Subarachnoid Hemorrhage Group Research Articles

Intracranial Aneurysms and Cerebral Small Vessel Disease: Is There an Association between Large- and Small-Artery Diseases?

Background/Objectives: Intracranial aneurysms (IAs) may be connected to interactions between large and small intracranial vessels. We aimed to investigate the association between IAs and cerebral small-vessel disease (CSVD) and assess CSVD impact on IA patient management. Methods: This retrospective study analyzed clinical data and MRI features of CSVD in 192 subarachnoid hemorrhage (SAH) patients: 136 with incidental IA, 147 with severe CSVD without SAH/IA, and 50 controls without SAH, IA, or severe CSVD. MRI assessments followed the Standards for Reporting Vascular Changes on Neuroimaging (STRIVE), with a total burden of small-vessel disease (TBSVD) score calculated. Statistical analyses included forward selection and binary logistic regression. Results: TBSVD differed significantly across groups (p < 0.001), except between SAH and IA groups (p = 0.8). Controls had the lowest TBSVD (1.00; 1.22 ± 0.996), followed by SAH (2.00; 2.08 ± 1.013) and IA groups (2.00; 2.04 ± 1.141), with the highest in the CSVD group (1.00; 1.22 ± 0.996). White-matter hyperintensity (WMH) patterns varied with IA rupture status (p = 0.044); type A was prevalent in SAH patients and type D in the IA group. Incorporating MRI CSVD features and TBSVD into risk assessments did not enhance IA prediction or outcome models. Conclusions: IA patients exhibit a higher CSVD burden than controls, suggesting a link between small and large intracranial vessels. WMH patterns distinguish between ruptured and unruptured IA patients, offering potential markers for IA rupture risk assessment and signaling a paradigm shift in understanding IAs and CSVD.

Polydatin ameliorates early brain injury after subarachnoid hemorrhage through up-regulating SIRT1 to suppress endoplasmic reticulum stress.

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. 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. 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. 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.

Effect of Levobupivacaine Hydrochloride-Loaded Nanospheres on Delayed Cerebral Vasospasm Following Subarachnoid Hemorrhage in Rabbits

This research was aimed to analyze the mechanism of action of levobupivacaine hydrochloride-loaded nanospheres on delayed cerebral vasospasm following subarachnoid hemorrhage (SAH). Levobupivacaine hydrochloride-loaded nanospheres (LevoBPV Hcl/PLGA) were prepared using the solvent evaporation methodology, with the raw material as a control. The blood drug concentrations were detected by HPLC after subcutaneous and subarachnoid administration in experimental rabbits. Forty New Zealand white rabbits were randomly assigned into Sham group, SAH group, LevoBPV Hcl group (10 mg/kg), and LevoBPV Hcl/PLGA group (10 mg/kg), with 10 rabbits in each group. The SAH model was induced using the double blood injection methodology combined with internal carotid artery ligation. Brain tissue samples were collected on day 7 for pathological characterization, determination of neuronal apoptosis, and measurement of basilar artery diameter and area. The levels of oxidative stress factors (superoxide (SOD), malondiadehyde (MDA), glutathione peroxidase (GSH-Px)) and vasoconstrictor factors (nitric oxide (NO), endothelin-1 (ET-1)) in the cerebrospinal fluid (CSF) were detected using assay kits. The results revealed that the drug loading capacity of LevoBPV Hcl/PLGA was 29.13%, encapsulation efficiency was 87.09%, and the average particle size was 81.43 μm. Under the same dosage, both subcutaneous and subarachnoid administration of LevoBPV Hcl/PLGA exhibited two concentration peaks in the blood drug concentration, with lower concentration values versus LevoBPV Hcl group, and a longer average residence time than LevoBPV Hcl group (P &lt; 0.05). Relative to Sham group, SAH group exhibited decreased diameter and area of the basilar artery, reduced neuronal density, increased neuronal apoptosis rate, decreased levels of SOD, GSH-Px, and NO in the CSF, and increased levels of MDA and ET-1 (P &lt; 0.05). Moreover, LevoBPV Hcl group and LevoBPV Hcl/PLGA group showed increased diameter and area of the basilar artery, higher neuronal density, reduced neuronal apoptosis rate, elevated levels of SOD, GSH-Px, and NO in the CSF, and decreased levels of MDA and ET-1 versus SAH group (P &lt; 0.05). The LevoBPV Hcl/PLGA group exhibited increased diameter and area of the basilar artery, higher neuronal density, reduced neuronal apoptosis rate, elevated levels of SOD, GSH-Px, and NO in the CSF, and decreased levels of MDA and ET-1 versus LevoBPV Hcl group (P &lt; 0.05). In short, LevoBPV HCl-loaded nanospheres can prolong the in vivo residence time of subcutaneous and subarachnoid administration, reduce the maximum blood drug concentration, and enhance drug safety. Furthermore, these nanospheres can inhibit neuronal apoptosis following SAH, regulate oxidative stress and vasoconstrictor factor expression, thereby suppressing the occurrence of delayed cerebral vasospasm and alleviating brain tissue damage.

Post-Thrombectomy Subarachnoid Hemorrhage: Incidence, Predictors, Clinical Relevance, and Effect Modulators.

Subarachnoid hemorrhage (SAH) following endovascular thrombectomy (EVT) is a poorly understood phenomenon, and whether it is associated with clinical detriment is unclear. This was an explorative analysis of a national database of real-world hospitalizations in the United States. Patients who underwent EVT were included. Patients were divided into SAH and non-SAH groups, and hospitalization outcomes were compared using multivariable logistic regression models. Regression models were also used to identify significant predictors for post-EVT SAH, and significant modulators of SAH's association with hospitalization outcomes were also assessed. A total of 99,219 EVT patients were identified; 6174 (6.2%) had SAH. Overall, SAH was independently associated with increased odds of in-hospital mortality (21.5% vs. 10.6%, adjusted OR 2.53 [95%CI 2.23-2.87], p < 0.001) and lower odds of routine discharge to home with self-care (18.2% vs. 28.0%, aOR 0.58 [95%CI 0.52-0.65], p < 0.001). Distal/medium vessel occlusion (DMVO), coagulopathy, angioplasty or stenting, concurrent intraparenchymal hemorrhage (IPH), and female sex were associated with higher odds of SAH. DMVO was associated with particularly heightened risk of death (31.8% vs. 7.9%, aOR 6.99 [95%CI 2.99 to 16.3], p < 0.001), which was an effect size significantly larger than other sites of vascular occlusion (interaction p > 0.05). SAH is an uncommon but likely clinically detrimental post-EVT complication. DMVO, coagulopathy, angioplasty or stenting, concurrent IPH, and female sex were independently associated with higher odds of post-EVT SAH. SAH associated with DMVO-EVT may be particularly harmful.

Secukinumab Ameliorates Oxidative Damage Induced by Subarachnoid Hemorrhage

This study aimed to investigate the histological and biochemical neuroprotective effects of secukinumab (SEC) on brain damage induced by subarachnoid hemorrhage (SAH) in male Wistar Albino rats. Forty male Wistar Albino rats were randomly divided into 4 groups of equal size: control, SEC, SAH, and SAH+SEC. SAH was induced the SAH and SAH+SEC groups by injecting autologous blood collected from the hearts of the rats into the subarachnoid space via the foramen magnum. SEC was administered intraperitoneally once a week to the SEC and SAH+SEC groups after the surgical procedure. On the 14th day of surgery, the rats were sacrificed and their cerebral tissues were collected for biochemical analysis and histopathological examination. SAH led to changes in oxidative stress parameters by increasing malondialdehyde levels and decreasing superoxide dismutase, glutathione, catalase, and glutathione peroxidase levels. Histopathologically, cerebral tissues in the SAH groups showed alterations such as congestion and cell infiltration. Treatment with SEC significantly reduced malondialdehyde levels and increased superoxide dismutase, glutathione, catalase, and glutathione peroxidase levels. SEC also decreased histopathological alterations in brain tissues. This study revealed that SEC (3mg/kg) therapeutically influenced oxidative and histopathological changes in blood parameters and brain tissues caused by experimental SAH. SEC helps reduce brain damage in rats with SAH and possesses antioxidant and neuroprotective properties. Further advanced studies are needed to prove its potential benefits for humans.

Analysis of different expression RNA binding protein genes in mouse microglia cell from the brains of mice 72 h after subarachnoid hemorrhage or sham operation

BackgroundThe prognosis of brain injury caused by subarachnoid hemorrhage (SAH) is poor. Previous studies showed that abnormal function of RBPs might be involved in brain injury, neuroinflammation and further affect microglia homeostasis. However, no studies have systematically analyzed the genome-wide abnormal expression of RBPs genes in microglia during SAH.MethodsRNA-seq data of microglia from the SAH mouse group (SAH) and control sham-operated mouse group (sham) were downloaded from the GEO database in GSE167957, including four samples from the sham group and four samples from the SAH group for subsequent analysis.Utilizing GO and KEGG functional enrichment analyses, we conducted a comprehensive study of differentially expressed genes (DEGs), alternative splicing patterns, and co-expression networks to gain deeper insights into the differential expression of RNA-binding proteins (RBPs) and differential alternative splicing events (ASEs) between the SAH (subarachnoid hemorrhage) and sham groups. This analysis aimed to elucidate the potential mechanisms underlying the aberrant expression of RBPs in microglia during brain injury caused by SAH.ResultsASEs and co-expression analyses of differentially expressed RBPs and differential ASEs were carried out in microglia in terms of gene expression. GO and KEGG functional enrichment analysis showed that aberrantly expressed RBPs such as Mcm7, Mtdh, SRSF3, and Hnrnpa2b1 may affect and regulate downstream Csnk1d, Uckl1 and other protein phosphorylation-related genes by alterative splicing.ConclusionRBPs were aberrantly expressed in microglia during the development of brain injury secondary to SAH, regulating alterative splicing of downstream genes and influencing the progression of SAH brain injury in this study. This implies that RBPs are important for the identification of new therapeutic targets for brain injury after SAH.

Injection of Collagen Binding Domain-Brain Derived Neurotrophic Factor Promotes SIRT1 Expression: Improving Neuroinflammation in Experimental Subarachnoid Hemorrhage.

Subarachnoid hemorrhage (SAH) is a severe cerebrovascular disease, often leading to neuroinflammation and neuronal damage. Activation of the Nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome is closely associated with post-SAH neuroinflammation, while activation of Nicotinamide Adenine Dinucleotide (NAD)-dependent deacetylase sirtuin-1 (SIRT1) has neuroprotective effects. This study aimed to investigate the impact of injectable Collagen Binding Domain-Brain Derived Neurotrophic Factor (CBD-BDNF) on neuroinflammation and neuronal damage following SAH. After establishing the SAH model, experimental animals were divided into three groups: sham surgery group (Sham), SAH group, and SAH+neuroregenerative scaffold (CBD-BDNF treatment) group. Behavioral performance was evaluated using neurofunctional deficit, beam balance, and Y-maze tests. Expression of inflammatory factors and essential proteins was quantitatively analyzed using Enzyme-Linked Immunosorbent Assay (ELISA) kits and immunoblotting. Terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) staining was used to assess cell apoptosis. To further investigate the mechanism of action of CBD-BDNF on SIRT1, the model animals were treated with EX527 (SIRT1 inhibitor) for comparative studies. Neurological deficit tests, CBD-BDNF improves functional outcomes after SAH. Compared to the SAH group, the SAH+neuroregenerative scaffold group showed significantly increased expression of SIRT1 protein and significantly decreased expression of NLRP3, Apoptosis-associated speck-like protein containing a CARD (ASC), and c-caspase-1. The inflammatory cytokines Interleukin-1 beta (IL-1β), IL-6, and IL-18 levels also significantly decreased in the SAH+neuroregenerative scaffold group. Additionally, animals in the SAH+neuroregenerative scaffold group showed better neurofunctional recovery in neurofunctional deficit and beam balance tests. The number of apoptotic cells significantly decreased in the SAH+neuroregenerative scaffold group compared to the SAH group. However, when SIRT1 was inhibited with EX527, the aforementioned neuroprotective effects were reversed, indicating the involvement of CBD-BDNF through SIRT1 activation. This study demonstrates that injectable CBD-BDNF can significantly alleviate neuroinflammation and neuronal damage resulting from SAH by blocking NLRP3 inflammasome activation and promoting SIRT1 expression. These findings provide a new therapeutic strategy for neuroprotection after SAH and reveal the mechanism of action of CBD-BDNF as a potential therapeutic agent. Future research will further explore the long-term efficacy and safety of CBD-BDNF.

Protective Effects of Adropin in Experimental Subarachnoid Hemorrhage

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.

Transcriptomics and metabolomics reveal hypothalamic metabolic characteristics and key genes after subarachnoid hemorrhage in rats

Subarachnoid hemorrhage (SAH) is a serious hemorrhagic event with high mortality and morbidity. Multiple injurious events produced by SAH can lead to a series of pathophysiologic processes in the hypothalamus that can severely impact patients’ life. These pathophysiologic processes usually result in physiologic derangements and dysfunction of the brain and multiple organs. This dysfunction involved multiple dimensions of the genome and metabolome. In our study, we induced the SAH model in rats to obtain hypothalamic tissue and serum. The samples were subsequently analyzed by transcriptomics and metabolomics. Next, the functional enrichment analysis of the differentially expressed genes and metabolites were performed by GO and KEGG pathway analysis. Through transcriptomic analysis of hypothalamus samples, 263 up-regulated differential genes, and 207 down-regulated differential genes were identified in SAH groups compared to Sham groups. In the KEGG pathway analysis, a large number of differential genes were found to be enriched in IL-17 signaling pathway, PI3K-Akt signaling pathway, and bile secretion. Liquid chromatography-mass spectrometry metabolomics technology was conducted on the serum of SAH rats and identified 11 up-regulated and 26 down-regulated metabolites in positive ion model, and 1 up-regulated and 10 down-regulated metabolites in negative ion model. KEGG pathways analysis showed that differentially expressed metabolites were mainly enriched in pathways of bile secretion and primary bile acid biosynthesis. We systematically depicted the neuro- and metabolism-related biomolecular changes occurring in the hypothalamus after SAH by performing transcriptomics and metabolomics studies. These biomolecular changes may provide new insights into hypothalamus-induced metabolic changes and gene expression after SAH.

Intimal Hemorrhage of Basilar Artery Induced by Severe Vasospasm Following Subarachnoid Hemorrhage: The Experimental Analysis.

Cerebral vasospasm, a serious complication of subarachnoid hemorrhage (SAH), has been extensively studied for its neurochemical and pathophysiologic mechanisms. However, the contribution of inner elastic membrane dissection and subintimal hemorrhage to basilar artery occlusion remains underexplored. This study investigates inner elastic membrane-related changes in the basilar artery after SAH. Twenty-four hybrid rabbits were divided into control, sham, and SAH groups, with SAH induced by autologous blood injection. After 2 weeks, basilar artery changes, vasospasm indexes (VSIs), and dissections were evaluated. The SAH group showed significantly higher VSI, with vascular wall thickening, luminal narrowing, convoluted smooth muscle cells, intimal elastic membrane disruption, endothelial cell desquamation, and apoptosis. Some SAH animals exhibited subintimal hemorrhage, inner elastic membrane dissection, and ruptures. Basilar arteries with subintimal hemorrhage had notably higher VSI. These findings highlight the role of subintimal hemorrhage and inner elastic membrane dissection in basilar artery occlusion post-SAH, offering valuable insights into vasospasm pathophysiology.

β-hydroxybutyrate alleviates neurological deficits by restoring glymphatic and inflammation after subarachnoid hemorrhage in mice

BackgroundBoth glymphatic system dysfunction and inflammatory response aggravate neurological dysfunction after subarachnoid hemorrhage (SAH). Studies have shown that β-hydroxybutyrate (BHB) may mitigate painful diabetic neuropathy (PDN) by upregulating SNTA1 expression and reinstating AQP4 polarity. However, the potential of BHB to ameliorate glymphatic system function and inflammatory response in SAH mice remains uncertain. MethodsThe SAH models were constructed by injection of arterial blood into cisterna Magana. Three groups of C57 mice were randomly assigned: Sham, SAH, and BHB. All mice were subjected to neurological function assessment, western blot, immunofluorescence double staining, and RNA-seq. Glymphatic system function was examined with tracer and immunofluorescence double staining, and the differential genes were examined with RNA-seq. In addition, the expression of related inflammation was detected. ResultsCompared with the SAH group, BHB reinstated AQP4 polarization by upregulating SNTA1 protein to enhance the glymphatic system. According to RNA-seq, the different genes were primarily connected to microglia activation, astrocytes, and inflammation. Western blot and immunofluorescence further confirmed that the related inflammatory protein expression levels were upregulated. BHB attenuated neuroinflammation after SAH. Ultimately, it can mitigate the neurological deficits in SAH mice. ConclusionThe study reveals a novel mechanism that BHB treatment mitigates neurologic impairment in SAH mice. We propose that BHB may play a neuroprotective effect by enhancing glymphatic system function and attenuating neuroinflammatory subarachnoid hemorrhage.

CDDO, an Anti-Inflammatory and Antioxidant Compound, Attenuates Vasospasm and Neuronal Cell Apoptosis in Rats Subjected to Experimental Subarachnoid Hemorrhage.

Subarachnoid hemorrhage (SAH) is a type of stroke caused by bleeding into the subarachnoid space. SAH is a medical emergency and requires prompt treatment to prevent complications such as seizures, stroke, or other brain damage. Treatment options may include surgery, medication, or a combination of both. 2-Cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO), a compound with anti-inflammatory and antioxidant properties, is currently being investigated as a potential treatment for various diseases, including chronic kidney disease and pulmonary arterial hypertension. In this study, the effects of CDDO on rats subjected to SAH were evaluated. Male Sprague-Dawley rats were divided into four groups (n = 6/group): (1) control group, (2) SAH group, (3) SAH + low-dose CDDO (10 mg/kg injected into the subarachnoid space at 24 h after SAH) group, and (4) SAH + high-dose CDDO (20 mg/kg) group. CDDO improved SAH-induced poor neurological outcomes and reduced vasospasm in the basal artery following SAH. It also decreased the SAH-induced expression of proinflammatory cytokines such as TNF-α, IL-1β, and IL-6 in both the cerebrospinal fluid and serum samples as determined by ELISA. A Western blot analysis confirmed an increase in the p-NF-κB protein level after SAH, but it was significantly decreased with CDDO intervention. Immunofluorescence staining highlighted the proliferation of microglia and astrocytes as well as apoptosis of the neuronal cells after SAH, and treatment with CDDO markedly reduced the proliferation of these glial cells and apoptosis of the neuronal cells. The early administration of CDDO after SAH may effectively mitigate neuronal apoptosis and vasospasm by suppressing inflammation.

Effect of Intrathecal Eugenol on Cerebral Vasospasm in an Experimental Subarachnoid Hemorrhage Model

Eugenol has various curative properties. It affects the dilatation of cerebral arteries through voltage-dependent Ca2+ channel inhibition. This study is the first to explore the impact of eugenol on neuroprotection and vasospasm in an experimental subarachnoid hemorrhage (SAH) model. Twenty-four adult male Sprague-Dawley rats were indiscriminately separated into 3 groups: the control group (n=8), the SAH group (n=8), and the eugenol group (n=8). A double-bleeding method was used. The eugenol group received intracisternal eugenol (Sigma-Aldrich, St. Louis, MO, USA) at 30μg/20μl after induction of SAH. On the day 7, all groups were euthanized. Measurements were taken for basilar artery wall thickness, lumen diameter, serum endothelin-1 (ET-1), and caspase-3 levels. The eugenol group exhibited significantly lower wall thickness, ET-1, oxidative stress index, and caspase-3 levels compared to the SAH group. In comparison to the control group, the eugenol group showed a higher oxidative stress index along with higher ET-1 and caspase-3 levels, but these differences were not statistically significant. Wall thickness was significantly higher in the eugenol group than in the control group. This study represents the first literature exploration of intrathecal eugenol's impact on vasospasm induced after experimental SAH. Administration of intrathecal eugenol demonstrates a positive effect on the treatment of experimental vasospasm as well as on the reduction of oxidative stress and apoptosis.

WITHDRAWN: Recombinant osteopontin stabilizes the blood brain barrier following subarachnoid hemorrhage in rats

Background and PurposeRecombinant osteopontin (rOPN) decreases neuronal cell death and brain edema and improves the neurological scores following subarachnoid hemorrhage (SAH) in rats. The molecular mechanisms of the preservation of blood-brain barrier of rOPN following SAH in rats were examined in this study. MethodsAdult rats were divided into 3 groups: sham, vehicle, and treatment groups. Each animal in the SAH group underwent a surgical procedure to induce SAH, and the brains was harvested at 24 hours for analysis. For the mechanism part of the study two additional groups were operated and treated with Fib-14 and Wortmannin additional to rOPN. rOPN was administered via the nasal route and neurological scores as well as brain water content were evaluated at 24 hours after SAH induction. The blood brain barrier (BBB) permeability was evaluated using Evans Blue dye extravasation. The expressions of tight junction proteins claudin-3, claudin-5, occludin and the phosphorylation of β-catenin were examined using Western blot analysis. ResultsrOPN improved neurological scores and reduced brain edema at 24 hours after SAH. The BBB preservation action of rOPN is mediated in part through stabilizing β-catenin and increasing expression of tight junction proteins, claudin-3, claudin-5, and occludin. rOPN is thought to exert its effects through FAK activated PI3K-Akt pathway. ConclusionSince BBB disruption is one of the major pathophysiology of EBI after SAH, rOPN may be a promising drug to maintain BBB integrity and functions in SAH treatment.

MiR-221-5p regulates blood–brain barrier dysfunction through the angiopoietin-1/-2/Tie-2 signaling axis after subarachnoid hemorrhage

ABSTRACT Aim To explore the potential role of microRNA miR-221-5p on the angiopoietin-1 (Ang-1)/Ang-2/Tie-2 signaling axis after subarachnoid hemorrhage (SAH) in a rat model. Methods Aspects of the rat’s behavior were measured using the Kaoutzanis scoring system to test neurological responses. This included feeding behavior, body contraction, motor, and eye-opening responses. Brain sections were studied using transmission electron microscopy and Evans blue extravasation. Levels of Ang-1, Ang-2, and Tie-2 were determined by Western blot, while miR-221-5p was quantified using stem-loop real-time quantitative PCR (RT-qPCR). Results The SAH group responded worse to the neurological response test than the sham-operated group. The intercellular space was widened in the SAH group, but not in the sham-operated group. Evans blue dye leaked significantly more into brain tissue cells of the SAH group. Stem-loop qRT-PCR showed elevated miR-221-5p levels. Additionally, Ang-1 and Tie-2 were reduced but Ang-2 expression was increased after SAH. This led to a significant reduction of the Ang-1/Ang-2 ratio in the brain tissue, which was associated with the destruction of the blood-brain barrier. Conclusion The data indicate that miR-221-5p might regulate blood-brain barrier dysfunction through the Ang-1/Ang-2/Tie-2 signaling axis, suggesting that it should be further investigated as a potential novel biomarker.

Abstract TP318: Evaluating Hypothalamic Injury in a Rat Model of Subarachnoid Hemorrhage

Background and purpose: Hypothalamus is one of the most affected parts of the brain by subarachnoid hemorrhage (SAH). There are some reports that hypothalamic disorders are important determinants of poor prognosis after SAH from acute to chronic phase. However, there have never been any reports on the development of therapeutic strategies targeting the hypothalamus for SAH, and few reports have even demonstrated immunohistological evidence of hypothalamic injury after SAH. Here, we demonstrated on the investigation of temporal changes in hypothalamic injury from the hyperacute phase to the chronic phase after SAH in a rat model of SAH. Methods: Moderate to severe endovascular perforation model of SAH was created using 300g - 450g Sprague-Dawley rats, and they were divided into two groups: Sham operated and SAH group.The endpoints were 3, 6, 12, 24, and 72 hours after SAH, and 7 days and 4 weeks after SAH, and physiological findings and neurological symptoms were measured and hypothalamic injury and related factors in the hypothalamus were studied immunohistochemically. Results: The SAH group showed significant neurological deterioration, and the expression of FJC, indicative of cell death, and TUNEL-positive cells, indicative of apoptosis, in the hypothalamus was significantly elevated in the early phase and decreased over time compared to the sham SAH group. On the other hand, oxytocin, a hypothalamic hormone associated with neuronal protection, was significantly decreased in the SAH group during the acute phase. Conclusions: The present study shows that hypothalamic injury appears hyper acute phase of SAH and persists at least during the acute phase of SAH. These findings suggest that the hypothalamus may be an important therapeutic target in the acute phase of SAH.

Abstract TP319: Time Course of Novel Hypothalamic Protein Sushi Repeat-Containing Protein X- Linked 2 Expression in a Rat Model of Subarachnoid Hemorrhage

Background: Hypothalamic injury after subarachnoid hemorrhage (SAH) is known to be associated with short- and long-term prognosis. Recently, a novel hypothalamic protein, Sushi repeat-containing protein X-linked 2 (SRPX2), was reported as a potential biomarker for hypothalamic damage after traumatic brain injury. However, there are no reports on SRPX2 in SAH, and its role is unknown. In this study, we investigated the expression of SRPX2 in the hypothalamus after SAH using a rat model of SAH. Methods: We made endovascular perforation model of SAH using 300g - 450g SD rats, and they were divided into two groups: Sham operated and SAH group. The endpoints were 3, 6, 12, 24, and 72 hours after SAH, and 7 days and 4 weeks after SAH, and physiological findings and neurological symptoms were measured. In addition, changes in SRPX-2 in the hypothalamic injury and related factors were examined immunohistochemically. Results: The SAH group showed significant neurological deterioration, and a significant decrease in body temperature after 3 h of SAH. Expression of SRPX2 in the hypothalamus was also significantly decreased at 3 h after SAH. However, it was not associated with changes in FJC- and TUNEL-positive cells suggestive of cell death or DHE expression suggestive of oxidative stress. On the other hand, OXT showed a significant decrease after 3 hours of SAH as measured by ELISA in serum from the jugular vein. Conclusions: This is the first study to investigate the expression of SRPX2 in the hypothalamus after SAH time course. Although our results suggest that SRPX2 may not be directly associated with hypothalamic injury after SAH, the fact that SRPX2 expression was decreased during the hyperacute phase and OXT and body temperature were also decreased at the same time suggests that SRPX2 may be indirectly associated with hypothalamic injury after SAH through regulation of endocrine and autonomic function in the hypothalamic-pituitary axis. Further studies are warranted to investigate the possibility that SRPX2 may be indirectly related to hypothalamic disturbances after SAH through endocrine and autonomic regulation of the hypothalamic-pituitary axis.

Abstract TMP90: Extension of Subarachnoid Hemorrhage Following Mechanical Thrombectomy is Associated With Clinical Outcomes: A Subgroup Analysis of CLEAR Trial

Introduction: Subarachnoid hemorrhage (SAH) following mechanical thrombectomy (MT) is not uncommon. The prognostic implication for these patients remains unclear and may be affected by the extension of SAH. Methods: We included patients with SAH detected on CT after MT from CLEAR Study (The Vesalio NeVa Stent Retriever Study for Treatment of Large Vessel Occlusion Strokes). SAH was further classified according to extension degree into diffuse (&gt; 1 extraparenchymal compartment) and non-diffuse. Unadjusted and adjusted logistic regressions were used to measure the association of both groups with modified Rankin Scale (mRS) (mRS) score at 90 days. Results: Among 139 patients, 20 SAH patients qualified for final analysis (10 with diffuse SAH: 10 with non-diffuse SAH). There were no statistically significant differences for sex, thrombolytics administration, pre mRS score, baseline NIHSS score, and procedure access (p &gt;0.1) while there were statistically significant imbalances for age and site of occlusion (p=0.02). At the end of the procedure, there was no statistically significant difference in successful recanalization rates defined as a Modified Treatment in Cerebral Ischemia (mTICI) score of 2b or greater (100% in non-diffuse vs. 90% diffuse, P&gt;0.99). However, non-diffuse SAH group were significantly associated with reduced disability at 90 days in both unadjusted (Common odds ratio [cOR] 11.09, 95% confidence interval [CI] (1.72-71.37), p = 0.01) and adjusted models (cOR 12.32, 95% CI 1.49-102.05, p = 0.02). Additionally, non-diffuse SAH group were significantly associated with significantly improved 90-day good functional outcomes defined as mRS 0-2 in unadjusted analysis (80% vs. 30%, OR 9.33, 95% CI 1.99-72.99, p = 0.03) but not in adjusted analysis (OR 7.84, 95% CI 0.55-109.94, p = 0.13). Median NIHSS at 24 hours was significantly lower in non-diffuse group compared to diffuse group (3 [2-6] vs. 17.5 [12-19], p&lt; 0.001) while mortality was reduced to half but did not reach a statistical significance level (10% vs. 20%, p&gt;0.99). Conclusions: Non-diffuse SAH was associated with better clinical outcomes compared to diffuse SAH. These findings may inform adjustable management approaches according to extension degree of SAH.

Abstract TP303: Perfluorocarbon Oxygent Limits Functional Impairment and Brain Damage Following Subarachnoid Hemorrhage

Introduction: Subarachnoid hemorrhage (SAH) is the deadliest form of hemorrhagic stroke. Post-SAH vasospasm induces brain tissue hypoxia-ischemia resulting in brain injury and functional impairments. However, translational studies focused on post-SAH brain tissue oxygenation for functional improvements remain limited. We propose the use of Oxygent, a perfluorocarbon (PFC) based lipid emulsion oxygen carrier, as a promising therapy to improve post-SAH functional outcomes. Here we propose the use of Oxygent, a perfluorocarbon (PFC), as effective therapeutics. Oxygent-PFC comes as a lipid emulsion of micro-particles with great flexibility. The ultra-smaller size of these particles as compared to RBCs lets them flow even when there is just a trickle of residual plasma and efficiently deliver oxygen to prevent tissue damage. We tested the hypothesis that Oxygent-PFC would attenuate post-SAH functional and anatomical impairments. Methods: Adult C57BL/6 wildtype mice were subjected to the endoperforation model of SAH followed by an i.v injection of Oxygent-PFC or saline (9ml/kg at 6h after SAH). At 48h after SAH, mice were tested for functional outcomes followed by blood collection through cardiac puncture. Thereafter, mice were transcardially perfused, and brains were harvested to assess various immunohistochemical and biochemical outcomes. Results and Conclusion: We found that SAH resulted in significant neurologic and motor deficits while Oxygent-PFC treatment attenuated these functional deficits. There was a significant neuronal death after SAH as compared with the sham group and Oxygent-PFC prevented neuronal death. Moreover, mitochondrial activity as assessed by OXPHOS was markedly decreased after SAH while Oxygent-PFC treatment significantly improved the mitochondrial activity as compared to the vehicle-treated SAH group. These data show that Oxygent-PFC treatment preserves mitochondrial activity, dimmish tissue damage, and improve functional outcomes. Our novel preliminary study in SAH encourages us to investigate the mechanism of action of Oxygent-PFC and a comprehensive preclinical trial to test its efficacy in different animal models of SAH.

Automated magnetic resonance imaging quantification of cerebral parenchymal and ventricular volume following subarachnoid hemorrhage: associations with cognition

This study aims to investigate cerebral parenchymal and ventricular volume changes after subarachnoid hemorrhage (SAH) and their potential association with cognitive impairment. 17 patients with aneurysmal SAH (aSAH) and 21 patients with angiographically negative SAH (anSAH) without visually apparent parenchymal loss on conventional magnetic resonance imaging (MRI) were included, along with 76 healthy controls. Volumetric analyses were performed using an automated clinical segmentation and quantification tool. Measurements were compared to on-board normative reference database (n = 1923) adjusted for age, sex, and intracranial volume. Cognition was assessed with tests for psychomotor speed, attentional control, (working) memory, executive functioning, and social cognition. All measurements took place 5 months after SAH. Lower cerebral parenchymal volumes were most pronounced in the frontal lobe (aSAH: n = 6 [35%], anSAH n = 7 [33%]), while higher volumes were most substantial in the lateral ventricle (aSAH: n = 5 [29%], anSAH n = 9 [43%]). No significant differences in regional brain volumes were observed between both SAH groups. Patients with lower frontal lobe volume exhibited significantly lower scores in psychomotor speed (U = 81, p = 0.02) and attentional control (t = 2.86, p = 0.004). Additionally, higher lateral ventricle volume was associated with poorer memory (t = 3.06, p = 0.002). Regional brain volume changes in patients with SAH without visible parenchymal abnormalities on MRI can still be quantified using a fully automatic clinical-grade tool, exposing changes which may contribute to cognitive impairment. Therefore, it is important to provide neuropsychological assessment for both SAH groups, also including those with clinically mild symptoms.