Acute Cerebral Injury Research Articles

Electroencephalographic monitoring in detection and prediction of delayed cerebral ischemia due to non-traumatic subarachnoid hemorrhage

Intensive care of patients with acute non-traumatic subarachnoid hemorrhage primarily relies on diagnostics of delayed cerebral ischemia (DCI). The major difficulty in detecting DCI emerges upon suppression of wakefulness, when clinical assessment of growing neurological deficit becomes complicated. Widely used transcranial dopplerography allows solely to verify a vasospasm development not always leading to DCI exhibiting a multifactorial underlying mechanism. Electroencephalography (EEG) is the only broadly available instrumental tool ensuring a continuous monitoring of cerebral functional status including in subjects at intensive care unit. To date, non-specific EEG parameters pointing at development of acute cerebral injury were identified that provide varying diagnostic and predictive informative value in DCI. We reviewed publications aimed at assessing the data on visual and quantitative EEG parameters such as regional slowing, alpha rhythm spectral power and relative variability, alpha-to-delta power ratio, and detection of epileptiform activity. Having searched international and Russia-wide medical databases, we found only 7 publications quantitatively assessing diagnostic value of EEG monitoring, which showed that for DCI diagnosis its sensitivity ranged from 76% to 100%, and specificity – from 54% to 100%. We also present a clinical case with a 70-year-old female patient who underwent surgery for non-traumatic subarachnoid hemorrhage due to a ruptured aneurysm of the communicating segment of the right internal carotid artery. During the continuous videoEEG monitoring 2 days before clinical deterioration and appearance of ischemic changes in the right cerebral hemisphere on computed tomography scans, an ictal-interictal continuum pattern was noted to emerge. Future studies should be aimed at clarifying and validating the most informative DCI biomarkers including while recording EEG with intracranial electrodes that may contribute to development of automated algorithms for DCI detection.

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

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

159 PD-1 Agonism as a Strategy to Prevent Neuroinflammation After Acute Large Vessel Occlusion

INTRODUCTION: Stroke is a leading cause of death and long-term disability worldwide. Acute ischemia results in a profound inflammatory response that is counterproductive to short- and long-term recovery. Programmed Death Protein 1 (PD-1) is an immune checkpoint that has been shown to be upregulated after acute cerebral injury, and—upon binding its ligand PD-L1—negatively regulates immune cells to limit the inflammatory response. METHODS: C57BL/6J mice underwent middle cerebral artery occlusion (MCAO) and were randomized into three arms: (1)sham surgery, (2)MCAO control, and (3)MCAO+PD-L1. Survival, brain water content, and volumetric MRI analysis of cerebral edema were measured. Brains were analyzed by flow cytometry to quantify PD-1 expression on infiltrating immune cells. Peripheral blood was harvested for single-cell RNA-sequencing. Blood from stroke patients was collected, and the frequency of PD-1+ monocytes was correlated to clinical outcomes. RESULTS: PD-L1 significantly decreased brain edema as measured by brain water content (p = 0.0277) and high-resolution MRI (p < 0.0001), and improved overall survival (p = 0.0022). PD-1+ monocytes are upregulated in the ischemic hemisphere, and appear to be critical mediators of edema. PD-L1 treatment decreased PD-1+ monocyte infiltration , while global PD-1 (PD-1-/-) and myeloid-specific knockout of PD-1 (PD-1f/fLysMcre) abrogated the treatment effect on edema. Single-cell RNA sequencing and differential expression analysis of peripheral monocytes revealed downregulation of multiple pro-inflammatory pathways in the treated mice versus the controls. Human correlative studies confirmed that PD-1+ monocytes were present in the peripheral blood of MCA stroke patients, and the frequency of this cell population correlated with post-stroke cerebral edema. CONCLUSIONS: Our results support PD-L1 as a novel therapeutic strategy for neuroinflammation and cerebral edema after acute ischemic stroke.

Electroacupuncture suppresses neuronal ferroptosis to relieve chronic neuropathic pain.

Growing evidence supports the analgesic efficacy of electroacupuncture (EA) in managing chronic neuropathic pain (NP) in both patients and NP models induced by peripheral nerve injury. However, the underlying mechanisms remain incompletely understood. Ferroptosis, a novel form of programmed cell death, has been found to be activated during NP development, while EA has shown potential in promoting neurological recovery following acute cerebral injury by targeting ferroptosis. In this study, to investigate the detailed mechanism underlying EA intervention on NP, male Sprague-Dawley rats with chronic constriction injury (CCI)-induced NP model received EA treatment at acupoints ST36 and GV20 for 14 days. Results demonstrated that EA effectively attenuated CCI-induced pain hypersensitivity and mitigated neuron damage and loss in the spinal cord of NP rats. Moreover, EA reversed the oxidative stress-mediated spinal ferroptosis phenotype by upregulating reduced expression of xCT, glutathione peroxidase 4 (GPX4), ferritin heavy chain (FTH1) and superoxide dismutase (SOD) levels, and downregulating increased expression of acyl-CoA synthetase long-chain family member 4 (ACSL4), malondialdehyde levels and iron overload. Furthermore, EA increased the immunofluorescence co-staining of GPX4 in neurons cells of the spinal cord of CCI rats. Mechanistic analysis unveiled that the inhibition of antioxidant pathway of Nrf2 signalling via its specific inhibitor, ML385, significantly countered EA's protective effect against neuronal ferroptosis in NP rats while marginally diminishing its analgesic effect. These findings suggest that EA treatment at acupoints ST36 and GV20 may protect against NP by inhibiting neuronal ferroptosis in the spinal cord, partially through the activation of Nrf2 signalling.

MiRNA-192-5p targets Dyrk1a to attenuate cerebral injury in MCAO mice by suppressing neuronal apoptosis and neuroinflammation.

Ischemic stroke (IS) is a leading cause of disability and mortality worldwide. Several studies have demonstrated the involvement of microRNAs (miRNAs) in brain diseases. miRNA-192-5p is a regulatory molecule in neurodegenerative diseases and its expression was found to be significantly downregulated in the whole blood samples of IS patients, but the specific role of miRNA-192-5p in IS not fully understood. Here, we investigated the role of miRNA-192-5p in a murine model of acute cerebral injury after IS. Male C57BL/6J mice received an intracerebroventricular (i.c.v.) injection of agomir-192-5p or antagomir-192-5p 2 h before middle cerebral artery occlusion (MCAO). Infarct volume was assessed by 2,3,5 triphenyltetrazolium chloride (TTC) staining. Brain slices were subjected to Fluoro-Jade B, TUNEL, and immunofluorescence stainings. Contents of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) were measured using enzyme-linked immunosorbent assay (ELISA) kits. In vitro, murine microglial BV-2 cells were subjected to oxygen-glucose deprivation (OGD), and the contents of pro-inflammatory cytokines were measured in cell lysates. miRNA-192-5p was downregulated in the ischemic penumbra of the cerebral cortex. Pretreatment with agomir-192-5p attenuated neurological deficits and reduced cerebral edema and infarct volume in MCAO mice. Agomir-192-5p-treated animals had fewer degenerating and apoptotic neurons in the ischemic penumbra. Additionally, agomir-192-5p significantly suppressed neuroinflammation as evidenced by decreased immunostaining for GFAP and Iba1 and decreased levels of pro-inflammatory cytokines. Antagomir-192-5p pretreatment showed the opposite effect. Furthermore, dual specificity tyrosine phosphorylation regulated kinase 1A (Dyrk1a) was identified as a target gene of miRNA-192-5p, and the elevated Dyrk1a expression in the ischemic penumbra was markedly reduced by agomir-192-5p. Dyrk1a overexpression in BV-2 microglial cells impaired miRNA-192-5p-mediated inhibition of OGD-induced activation of BV-2 microglial cells. Opposite results were obtained using miRNA-192-5p inhibitor and Dyrk1a siRNA. We found that intracerebroventricular administration of miRNA-192-5p before MCAO attenuatedacute cerebral injury by suppressing neuronal apoptosis and neuroinflammation in mice, and these protective effects might be mediated by downregulation of Dyrk1a. This study would help identify novel therapeutic targets for IS.

PI3K/AKT and STAT3 pathways mediate the neuroprotective effect of dasatinib from acute cerebral injury in endotoxemic mice.

Sepsis induces brain dysfunction and there is still a requirement for an unemployed viable restorative approach. This study aimed to investigate the role of dasatinib in the modulation of proinflammatory mediators, attenuating neuroinflammatory response, and it's signaling pathway during endotoxemia. Twenty-four adult male Swiss-albino mice were randomized into four groups: sham (undergo laparotomy without cecal ligation and puncture, sepsis (laparotomy with cecal ligation and puncture), vehicle-dimethyl sulfoxide, dasatinib (20 mg/kg/day) intraperitoneally. Brain tissue used for assessment of interleukin (IL)-6, IL-1β, tumor necrosis factor-alpha (TNF-α), IL-10, Toll-like receptor 4 (TLR4), protein kinase B (AKT), phosphoinositide 3-kinases (PI3K), signal transducer and activator of transcription 3 (STAT3), and histopathological examination. Brain tissue levels of TNF-α, IL-6, and IL1 β were higher in the sepsis group than in the sham and vehicle groups. The dasatinib group had considerably lower tissue levels of these markers and significantly higher tissue values of IL-10 than the sepsis and vehicle groups. The sham group had much lower tissue values of TLR4, AKT, STAT3, and PI3k than in sepsis and vehicle groups. Furthermore, tissue levels of these markers in the dasatinib group were considerably lower than those in the sepsis and vehicle groups. Histopathology demonstrated that dasatinib might considerably reduce brain damage and the intensity of neuroinflammation when compared to sepsis and vehicle groups that showed extensive brain inflammation and damage. Dasatinib attenuated endotoxemia-induced acute brain damage in mice via modulating effects on TLR4, PI3K, AKT, and STAT3 downstream signaling pathways.

Interaction of heart failure and stroke: A clinical consensus statement of the ESC Council on Stroke, the Heart Failure Association (HFA) and the ESC Working Group on Thrombosis.

Heart failure (HF) is a major disease in our society that often presents with multiple comorbidities with mutual interaction and aggravation. The comorbidity of HF and stroke is a high risk condition that requires particular attention to ensure early detection of complications, efficient diagnostic workup, close monitoring, and consequent treatment of the patient. The bi-directional interaction between the heart and the brain is inherent in the pathophysiology of HF where HF may be causal for acute cerebral injury, and-in turn-acute cerebral injury may induce or aggravate HF via imbalanced neural and neurovegetative control of cardiovascular regulation. The present document represents the consensus view of the ESC Council on Stroke, the Heart Failure Association and the ESC Working Group on Thrombosis to summarize current insights on pathophysiological interactions of the heart and the brain in the comorbidity of HF and stroke. Principal aspects of diagnostic workup, pathophysiological mechanisms, complications, clinical management in acute conditions and in long-term care of patients with the comorbidity are presented and state-of-the-art clinical management and current evidence from clinical trials is discussed. Beside the physicians perspective, also the patients values and preferences are taken into account. Interdisciplinary cooperation of cardiologists, stroke specialists, other specialists and primary care physicians is pivotal to ensure optimal treatment in acute events and in continued long-term treatment of these patients. Key consensus statements are presented in a concise overview on mechanistic insights, diagnostic workup, prevention and treatment to inform clinical acute and continued care of patients with the comorbidity of HF and stroke.

Prospective evaluation of acute cerebral injury by DW-MRI following transcarotid artery revascularization using a double-layer micromesh stent.

Transcervical carotid artery revascularization (TCAR) has demonstrated a low overall stroke rate in carotid artery stenting (CAS). Furthermore, the use of a double-layer micromesh stent is expected to reduce embolization and plaque prolapse. The combination of TCAR and the double layer stent may lead to improved results compared to previously reported outcomes. The objective of this study is to present the findings of a prospective study including patients treated with the Roadsaver stent and TCAR. Between January 2017 and May 2022, 85 patients were enrolled. Every patient underwent TCAR with the Roadsaver stent. As per our protocol, a neurological examination and an ultrasound were performed within 24 hours before and after the procedure, and again 30 days after. A diffusion-weighted magnetic resonance imaging (DW-MRI) was conducted 24 hours before the procedure and 48-72 hours after the procedure. The primary endpoint was the detection of new ischemic lesions on postoperative DW-MRI. The secondary endpoint was a composite of all strokes, death, and myocardial infarction within 30 days. Sixty-four patients (75.29%) were symptomatic, out of which 25 were treated within 14 days of the onset of the symptoms. Pre and postprocedural DW-MRI were performed in 83 patients. Postprocedural lesions were found in nine patients (10.84%). There were no strokes or death within 30 days, but two patients experienced a myocardial infarction. Our study suggests that the use of TCAR and the Roadsaver stent could be a safe alternative to carotid endarterectomy because it entails a low incidence of cerebral embolization, even in recently symptomatic and elderly patients.

Citrate-coated silver nanoparticles loaded with agomelatine provide neuronal therapy in acute cerebral ischemia/reperfusion of rats by inhibiting the oxidative stress, endoplasmic reticulum stress, and P2X7 receptor-mediated inflammasome.

Cerebral ischemia and reperfusion are related to various situations like injuries after various traumas, oxidative stress, increased calcium ion, capillary hypoperfusion, microvascular hyperpermeability, leukocyte infiltration, and blood-brain barrier disruption. An antidepressant Agomelatine which is a melatonin receptor (MT1/MT2) agonist and serotonin receptor (5-HT2C) antagonist has been reported by studies to have antioxidant and anti-inflammatory effects. In our study, we aimed to detect the effects of citrate-coated silver nanoparticle-loaded agomelatine application on neurodegeneration, endoplasmic reticulum stress, autophagic and apoptotic cell death, inflammation, and P2X7R expression in the cerebral ischemia-reperfusion model to facilitate the passage of blood-brain barrier. Forty two Sprague-Dawley rats in total were divided into six equal groups (n:7) and applications were performed. Acute cerebral injury in the ischemia-reperfusion model was created 2 h after internal carotid artery ligation in rats and then at the 2nd hour of reperfusion citrate-coated silver nanoparticles loaded with Agomelatine were applied. Twenty four hours later, neurologic analysis on animals in experimental groups was performed, animals were decapitated and GSH, GPx, SOD, CAT, MDA, IL-1β, and TNF-α parameters were examined after taking blood and the cerebral tissue samples. As a result, it was determined that ischemia-reperfusion caused endoplasmic reticulum stress in the cerebral tissues and thus caused cellular injury.

Ethanol extract of Verbena officinalis alleviates MCAO-induced ischaemic stroke by inhibiting IL17A pathway-regulated neuroinflammation

BackgroundThe prevention and treatment of ischaemic stroke is a worldwide challenge, and effective clinical treatment strategies are lacking. Studies have demonstrated the efficacy of Verbena officinalis in managing cerebrovascular disorders. However, the neuroprotective bioactive components and mechanisms remain unclear. PurposeTo investigate the pharmacological combinatorial components and mechanism underlying the anti-ischemic stroke effect of the ethanol extract of Verbena officinalis (VO Ex). Study design and methodsThe components of VO Ex were identified by HPLC. A middle cerebral artery occlusion (MCAO) induced brain injury model was used to assess the therapeutic effect of VO Ex. The activity of the chemical components of VO Ex was evaluated using a primary astrocyte injury model induced by oxygen-glucose deprivation/reperfusion (OGD/R). RNA sequencing was used to reveal the potential targets of VO Ex against cerebral ischemia–reperfusion injury (CIRI), and the results were verified by qRT-PCR and western blotting. The key components and target binding ability were predicted by molecular docking. Finally, the mechanism of combinatorial components was verified by experiments. ResultsThe HPLC results indicated that the main ingredients of VO Ex were hastatoside, verbenalin, acteoside, luteolin, apigenin and hispidulin. In vivo experiments showed that VO Ex improved MCAO-induced acute cerebral ischemic injury. Transcriptomic data and biological experiments suggested that VO Ex exerted therapeutic effects through IL17A signalling pathways. The in vitro experiments indicated that verbenalin, acteoside, luteolin, apigenin and hispidulin exhibited neuroprotective activities. The novel formula of VALAH, derived from the aforementioned active ingredients, exhibited superior efficacy compared to each individual component. Molecular docking and mechanistic studies have confirmed that VALAH functions in the treatment of ischaemic stroke by suppressing the activation of the IL17A signalling pathway. ConclusionThis work is the first to reveal that VO Ex effectively inhibits the IL17A signaling pathway and mitigates neuroinflammation following ischemic stroke. Moreover, we identified the novel formula VALAH as the bioactive combinatorial components for VO Ex. Further research suggests that the activity of VALAH is associated with IL17A-mediated regulation of neuroinflammation. This finding provides new insights into the efficacious components and mechanisms of traditional Chinese medicine.

Pro‑angiogenic activity of salvianolate and its potential therapeutic effect against acute cerebral ischemia.

Salvianolate (Sal) is a medicinal composition that is widely used in China for the treatment of coronary heart disease and angina pectoris. The aim of the present study was to investigate the potential macrophage-mediated pro-angiogenic effects of Sal in vitro. In addition, another aim was to explore the effects of Sal in a rat model of transient middle cerebral artery occlusion (tMCAO) along with the potential mechanism by which it promotes angiogenesis. In this study, human umbilical vein endothelial cells (HUVECs) and Raw264.7 macrophages in vitro, and a rat tMCAO model in vivo were used to detect the pro-angiogenic effect and mechanism of Sal. The results of in vitro experiments showed that the viability, migration and tube formation of HUVECs were promoted by the supernatant of Sal-treated Raw264.7 macrophages (s-Sal) but not by Sal alone. s-Sal also increased the levels of phosphorylated (p-)VEGFR-2, p-AKT and p-p38 MAPK in HUVECs while Sal alone did not. In vivo, treatment with Sal significantly reduced the cerebral infarction volume and neurological deficit scores in the rat tMCAO model. Similar to the mechanism observed in the in vitro experiments, Sal treatment upregulated the protein expression of VEGF and VEGFR-2, in addition to the phosphorylation of VEGFR-2, AKT and p38, in the brain tissues of the tMCAO model rats. In summary, the results of the present study suggest that the mechanism of Sal-mediated angiogenesis is associated with stimulation of the VEGF/VEGFR-2 signaling pathway by macrophages. This suggests the potential of Sal as a therapeutic option for the treatment of acute cerebral ischemic injury, which may act via the promotion of angiogenesis.

Protective effect and underlying mechanism of muscone on acute cerebral ischemia-reperfusion injury in rats.

Musk is a widely used traditional Chinese medicine, which has resuscitation, activating blood, and disperse swelling effects. Musk is commonly used in the prevention of myocardial infarction and ischemic stroke, and muscone is its main active component. The effect and mechanism of muscone to improve the condition of ischemic stroke is not clear, accordingly, we verified its efficacy in ischemia-reperfused rats, and investigated its mechanism by PC12 and THP-1cells. A transient middle cerebral artery occlusion (tMCAO) rat model was established for in vivo experiments. 2,3,5-Triphenyl Tetrazolium Chloride (TTC) staining was used to calculate infarct rate. Neuroprotection and angiogenesis were assessed by Hematoxylin-eosin (HE) staining, nissl staining, immunofluorescence staining, and quantitative real-time PCR (qRT-PCR). Oxygen glucose deprivation-reperfusion (OGD/R) model of PC12cells was established for neuroprotection analysis, where CCK-8 assay was used to measure cell viability, flow cytometry and Hoechst 33258 staining were used to demonstrate apoptosis, and protein levels were detected by Western blot. For angiogenesis analysis, enzyme-linked immunosorbent assay (ELISA) and qRT-PCR were used to detect angiogenic factors expressed by THP-1. Cell viability assay, scratch wound assay, and tube formation assay were used to evaluate angiogenic effect of HUVECs treated with medium of THP-1. And the angiogenic pathway in HUVECs was detected by Western blot. According to the results, in cerebral ischemia-reperfusion rats, the infarct rate and tissue damage were significantly reduced by muscone, and the expression of neurotrophic factors and angiogenesis-related factors were all elevated. In OGD/R-PC12cell models, muscone could increase cell viability and inhibit apoptosis via Bax/Bcl-2/Caspase-3 pathway. In THP-1-mediated angiogenesis of HUVECs, muscone promoted the secretion of angiogenesis-related factors in THP-1 and thus indirectly promoted the proliferation, migration and tube formation of HUVECs, and then regulated phosphorylation of VEGFR2 and Akt in HUVECs. Our study indicated that muscone may be a potential neuroprotective and proangiogenic agent in cerebral ischemia.

Multi-pathway neuroprotective effects of a novel salidroside derivative SHPL-49 against acute cerebral ischemic injury

SHPL-49 ((2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-(4-(4-methoxyphenyl) butoxy) tetrahydro-2H-pyran-3,4,5-triol) is a novel glycoside derivative obtained from structural modification of salidroside, which is isolated from the medicinal plant Rhodiola rosea L. SHPL-49 was administered to rats with permanent middle cerebral artery occlusion (pMCAO) for 5 days, and it was found that SHPL-49 could alleviate the cerebral infarct volume and reduce the neurological deficit score. Moreover, the effective time window of SHPL-49 in the pMCAO model was from 0.5 to 8 h after embolization. In addition, the result of immunohistochemistry showed that SHPL-49 could increase the number of neurons in the brain tissue and reduce the occurrence of apoptosis. Morris water maze and Rota-rod experiments showed that SHPL-49 could improve neurological deficits, repair neurocognitive and motor dysfunction, and enhance learning and memory ability in the pMCAO model after 14 days of SHPL-49 treatment. Further in vitro experiments showed that SHPL-49 significantly reduced the calcium overload of PC-12 cells and the production of reactive oxygen species (ROS) induced by oxygen and glucose deprivation (OGD), and increased the levels of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), decreased the production of malondialdehyde (MDA). Furthermore, SHPL-49 could reduce cell apoptosis by increasing protein expression ratio of anti-apoptotic factor Bcl-2 to pro-apoptotic factor Bax in vitro. SHPL-49 also regulated the expression of Bcl-2 and Bax in ischemic brain tissue, and even inhibited the caspase cascade of pro-apoptotic proteins Cleaved-caspase 9 and Cleaved-caspase 3. Taken together, SHPL-49 exhibited neuroprotective effects against cerebral ischemic injury through multiple pathways, such as alleviating calcium overload, reducing oxidative stress damage, and inhibiting apoptosis.

Pre exposure to enriched environment alleviates brain injury after ischemia-reperfusion by inhibiting p38MAPK/STAT1 pathway

BackgroundStroke is one of the major diseases that endangers human health. It is widely reported that enriched environment (EE) can improve the neurological function in different brain injury models. Recently, relevant researches have indicated that MAPK pathway is closely related to the inflammatory response in nervous system related diseases. However, whether pre exposure to EE (EE pretreatment) has a preventive effect, and its mechanism are not clear. Therefore, this study aimed to determine the possible benefits and related mechanisms of EE in preventing brain injury after acute ischemia-reperfusion.MethodsAdult Sprague Dawley rats were kept in enriched or standardized environments for 21 days. Then the middle cerebral artery of rats was occluded for one hour and 30 min, and then reperfusion was performed. Then their neurological deficit score was evaluated. Cerebral edema, along with ELISA and protein quantities of p38MAPK, JNK, ERK, IL-1β, TNF-α, and co-localization of Iba1 were assessed. Changes in neuroinflammation and apoptosis were also detected in the penumbra cortex.ResultsOur research showed that EE pretreatment significantly alleviated acute cerebral ischemia-reperfusion injury in rats. Including the reduction of brain edema and apoptosis, and the improvement of neurological scores. In addition, the protein level of p38MAPK was significantly down regulated in EE pretreatment group, and the downstream protein STAT1 had the same trend. In addition, immunofluorescence results showed that Iba1 in EE pretreatment group decreased, the ELISA results showed that the classical proinflammatory cytokines increased significantly, while anti-inflammatory cytokines in EE pretreatment group increased, and the same results were obtained by Western blot analysis.ConclusionOn the whole, our research demonstrated that EE pretreatment can have a protective effect on the organism by inhibiting the p38 MAPK/STAT1 pathway. Thus, EE can be one of the most promising means of disease prevention. Secondly, p38MAPK/STAT1 pathway may be a latent target for the prevention of acute ischemic stroke.

Salvianolic acids for injection alleviates cerebral ischemia-induced neurodegeneration by inhibiting endoplasmic reticulum stress and neuroinflammation

BackgroundCerebral ischemia is one of the leading causes of neurological deficit, dementia, and disability globally. Salvianolic acids for injection (SAFI), a multi-component drug derived from Salvia miltiorrhiza L., has been clinically used in China to treat ischemic stroke. PurposeThis study was designed to investigate the mechanisms of SAFI in alleviating cerebral ischemia-induced neurodegeneration, especially its regulatory effects on excessive ER stress. Basic proceduresThe rat acute cerebral ischemic injury model was established by a 1.5 h occlusion of the middle cerebral artery followed by 24 h of reperfusion. The neurological deficits, neurobehavior, cerebral infarct volume and edema of rats were examined. Hematoxylin and eosin staining, transmission electron microscopy analysis and TUNEL staining were performed to study the brain injury and cell apoptosis. Western blot and immunofluorescence assay were carried out to study the effects and mechanism of SAFI on ischemic injury. Main findingsResults showed that SAFI significantly inhibited the acute neurodegeneration, reduced brain infarct volumes and decreased brain water content of rats. SAFI also downregulated the relative protein levels of Bax/Bcl-2, Bim, Caspase-12, and reduced the number of TUNEL-positive cells in brain tissue, indicating the anti-apoptotic effects of SAFI. Both of immunofluorescence assay and western blot results showed that SAFI downregulated the expression of endoplasmic reticulum (ER) stress maker GRP78. SAFI dramatically inhibited the ER stress-related PERK/eIF2α/ATF4/CHOP and IRE1α/TRAF2/ASK1/JNK signaling pathways. SAFI also alleviated NF-κB triggered inflammatory response, and inhibited the production of IL-6 and IL-β. ConclusionsOur studies indicated that inhibition of excessive ER stress contributes to the protective effects of SAFI against cerebral ischemia-induced neurodegeneration and neuroinflammation.

TJ-M2010-5, a novel CNS drug candidate, attenuates acute cerebral ischemia-reperfusion injury through the MyD88/NF-κB and ERK pathway.

Background: Cerebral ischemia-reperfusion injury (CIRI) inevitably occurs after vascular recanalization treatment for ischemic stroke. The accompanying inflammatory cascades have a major impact on outcome and regeneration after ischemic stroke. Evidences have demonstrated that TLR/MyD88/NF-κB signaling contributes to CIRI. This study aimed to investigate the druggability of MyD88 in the central nervous system (CNS) and the neuroprotective and anti-neuroinflammatory effects of the MyD88 inhibitor TJ-M2010-5 on CIRI. Methods: A middle cerebral artery occlusion (MCAO) model was used to simulate CIRI in mice. BV-2 cells were stimulated with oxygen glucose deprivation/reoxygenation (OGD/R) or lipopolysaccharide, and SH-SY5Y cells were induced by OGD/R in vitro. Neurological deficit scores and cerebral infarction volumes were evaluated. Immunofluorescence staining was performed to measure neuronal damage and apoptosis in the brain. The anti-neuroinflammatory effect of TJ-M2010-5 was evaluated by analyzing the expression of inflammatory cytokines, activation of microglia, and infiltration of peripheral myeloid cells. The expression of proteins of the MyD88/NF-κB and ERK pathway was detected by Simple Western. The concentrations of TJ-M2010-5 in the blood and brain were analyzed by liquid chromatography-mass spectrometry. Results: The cerebral infarction volume decreased in mice treated with TJ-M2010-5, with the most prominent decrease being approximately 80% of the original infarction volume. Neuronal loss and apoptosis were reduced following TJ-M2010-5 treatment. TJ-M2010-5 inhibited the infiltration of peripheral myeloid cells and the activation of microglia. TJ-M2010-5 also downregulated the expression of inflammatory cytokines and inhibited the MyD88/NF-κB and ERK pathway. Furthermore, TJ-M2010-5 showed good blood-brain barrier permeability and no neurotoxicity. Conclusion: TJ-M2010-5 has an excellent therapeutic effect on CIRI as a novel CNS drug candidate by inhibiting excessive neuroinflammatory responses.

Eye acupuncture improves cerebral ischemia reperfusion injury by improving autophagy via ATF6 pathway in cerebral ischemia reperfusion injury rats

To explore the effect of eye acupuncture on autophagy and expressions of autophagy-related proteins Beclin1, LC3B, ATF6 and XBP1 in the infarction area of brain tissue in rats with acute cerebral ischemia-reperfusion injury (CIRI), so as to explore its mechanisms underlying improvement of CIRI. Male SD rats were randomly divided into sham operation, model and eye acupuncture groups (n=16 in each group). The CIRI model was prepared by occlusion of the middle cerebral artery. Eye acupuncture stimulation was applied to bilateral "Gan"(Liver), "Shangjiao"(Upper-energizer), "Xiajiao"(Lower-energizer) and "Shen"(Kidney) regions at 0, 12 and 24 h after CIRI, 30 min each time. The neurological deficit score was given by referring to Longa's method, and TTC staining used to determine the success of model replication. After the treatment, the pathological changes of the cerebral infarction area were observed under light microscope, and the autophagosomes were observed by electron microscope. The protein expression levels of LC3B, Beclin1, ATF6 and XBP1 in the infarction area of brain tissue were detected by Western blot. The immunoactivity of Beclin1 and the immunofluorescence density of ATF6 and XBP1 in the infarction area of brain tissue were determined by immunohistochemistry. The Longa's score, and the protein expression levels of LC3B, Beclin1, ATF6 and XBP1 and immunoactivity or immunofluorescence density of Beclin1, ATF6 and XBP1 were significantly higher in the model group than those in the sham operation group (P<0.01), and considerably lower in the eye acupuncture group than those in the model group (P<0.01). Under light microscope, the model group had typical ethmoidal reticular cerebral infarction, while the eye acupuncture group had significantly smaller areas and clearer edges. Under electron microscope, there were more autophagosomes in the cytoplasm of neurons in the model group, and fewer autophagosomes in the eye acupuncture group (in contrast to the model group). Eye acupuncture can improve the neurological function and mitigate cerebral injury in CIRI rats which may be associated with its function in inhibiting autophagy in the brain tissue by regulating ATF6 pathway.

Rapid chest compression effects on intracranial pressure in patients with acute cerebral injury

BackgroundPatients with acute brain injury often require invasive mechanical ventilation, increasing the risk of developing complications such as respiratory secretions retention. Rapid chest compression is a manual chest physiotherapy technique that aims to improve clearance of secretions in these patients. However, the rapid chest compression technique has been suggested to be associated with increased intracranial pressure in patients with acute brain injury. The aim of this work is to elucidate the effects of the technique on intracranial pressure in mechanically ventilated patients with acute brain injury. Furthermore, the effects of the technique in different volumes and flows recorded by the ventilator and the relationship between the pressure applied in the intervention group and the different variables will also be studied.MethodsRandomized clinical trial, double-blinded. Patients with acute brain injury on invasive mechanical ventilation > 48 h will be included and randomized in two groups. In the control group, a technique of passive hallux mobilization will be applied, and in the intervention group, it will be performed using the rapid chest compression technique. Intracranial pressure (main variable) will be collected with an intracranial pressure monitoring system placed at the lateral ventricles (Integra Camino).DiscussionThe safety of chest physiotherapy techniques in patients at risk of intracranial hyperpressure is still uncertain. The aim of this study is to identify if the rapid manual chest compression technique is safe in ventilated patients with acute brain injury.Trial registrationNCT03609866. Registered on 08/01/2018.

Electroencephalography at the height of a pandemic: EEG findings in patients with COVID-19

ObjectiveTo characterize continuous video electroencephalogram (VEEG) findings of hospitalized COVID-19 patients. MethodsWe performed a retrospective chart review of patients admitted at three New York City hospitals who underwent VEEG at the peak of the COVID-19 pandemic. Demographics, comorbidities, neuroimaging, VEEG indications and findings, treatment, and outcomes were collected. ResultsOf 93 patients monitored, 77% had severe COVID-19 and 40% died. Acute ischemic or hemorrhagic stroke was present in 26% and 15%, respectively. Most common VEEG indications were encephalopathy/coma (60%) and seizure-like movements (38%). Most common VEEG findings were generalized slowing (97%), generalized attenuation (31%), generalized periodic discharges (17%) and generalized sharp waves (15%). Epileptiform abnormalities were present in 43% and seizures in 8% of patients, all of whom had seizure risk factors. Factors associated with an epileptiform VEEG included increasing age (OR 1.07, p = 0.001) and hepatic/renal failure (OR 2.99, p = 0.03). ConclusionsMost COVID-19 patients who underwent VEEG monitoring had severe COVID-19 and over one-third had acute cerebral injury (e.g., stroke, anoxia). Seizures were uncommon. VEEG findings were nonspecific. SignificanceVEEG findings in this cohort of hospitalized COVID-19 patients were those often seen in critical illness. Seizures were uncommon and occurred in the setting of common seizure risk factors.

Circular RNA expression alteration and bioinformatics analysis in patients with acute cerebral infarction injury

ABSTRACT In recent years, a steady increase has been detected in the incidence of acute cerebral infarction (ACI). ACI is caused by blood flow disruption, leading to high disability and mortality rates. Understanding the underlying molecular mechanisms is critical toward developing effective therapeutic approaches. Circular RNAs (circRNAs) are an important class of non-coding RNAs, which have been implicated in several molecular pathways, and their dysregulation has been described in several disease conditions. Here, we set out to explore the possible regulatory role of circRNAs in ischemic stroke and study their molecular function in disease. First, we applied high-throughput sequencing techniques to identify the differential changes of plasma circRNAs expression in patients with acute cerebral infarction. Next, we used GO and KEGG pathway analysis to predict the function of differentially expressed circRNAs. Moreover, we have assessed the possible interaction between the identified differentially expressed circRNAs and miRNAs. Finally, we have selected and validated five downregulated circRNAs by RT-qPCR. Together, the results of this study provide evidence that circRNAs are potential biomarkers for early diagnosis of cerebral infarction and have to be considered as targets for drug treatment.