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Objective: This study aims to investigate the inhibitory effect of Polydatin (PD) on endoplasmic reticulum (ER) stress following subarachnoid hemorrhage (SAH) and to elucidate the underlying mechanisms. Methods: A standard intravascular puncture model was established to mimic SAH in mice. Neurological functions were assessed using neurological scoring, Grip test, and Morris water maze. Brain edema and Evans blue extravasation were measured to evaluate blood-brain barrier permeability. Western blot and quantitative real-time polymerase chain reaction (PCR) analyses were performed to examine protein and mRNA expressions related to ER stress. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was used to detect cell apoptosis, and transmission electron microscopy was used to observe the ultrastructure of the endoplasmic reticulum. Results: The results indicated that PD significantly reduced brain edema and Evans blue extravasation after SAH, improving neurological function. Compared to the SAH group, the expression levels of ER stress-related proteins including glucose-regulated protein 78 (GRP78), phosphorylated protein kinase R-like endoplasmic reticulum kinase (p-PERK), phosphorylated eukaryotic initiation factor 2α (p-eIF2α), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP), were significantly lower in the PD-treated group. Moreover, PD significantly enhances the protein expression of Sirtuin 1 (SIRT1). Validation with sh-SIRT1 confirmed the critical role of SIRT1 in ER stress, with PD's inhibitory effect on ER stress being dependent on SIRT1 expression. Additionally, PD attenuated ER stress-mediated neuronal apoptosis and SAH-induced ferroptosis through upregulation of SIRT1. Conclusion: PD alleviates ER stress following SAH by upregulating SIRT1 expression, thereby mitigating early brain injury. The protective effects of PD are mediated through SIRT1, which inhibits ER stress and reduces neuronal apoptosis and ferroptosis.
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The benefits of hypothermia for the treatment of subarachnoid hemorrhage (SAH) remain controversial. In 1999, we initiated brain hypothermia treatment (BHT) in the hyperacute phase to mitigate the evolution of early brain injury in patients with World Federation of Neurological Surgeons (WFNS) grade V SAH. In June 2014, we introduced endovascular cooling to maintain normothermia for seven days following the initial BHT period. Immediately after the decision to treat the sources of bleeding, cooling was initiated, with a target temperature of 33-34°C. Bleeding sources were extirpated primarily by clipping with decompressive craniectomy. Patients were rewarmed at a rate of ≤1°C/day after ≥48 hours of surface cooling. After being rewarmed to 36°C, temperatures were controlled with antipyretic (chronologically divided into groups A-C with 47, 46, and 46 patients, respectively) or endovascular (group D, 38 patients) cooling. Overall, 177 patients (median age, 62 [52-68] years; 94 [53.1%] women; onset-to-arrival time, 36 minutes [28-50]) were included. The median Glasgow Coma Scale (GCS) score upon admission was 4 (3-6). Median core body temperature was 36 (35.3-36.6)°C on arrival, 34.6 (34.0-35.3)°C on entering the operating room, 33.8 (33.4-34.3)°C upon starting the microsurgical or interventional radiology procedure, and 33.7 (33.3-34.2)°C upon admission to the intensive care unit. There were no significant differences in age, sex, GCS score, pupillary findings, location of bleeding sources, or treatment methods. There were 69 (39.0%) overall favorable outcomes (modified Rankin Scale score of 0-3) at 6 months and 11 (23.4%), 18 (39.1%), 17 (37.0%), and 23 (60.5%) in groups A-D, respectively (p = 0.0065). The outcomes of patients with WFNS grade V SAH improved over time. Herein, we report our experience using BHT for severe SAH through a narrative review.
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AIMS: We aimed to resolve the uncertainty as to whether betulin exerted neuroprotection on early brain injury (EBI) caused by subarachnoid hemorrhage (SAH), and to investigate the related molecular mechanisms. METHODS: Bioinformatic analysis was performed to pre-study the differently expressed genes (DEGs) and the possible signaling pathways. Rat and cellular model of SAH were introduced in this study, and betulin, an activator of DJ-1 protein, was administered to reveal the effect. Gross assessment regarding mortality, neurofunctions, SAH grade, brain water content (BWC) along with multiple cellular and molecular studies in vivo or/and in vitro such as immunofluorescence (IF) staining, western blot (WB), reactive oxygen species (ROS) assay, and flow cytometry (FCM) were all conducted after SAH induction to verify the protective effect and the relevant mechanisms of DJ-1 in diverse levels. In addition, MK2206 (selective inhibitor of Akt) and iRNADj-1 (interfering RNA to Dj-1) were utilized to confirm the mechanisms of the effect. RESULTS: The data from our study showed that DJ-1 protein was moderately expressed in neurons, microglia, and astrocytes; its level in brain tissue elevated and peaked at 24-72 h after SAH induction. Betulin could efficaciously induce the expression of DJ-1 which in turn activated Akt and Bcl-2, and anti-oxidative enzymes SOD2 and HO-1, functioning to reduce the activation of cleaved caspase-3 (c-Casp-3) and reactive oxygen species (ROS). The induced DJ-1 could upregulate the expression of Nrf2. However, Akt seemed no direct effect on elevating the expression of Nrf2. DJ-1 alone could as well activate Akt-independent antiapoptotic pathway via suppressing the activation of caspase-8 (Casp-8). CONCLUSIONS: Betulin which was a potent agonist of DJ-1 had the ability to induce its expression in brain tissue. DJ-1 had neuroprotective effect on EBI through comprehensive mechanisms, including facilitating intrinsic and extrinsic antiapoptotic pathway, and reducing oxidative injury by upregulating the expression of redox proteins. Betulin as an inexpensive drug showed the potential for SAH treatment.
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Apoptosis , Factor 2 Relacionado con NF-E2 , Neuronas , Estrés Oxidativo , Proteína Desglicasa DJ-1 , Proteínas Proto-Oncogénicas c-akt , Ratas Sprague-Dawley , Transducción de Señal , Hemorragia Subaracnoidea , Triterpenos , Hemorragia Subaracnoidea/metabolismo , Hemorragia Subaracnoidea/tratamiento farmacológico , Hemorragia Subaracnoidea/patología , Animales , Proteína Desglicasa DJ-1/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Ratas , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Apoptosis/efectos de los fármacos , Triterpenos/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Masculino , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fármacos Neuroprotectores/farmacología , Especies Reactivas de Oxígeno/metabolismo , Ácido BetulínicoRESUMEN
Introduction: Early focal brain injuries lead to long-term disabilities with frequent cognitive impairments, suggesting global dysfunction beyond the lesion. While plasticity of the immature brain promotes better learning, outcome variability across individuals is multifactorial. Males are more vulnerable to early injuries and neurodevelopmental disorders than females, but long-term sex differences in brain growth after an early focal lesion have not been described yet. With this MRI longitudinal morphometry study of brain development after a Neonatal Arterial Ischemic Stroke (NAIS), we searched for differences between males and females in the trajectories of ipsi- and contralesional gray matter growth in childhood and adolescence, while accounting for lesion characteristics. Methods: We relied on a longitudinal cohort (AVCnn) of patients with unilateral NAIS who underwent clinical and MRI assessments at ages 7 and 16 were compared to age-matched controls. Non-lesioned volumes of gray matter (hemispheres, lobes, regions, deep structures, cerebellum) were extracted from segmented T1 MRI images at 7 (Patients: 23 M, 16 F; Controls: 17 M, 18 F) and 16 (Patients: 18 M, 11 F; Controls: 16 M, 15 F). These volumes were analyzed using a Linear Mixed Model accounting for age, sex, and lesion characteristics. Results: Whole hemisphere volumes were reduced at both ages in patients compared to controls (gray matter volume: -16% in males, -10% in females). In ipsilesional hemisphere, cortical gray matter and thalamic volume losses (average -13%) mostly depended on lesion severity, suggesting diaschisis, with minimal effect of patient sex. In the contralesional hemisphere however, we consistently found sex differences in gray matter volumes, as only male volumes were smaller than in male controls (average -7.5%), mostly in territories mirroring the contralateral lesion. Females did not significantly deviate from the typical trajectories of female controls. Similar sex differences were found in both cerebellar hemispheres. Discussion: These results suggest sex-dependent growth trajectories after an early brain lesion with a contralesional growth deficit in males only. The similarity of patterns at ages 7 and 16 suggests that puberty has little effect on these trajectories, and that most of the deviation in males occurs in early childhood, in line with the well-described perinatal vulnerability of the male brain, and with no compensation thereafter.
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BACKGROUND: Early brain injury is the leading cause of poor outcomes in spontaneous subarachnoid hemorrhage (sSAH). Plasma D-dimer levels and acute cerebral ischemia have been highlighted as relevant findings in early brain injury; however, their correlation has not been substantially investigated. METHODS: This retrospective, single-center cohort study was conducted at a tertiary emergency medical center from January 2004 to June 2022. Consecutive patients with sSAH who presented within 12 hours of ictus and underwent magnetic resonance imaging within 3 days were included. We assessed the correlation of plasma D-dimer levels with acute ischemic lesions detected on the diffusion-weighted imageing and the clinical characteristics. RESULTS: Among 402 eligible patients (mean age, 63.5 years; 62.7% women; median time from onset to arrival, 45.5 minutes), 140 (34.8%) had acute ischemic lesions. Higher plasma D-dimer levels linearly correlated with worse neurological grades, more severe SAH on initial computed tomography, acute ischemic lesions, and poor outcomes, except for patients with neurogenic stunned myocardium. In the multivariate analysis, acute ischemic lesions were significantly associated with worse neurological grades, higher plasma D-dimer levels, bilateral loss of light reaction, and advanced age. The receiver operating characteristic curve analysis showed D-dimer levels as excellent predictors for acute ischemic lesions (area under the curve, 0.897; cut-off value, 5.7 µg/mL; P<0.0001) and unfavorable outcomes (area under the curve, 0.786; cut-off value, 4.0 µg/mL; P<0.0001). CONCLUSIONS: High plasma D-dimer levels correlated with the appearance of acute ischemic lesions on diffusion-weighted imaging and were dose-dependently associated with worse neurological grades, more severe hemorrhage, and worse outcomes.
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Intracerebral hemorrhage (ICH), known as non-traumatic cerebrovascular rupture and hemorrhage, often occurs in the deep basal brain segment. It is known for its high morbidity and mortality rates. Subarachnoid hemorrhage (SAH) is a clinical syndrome caused by the rupture of blood vessels at the base or surface of the brain that allows blood to flow directly into the subarachnoid space. It progresses quickly and typically manifests at younger ages compared with ICH. ICH and SAH are both devastating events in the category of hemorrhagic strokes and are attracting increasing attention from researchers. Flavonoids, being important natural molecules, have remarkable anti-inflammatory and antioxidant effects. Flavonoids have extensive biological activities in inflammation and oxidative stress (OS), and have protective effects in vascular function associated with cerebrovascular diseases. They have an impact on the onset of ICH and SAH by targeting various pathways, including the suppression of inflammation and OS. Recently, the role of flavonoid compounds in ICH and SAH has also received increasing interest. Thus, to serve as a resource for the prevention and treatment of ICH and SAH, the present review provided an overview of the research on flavonoid compounds in the prevention of brain damage after these two conditions have occurred.
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Hyperglycemia during early brain injury (EBI) period after spontaneous subarachnoid hemorrhage (SAH) is associated with poor outcome, but the underlying physiopathology is unknown. This study assessed if hyperglycemia during EBI is associated with markers of neuroaxonal injury and whether these biomarkers partially account for the association between hyperglycemia and poor clinical outcome. Ninety-two SAH patients admitted within 24 h of bleeding onset were prospectively included. Glucose levels were measured at arrival and every 6 h for 72 h. Serum neurofilament light chain (NFL) levels were measured at 72 h. Functional outcome was assessed with the modified Rankin Scale (mRS) at 90 days (poor outcome, mRS > 2). The association between glucose metrics, NFL levels, and clinical outcome was assessed with univariate and multivariate analyses. Mediation analysis was performed to examine the potential chain in which NFL may mediate the relationship between glucose and functional outcome. Higher glucose and NFL levels during EBI were associated with poor clinical outcome in adjusted analysis. NFL levels were associated with older age, higher initial severity, and higher glucose levels during EBI period. In adjusted mediation analyses, the association between glucose and clinical outcome was significantly mediated by NFL levels. The mediator NFL explained 25% of the association between glucose during EBI period and poor functional outcome at 90 days. In SAH, the association between glucose levels during EBI and poor clinical outcome might be significantly mediated by NFL levels. The link between hyperglycemia and poor clinical outcome might be explained in part through secondary neuroaxonal injury.
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PURPOSE: We aimed to investigate early effects of exogenously administered adropin (AD) on neurological function, endothelial nitric oxide synthase (eNOS) expression, nitrite/nitrate levels, oxidative stress, and apoptosis in subarachnoid hemorrhage (SAH). METHODS: Following intracerebroventricular AD administration (10 µg/5 µl at a rate of 1 µl/min) SAH model was carried out in Sprague-Dawley rats by injection of autologous blood into the prechiasmatic cistern. The effects of AD were assessed 24 h following SAH. The modified Garcia score was employed to evaluate functional insufficiencies. Adropin and caspase-3 proteins were measured by ELISA, while nitrite/nitrate levels, total antioxidant capacity (TAC) and reactive oxygen/nitrogen species (ROS/RNS) were assayed by standard kits. eNOS expression and apoptotic neurons were detected by immunohistochemical analysis. RESULTS: The SAH group performed notably lower on the modified Garcia score compared to sham and SAH + AD groups. Adropin administration increased brain eNOS expression, nitrite/nitrate and AD levels compared to SHAM and SAH groups. SAH produced enhanced ROS/RNS generation and reduced antioxidant capacity in the brain. Adropin boosted brain TAC and diminished ROS/RNS production in SAH rats and no considerable change amongst SHAM and SAH + AD groups were detected. Apoptotic cells were notably increased in intensity and number after SAH and were reduced by AD administration. CONCLUSIONS: Adropin increases eNOS expression and reduces neurobehavioral deficits, oxidative stress, and apoptotic cell death in SAH model. Presented results indicate that AD provides protection in early brain injury associated with SAH.
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Fármacos Neuroprotectores , Óxido Nítrico Sintasa de Tipo III , Estrés Oxidativo , Hemorragia Subaracnoidea , Animales , Masculino , Ratas , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Proteínas Sanguíneas , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/patología , Modelos Animales de Enfermedad , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Neuronas/patología , Fármacos Neuroprotectores/farmacología , Nitratos/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Nitritos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Péptidos/farmacología , Ratas Sprague-Dawley , Especies de Nitrógeno Reactivo/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Hemorragia Subaracnoidea/metabolismo , Hemorragia Subaracnoidea/tratamiento farmacológico , Hemorragia Subaracnoidea/patologíaRESUMEN
Regulation of the redox system by branched-chain amino acid transferase 1 (BCAT1) is of great significance in the occurrence and development of diseases, but the relationship between BCAT1 and subarachnoid hemorrhage (SAH) is still unknown. Ferroptosis, featured by iron-dependent lipid peroxidation accompanied by the depletion of glutathione peroxidase 4 (GPX4), has been implicated in the pathological process of early brain injury after subarachnoid hemorrhage. This study established SAH model by endovascular perforation and adding oxyhemoglobin (Hb) to HT22 cells and delved into the mechanism of BCAT1 in SAH-induced ferroptotic neuronal cell death. It was found that SAH-induced neuronal ferroptosis could be inhibited by BCAT1 overexpression (OE) in rats and HT22 cells, and BCAT1 OE alleviated neurological deficits and cognitive dysfunction in rats after SAH. In addition, the effect of BCAT1 could be reversed by the Ly294002, a specific inhibitor of the PI3K pathway. In summary, our present study indicated that BCAT1 OE alleviated early brain injury EBI after SAH by inhibiting neuron ferroptosis via activation of PI3K/AKT/mTOR pathway and the elevation of GPX4. These results suggested that BCAT1 was a promising therapeutic target for subarachnoid hemorrhage.
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Lesiones Encefálicas , Ferroptosis , Fosfatidilinositol 3-Quinasas , Fosfolípido Hidroperóxido Glutatión Peroxidasa , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Hemorragia Subaracnoidea , Serina-Treonina Quinasas TOR , Animales , Masculino , Ratones , Ratas , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/patología , Lesiones Encefálicas/tratamiento farmacológico , Lesiones Encefálicas/etiología , Cromonas/farmacología , Modelos Animales de Enfermedad , Ferroptosis/efectos de los fármacos , Ferroptosis/genética , Peroxidación de Lípido/efectos de los fármacos , Morfolinas/farmacología , Neuronas/metabolismo , Neuronas/patología , Neuronas/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Fosfolípido Hidroperóxido Glutatión Peroxidasa/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Ratas Sprague-Dawley , Hemorragia Subaracnoidea/patología , Hemorragia Subaracnoidea/metabolismo , Hemorragia Subaracnoidea/tratamiento farmacológico , Hemorragia Subaracnoidea/genética , Serina-Treonina Quinasas TOR/metabolismo , Serina-Treonina Quinasas TOR/genéticaRESUMEN
Background: Subarachnoid hemorrhage (SAH) serves as a disease characterized by high incidence rate, which is exceedingly prevalent and severe. Presently, there is no unambiguous or efficacious intervention for the neurological impairment following SAH. Administering multi-targeted neuroprotective agents to reduce oxidative stress (OS) and neuroinflammation caused by early brain injury (EBI) has been demonstrated to improve neurological function and prognosis following SAH. Edaravone dexborneol (EDB), a novel multi targeted neuroprotective medication, combines four parts edaravone (EDA) with 1 part (+)-borneol in proportion. Clinical trials conducted in China have revealed during 2 days of acute ischemic stroke (AIS), early administration of EDB leads to improved therapeutic outcomes compared to treatment in EDA monotherapy. Currently, there is no clear evidence that EDB can effectively treat SAH, therefore, our study aims to investigate its potential therapeutic effects and mechanisms on EBI after SAH. Method: We used the intravascular threading method to establish a mouse model of SAH to explore whether EDA and EDB could produce anti-OS and anti-apoptosis effects. Behavioral assessment of mice was conducted using the balance beam experiment and the modified Garcia scoring system. Neuronal damage due to OS and Keap1/Nrf2 signaling pathway were detected through techniques of immunofluorescence, Western blotting, spectrophotometry. The group of EDA and EDB were injected intraperitoneally for 72 h after SAH. Results: The experiment results indicated that EDB lead to remarkably positive results by significantly enhancing neurological function, reducing blood-brain barrier (BBB) injury, and effectively inhibiting neuronal apoptosis after SAH. Further examination indicated EDB significantly reduced the expression of Keap1 and increased the expression of Nrf2, and it inhibited MDA, and enhanced SOD activity after SAH. These outcomes surpassed the effectiveness observed in EDA monotherapy. However, the application of ML385 reversed the anti-OS effects of EDB and EDA. Conclusion: Our experimental findings indicated that EDB could activate Keap1/Nrf2 signaling pathway to reduce OS damage, thereby protecting neurological function and enhancing behavioral abilities after SAH. These outcomes could facilitate the creation of new approaches for the clinical management of SAH.
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At present, it appears that the prognosis for subarachnoid haemorrhage (SAH), which has a high death and disability rate, cannot be greatly improved by medication or other treatment. Recent research suggests that different types of cell death are implicated in early brain injury (EBI) after SAH, and this has been recognised as a major factor impacting the prognosis of SAH. Ferroptosis, which is a recently identified imbalance of iron metabolism and programmed cell death triggered by phospholipid peroxidation, has been shown to be involved in EBI after SAH and is thought to have a significant impact on EBI. The decomposition of cleaved haemoglobin during SAH involves the release of enormous amounts of free iron, resulting in iron metabolism disorders. Potential therapeutic targets for the signalling pathways of iron metabolism disorders and ferroptosis after SAH are constantly being discovered. To serve as a guide for research into other possible therapeutic targets, this paper will briefly describe the mechanisms of dysregulated iron metabolism and ferroptosis in the pathogenesis of SAH and highlight how they are involved in the development and promotion of EBI in SAH.
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PURPOSE: Progressive cerebral edema with refractory intracranial hypertension (ICP) requiring decompressive hemicraniectomy (DHC) is a severe manifestation of early brain injury (EBI) after aneurysmal subarachnoid hemorrhage (aSAH). The purpose of the study was to investigate whether a more pronounced cerebrospinal fluid (CSF) drainage has an influence on cerebral perfusion pressure (CPP) and the extent of EBI after aSAH. METHODS: Patients with aSAH and indication for ICP-monitoring admitted to our center between 2012 and 2020 were retrospectively included. EBI was categorized based on intracranial blood burden, persistent loss of consciousness, and SEBES (Subarachnoid Hemorrhage Early Brain Edema Score) score on the third day after ictus. The draining CSF and vital signs such as ICP and CPP were documented daily. RESULTS: 90 out of 324 eligible aSAH patients (28%) were included. The mean age was 54.2 ± 11.9 years. DHC was performed in 24% (22/90) of patients. Mean CSF drainage within 72 h after ictus was 168.5 ± 78.5 ml. A higher CSF drainage within 72 h after ictus correlated with a less severe EBI and a less frequent need for DHC (r=-0.33, p = 0.001) and with a higher mean CPP on day 3 after ictus (r = 0.2351, p = 0.02). CONCLUSION: A more pronounced CSF drainage in the first 3 days of aSAH was associated with higher CPP and a less severe course of EBI and required less frequently a DHC. These results support the hypothesis that an early and pronounced CSF drainage may facilitate blood clearance and positively influence the course of EBI.
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Aneurisma Roto , Drenaje , Hemorragia Subaracnoidea , Humanos , Persona de Mediana Edad , Masculino , Hemorragia Subaracnoidea/cirugía , Hemorragia Subaracnoidea/complicaciones , Femenino , Drenaje/métodos , Estudios Retrospectivos , Adulto , Aneurisma Roto/cirugía , Aneurisma Roto/complicaciones , Anciano , Craniectomía Descompresiva/métodos , Lesiones Encefálicas , Edema Encefálico/etiología , Edema Encefálico/líquido cefalorraquídeo , Edema Encefálico/cirugía , Líquido Cefalorraquídeo , Hipertensión Intracraneal/etiología , Hipertensión Intracraneal/cirugía , Hipertensión Intracraneal/líquido cefalorraquídeo , Aneurisma Intracraneal/cirugía , Aneurisma Intracraneal/complicacionesRESUMEN
OBJECTIVES: Subarachnoid hemorrhage (SAH) is a major cause of incapacity and death, imposing a significant economic burden globally. Additionally, SAH is the third most prevalent form of stroke. Semaglutide affects oxidative stress, inflammation, and mitochondrial biogenesis. Specifically, the potential neuroprotective effect of semaglutide in SAH and its underlying mechanism is unclear. Accordingly, the present research intended to explore the neuroprotective effect of semaglutide in SAH and its potential molecular mechanisms. METHODS: We constructed a C57BL/6 mouse model of SAH. The parameters assessed were neuronal ferroptosis, neuroinflammatory cytokine levels, reactive oxygen species (ROS) levels, glutathione (GSH) and malondialdehyde (MDA) levels, brain water content, and neurological score. RESULTS: The results showed that the activation of semaglutide significantly increased neurological scores, relieved cerebral edema, decreased the levels of inflammatory cytokine nuclear factor kappa B, interleukin (IL)-1ß, IL-6, tumor necrosis factor-alpha, MDA, and ROS, and increased the levels of GSH. Suppression of SIRT1 reversed these effects, indicating that semaglutide activated SIRT1 to reduce neuroinflammation, ferroptosis, and neuronal cell death after SAH. Thus, the activation of the Nrf2/HO-1 signaling pathway contributes to the neuroprotective properties of semaglutide. CONCLUSIONS: Semaglutide can improve murine neurological outcomes and reduce neuronal damage against neuroinflammation and ferroptosis.
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Background: This study focuses on the role of SIRT1 in neuroinflammation caused by early brain injury (EBI) after subarachnoid hemorrhage (SAH), and explores its mechanism in mitophagy after SAH. Methods: C57BL/6J mice and primary microglia SAH in vivo and in vitro models were constructed to explore the expression level of SIRT1 in neuroinflammation after SAH. Subsequently, the brain edema content, blood-brain barrier (BBB) damage and neurological function scores of the mice were observed after using the SIRT1 inhibitor EX-527. q-PCR and Western blot were used to detect relevant genes and proteins, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of IL-6, IL-1ß, and TNF-α inflammatory factors. Immunofluorescence staining was used to observe the positive level of SIRT1 and the degree of mitochondria-lysosome fusion, and transmission electron microscopy was used to observe mitochondrial damage and autophagosome levels. Results: In in vivo and in vitro experiments, we found that SIRT1 expression increased after SAH, and neurological deficits, brain edema, and blood-brain barrier damage after SAH were aggravated. Inhibiting SIRT1 further aggravates the aforementioned damage. In addition, EX-527 can also inhibit the level of mitophagy and aggravate neuroinflammation after SAH. Conclusion: Our results indicated that SIRT1 promotes mitophagy and alleviates neuroinflammation after SAH.
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Subarachnoid hemorrhage (SAH) is a neurological disorder that severely damages the brain and causes cognitive impairment. MicroRNAs are critical regulators in a variety of neurological diseases. MiR-497-5p has been found to be downregulated in the aneurysm vessel walls obtained from patients with aneurysmal subarachnoid hemorrhage, but its functions and mechanisms in SAH have not been reported. Therefore, this study was designed to investigate the effect of miR-497-5p and its related mechanisms in SAH. We established an in vitro SAH model by exposing PC12 cells to oxyhemoglobin (oxyHb). We found that miR-497-5p was downregulated in SAH serum and oxyHb-treated PC12 cells, and its overexpression inhibited the oxyHb-induced apoptosis, inflammatory response and oxidative stress via activation of the Nrf2 pathway. Mechanistically, the targeting relationship between miR-497-5p and Otx1 was verified by luciferase reporter assays. Moreover, Otx1 upregulation abolished the protective effects of miR-497-5p upregulation against oxyHb-induced apoptosis, inflammation and oxidative stress in PC12 cells. Collectively, our findings indicate that miR-497-5p could inhibit the oxyHb-induced SAH damage by targeting Otx1 to activate the Nrf2/HO-1 pathway, which provides a potential therapeutic target for SAH treatment.
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MicroARNs , Factores de Transcripción Otx , Hemorragia Subaracnoidea , Animales , Ratas , Proteínas de Homeodominio , MicroARNs/genética , Factor 2 Relacionado con NF-E2 , Oxihemoglobinas , Factores de Transcripción Otx/genéticaRESUMEN
BACKGROUND AND PURPOSE: The poor prognosis in patients with subarachnoid hemorrhage (SAH) is often attributed to neuronal apoptosis. Recent evidence suggests that Laminin subunit gamma 1 (LAMC1) is essential for cell survival and proliferation. However, the effects of LAMC1 on early brain injury after SAH and the underlying mechanisms are unknown. The current study aimed to reveal the anti-neuronal apoptotic effect and the potential mechanism of LAMC1 in the rat and in the in vitro SAH models. METHODS: The SAH model of Sprague-Dawley rats was established by endovascular perforation. Recombinant LAMC1 (rLAMC1) was administered intranasally 30 min after modeling. LAMC1 small interfering RNA (LAMC1 siRNA), focal adhesion kinase (FAK)-specific inhibitor Y15 and PI3K-specific inhibitor LY294002 were administered before SAH modeling to explore the neuroprotection mechanism of rLAMC1. HT22 cells were cultured and stimulated by oxyhemoglobin to establish an in vitro model of SAH. Subsequently, SAH grades, neurobehavioral tests, brain water content, blood-brain barrier permeability, western blotting, immunofluorescence, TUNEL, and Fluoro-Jade C staining were performed. RESULTS: The expression of endogenous LAMC1 was markedly decreased after SAH, both in vitro and in vivo. rLAMC1 significantly reduced the brain water content and blood-brain barrier permeability, improved short- and long-term neurobehavior, and decreased neuronal apoptosis. Furthermore, rLAMC1 treatment significantly increased the expression of p-FAK, p-PI3K, p-AKT, Bcl-XL, and Bcl-2 and decreased the expression of Bax and cleaved caspase -3. Conversely, knockdown of endogenous LAMC1 aggravated the neurological impairment, suppressed the expression of Bcl-XL and Bcl-2, and upregulated the expression of Bax and cleaved caspase-3. Additionally, the administration of Y15 and LY294002 abolished the protective roles of rLAMC1. In vitro, rLAMC1 significantly reduced neuronal apoptosis, and the protective effects were also abolished by Y15 and LY294002. CONCLUSION: Exogenous LAMC1 treatment improved neurological deficits after SAH in rats, and attenuated neuronal apoptosis in both in vitro and in vivo SAH models, at least partially through the FAK/PI3K/AKT pathway.
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Apoptosis , Laminina , Neuronas , Transducción de Señal , Hemorragia Subaracnoidea , Animales , Masculino , Ratones , Ratas , Apoptosis/efectos de los fármacos , Modelos Animales de Enfermedad , Quinasa 1 de Adhesión Focal/metabolismo , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Proteína-Tirosina Quinasas de Adhesión Focal/antagonistas & inhibidores , Laminina/metabolismo , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Neuronas/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Hemorragia Subaracnoidea/metabolismo , Hemorragia Subaracnoidea/patología , Hemorragia Subaracnoidea/tratamiento farmacológicoRESUMEN
Neuronal apoptosis is a common pathological change in early brain injury after subarachnoid hemorrhage (SAH), and it is closely associated with neurological deficits. According to previous research, p97 exhibits a remarkable anti-cardiomyocyte apoptosis effect. p97 is a critical molecule in the growth and development of the nervous system. However, it remains unknown whether p97 can exert an anti-neuronal apoptosis effect in SAH. In the present study, we examined the role of p97 in neuronal apoptosis induced after SAH and investigated the underlying mechanism. We established an in vivo SAH mice model and overexpressed the p97 protein through transfection of the mouse cerebral cortex. We analyzed the protective effect of p97 on neurons and evaluated short-term and long-term neurobehavior in mice after SAH. p97 was found to be significantly downregulated in the cerebral cortex of the affected side in mice after SAH. The site showing reduced p97 expression also exhibited a high level of neuronal apoptosis. Adeno-associated virus-mediated overexpression of p97 significantly reduced the extent of neuronal apoptosis, improved early and long-term neurological function, and repaired the neuronal damage in the long term. These neuroprotective effects were accompanied by enhanced proteasome function and inhibition of the integrated stress response (ISR) apoptotic pathway involving eIF2α/CHOP. The administration of the p97 inhibitor NMS-873 induced a contradictory effect. Subsequently, we observed that inhibiting the function of the proteasome with the proteasome inhibitor PS-341 blocked the anti-neuronal apoptosis effect of p97 and enhanced the activation of the ISR apoptotic pathway. However, the detrimental effects of NMS-873 and PS-341 in mice with SAH were mitigated by the administration of the ISR inhibitor ISRIB. These results suggest that p97 can promote neuronal survival and improve neurological function in mice after SAH. The anti-neuronal apoptosis effect of p97 is achieved by enhancing proteasome function and inhibiting the overactivation of the ISR apoptotic pathway.
Asunto(s)
Apoptosis , Ratones Endogámicos C57BL , Neuronas , Complejo de la Endopetidasa Proteasomal , Hemorragia Subaracnoidea , Animales , Hemorragia Subaracnoidea/patología , Hemorragia Subaracnoidea/metabolismo , Hemorragia Subaracnoidea/complicaciones , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Ratones , Complejo de la Endopetidasa Proteasomal/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Masculino , Modelos Animales de Enfermedad , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Corteza Cerebral/efectos de los fármacosRESUMEN
BACKGROUND: Aneurysmal subarachnoid hemorrhage (SAH) is a devastating acute cerebrovascular event with high mortality and permanent disability rates. Higher galectin-3 levels on days 1-3 have been shown to predict the development of delayed cerebral infarction or adverse outcomes after SAH. Recent single-cell analysis of microglial transcriptomic diversity in SAH revealed that galectin could influence the development and course of neuroinflammation after SAH. METHODS: This study aimed to investigate the role and mechanism of galectin-3 in SAH and to determine whether galectin-3 inhibition prevents early brain injury by reducing microglia polarization using a mouse model of SAH and oxyhemoglobin-treated activation of mouse BV2 cells in vitro. RESULTS: We found that the expression of galectin-3 began to increase 12 h after SAH and continued to increase up to 72 h. Importantly, TD139-inhibited galectin-3 expression reduced the release of inflammatory factors in microglial cells. In the experimental SAH model, TD139 treatment alleviated neuroinflammatory damage after SAH and improved defects in neurological functions. Furthermore, we demonstrated that galectin-3 inhibition affected the activation and M1 polarization of microglial cells after SAH. TD139 treatment inhibited the expression of TLR4, p-NF-κB p65, and NF-κB p65 in microglia activated by oxyhemoglobin as well as eliminated the increased expression and phosphorylation of JAK2 and STAT3. CONCLUSION: These findings suggest that regulating microglia polarization by galectin-3 after SAH to improve neuroinflammation may be a potential therapeutic target.
Asunto(s)
Galectina 3 , Ratones Endogámicos C57BL , Microglía , Enfermedades Neuroinflamatorias , Hemorragia Subaracnoidea , Animales , Microglía/metabolismo , Microglía/efectos de los fármacos , Galectina 3/metabolismo , Galectina 3/antagonistas & inhibidores , Ratones , Hemorragia Subaracnoidea/complicaciones , Hemorragia Subaracnoidea/metabolismo , Hemorragia Subaracnoidea/patología , Enfermedades Neuroinflamatorias/etiología , Enfermedades Neuroinflamatorias/metabolismo , Masculino , Lesiones Encefálicas/etiología , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/patologíaRESUMEN
BACKGROUND: Early brain injury (EBI) is closely associated with poor prognosis in patients with subarachnoid haemorrhage (SAH), with autophagy playing a pivotal role in EBI. However, research has shown that the stimulator of interferon genes (STING) pathway impacts autophagic flux. While the regulatory impact of neuritin on EBI and autophagic flux has been established previously, the underlying mechanism remains unclear. This study aimed to determine the role of the cGAS-STING pathway in neuritin-mediated regulation of autophagic flux following SAH. METHODS: A SAH model was established in male Sprague-Dawley rats via intravascular perforation. Neuritin overexpressions using adeno-associated virus, the STING antagonist "C-176," and the activator, "CMA," were determined to investigate the cGAS-STING pathway's influence on autophagic flux and brain injury post-SAH, along with the neuritin's regulatory effect on STING. In this study, SAH grade, neurological score, haematoxylin and eosin (H&E) staining, brain water content (BWC), sandwich enzyme-linked immunosorbent assay, Evans blue staining, immunofluorescence staining, western blot analysis, and transmission electron microscopy (TEM) were examined. RESULTS: Neuritin overexpression significantly ameliorated neurobehavioural scores, blood-brain barrier injury, brain oedema, and impaired autophagic flux in SAH-induced rats. STING expression remarkably increased post-SAH. C-176 and CMA mitigated and aggravated autophagic flux injury and brain injury, respectively, while inhibiting and enhancing STING, respectively. Particularly, CMA treatment nullified the protective effects of neuritin against autophagic flux and mitigated brain injury. CONCLUSION: Neuritin alleviated EBI by restoring impaired autophagic flux after SAH through the regulation of the cGAS-STING pathway.