. The protective effects of NDSP in vitro were abolished by the GPX4 inhibitor RSL3. Network pharmacology analysis revealed that ERK1/2 was the core target gene and that NDSP reduced the amount of phosphorylated ERK1/2. NDSP exerts its protective effects against I/R by inhibiting cerebral I/R-induced ferroptosis, and this mechanism is associated with the regulation of ferroptosis via the ERK1/2 signaling pathway.

Cytisine–N-methylene-(5,7,4’-trihydroxy)- isoflavone ameliorates ischemic stroke-induced brain injury in mouse by regulating the oxidative stress and BDNF-Trkb/Akt pathway

BackgroundA novel compound Cytisine–N-methylene-(5,7,4′-trihydroxy)- isoflavone (LY01) found in the Sophora alopecuroides L is a neuroprotective agent. However, the effect and potential mechanism of LY01 treatment for ischemic stroke (IS) have not been fully elucidated. Aim of the studyThe aim of this study is to demonstrate whether LY01 can rescue ischemic stroke-induced brain injury and oxygen–glucose deprivation/reperfusion (OGD/R). ResultsOur results show that intragastric administration of LY01 improves ischemic stroke behaviors in mice, as demonstrated by neurological score, infarct volume, cerebral water content, rotarod test for activity. Compared with the model group, the ginkgo biloba extract (EGb) and LY01 reversed the neurological score, infarct volume, cerebral water content, rotarod test in model mice. Further analysis showed that the LY01 rescued oxidative stress in the model mice, which was reflected in the increased levels of catalase, superoxide dismutase, total antioxidant capacity and decreased levels of malondialdehyde in the serum of the model mice. Moreover, the expression of the brain-derived neurotrophic factor brain-derived neurotrophic factor (BDNF), phosphorylated protein kinase B (p-Akt), Bax, Bcl-2, (p)-tropomysin related kinase B (p-Trkb) was restored and the expression of Bax, glial fibrillary acidic protein (GFAP) in the brains of the model mice was inhibited through LY01 treatment. In the polymerase chain reaction (PCR) data, after giving LY01, the expression in the brains of model mice was that, IL-10 increased and IL-1β, Bax, Bcl-2 decreased. Furthermore, the results indicated that LY01 improved cell viability, reactive oxygen species content, and mitochondrial membrane potential dissipation induced by OGD/R in primary culture of rat cortical neurons. Bax and caspase-3 activity was upregulated compared to the before after treatment with LY01. ConclusionsOur study suggests that LY01 reversed ischemic stroke by reducing oxidative stress and activating the BDNF-TrkB/Akt pathway and exerted a neuroprotective action against OGD/R injury via attenuation, a novel approach was suggested to treat ischemic stroke. Our observations justify the traditional use of LY01 for a treatment of IS in nervous system.

Use of Network Pharmacology and Experiment Validation to Uncover the Mechanism of Jianshen Lishui Prescription in the Treatment of Intracerebral Hemorrhage.

As a Chinese medicinal formula, the Jianshen Lishui prescription has been clinically proven to be effective in treating intracerebral hemorrhage (ICH). Yet, the mechanisms involved are unknown. (1) Network pharmacology analysis: It involved the screening of active components in the Jianshen Lishui prescription, identification of potential targets for these components, and the screening of ICH-related targets. Common targets for both disease and drug were identified. Protein- protein interaction networks were constructed, followed by further screening of core targets. Gene Ontology(GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes( KEGG) pathway enrichment analysis were performed on these core targets. Finally, molecular docking verification was carried out using the active components and core targets. (2) Experimental verification: It was conducted using a rat model of intracerebral hemorrhage. This involved observing neurological deficit scores in the rats and measuring cerebral water content. The effects of Jianshen Lishui prescription on the neurological function, cerebral water content, and brain tissue core targets were observed through HE staining, Western blot and qPCR. (1) In this study, 29 common targets were obtained by intersecting 256 potential drug targets and 642 genes associated with ICH. 9 core targets were obtained by employing the protein- protein interaction (PPI) construction system to screen more specific targets. In addition, the findings revealed that the molecular mechanism of Jianshen Lishui prescription in treating ICH was mainly related to cancer signaling pathways and signal transduction pathways, based on the results of GO and KEGG enrichment analysis. Molecular docking results showed that the active constituent of Jianshen Lishui prescription mannitol has the highest binding activity with KRAS, luteolin, and Poria sterol with AR, INS1 and KRAS, cerebrosterol with GNB1, INS and ESR1, and sitosterol with AR, INS1 and KRAS. (2) Animal experiments verified that Jianshen Lishui prescription significantly alleviated encephaledema and improved nerve functions of the rat model of ICH. And INS1 expression levels were upregulated and the expression levels of AR, KRAS, PTGS2, and ESR1 were down-regulated by the prescription. Jianshen Lishui prescription protects the nerve function of ICH patients by inhibiting inflammation and reducing cerebral edema. This study provides more supportive evidences for the clinical use of traditional Chinese prescriptions in ICH treatment.

Angong Niuhuang Wan ameliorates LPS-induced cerebrovascular edema by inhibiting blood‒brain barrier leakage and promoting the membrane expression of AQP4.

Angong Niuhuang Wan (AGNHW), developed during the Qing dynasty (18th century) for the treatment of consciousness disturbances caused by severe infections, has been used to treat brain edema caused by ischemia‒reperfusion. However, it remains unclear whether AGNHW can ameliorate vascular-origin brain edema caused by lipopolysaccharides (LPS). This study explored the ameliorative effects of AGNHW on LPS-induced cerebrovascular edema in mice, as well as the potential underlying mechanisms. A cerebrovascular edema model was established in male C57BL/6N mice by two intraperitoneal injections of LPS (15mg/kg), at 0 and 24h. AGNHW was administered by gavage at doses of 0.2275g/kg, 0.455g/kg, and 0.91g/kg, 2h after LPS administration. In control mice, normal saline (NS) or AGNHW (0.455g/kg) was administered by gavage 2h after intraperitoneal injection of NS. The survival rate, cerebral water content, cerebral venous FITC-dextran leakage, Evans blue extravasation, and expression of vascular endothelial cadherin (VE-cadherin), zonula occludens-1 (ZO-1), claudin-5, phosphorylated caveolin-1 (CAV-1), and cytomembrane and cytoplasmic aquaporin 1 (AQP1) and aquaporin 4 (AQP4) were evaluated. The cerebral tissue phosphoproteome, blood levels of AGNHW metabolites, and the relationships between these blood metabolites and differentially phosphorylated proteins were analyzed. AGNHW inhibited the LPS-induced decrease in survival rate, increase in cerebral water content, decrease in VE-Cadherin expression and increase in phosphorylated CAV-1 (P-CAV-1). AGNHW treatment increased the expression of AQP4 on astrocyte membrane after LPS injection. AGNHW also inhibited the LPS-induced increases in the phosphorylation of 21 proteins, including protein kinase C-α (PKC-α) and mitogen-activated protein kinase 1 (MAPK1), in the cerebral tissue. Eleven AGNHW metabolites were detected in the blood. These metabolites might exert therapeutic effects by regulating PKC-α and MAPK1. AGNHW can ameliorate cerebrovascular edema caused by LPS. This effect is associated with the inhibition of VE-Cadherin reduction and CAV-1 phosphorylation, as well as the upregulation of AQP4 expression on the astrocyte membrane, following LPS injection.

PSD-95 inhibitor Tat-NR2B9c (NA-1) protects the integrity of the blood-brain barrier after transient middle artery occlusion in rats by downregulating matrix metalloprotease-9 and upregulating endothelial nitric oxide synthase

BackgroundProtection against ischemic stroke may be most effective when multiple components of the neurovascular unit are protected, yet current treatments target mainly neurons. Here we explored whether the PSD-95 inhibitor Tat-NR2B9c (NA-1) can protect not only neurons but also the blood-brain barrier. MethodsAdult male Sprague-Dawley rats were randomly divided into three groups, which were subjected to either sham surgery or transient cerebral ischemia-reperfusion, after which some animals were treated with Tat-NR2B9c. The therapeutic efficacy of Tat-NR2B9c was assessed in terms of the degree of neurological deficit and cerebral infarction, integrity of the blood-brain barrier, cerebral water content, as well as expression of PSD-95, nitric oxide synthase, and matrix metalloprotease-9. ResultsTat-NR2B9c (NA-1) ameliorated neurofunctional deficit, reduced cerebral infarction, mitigated blood-brain barrier injury and improved its integrity following ischemia-reperfusion, leading to less cerebral edema. These improvements were associated with upregulation of tight junction proteins in the blood-brain barrier. At the same time, Tat-NR2B9c (NA-1) downregulated neuronal nitric oxide synthase and matrix metalloprotease-9, while reversing the ischemia-induced downregulation of endothelial nitric oxide synthase in brain. We report here the first evidence that PSD-95 is expressed in vascular endothelial cells in the brain. ConclusionOur experiments in a rat model of transient occlusion of the middle cerebral artery suggest that Tat-NR2B9c (NA-1) can mitigate ischemic injury to the blood-brain barrier, and that it may do so by downregulating matrix metalloprotease-9 and upregulating endothelial nitric oxide synthase.

YangXueQingNaoWan attenuated blood brain barrier disruption after thrombolysis with tissue plasminogen activator in ischemia stroke

Ethnopharmacological relevantYangXueQingNaoWan (YXQNW), a compound Chinese medicine, has been widely used for dizziness, irritability, insomnia, and dreaminess caused by blood deficiency and liver hyperactivity in China. However, whether YXQNW can inhibit cerebral microvascular exudation and cerebral hemorrhage (CH) caused by blood brain barrier (BBB) damage after tissue plasminogen activator (tPA) still unknown. Aim of the researchTo observe the effect of YXQNW on cerebral microvascular exudation and CH after tPA and investigate its mechanism in protecting BBB. Materials and methodsMale C57BL/6 N mice suffered from ischemia stroke by mechanical detachment of carotid artery thrombi with the stimulation of ferric chloride. Then mice were treated with tPA (10 mg/kg) and/or YXQNW (0.72 g/kg) at 4.5 h. Cerebral blood flow (CBF), infarct size, survival rate, neurological scores, gait analysis, Evans blue extravasation, cerebral water content, fluorescein isothiocyanate-labeled albumin leakage, hemorrhage, junction and basement membrane proteins expression, leukocyte adhesion and matrix metalloproteinases (MMPs) expression were evaluated 24 h after tPA. Proteomics was used to identify target proteins. ResultsYXQNW inhibited cerebral infarction, neurobehavioral deficits, decreased survival, Evans blue leakage, albumin leakage, cerebral water content and CH after tPA thrombolysis; improved CBF, low-expression and degradation of junction proteins, basement membrane proteins, Arhgap21 and its downstream α-catenin and β-catenin proteins expression; and suppressed the increase of adherent leukocytes and the release of MMP-9 derived from macrophage. ConclusionYXQNW relieved BBB damage and attenuated cerebral microvascular exudation and CH after tPA thrombolysis. The effect of YXQNW on cerebral microvascular exudation was associated with the inhibition of the low-expression of junction proteins, especially AJs mediated by Rho GTPase-activating protein 21 (Arhgap21), while the effect on CH was associated with the inhibition of leukocyte adhesion, the release of MMP-9 derived from macrophage, and low-expression and degradation of collagen IV and laminin in the vascular basement membrane.

Schisandrin B Protects against Ischemic Brain Damage by Regulating PI3K/AKT Signaling in Rats.

To explore the effect and mechanism of schisandrin B (Sch B) in the treatment of cerebral ischemia in rats. The cerebral ischemia models were induced by middle cerebral artery occlusion (MCAO) and reperfusion. Sprague-Dawley rats were divided into 6 groups using a random number table, including sham, MCAO, MCAO+Sch B (50 mg/kg), MCAO+Sch B (100 mg/kg), MCAO+Sch B (100 mg/kg)+LY294002, and MCAO+Sch B (100 mg/kg)+wortmannin groups. The effects of Sch B on pathological indicators, including neurological deficit scores, cerebral infarct volume, and brain edema, were subsequently studied. Tissue apoptosis was identified by terminal transferase-mediated dUTP nick end-labeling (TUNEL) staining. The protein expressions involved in apoptosis, inflammation response and oxidative stress were examined by immunofluorescent staining, biochemical analysis and Western blot analysis, respectively. The effect of Sch B on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling was also explored. Sch B treatment decreased neurological deficit scores, cerebral water content, and infarct volume in MCAO rats (P<0.05 or P<0.01). Neuronal nuclei and TUNEL staining indicated that Sch B also reduced apoptosis in brain tissues, as well as the Bax/Bcl-2 ratio and caspase-3 expression (P<0.01). Sch B regulated the production of myeloperoxidase, malondialdehyde, nitric oxide and superoxide dismutase, as well as the release of cytokine interleukin (IL)-1 β and IL-18, in MCAO rats (P<0.05 or P<0.01). Sch B promoted the phosphorylation of PI3K and AKT. Blocking the PI3K/AKT signaling pathway with LY294002 or wortmannin reduced the protective effect of Sch B against cerebral ischemia (P<0.05 or P<0.01). Sch B reduced apoptosis, inflammatory response, and oxidative stress of MCAO rats by modulating the PI3K/AKT pathway. Sch B had a potential for treating cerebral ischemia.

Optimizing intra-arterial hypothermia scheme for acute ischemic stroke in an MCAO/R rat model

Hypothermia is a promising neuroprotective treatment. This study aims to explore and optimize the intervention scheme of intra-arterial hypothermia (IAH) in a middle cerebral artery occlusion and reperfusion (MCAO/R) rat model. The MCAO/R model was established with a thread that could be retracted 2 h after occlusion. Cold normal saline was injected into the internal carotid artery (ICA) through a microcatheter in different infusion conditions. Grouping followed an orthogonal design (L9[34]) based on three critical factors closely associated with IAH: perfusate temperature (4, 10, 15 °C), infusion flow rate (1/3, 1/2, 2/3 blood flow rate of ICA), and duration (10, 20, 30 min), resulting in 9 subgroups (H1, H2 to H9). A myriad of indexes were monitored, such as vital signs, blood parameters, changes in local ischemic brain tissue temperature (Tb), ipsilateral jugular venous bulb temperature (Tjvb), and the core temperature of the anus (Tcore). After 24 h and 72 h of cerebral ischemia, cerebral infarction volume, cerebral water content, and neurological function were assessed to explore the optimal IAH conditions. The results revealed that the three critical factors were independent predictors for cerebral infarction volume, cerebral water content, and neurological function. The optimal perfusion conditions were 4 °C, 2/3 RICA (0.50 ml/min) for 20 min, and there was a significant correlation between Tb and Tjvb (R = 0.994, P < 0.001). The vital signs, blood routine tests and biochemical indexes showed no significant abnormal changes. These findings revealed that IAH was safe and feasible with the optimized scheme in an MCAO/R rat model.

Mechanism of miR-125b-5p Carried with Albumin Nanoparticles in Protecting the Injured Nerve Cells in Ischemia-Reperfusion Cerebral Injury

This study assessed the mechanism of miR-125b-5p carried with albumin nanoparticles on injured nerve cells in ischemia-reperfusion cerebral injury. 50 rats were assigned into control set, model set, miR-125b-5p set, IL-6/STAT3 agonist set, and positive control set. The score of neurological impairment, cerebral infarction volume, cerebral water content, apoptosis index of brain cells, synaptic ultrastructure, miR-125b-5p expression, level of IL-6/STAT3 pathway factors, targeting correlation between miR-125b-5p and IL-6 were observed. There was a good dispersibility and uniform size in albumin nanoparticles with an average particle size of 15.5 nanometer. The neurological impairment, cerebral infarction volume, cerebral water content, apoptosis index of brain cells in model set and IL-6/STAT3 agonist set were the highest followed by miR-125b-5p set and positive control set. The level of inflammatory reaction in model set and IL-6/STAT3 agonist set were the highest and oxidative stress were the lowest. miR-125b-5p carried with albumin nanoparticles could directly target on IL-6. The phosphorylation level of IL-6 and STAT3 could be restrained. The activity of IL-6/STAT3 signal pathway could be inhibited, leading to restrained inflammation and oxidative stress in nervous system and reduced cerebral water content, therefore protecting nerve cells. The mechanism might be related with restrained IL-6/STAT3 pathway.

Non-invasive diffuse optical monitoring of cerebral physiology in an adult swine-model of impact traumatic brain injury.

In this study, we used diffuse optics to address the need for non-invasive, continuous monitoring of cerebral physiology following traumatic brain injury (TBI). We combined frequency-domain and broadband diffuse optical spectroscopy with diffuse correlation spectroscopy to monitor cerebral oxygen metabolism, cerebral blood volume, and cerebral water content in an established adult swine-model of impact TBI. Cerebral physiology was monitored before and after TBI (up to 14 days post injury). Overall, our results suggest that non-invasive optical monitoring can assess cerebral physiologic impairments post-TBI, including an initial reduction in oxygen metabolism, development of cerebral hemorrhage/hematoma, and brain swelling.

Probing cerebrospinal fluid mobility for human brain clearance imaging MRI: water transport across the blood-cerebrospinal fluid barrier and mobility of cerebrospinal fluid in perivascular spaces

Background. The growing interest in the brain clearance system in the last decade has led to great insights into how waste clearance via perivascular spaces acts like a lymphatic-like system. However, most of these observations have been done in rodent studies, often with invasive techniques. When aiming to understand the human brain clearance system, the main technology has so far relied on intrathecal injections1 and cerebrospinal fluid (CSF) flow in larger structures like the fourth ventricle2 or the aqueduct. The availability of non-invasive imaging technology would be an important driver to probe human brain clearance in health and disease.&#x0D; Methods. When looking at the current knowledge on brain clearance, it is clear that CSF and interstitial fluid (ISF) are the main solvents that propel waste out of the brain. The insight that CSF and ISF mainly consist of water makes magnetic resonance imaging (MRI) an attractive modality, since many possibilities exist to measure cerebral water dynamics, such as transitions between compartments, as well as water flow/diffusion in sub-compartments. MRI does provide excellent opportunities to image CSF/ISF, due to the long T2 of these compared to background tissue. By using long echo-time imaging, MRI sequences can be tuned towards CSF and ISF. This approach is applied both to arterial spin labeling (ASL) MRI to measure water transport across the blood-CSF barrier, as well as to high spatial resolution imaging at 7 tesla MRI to measure CSF mobility in perivascular spaces.&#x0D; Results. By using ASL that magnetically labels inflowing blood, we could prove that water exchange into CSF is not only taking place in the choroid plexus, but also in the subarachnoid space.3 We refer to the reference for a complete description of the method and results.3 The second technique also exploits long echo times to isolate CSF-signal, but combines this with high spatial resolution readouts and motion-sensitizing gradients to allow measurement of the CSF-mobility in the perivascular spaces of penetrating arteries (Figure 1) and e.g. the subarachnoid space around the MCA. Retrospective triggering allows studying how the cardiac and respiratory cycle influence the CSF-mobility, i.e. the driving forces of propulsion and mixing processes within the perivascular spaces (PVS). Preliminary results show approximately equal contributions from the cardiac and respiratory cycles in smaller PVS.4 Conclusions The exchange of water between the vascular and CSF compartments does not exclusively happen in the choroid plexus, but also in the subarachnoid arteries along the cortex. CSF mobility is influenced both by cardiac and respiratory cycles in approximately equal contributions in the PVS of penetrating arteries.

Tetrandrine alleviates inflammation and neuron apoptosis in experimental traumatic brain injury by regulating the IRE1α/JNK/CHOP signal pathway.

The aim of this study was to investigate the therapeutic roles of Tetrandrine (TET) on traumatic brain injury (TBI) and the underlying mechanism. Traumatic injury model of hippocampal neurons and TBI mouse model were established to evaluate the therapeutic effects. The expression of neuron-specific enolase (NSE), Caspase 3, and Caspase 12 was detected by immunofluorescence. The expression of TNF-α, NF-κB, TRAF1, ERS markers (GADD34 and p-PERK), IRE1α, CHOP, JNK, and p-JNK were evaluated by western blot. Flow cytometry was used to determine the apoptosis of neurons. Brain injury was assessed by Garcia score, cerebral water content, and Evan blue extravasation test. Hematoxylin and eosin staining was used to determine the morphological changes of hippocampal tissue. Apoptosis was assessed by TUNEL staining. In traumatic injury model of hippocampal neurons, TET downregulated NSE, TNF-α, NF-κB, TRAF1, GADD34, p-PERK, IRE1α, CHOP, and p-JNK expression. TET reduced Caspase 3 and Caspase 12 cleavage. Apoptosis rate was inhibited by the introduction of TET. TET improved the Garcia neural score, decreased the cerebral water content and Evans blue extravasation, and reduced NSE, TNF-α, NF-κB, TRAF1, IRE1α, CHOP, and p-JNK expression in mice with TBI, which was significantly reversed by Anisomycin, a JNK selective activator. TET alleviated inflammation and neuron apoptosis in experimental TBI by regulating the IRE1α/JNK/CHOP signal pathway.

Altered Expression of AQP1 and AQP4 in Brain Barriers and Cerebrospinal Fluid May Affect Cerebral Water Balance during Chronic Hypertension.

Hypertension is the leading cause of cardiovascular affection and premature death worldwide. The spontaneously hypertensive rat (SHR) is the most common animal model of hypertension, which is characterized by secondary ventricular dilation and hydrocephalus. Aquaporin (AQP) 1 and 4 are the main water channels responsible for the brain’s water balance. The present study focuses on defining the expression of AQPs through the time course of the development of spontaneous chronic hypertension. We performed immunofluorescence and ELISA to examine brain AQPs from 10 SHR, and 10 Wistar–Kyoto (WKY) rats studied at 6 and 12 months old. There was a significant decrease in AQP1 in the choroid plexus of the SHR-12-months group compared with the age-matched control (p < 0.05). In the ependyma, AQP4 was significantly decreased only in the SHR-12-months group compared with the control or SHR-6-months groups (p < 0.05). Per contra, AQP4 increased in astrocytes end-feet of 6 months and 12 months SHR rats (p < 0.05). CSF AQP detection was higher in the SHR-12-months group than in the age-matched control group. CSF findings were confirmed by Western blot. In SHR, ependymal and choroidal AQPs decreased over time, while CSF AQPs levels increased. In turn, astrocytes AQP4 increased in SHR rats. These AQP alterations may underlie hypertensive-dependent ventriculomegaly.

Silencing of Long Noncoding RNA GAS5 Blocks Experimental Cerebral Ischemia-Reperfusion Injury by Restraining AQP4 Expression via the miR-1192/STAT5A Axis.

The long noncoding RNA (lncRNA) GAS5 has been shown to affect disease development in stroke. This study aimed to elucidate the regulatory mechanism of the lncRNA GAS5 on STAT5A in cerebral ischemia/reperfusion (I/R) injury. First, GAS5 and STAT5A levels in the blood of patients with stroke were determined. Then, a middle cerebral artery occlusion and reperfusion rat model was established in which short hairpin RNAs targeting GAS5 or STAT5A were intracranially injected, followed by the assessment of neurological function, cerebral injury and water content, and inflammation. Primary rat astrocytes were induced with oxygen-glucose deprivation/reoxygenation (OGD/R), and cell proliferation, apoptosis, and inflammation were evaluated. Moreover, the interplay between GAS5, miR-1192, and STAT5A and the binding of STAT5A to the AQP4 promoter were identified. GAS5 and STAT5A were strongly expressed in stroke patients, and inhibition of GAS5 or STAT5A in model rats improved neurological function, reduced infarction and neuronal apoptosis, and diminished cerebral water content and astrocyte activation. Furthermore, GAS5 or STAT5A downregulation restored proliferation and restrained apoptosis and inflammation in OGD/R-induced astrocytes. Mechanistically, GAS5 targeted miR-1192, which negatively regulated STAT5A. Astrocytes showed perturbed proliferation and strengthened apoptosis and inflammation when miR-1192 was inhibited despite the silencing of GAS5, while these unfavorable effects were abolished by STAT5A silencing. STAT5A binds to the AQP4 promoter and regulates its expression. Silencing of GAS5 and overexpresion ofAQP4 led to lower cell viability and higher apoptosis and inflammation than GAS5 silencing alone. Overall, GAS5 silencing inhibited AQP4 through the miR-1192/STAT5A axis, thus alleviating cerebral I/R injury.

Potential cerebrovascular protective functions of lycium barbarum polysaccharide in alleviating hyperglycemia-aggravated cerebral ischemia/reperfusion injury in hyperglycemic rats.

Lycium barbarum polysaccharide (LBP) is the efficient primary compound of Lycium barbarum and has been shown to alleviate hyperglycemia-aggravated cerebral ischemia/reperfusion (I/R) injury. However, the cerebrovascular changes related to diabetes mellitus (DM) and the potential cerebrovascular protective effects of LBP are still unknown. This study aimed to explore the cerebrovascular protective functions of LBP on cerebral I/R injury in diabetic rats and its potential mechanisms. Sprague Dawley (SD) rats were separated into three groups: the normoglycemic (NG), diabetic hyperglycemic (HG), and HG + LBP (50 mg/kg) treatment groups. A 30 min transient middle cerebral artery occlusion (tMCAO) with 24 h reperfusion was established. The neurological deficits, cerebral water content, infarct volume, and cerebrovascular permeability were assessed to evaluate the extent of cerebral injury. Histopathological alterations were assessed by hematoxylin and eosin, Nissl, immunohistochemical, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. A transmission electron microscope was used to detect ultrastructural alterations, and a western blot was used to examine protein expression. The HG rats exhibited a significant increase in neurological deficits, cerebral water content, infarct volume, cerebrovascular permeability, neural cell death, and apoptosis compared with the NG rats, and the LBP treatment alleviated these effects. Cerebrovascular structure analysis showed that the cross-sectional area (CSA) and wall thickness were remarkably altered in the HG rats compared with the NG rats. The LBP treatment protected the cerebrovascular structure and vasoreactivity by decreasing the wall thickness and increasing the CSA, α-smooth muscle actin, and endothelial nitric oxide synthase expression of cerebral vessels. The intake of LBP benefits the cerebrovascular structure and vasoreactivity in diabetic rats. Our research provides a possible new strategy for treating stroke in patients with DM.

TIPE2 attenuates neuroinflammation and brain injury through Bcl-2/Bax/cleaved caspase-3 apoptotic pathways after intracerebral hemorrhage in mice

BackgroundIntracerebral hemorrhage (ICH) is a serious disease with high mortality and morbidity, and effective treatment is limited. A large amount of evidence suggests that the inflammatory response contributes to secondary brain damage following ICH. TIPE2 is an essential negative regulator of both innate and adaptive immunity, and depletion of TIPE2 causes inflammatory disease. However, the possible role of TIPE2 following ICH has not been reported. MethodsIn this study, we investigated TIPE2 levels and inflammation in microglia treated with erythrocyte lysate in vitro. In addition, we analyzed the role of Bcl-2/Bax/cleaved caspase-3 apoptotic pathways in ICH mice. Furthermore, we observed proinflammatory cytokine production, BBB disruption, cerebral water content and neurological damage in ICH mice. ResultsWe found that TIPE2 levels were significantly decreased in erythrocyte lysate-treated microglia compared to control microglia.Upregulation of TIPE2 decreased microglia activation and cytokine production and accelerated brain damage in ICH mice. Furthermore, upregulation of TIPE2 decreased the higher ratio of Blc-2/Bax and increased cleaved caspase-3 levels in ICH mice. In addition, upregulation of TIPE2 attenuated proinflammatory cytokine production, BBB disruption, and severe brain inflammation after ICH. ConclusionThese results demonstrated that TIPE2 was negatively correlated with the pathogenesis of ICH, which prevented brain injury and attenuated deleterious inflammatory responses following ICH. TIPE2 might serve as a novel target for ICH therapy.

The pathogenesis of idiopathic normal pressure hydrocephalus based on the understanding of AQP1 and AQP4.

Idiopathic normal pressure hydrocephalus (iNPH) is a neurological disorder without a recognized cause. Aquaporins (AQPs) are transmembrane channels that carry water through cell membranes and are critical for cerebrospinal fluid circulation and cerebral water balance. The function of AQPs in developing and maintaining hydrocephalus should be studied in greater detail as a possible diagnostic and therapeutic tool. Recent research indicates that patients with iNPH exhibited high levels of aquaporin 1 and low levels of aquaporin 4 expression, suggesting that these AQPs are essential in iNPH pathogenesis. To determine the source of iNPH and diagnose and treat it, it is necessary to examine and appreciate their function in the genesis and maintenance of hydrocephalus. The expression, function, and regulation of AQPs in iNPH are reviewed in this article, in order to provide fresh targets and suggestions for future research.