The influence of the prolactin/vasoinhibin axis on post-stroke lesion volume, astrogliosis, and survival.

Ischemic stroke is a significant global health issue, ranking fifth among all causes of death and a leading cause of serious long-term disability. Ischemic stroke leads to severe outcomes, including permanent brain damage and neuronal dysfunction. Therefore, decreasing and preventing neuronal injuries caused by stroke has been the focus of therapeutic research. In recent years, many studies have shown that fluctuations in hormonal levels influence the prognosis of ischemic stroke. Thus, it is relevant to understand the role of hormones in the pathophysiological mechanisms of ischemic stroke for preventing and treating this health issue. Here, we investigate the contribution of the prolactin/vasoinhibin axis, an endocrine system regulating blood vessel growth, immune processes, and neuronal survival, to the pathophysiology of ischemic stroke. Male mice with brain overexpression of prolactin or vasoinhibin by adeno-associated virus (AAV) intracerebroventricular injection or lacking the prolactin receptor (Prlr-/-) were exposed to transient middle cerebral artery occlusion (tMCAO) for 45 min followed by 48 h of reperfusion. Overexpression of vasoinhibin or the absence of the prolactin receptor led to an increased lesion volume and decreased survival rates in mice following tMCAO, whereas overexpression of prolactin had no effect. In addition, astrocytic distribution in the penumbra was altered, glial fibrillary acidic protein and S100b mRNA expressions were reduced, and interleukin-6 mRNA expression increased in the ischemic hemisphere of mice overexpressing vasoinhibin. Of note, prolactin receptor-null mice (Prlr-/-) showed a marked increase in serum vasoinhibin levels. Furthermore, vasoinhibin decreased astrocyte numbers in mixed hippocampal neuron-glia cultures. These observations suggest that increased vasoinhibin levels may hinder astrocytes' protective reactivity. Overall, this study suggests the involvement of the prolactin/vasoinhibin axis in the pathophysiology of ischemic stroke-induced brain injury and provides insights into the impact of its dysregulation on astrocyte reactivity and lesion size. Understanding these mechanisms could help develop therapeutic interventions in ischemic stroke and other related neurological disorders.

Combination therapy of Epidermal Growth Factor and Growth Hormone-Releasing Hexapeptide in acute ischemic stroke: a phase I/II non-blinded, randomized clinical trial.

Objective: This study tested the hypothesis that a neuroprotective combined therapy based on epidermal growth factor (EGF) and growth hormone-releasing hexapeptide (GHRP6) could be safe for acute ischemic stroke patients, admitting up to 30% of serious adverse events (SAE) with proven causality. Methods: A multi-centric, randomized, open-label, controlled, phase I-II clinical trial with parallel groups was conducted (July 2017 to January 2018). Patients aged 18-80 years with a computed tomography-confirmed ischemic stroke and less than 12 h from the onset of symptoms were randomly assigned to the study groups I (75 µg rEGF + 3.5 mg GHRP6 i.v., n=10), II (75 µg rEGF + 5 mg GHRP6 i.v., n=10), or III (standard care control, n=16). Combined therapy was given BID for 7 days. The primary endpoint was safety over 6 months. Secondary endpoints included neurological (NIHSS) and functional [Barthel index and modified Rankin scale (mRS)] outcomes. Results: The study population had a mean age of 66 ± 11 years, with 21 men (58.3%), a baseline median NIHSS score of 9 (95% CI: 8-11), and a mean time to treatment of 7.3 ± 2.8 h. Analyses were conducted on an intention-to-treat basis. SAEs were reported in 9 of 16 (56.2%) patients in the control group, 3 of 10 (30%) patients in Group I (odds ratio (OR): 0.33; 95% CI: 0.06-1.78), and 2 of 10 (20%) patients in Group II (OR: 0.19; 95% CI: 0.03-1.22); only two events in one patient in Group I were attributed to the intervention treatment. Compliance with the study hypothesis was greater than 0.90 in each group. Patients treated with EGF + GHRP6 had a favorable neurological and functional evolution at both 90 and 180 days, as evidenced by the inferential analysis of NIHSS, Barthel, and mRS and by their moderate to strong effect size. At 6 months, proportion analysis evidenced a higher survival rate for patients treated with the combined therapy. Ancillary analysis including merged treated groups and utility-weighted mRS also showed a benefit of this combined therapy. Conclusion: EGF + GHRP6 therapy was safe. The functional benefits of treatment in this study supported a Phase III study. Clinical Trial Registration: RPCEC00000214 of the Cuban Public Registry of Clinical Trials, Unique identifier: IG/CIGB-845I/IC/1601.

A Brain Ischemia-Reperfusion Model for the Study of Tau Phosphorylation and O-GlcNAcylation.

Cerebral ischemia produces a decrease, loss, or instability of the assembly processes in the neuronal cytoskeleton, related to the alteration in the normal processes of phosphorylation of the Tau protein, triggering its hyperphosphorylation and altering the normal processes of formation of neuronal microtubules. Here we describe the methods used to study the impact of middle cerebral artery occlusion (MCAo) on neurological functions and Tau phosphorylation in Wistar rat brain.

Diferencias cliniconeurológicas en pacientes con enfermedad cerebrovascular isquémica de edades menores y mayores de 65 años

Introducción: La enfermedad cerebrovascular isquémica tiene una alta frecuencia debida, fundamentalmente, al envejecimiento poblacional. Objetivo: Comparar las características clínicas de pacientes con enfermedad cerebrovascular isquémica de dos grupos etarios. Métodos: Se realizó un estudio descriptivo, transversal y retrospectivo en 36 pacientes con enfermedad cerebrovascular isquémica correspondientes a dos grupos etarios (65 y menos años y mayores de 65), quienes fueron atendidos en el Instituto de Neurología y Neurocirugía, La Habana, de enero a diciembre del 2017. Al respecto, se analizaron variables demográficas y clínicas y se aplicaron diferentes pruebas estadísticas para comparar. Resultados: Se obtuvo un aumento significativo de pacientes hipertensos (88,9 %) en el grupo etario mayor de 65 años. La mediana de la escala de ictus del National Institute of Health fue superior en estos pacientes (mediana [10-90 percentil]: 9,5 (4-19]). Hubo incremento estadístico de los mayores de 65 años con parálisis parcial de la mirada y ataxia; en tanto, la monoparesia y la extinción visual predominaron en los de 65 y menos años. Dicha escala mostró un aumento estadístico en el ictus aterotrombótico y cardioembólico en comparación con otras causas en ambos grupos. Los pacientes mayores de 65 años con solo un factor de riesgo o ninguno y los que eran hipertensos tuvieron mayor puntuación de la escala. Conclusiones: El grado de afectación neurológica fue superior en los mayores de 65 años que tenían un factor de riesgo y en aquellos con hipertensión arterial. Puede sugerirse que los mecanismos moleculares y fisiopatológicos de estos pacientes varían según la edad.

Introduction: The ischemic cerebrovascular disease has a high frequency due to the population aging mainly. Objective: To compare clinical characteristics of patients with ischemic cerebrovascular of two age groups. Methods: A descriptive, cross-sectional, retrospective study was carried out in the Neurology and Neurosurgery Institute in Havana, from January to December, 2017 in patients with ischemic cerebrovascular disease; 36 individuals of both age groups. In this regard, demographic variables, risk factors, clinical manifestations, coma scale and neurological deficiency, etiology and localization of the ischemic ictus were analyzed. Results: The 65 years group had a significant increase of hypertensive patients (88.9%). The average of the National Institute of Health stroke scale was superior in these patients (median [10-90 percentile]: 9.5 [4-19]). There was statistical increment of over 65 years patients with partial paralysis of the look and ataxia, but monoparesis and visual extinction in the age under 65 years. Such a scale had a statistical increase in the atherothrombotic and cardioembolic ictus in comparison with other etiologies in both patient groups. The over 65 years patients with just one risk factor or and those with hypertension had a higher punctuation of the scale. Conclusions: The degree of neurological affectation was higher in over 65 years patients that had a risk factor and in those with hypertension. As a result it could be suggested that the molecular and pathophysiolologic mechanisms of these patients vary with the age.

Internal maxillary artery (IMax) - middle cerebral artery bypass in a patient with bilateral atherosclerotic carotid occlusion: A technical case report.

Since the first description of the possible utilization of the internal maxillary artery for bypass surgery, there are some reports of its use in aneurysm cases; however, there is no information about the possible advantages of this type of bypass for cerebral ischemic disease. We present a 77-year-old man with a history of diabetes, hypertension, systemic atherosclerosis, and two acute myocardial infarctions with left hemiparesis. Imaging studies reported total occlusion of the right internal carotid artery and 75% occlusion on the left side, with an old opercular infarction and repeated transient ischemic attacks in the right middle cerebral artery territory despite medical treatment. After a consensus, we decided to perform a bypass from the internal maxillary artery to the M2 segment of the middle cerebral artery using a radial artery graft. After performing the proximal anastomosis, the calculated graft's free flow was 216 ml/min. Subsequently, after completing the bypass, the patency was confirmed with fluorescein videoangiography and intraoperative Doppler. Postoperatively, imaging studies showed improvement in the perfusion values and the hemiparesis from 3/5 to 4+/5. The patient was discharged one week after the operation, with a modified Rankin scale of 1, without added deficits. The use of revascularization techniques in steno-occlusive disease indicates a select group of patients that may benefit from this procedure. In addition, internal maxillary artery bypass has provided a safe option for large areas of ischemia that cannot be supplied with a superficial temporal artery - middle cerebral artery bypass.

Neuroprotective effects of the combined treatment of resveratrol and urapidil in experimental cerebral ischemia-reperfusion injury in rats

ABSTRACT Purpose: To evaluate the neuroprotective effect of resveratrol, urapidil, and a combined administration of these drugs against middle cerebral artery occlusion (MCAO) induced ischemia/reperfusion (IR) injury model in rats. Methods: Thirty-five rats were divided into five groups of seven animals each. Animals in IR, IR resveratrol (IRr), IR urapidil (IRu), and IR + combination of resveratrol and urapidil (IRc) were exposed to MCAO induced cerebral ischemia reperfusion injury model. Rats in IRr and IRu groups received 30-mg/kg resveratrol and 5-mg/kg urapidil respectively. Animals in IRc received a combined treatment of both drugs. At the end of the study, brain tissues were used for oxidative stress (malondialdehyde, glutathione, and superoxide dismutase), pro-apoptotic caspase-3, anti-apoptotic Bcl-2, and pro-inflammatory tumor necrosis factor-α cytokine level measurements. Results: The MCAO model successfully replicated IR injury with significant histopathological changes, elevated tissue oxidative stress, and upregulated apoptotic and inflammatory protein expression in IR group compared to control group (p < 0.001). All parameters were significantly alleviated in IRr group compared to IR group (all p < 0.05). In IRu group, all parameters except for caspase-3 and Bcl-2 were also significantly different than IR group (all p < 0.05). The IRc group showed the biggest difference compared to IR group in all parameters (all p < 0.001). The IRc had higher superoxide dismutase and Bcl-2 levels, and lower caspase-3 levels compared to both IRr and IRu groups (all p < 0.05). Also, the IRc group had lower MDA and TNF-α levels compared to IRu group (all p < 0.05). Conclusions: The results indicate that combined treatment of resveratrol and urapidil may be a novel strategy to downregulate neurodegeneration in cerebral IR injury.

Effects of riboflavin in the treatment of brain damage caused by oxygen deprivation: an integrative systematic review.

Brain oxygen deprivation causes morphological damage involved in the formation of serious pathological conditions such as stroke and cerebral palsy. Therapeutic methods for post-hypoxia/anoxia injuries are limited and still have deficiencies in terms of safety and efficacy. Recently, clinical studies of stroke have reported the use of drugs containing riboflavin for post-injury clinical rehabilitation, however, the effects of vitamin B2 on exposure to cerebral oxygen deprivation are not completely elucidated. This review aimed to investigate the potential antioxidant, anti-inflammatory and neuroprotective effects of riboflavin in cerebral hypoxia/anoxia. After a systematic search, 21 articles were selected, 8 preclinical and 12 clinical studies, and 1 translational study. Most preclinical studies used B2 alone in models of hypoxia in rodents, with doses of 1-20 mg/kg (in vivo) and 0.5-5 µM (in vitro). Together, these works suggested greater regulation of lipid peroxidation and apoptosis and an increase in neurotrophins, locomotion, and cognition after treatment. In contrast, several human studies have administered riboflavin (5 mg) in combination with other Krebs cycle metabolites, except one study, which used only B2 (20 mg). A reduction in lactic acidosis and recovery of sensorimotor functions was observed in children after treatment with B2, while adults and the elderly showed a reduction in infarct volume and cognitive rehabilitation. Based on findings from preclinical and clinical studies, we conclude that the use of riboflavin alone or in combination acts beneficially in correcting the underlying brain damage caused by hypoxia/anoxia and its inflammatory, oxidative, and behavioral impairments.

Correlation between tomographic scales and vasospasm and delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage / Correlación entre escalas tomográficas y vasoespasmo e isquemia cerebral diferida en la hemorragia subaracnoidea aneurismática

ABSTRACT Objective: To determine the prevalence of sonographic vasospasm and delayed ischemic deficit in patients with aneurysmal subarachnoid hemorrhage, to evaluate the correlation between different tomographic scales and these complications, and to study prognostic factors in this group of patients. Methods: This was a prospective study of patients admitted to the intensive care unit with a diagnosis of aneurysmal subarachnoid hemorrhage. The prevalence of sonographic vasospasm and radiological delayed cerebral ischemia was analyzed, as was the correlation between different tomographic scales and these complications. Results: A total of 57 patients were studied. Sixty percent of the patients developed sonographic vasospasm, which was significantly associated with delayed cerebral ischemia and mortality. The Claassen and Hijdra scales were better correlated with the development of cerebral vasospasm (areas under the curve of 0.78 and 0.68) than was Fisher's scale (0.62). Thirty-two patients (56.1%) developed cerebral infarction on CT; the significantly associated factors were poor clinical grade at admission (p = 0.04), sonographic vasospasm (p = 0.008) and severity of vasospasm (p = 0.015). Only the semiquantitative Hijdra scale was significantly correlated with the development of radiological delayed cerebral ischemia (p = 0.009). The patients who presented cerebral infarction had worse neurological evolution and higher mortality. Conclusion: This is the first study in our environment on the subject. The Claassen and Hijdra tomographic scales showed better prognostic performance than the Fisher scale for the development of cerebral vasospasm. The finding of sonographic vasospasm could be a noninvasive criterion for the early detection of delayed cerebral ischemia and neurological deterioration in patients with aneurysmal subarachnoid hemorrhage.

RESUMO Objetivo: Determinar la prevalencia de vasoespasmo sonográfico y déficit isquémico diferido en pacientes con hemorragia subaracnoidea aneurismática, evaluar la correlación entre las diferentes escalas tomográficas con dichas complicaciones, así como estudiar los factores pronósticos en este grupo de pacientes. Métodos: Estudio prospectivo de pacientes ingresados a la unidad de cuidados intensivos con diagnóstico de hemorragia subaracnoidea aneurismática. Se analizó la prevalencia de vasoespasmo sonográfico e isquemia cerebral diferida radiológica, así como la correlación entre diferentes escalas tomográficas con dichas complicaciones. Resultados: Se estudiaron 57 pacientes. El 60% de los pacientes desarrollaron vasoespasmo sonográfico, el cual se asoció significativamente con isquemia cerebral diferida y mortalidad. Las escalas de Claassen y de Hijdra tuvieron una mejor correlación con el desarrollo de vasoespasmo cerebral (área bajo la curva de 0,78 y 0,68) que la de Fisher (0,62). Treinta y dos pacientes (56,1%) desarrollaron infarto cerebral en la TC, siendo los factores que se asociaron en forma estadísticamente significativa al mismo: pobre grado clínico al ingreso (p = 0,04), vasoespasmo sonográfico (p = 0,008) y severidad del vasoespasmo (p = 0,015). Solamente la escala semicuantitativa de Hijdra se correlacionó significativamente con el desarrollo de isquemia cerebral diferida radiológica (p = 0,009). Los pacientes que presentaron infarto cerebral tuvieron peor evolución neurológica y mayor mortalidad. Conclusion: Se presenta el primer estudio en nuestro medio sobre el tema. Las escalas tomográficas de Claassen y Hijdra presentaron un mejor rendimiento pronóstico que la de Fisher para desarrollo de vasoespasmo cerebral. El hallazgo de vasoespasmo sonográfico podría ser un criterio no invasivo de detección temprana de isquemia cerebral diferida y peoría neurológica en los pacientes con hemorragia subaracnoidea aneurismática.

Regulation of Tau protein phosphorylation by glucosamine-induced O-GlcNAcylation as a neuroprotective mechanism in a brain ischemia-reperfusion model.

Purpose:Tau hyperphosphorylation is a modification frequently observed after brain ischemia which has been related to the aggregation of this protein, with subsequent cytoskeletal damage, and cellular toxicity. The present study tests the hypothesis of using glucosamine, an agent that increases protein O-GlcNAcylation, to decrease the levels of phosphorylation in Tau during ischemia-reperfusion.Material and methods: Transient focal ischemia was artificially induced in male Wistar rats by occlusion of the middle cerebral artery (MCAO) with an intraluminal monofilament. A single dose of intraperitoneal glucosamine of 200 mg/kg diluted in normal saline (SSN) was administered 60 min before ischemia. Histological brain sections were processed using indirect immunofluorescence with primary antibodies (anti-O-GlcNAc and anti pTau-ser 396). The Image J software was used to calculate the immunofluorescence signal intensity.Results: The phosphorylation of Tau at the serine residue 396 had a significant decrease with the administration of glucosamine during ischemia-reperfusion compared with the administration of placebo.Conclusions: These results show that glucosamine can reduce the phosphorylation levels of Tau in rodents subjected to ischemia and cerebral reperfusion, which implies a neuroprotective role of glucosamine.

Naringenin attenuates cerebral ischemia/reperfusion injury by inhibiting oxidative stress and inflammatory response via the activation of SIRT1/FOXO1 signaling pathway in vitro

Purpose: To explore the protection of naringenin against oxygen-glucose deprivation/reperfusion (OGD/R)-induced HT22 cell injury, a cell model of cerebral ischemia/reperfusion (I/R) injury in vitro, focusing on SIRT1/FOXO1 signaling pathway. Methods: Cytotoxicity, apoptosis, reactive oxygen species (ROS) generation, malondialdehyde (MDA) content, 4-hydroxynonenoic acid (4-HNE) level, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were measured by commercial kits. Inflammatory cytokines levels were determined by enzyme-linked immunosorbent assay (ELISA). The protein expressions were monitored by Western blot analysis. Results: Naringenin significantly ameliorated OGD/Rinduced cytotoxicity and apoptosis in HT22 cells. Meanwhile, naringenin promoted SIRT1 and FOXO1 protein expressions in OGD/R-subjected HT22 cells. In addition, naringenin attenuated OGD/R-induced cytotoxicity, apoptosis, oxidative stress (the increased ROS, MDA and 4-HNE levels, and the decreased SOD, GSH-Px and CAT activities) and inflammatory response (the increased tumor necrosis factor-α, interleukin [IL]-1ß, and IL-6 levels and the decreased IL-10 level), which were blocked by the inhibition of the SIRT1/FOXO1 signaling pathway induced by SIRT1-siRNA transfection. Conclusion: Naringenin protected HT22 cells against OGD/R injury depending on its antioxidant and anti-inflammatory activities via promoting the SIRT1/FOXO1 signaling pathway.

Cerebrovascular mortality: trend and seasonality in Brazilian capitals, 2000-2019 / Mortalidade cerebrovascular: tendência e sazonalidade nas capitais brasileiras, 2000-2019

ABSTRACT OBJECTIVE To evaluate the trend and seasonality of cerebrovascular mortality rates in the adult population of Brazilian capitals from 2000 to 2019. METHODS This is an ecological and descriptive study of a time series of mortality due to cerebrovascular causes in adults (≥ 18 years) living in Brazilian capitals from 2000 to 2019, based on the Brazilian Mortality Information System. Descriptive statistical techniques were applied in the exploratory analysis of data and in the summary of specific, standardized rates and ratios by sociodemographic characteristics. The jointpoint regression model was used to estimate the trend of cerebrovascular mortality rates by gender, age groups, and geographic regions. The seasonal variability of rates by geographic regions was estimated using the generalized additive model by smoothing cubic splines. RESULTS People aged over 60 years comprised 77% of all cerebrovascular deaths. Women (52%), white individuals (47%), single people (59%), and those with low schooling (57%, elementary school) predominated in our sample. Recife (20/1,000 inhab.) and Vitória (16/1,000 inhab.) showed the highest crude mortality rates. Recife (49/10,000 inhab.) and Palmas (47/10,000 inhab.) prevailed after we applied standardized rates. Cerebrovascular mortality rates in Brazil show a favorable declining trend for adults of all genders. Seasonality influenced rate increase from July to August in almost all region capitals, except in the North, which rose in March, April, and May. CONCLUSIONS Deaths due to cerebrovascular causes prevailed in older single adults with low schooling. The trend showed a tendency to decline and winter, the greatest risk. Regional differences can support decision-makers in implementing public policies to reduce cerebrovascular mortality.

RESUMO OBJETIVO Avaliar a tendência e a sazonalidade das taxas de mortalidade cerebrovascular na população adulta das capitais brasileiras de 2000 a 2019. MÉTODOS Estudo ecológico e descritivo de séries temporais de mortalidade por causas cerebrovasculares em adultos (≥ 18 anos) residentes nas capitais do Brasil no período 2000-2019, obtidas do Sistema de Informações sobre Mortalidade. Técnicas de estatística descritiva foram aplicadas na análise exploratória dos dados e no resumo de taxas específicas, padronizadas e razões por características sociodemográficas. A regressão de pontos de junção (jointpoint regression model) estimou a tendência das taxas de mortalidade cerebrovascular por sexo, grupos etários e regiões geográficas. A variabilidade sazonal por regiões geográficas das taxas foi estimada utilizando o modelo aditivo generalizado por meio de splines de suavização cúbica. RESULTADOS As pessoas maiores de 60 anos representaram 77% dos óbitos cerebrovasculares. Predominaram o sexo feminino (52%), a raça branca (47%), os solteiros (59%) e a baixa escolaridade (57%, ensino fundamental). As capitais Recife (20/1.000 hab.) e Vitória (16/1.000 hab.) apresentaram as maiores taxas brutas de mortalidade. Aplicando as taxas padronizadas Recife (49/10.000 hab.) e Palmas (47/10.000 hab.) prevaleceram. As taxas de mortalidade cerebrovascular no Brasil apresentam uma tendência favorável ao declínio em ambos os sexos e em adultos. A sazonalidade mostrou influenciar na elevação das taxas entre os meses de julho a agosto em quase todas as capitais das regiões, exceto na Norte, que se elevaram nos meses de março, abril e maio. CONCLUSÕES Os óbitos por causa cerebrovascular prevaleceram em pessoas idosas, solteiras e com baixa escolaridade. A tendência foi favorável ao declínio, sendo o inverno o período de maior risco. As diferenças regionais permitem subsidiar os tomadores de decisões em relação à implementação de políticas públicas para reduzir a mortalidade cerebrovascular.

Fasudil mediates neuroprotection in ischemia/reperfusion by modulating the ROCK-PPARα-NOX axis

Purpose: Cerebral ischemia-reperfusion (I/R) is a neurovascular disorder that leads to brain injury. In mice, Fasudil improves nerve injury induced by I/R. However, it is unclear if this is mediated by increased peroxisome proliferator-activated receptor-α (PPARα) expression and reduced oxidative damage. This study aimed to investigate the neuroprotective mechanism of action of Fasudil. Methods: MCAO (Middle cerebral artery occlusion) was performed in male C57BL/6J wild-type and PPARα KO mice between September 2021 to April 2023. Mice were treated with Fasudil and saline; 2,3,5-Triphenyltetrazolium chloride (TTC) staining was performed to analyze cerebral infarction. PPARα and Rho-associated protein kinase (ROCK) expression were detected using Western blot, and the expression of NADPH subunit Nox2 mRNA was detected using real-time polymerase chain reaction. The NADPH oxidase activity level and reactive oxygen species (ROS) content were also investigated. Results: After cerebral ischemia, the volume of cerebral necrosis was reduced in wild-type mice treated with Fasudil. The expression of PPARα was increased, while ROCK was decreased. Nox2 mRNA expression, NADPH oxidase activity, and ROS content decreased. There were no significant changes in cerebral necrosis volumes, NADPH oxidase activity, and ROS content in the PPARα KO mice treated with Fasudil. Conclusions: In mice, the neuroprotective effect of Fasudil depends on the expression of PPARα induced by ROCK-PPARα-NOX axis-mediated reduction in ROS and associated oxidative damage.

Novel Insights into the Molecular Mechanisms Involved in the Neuroprotective Effects of C-Phycocyanin against Brain Ischemia in Rats.

BACKGROUND: Ischemic stroke produces a large health impact worldwide, with scarce therapeutic options. OBJECTIVE: This study aimed to reveal the role of NADPH oxidase and neuroinflammatory genes in the cerebral anti-ischemic effects of C-Phycocyanin (C-PC), the chief biliprotein of Spirulina platensis. METHODS: Rats with either focal cerebral ischemia/reperfusion (I/R) or acute brain hypoperfusion, received C-PC at different doses, or a vehicle, for up to 6 h post-stroke. Neurological, behavioral and histochemical parameters were assessed in I/R rats at 24 h. Cerebral gene expression and hippocampal neuron viability were evaluated in hypoperfused rats at acute (24 h) or chronic phases (30 days), respectively. A molecular docking analysis of NOX2 and C-PC-derived Phycocyanobilin (PCB) was also performed. RESULTS: C-PC, obtained with a purity of 4.342, significantly reduced the infarct volume and neurological deficit in a dose-dependent manner, and improved the exploratory activity of I/R rats. This biliprotein inhibited NOX2 expression, a crucial NADPH oxidase isoform in the brain, and the superoxide increase produced by the ischemic event. Moreover, C-PC-derived PCB showed a high binding affinity in silico with NOX2. C-PC downregulated the expression of pro-inflammatory genes (IFN-γ, IL-6, IL-17A, CD74, CCL12) and upregulated immune suppressive genes (Foxp3, IL-4, TGF-ß) in hypoperfused brain areas. This compound also decreased chronic neuronal death in the hippocampus of hypoperfused rats. CONCLUSION: These results suggest that the inhibition of cerebral NADPH oxidase and the improvement of neuroinflammation are key mechanisms mediating the neuroprotective actions of C-PC against brain ischemia.

Decompressive craniectomy for malignant middle cerebral artery infarction at an emergency hospital in Peru / Craniectomía descompresiva en infarto maligno de la arteria cerebral media en un hospital de emergencias en Perú

SUMMARY Objective : To describe clinical, surgical and post-operative characteristics of patients with the diagnosis of malignant infarction of the middle cerebral artery who underwent decompressive craniectomy. Methods : Descriptive, retrospective case series study, performed between March 2017 and March 2020. Data from consecutive patients with the diagnosis of malignant middle cerebral artery infarction were collected. Results : Ten cases were reviewed. Eighty percent of the patients were men, the mean age was 64 years and 60% of the patients were older than 60 years. At admission, the mean Glasgow was 11 points and the mean mRS was 4. The mean time from diagnosis to surgery was 89.7 hours. The anterior cerebral artery was comprised in two cases. Hemorrhagic transformation occurred in three cases. The mean anterior-posterior diameter of the skull flap was 116 mm. The mean ICU and hospital length of stay were 14.1 and 27.5 days, respectively. Three patients died. Conclusions : Decompressive craniectomy is a life-saving procedure in an emergency hospital-setting with an acceptable in-hospital mortality rate within one-month follow-up.

RESUMEN Objetivo : Describir las características clínicas, quirúrgicas y postoperatorias en pacientes con diagnóstico de infarto maligno de la arteria cerebral media sometidos a craniectomía descompresiva. Material y métodos : Estudio observacional, descriptivo, retrospectivo, tipo serie de casos, realizado entre marzo 2017 y marzo 2020. Se recolectaron los datos de pacientes consecutivos con diagnóstico de infarto maligno de arteria cerebral. Resultados : Diez casos fueron revisados. Ochenta por ciento fueron hombres, la edad promedio fue 64 años y 60% de los pacientes fueron mayores de 60 años. En la admisión, el Glasgow promedio fue de 11 puntos y el mRS fue de 4. El tiempo promedio desde el diagnostico hasta la cirugía fue de 89,7 horas. La arteria cerebral anterior estuvo comprometida en dos casos. La transformación hemorrágica ocurrió en tres casos. El diámetro anteroposterior promedio de la plaqueta ósea fue de 116 mm. El tiempo promedio de estancia en UCI y estancia hospitalaria fueron de 14,1 días y 27,5 días, respectivamente. Tres pacientes murieron. Conclusiones : La craniectomía descompresiva es un procedimiento que salva vidas en un ambiente hospitalario de emergencia con una aceptable mortalidad intrahospitalaria dentro del primer mes de seguimiento.

Alamandine Induces Neuroprotection in Ischemic Stroke Models.

BACKGROUND AND OBJECTIVE: Stroke, a leading cause of mortality and disability, characterized by neuronal death, can be induced by a reduction or interruption of blood flow. In this study, the role of Alamandine, a new peptide of the renin-angiotensin system, was evaluated in in-vitro and in-vivo brain ischemia models. METHODS: In the in-vitro model, hippocampal slices from male C57/Bl6 mice were placed in a glucose-free aCSF solution and bubbled with 95% N2 and 5% CO2 to mimic brain ischemia. An Alamandine concentration-response curve was generated to evaluate cell damage, glutamatergic excitotoxicity, and cell death. In the in-vivo model, cerebral ischemia/ reperfusion was induced by bilateral occlusion of common carotid arteries (BCCAo-untreated) in SD rats. An intracerebroventricular injection of Alamandine was given 20-30 min before BCCAo. Animals were subjected to neurological tests 24 h and 72 h after BCCAo. Cytokine levels, oxidative stress markers, and immunofluorescence were assessed in the brain 72 h after BCCAo. RESULTS: Alamandine was able to protect brain slices from cellular damage, excitotoxicity and cell death. When the Alamandine receptor was blocked, protective effects were lost. ICV injection of Alamandine attenuated neurological deficits of animals subjected to BCCAo and reduced the number of apoptotic neurons/cells. Furthermore, Alamandine induced anti-inflammatory effects in BCCAo animals as shown by reductions in TNFα, IL- 1ß, IL-6, and antioxidant effects through attenuation of the decreased SOD, catalase, and GSH activities in the brain. CONCLUSION: This study showed, for the first time, a neuroprotective role for Alamandine in different ischemic stroke models.

High fructose diet-induced obesity worsens post-ischemic brain injury in the hippocampus of female rats.

Objectives: Cerebral ischemia is caused by a reduction of the blood flow in a specific area in the brain, triggering cellular cascades in the tissue that result in neuronal death. This phenomenon leads to neurological decline in patients with stroke. The extent of the injury after stroke could be related to the condition of obesity. Thus, we aim to analyze the effect of obesity induced by a high fructose diet (HFD) on the brain after cerebral ischemia in rats.Methods: We induced the obesity model in female Wistar rats with 20% fructose in water for 11 weeks. We then performed cerebral ischemia surgery (2-vessel occlusion), carried out the neurological test 6, 24 and 48 h post-ischemia and analyzed the histological markers.Results: The HFD induced an obese phenotype without insulin resistance. The obese rats exhibited worse neurological performance at 6 h post-ischemia and showed neuronal loss and astroglial and microglial immunoreactivity changes in the caudate putamen, motor cortex, amygdala and hippocampus at 48 h post-ischemia. However, the most commonly affected area was the hippocampus, where we found an increase in interleukin 1ß in the blood vessels of the dentate gyrus, a remarkable disruption of MAP-2+ dendrites, a loss of brain-derived neurotrophic factor and the presence of PHF-tau. In conclusion, a HFD induces an obese phenotype and worsens the neuronal loss, inflammation and plasticity impairment in the hippocampus after cerebral ischemia.

Therapeutic Effects of Dimethyl Fumarate on the Rat Model of Brain Ischemia

Abstract Blood-brain barrier (BBB) disruption, inflammation, and cell death are major pathogenic mechanisms in ischemic stroke. Dimethyl fumarate (DMF) has anti-inflammatory and immune-modulatory effects. So, this study aimed to elucidate the effects of DMF on brain ischemia in the middle cerebral artery occlusion (MCAO) model. 69 Sprague-Dawley male rats were allocated into a sham group that was just subjected to surgery stress; vehicle and DMF groups, after MCAO, received vehicle or 30 mg/kg DMF for three days. Neurological scores were evaluated every day. BBB disruption was evaluated by the extravasation of Evans blue. In addition to the measurement of brain water content, the total and infarct volume, numerical density, and the total number of neurons, non-neurons, and dead neurons in the right cortex were estimated by stereological methods. RT-PCR was done to analyze the expression levels of NF-κB and Nrf2. Although brain ischemia treatment with DMF did not have a significant effect on the infarction size, it improved neurobehavioral function, BBB disruption, cerebral edema, increased number of neurons, and expression of Nrf2. It also decreased the number of dead neurons and the expression of NF-κB. DMF beneficial effects on stroke may be mediated through both increase of the Nrf2 and decrease of NF-κB expression

Effects of pre-treatment with metoprolol and diltiazem on cerebral ischemia/reperfusion-induced injuries

Abstract Stroke is one of the most important health concerns worldwide. Calcium ions accumulation in the nerve cells and increase in the catecholamines level of the brain following cerebral ischemia/reperfusion (I/R) are accompanied by damaging effects. Therefore, the present study aimed to evaluate the effects of diltiazem, as a calcium channel blocker, and metoprolol, as a β-adrenoceptors antagonist, on I/R injury. In this study, 30 male Wistar rats were divided into control, I/R, metoprolol, diltiazem, and metoprolol plus diltiazem groups (n=6 in each). Metoprolol (1 mg/kg/day) and diltiazem (5 mg/kg/day) were injected intraperitoneally (i.p.) for 7 days before I/R induction. On day 8, the animals underwent ischemia by bilateral common carotid arteries occlusion for 20 min. Histopathological analysis showed a significant reduction in leukocyte infiltration in diltiazem, metoprolol, and diltiazem plus metoprolol treated rats compared with the I/R group (P<0.05, P<0.01, P<0.01, respectively). In addition, in all treated groups, myeloperoxidase activity and malondialdehyde levels in the brain tissue significantly declined compared with the I/R group (P<0.001). Furthermore, pre-treatment with diltiazem and metoprolol alone or in co-administration remarkably reduced infarct size following I/R (P<0.001). Overall, the results indicate the considerable neuroprotective effects of metoprolol and diltiazem in cerebral I/R.

Importance of computed tomography angiography in acute/hyperacute ischemic stroke.

OBJECTIVE: To evaluate the importance of computed tomography and computed tomography angiography (CTA) in stroke protocols, as well as their impact on endovascular treatment and on the determination of the etiology. MATERIALS AND METHODS: Were evaluated 28 patients with acute/hyperacute stroke in the anterior circulation who underwent intracranial and cervical CTA between April 2018 and August 2019. The parameters evaluated were the degree of stenosis, plaque characteristics, type of infarct, treatment, etiology, and the Alberta Stroke Program Early CT Score (ASPECTS). RESULTS: Of the 28 patients evaluated, 16 (57.1%) had an ASPECTS of 10 (the maximum score, indicative of normality). Four patients (14.3%) underwent thrombolytic treatment, and seven (25.0%) underwent mechanical thrombectomy. The etiology was atherosclerosis in 32.1% of the patients, cerebral small-vessel disease in 7.1%, cardioembolic in 7.1%, and undetermined in 53.6%. Regarding plaque, 17.9% of the patients presented stenosis ≥ 50%, 21.4% presented stable plaques, and 42.9% presented vulnerable plaques. Patients with a lower ASPECTS were more likely to have relevant stenosis and were more likely to have a total infarct. CONCLUSION: In the evaluation of patients with acute/hyperacute strokes, CTA provides important information, identifying occlusion, as well as helping define the etiology and inform decisions regarding treatment.

OBJETIVO: Avaliar a importância da tomografia computadorizada e angiotomografia computadorizada (ATC) no protocolo de acidente vascular encefálico (AVE) e o seu impacto no tratamento endovascular e na determinação da etiologia.Materiais e Métodos: Foram avaliados 28 pacientes com AVE agudo/hiperagudo da circulação anterior que realizaram ATC intracraniana e cervical, no período de abril de 2018 a agosto de 2019. Os parâmetros avaliados foram grau de estenose, placa, tipo do infarto, tratamento, etiologia e classificação Alberta Stroke Program Early CT Score (ASPECTS). RESULTADOS: A maioria dos casos (16; 57,1%) apresentou ASPECTS de 10. Quatro pacientes (14,3%) realizaram tratamento trombolítico e sete (25%) foram submetidos a trombectomia mecânica. A etiologia foi aterosclerose em 32,1% dos pacientes, doença de pequenas artérias em 7,1%, cardioembólico em 7,1% e indeterminada em 53,6%. Em relação à placa, 17,9% apresentaram estenose maior que 50%, 21,4% apresentaram placas estáveis e 42,9%, placas instáveis. Pacientes com ASPECTS mais baixo apresentavam maior probabilidade de ter estenose relevante e apresentavam maior chance de ocorrência de infarto total. CONCLUSÃO: A ATC fornece informações importantes na avaliação do paciente com AVE agudo/hiperagudo, identificando a oclusão e auxiliando na definição da etiologia e no direcionamento do tratamento.

Importance of computed tomography angiography in acute/hyperacute ischemic stroke / Importância da angiotomografia computadorizada no acidente vascular encefálico isquêmico agudo/hiperagudo

Abstract Objective: To evaluate the importance of computed tomography and computed tomography angiography (CTA) in stroke protocols, as well as their impact on endovascular treatment and on the determination of the etiology. Materials and Methods Were evaluated 28 patients with acute/hyperacute stroke in the anterior circulation who underwent intracranial and cervical CTA between April 2018 and August 2019. The parameters evaluated were the degree of stenosis, plaque characteristics, type of infarct, treatment, etiology, and the Alberta Stroke Program Early CT Score (ASPECTS). Results: Of the 28 patients evaluated, 16 (57.1%) had an ASPECTS of 10 (the maximum score, indicative of normality). Four patients (14.3%) underwent thrombolytic treatment, and seven (25.0%) underwent mechanical thrombectomy. The etiology was atherosclerosis in 32.1% of the patients, cerebral small-vessel disease in 7.1%, cardioembolic in 7.1%, and undetermined in 53.6%. Regarding plaque, 17.9% of the patients presented stenosis ≥ 50%, 21.4% presented stable plaques, and 42.9% presented vulnerable plaques. Patients with a lower ASPECTS were more likely to have relevant stenosis and were more likely to have a total infarct. Conclusion: In the evaluation of patients with acute/hyperacute strokes, CTA provides important information, identifying occlusion, as well as helping define the etiology and inform decisions regarding treatment.

Resumo Objetivo: Avaliar a importância da tomografia computadorizada e angiotomografia computadorizada (ATC) no protocolo de acidente vascular encefálico (AVE) e o seu impacto no tratamento endovascular e na determinação da etiologia. Materiais e Métodos: Foram avaliados 28 pacientes com AVE agudo/hiperagudo da circulação anterior que realizaram ATC intracraniana e cervical, no período de abril de 2018 a agosto de 2019. Os parâmetros avaliados foram grau de estenose, placa, tipo do infarto, tratamento, etiologia e classificação Alberta Stroke Program Early CT Score (ASPECTS). Resultados: A maioria dos casos (16; 57,1%) apresentou ASPECTS de 10. Quatro pacientes (14,3%) realizaram tratamento trombolítico e sete (25%) foram submetidos a trombectomia mecânica. A etiologia foi aterosclerose em 32,1% dos pacientes, doença de pequenas artérias em 7,1%, cardioembólico em 7,1% e indeterminada em 53,6%. Em relação à placa, 17,9% apresentaram estenose maior que 50%, 21,4% apresentaram placas estáveis e 42,9%, placas instáveis. Pacientes com ASPECTS mais baixo apresentavam maior probabilidade de ter estenose relevante e apresentavam maior chance de ocorrência de infarto total. Conclusão: A ATC fornece informações importantes na avaliação do paciente com AVE agudo/hiperagudo, identificando a oclusão e auxiliando na definição da etiologia e no direcionamento do tratamento.