UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: The study showed that pretreatment with DCW with its neuron protection potential reduces the infarct area and restores motor function after MCAO.

OBJECTIVE: The glymphatic system serves as a perivascular pathway that aids in clearing liquid and solute waste from the brain, thereby enhancing neurological function. Disorders in glymphatic drainage contribute to the development of vasogenic edema following cerebral ischemia, although the molecular mechanisms involved remain poorly understood. This study aims to determine whether a deficiency in dystrophin 71 (DP71) leads to aquaporin-4 (AQP4) depolarization, contributing to glymphatic dysfunction in cerebral ischemia and resulting in brain edema.
METHODS: A mice model of middle cerebral artery occlusion and reperfusion was used. A fluorescence tracer was injected into the cortex and evaluated glymphatic clearance. To investigate the role of DP71 in maintaining AQP4 polarization, an adeno-associated virus with the astrocyte promoter was used to overexpress Dp71. The expression and distribution of DP71 and AQP4 were analyzed using immunoblotting, immunofluorescence, and co-immunoprecipitation techniques. The behavior ability of mice was evaluated by open field test. Open-access transcriptome sequencing data were used to analyze the functional changes of astrocytes after cerebral ischemia. MG132 was used to inhibit the ubiquitin-proteasome system. The ubiquitination of DP71 was detected by immunoblotting and co-immunoprecipitation.
RESULTS: During the vasogenic edema stage following cerebral ischemia, a decline in the efflux of interstitial fluid tracer was observed. DP71 and AQP4 were co-localized and interacted with each other in the perivascular astrocyte endfeet. After cerebral ischemia, there was a notable reduction in DP71 protein expression, accompanied by AQP4 depolarization and proliferation of reactive astrocytes. Increased DP71 expression restored glymphatic drainage and reduced brain edema. AQP4 depolarization, reactive astrocyte proliferation, and the behavior of mice were improved. After cerebral ischemia, DP71 was degraded by ubiquitination, and MG132 inhibited the decrease of DP71 protein level.
CONCLUSIONS: AQP4 depolarization after cerebral ischemia leads to glymphatic clearance disorder and aggravates cerebral edema. DP71 plays a pivotal role in regulating AQP4 polarization and consequently influences glymphatic function. Changes in DP71 expression are associated with the ubiquitin-proteasome system. This study offers a novel perspective on the pathogenesis of brain edema following cerebral ischemia.

BACKGROUND: Astrocytes are the most abundant cell type of the central nervous system and are fundamentally involved in homeostasis, neuroprotection, and synaptic plasticity. This regulatory function of astrocytes on their neighboring cells in the healthy brain is subject of current research. In the ischemic brain we assume disease specific differences in astrocytic acting. The renin-angiotensin-aldosterone system regulates arterial blood pressure through endothelial cells and perivascular musculature. Moreover, astrocytes express angiotensin II type 1 and 2 receptors. However, their role in astrocytic function has not yet been fully elucidated. We hypothesized that the angiotensin II receptors impact astrocyte function as revealed in an in vitro system mimicking cerebral ischemia. Astrocytes derived from neonatal wistar rats were exposed to telmisartan (angiotensin II type 1 receptor-blocker) or PD123319 (angiotensin II type 2 receptor-blocker) under normal conditions (control) or deprivation from oxygen and glucose. Conditioned medium (CM) of astrocytes was harvested to elucidate astrocyte-mediated indirect effects on microglia and cortical neurons.
RESULTS: The blockade of angiotensin II type 1 receptor by telmisartan increased the survival of astrocytes during ischemic conditions in vitro without affecting their proliferation rate or disturbing their expression of S100A10, a marker of activation. The inhibition of the angiotensin II type 2 receptor pathway by PD123319 resulted in both increased expression of S100A10 and proliferation rate. The CM of telmisartan-treated astrocytes reduced the expression of pro-inflammatory mediators with simultaneous increase of anti-inflammatory markers in microglia. Increased neuronal activity was observed after treatment of neurons with CM of telmisartan- as well as PD123319-stimulated astrocytes.
CONCLUSIONS: Data show that angiotensin II receptors have functional relevance for astrocytes that differs in healthy and ischemic conditions and effects surrounding microglia and neuronal activity via secretory signals. Above that, this work emphasizes the strong interference of the different cells in the CNS and that targeting astrocytes might serve as a therapeutic strategy to influence the acting of glia-neuronal network in de- and regenerative context.

Microglia, resident immune cells in the central nervous system (CNS), play a critical role in maintaining CNS homeostasis. However, microglia activated in response to brain injury produce various inflammatory mediators, including nitric oxide (NO) and proinflammatory cytokines, leading to considerable neuronal damage. NO generated by inducible NO synthase (iNOS) rapidly reacts with superoxide to form a highly toxic product, peroxynitrite. Therefore, iNOS is considered to be a putative therapeutic target for cerebral ischemia. Here, we examined the effects of panobinostat (Pano), a histone deacetylase inhibitor, on lipopolysaccharide (LPS)-induced iNOS expression using rat immortalized microglia HAPI cells. Pano inhibited LPS-induced expression of iNOS mRNA and NO production in a dose-dependent manner; however, it had little effect on the LPS-induced activation of c-Jun N-terminal kinase (JNK) and p38 or nuclear translocation of nuclear factor-κB (NF-κB). The interferon-β (IFN-β)/signal transducer and activator of transcription (STAT) pathway is essential for LPS-induced iNOS expression in macrophages/microglia. We also examined the effects of Pano on LPS-induced IFN-β signaling. Pano markedly inhibited LPS-induced IFN-β expression and subsequent tyrosine phosphorylation of STAT1. However, the addition of IFN-β restored the decreased STAT1 phosphorylation but not the decreased iNOS expression. In addition, Pano inhibited the LPS-increased expression of octamer binding protein-2 and interferon regulatory factor 9 responsible for iNOS expression, but IFN-β addition also failed to restore the decreased expression of these factors. Thus, we conclude that the inhibitory effects of Pano are due not only to the inhibition of the IFN-β/STAT axis but also to the downregulation of other factors not involved in this axis.

Microsurgeries are common for complex aneurysms of the middle cerebral artery (MCA).
OBJECTIVE: To evaluate the incidence and types of venous cerebral disorders after microsurgeries for complex MCA aneurysms.
METHODS: A retrospective study included 285 patients with complex MCA aneurysms between 2009 and 2020. Pterional craniotomy and transsylvian approach were used in all cases. Aneurysm clipping was performed in 230 cases, revascularization - 27, trapping without bypass - 17, reinforcement - in 11 cases. Computed tomography within 1-3 days after surgery recognized venous cerebral disorders as heterogeneous foci of abnormal brain density with unclear boundaries. These foci were crescent-shaped as a rule and located in deep and basal parts of the frontal lobes.
RESULTS: Venous abnormalities occurred in 76 (26.7%) patients. Thirty-five (12.3%) patients had mild venous edema of the frontal lobe alone. In 35 (12.3%) patients, we found moderate disorders with focus in the frontal lobe and compression of anterior horn of the left lateral ventricle with or without hemorrhagic imbibition. Severe disorders occurred in 6 (2.1%) patients with lesion extending to the frontal, insular and temporal lobes. These lesions were accompanied by hemorrhagic imbibition, and lateral dislocation exceeded 5 mm.
CONCLUSIONS: Careful dissection of veins in Sylvian fissure with preservation of bridging veins is likely to reduce the risk of this complication. Cauterization of a large vein in Sylvian fissure should be followed by careful hemostasis within frontal or temporal cortex. Bleeding and cortical tension can indicate intracerebral hematoma whose likelihood is higher in patients with venous cerebral disorders.
Для лечения сложных аневризм средних мозговых артерий (СМА) в большинстве случаев применяются микрохирургические операции.
UNASSIGNED: Оценить частоту и виды венозных церебральных нарушений после микрохирургических операций при сложных аневризмах СМА.
UNASSIGNED: В ретроспективное исследование включены 285 пациентов со сложными аневризмами СМА, оперированных в ФГАУ «Национальный медицинский исследовательский центр нейрохирургии им. акад. Н.Н. Бурденко» Минздрава России за период с 2009 по 2020 г. Во всех случаях были использованы птериональная краниотомия и трансильвиевый доступ. Клипирование аневризмы проведено в 230 случаях, реваскуляризирующие операции — в 27, треппинг без байпаса — в 17, укрепление — в 11. К венозным церебральным нарушениям, по данным компьютерной томографии (КТ), выполненной на 1—3-и сутки после операции, были отнесены гетерогенные очаги изменения плотности мозгового вещества с нечеткими границами. Они имели форму полумесяца и чаще располагались в глубинных и базальных отделах лобных долей.
UNASSIGNED: Венозные нарушения отмечены у 76 (26,7%) пациентов. У 35 (12,3%) больных фиксировалась легкая степень венозного отека, которая локализовалась только в лобной доле. У 35 (12,3%) пациентов выявлены умеренные нарушения, при которых наблюдался очаг в лобной доле с компрессией переднего рога левого бокового желудочка с или без геморрагической имбибиции. Выраженные нарушения отмечены у 6 (2,1%) пациентов, при которых очаг распространялся на лобную, островковую и височную доли и сопровождался геморрагической имбибицией, а латеральная дислокация превышала 5 мм.
UNASSIGNED: Аккуратная диссекция вен сильвиевой щели с сохранением мостиковых вен, вероятно, может снизить риск данного осложнения. При коагуляции крупной вены сильвиевой щели следует провести очень тщательный гемостаз в области коры лобной или височной доли. При появлении кровоточивости и напряжения коры следует убедиться в отсутствии внутримозговой гематомы, вероятность которой увеличивается при венозных церебральных нарушениях.

Clinical trials of hypothermia after pediatric cardiac arrest (CA) have not seen robust improvement in functional outcome, possibly because of the long delay in achieving target temperature. Previous work in infant piglets showed that high nasal airflow, which induces evaporative cooling in the nasal mucosa, reduced regional brain temperature uniformly in half the time needed to reduce body temperature. Here, we evaluated whether initiation of hypothermia with high transnasal airflow provides neuroprotection without adverse effects in the setting of asphyxic CA. Anesthetized piglets underwent sham-operated procedures (n=7) or asphyxic CA with normothermic recovery (38.5°C; n=9) or hypothermia initiated by surface cooling at 10 (n=8) or 120 (n=7) minutes or transnasal cooling initiated at 10 (n=7) or 120 (n=7) minutes after resuscitation. Hypothermia was sustained at 34°C with surface cooling until 20 hours followed by 6 hours of rewarming. At four days of recovery, significant neuronal loss occurred in putamen and sensorimotor cortex. Transnasal cooling initiated at 10 minutes significantly rescued the number of viable neurons in putamen, whereas levels in putamen in other hypothermic groups remained less than sham levels. In sensorimotor cortex, neuronal viability in the four hypothermic groups was not significantly different from the sham group. These results demonstrate that early initiation of high transnasal airflow in a pediatric CA model is effective in protecting vulnerable brain regions. Because of its simplicity, portability, and low cost, transnasal cooling potentially could be deployed in the field or emergency room for early initiation of brain cooling after pediatric CA.

OBJECTIVE: Matrix metalloproteinases 9 (MMP9) plays a role in the destruction of blood-brain barrier (BBB) and cell death after cerebral ischemic/reperfusion (I/R). Esculentoside H (EH) is a saponin found in Phytolacca esculenta. It can block JNK1/2 and NF-κB signal mediated expression of MMP9. In this study, we determined whether EH can protect against cerebral I/R injury by inhibiting MMP9 and elucidated the underlying mechanism.
METHODS: Male SD rats were used to construct middle cerebral artery occlusion (MCAO) models. We determined the effect of EH on MMP9 inhibition, BBB destruction, neuronal death, PANoptosis, infarct volume, and the protective factor TLE1. Adeno-associated virus (AAV) infection was used to establish TLE1 gene overexpression and knockdown rats, which were used to determine the function. LY294002 was used to determine the role of PI3K/AKT signaling in TLE1 function.
RESULTS: After EH treatment, MMP9 expression, BBB destruction, neuronal death, and infarct volume decreased. We found that TLE1 expression decreased obviously after cerebral I/R. TLE1-overexpressing rats revealed distinct protective effects to cerebral I/R injury. After treatment with LY294002, the protective effect was inhibited. The curative effect of EH also decreased when TLE1 was knocked down.
CONCLUSIONS: EH alleviates PANoptosis and protects BBB after cerebral I/R via the TLE1/PI3K/AKT signaling pathway. Our findings reveal a novel strategy and new target for treating cerebral I/R injury.

Cerebral ischemic stroke is a serious disease with high mortality and disability rates. However, few neuroprotective drugs have been used for ischemic stroke in the clinic. Two main reasons may be responsible for this failure: difficulty in penetrating the blood-brain barrier (BBB) and easily inactivated in the blood circulation. Ferroptosis, a lipid oxidation-related cell death, plays significant roles in cerebral ischemia-reperfusion injury. We utilized RVG29, a peptide derived from Rabies virus glycoprotein, to obtain BBB-targeted lipid nanoparticles (T-LNPs) in order to investigate whether T-LNPs improved the neuroprotective effects of Ferrostatin-1 (Fer1, an inhibitor of ferroptosis) against cerebral ischemic damage. T-LNPs significantly increased BBB penetration following oxygen/glucose deprivation exposure in an in vitro BBB model and enhanced the fluorescence distribution in brain tissues at 6 h post-administration in a cerebral ischemic murine model. Moreover, T-LNPs encapsulated Fer1 (T-LNPs-Fer1) significantly enhanced the inhibitory effects of Fer1 on ferroptosis by maintaining the homeostasis of NADPH oxidase 4 (NOX4) and glutathione peroxidase 4 (GPX4) signals in neuronal cells after cerebral ischemia. T-LNPs-Fer1 significantly suppressed oxidative stress [heme oxygenase-1 expression and malondialdehyde (the product of lipid ROS reaction)] in neurons and alleviated ischemia-induced neuronal cell death, compared to Fer1 alone without encapsulation. Furthermore, T-LNPs-Fer1 significantly reduced cerebral infarction and improved behavior functions compared to Fer1-treated cerebral ischemic mice after 45-min ischemia/24-h reperfusion. These findings showed that the T-LNPs helped Fer1 penetrate the BBB and improved the neuroprotection of Fer1 against cerebral ischemic damage in experimental stroke, providing a feasible translational strategy for the development of clinical drugs for the treatment of ischemic stroke.

Endogenous brain repair occurs following an ischemic stroke but is transient, thus unable to fully mount a neuroprotective response against the evolving secondary cell death. Finding a treatment strategy that may render robust and long-lasting therapeutic effects stands as a clinically relevant therapy for stroke. Extracellular vesicles appear to be upregulated after stroke, which may represent a candidate target for neuroprotection. In this study, we probed whether transplanted stem cells could enhance the expression of extracellular vesicles to afford stable tissue remodeling in the ischemic stroke brain. Aged rats were initially exposed to the established ischemic stroke model of middle cerebral artery occlusion then received intravenous delivery of either bone marrow-derived mesenchymal stem cell transplantation or vehicle. A year later, the animals were assayed for brain damage, inflammation, and extracellular vesicle expression. Our findings revealed that while core infarction was not reduced, the stroke animals transplanted with stem cells displayed a significant reduction in peri-infarct cell loss that coincided with downregulated Iba1-labeled inflammatory cells and upregulated CD63-positive extracellular vesicles that appeared to be co-localized with GFAP-positive astrocytes. Interestingly, grafted stem cells were not detected at one year post-transplantation period, suggesting that the extracellular vesicles likely originated within the host brain. That long-lasting functional benefits persisted in the absence of surviving transplanted stem cells, but with upregulation of endogenous extracellular vesicles, advances the concept that transplantation of stem cells acutely after stroke propels host extracellular vesicles to the ischemic brain, altogether promoting chronic brain remodeling.

Estrogen receptor (ER) activation by 17-ß estradiol (E2) can attenuate neuronal injury and behavioral impairments following global cerebral ischemia (GCI) in rodents. This study sought to further examine the discrete roles of ERs through characterization of the effects of selective ER activation on post-ischemic pro-inflammatory microglial activation, hippocampal neuronal injury, and anxiety-like behaviors. Forty-six ovariectomized (OVX) adult female Wistar rats received daily s.c injections (100 μg/kg/day) of propylpyrazole triol (PPT; ERα agonist), diarylpropionitrile (DPN; ERβ agonist), G-1 (G-protein coupled ER agonist; GPER), E2 (activating all receptors), or vehicle solution (VEH) for 21 days. After final injection, rats underwent GCI via 4-vessel occlusion (n=8 per group) or sham surgery (n=6, vehicle injections). The Open Field Test (OFT), Elevated Plus Maze (EPM), and Hole Board Test (HBT) assessed anxiety-like behaviors. Microglial activation (Iba1, CD68, CD86) in the basolateral amygdala (BLA), CA1 of the hippocampus, and paraventricular nucleus of the hypothalamus (PVN) was determined 8 days post-ischemia. Compared to sham rats, Iba1 activation and CA1 neuronal injury were increased in all ischemic groups except DPN-treated rats, with PPT-treated ischemic rats also showing increased PVN Iba1-ir expression. Behaviorally, VEH ischemic rats showed slightly elevated anxiety in the EPM compared to sham counterparts, with no significant effects of agonists. While no changes were observed in the OFT, emotion regulation via grooming in the HBT was increased in G-1 rats compared to E2 rats. Our findings support selective ER activation to regulate post-ischemic microglial activation and coping strategies in the HBT, despite minimal impact on hippocampal injury.