The mechanism and relevant mediators associated with neuronal apoptosis and potential therapeutic targets in subarachnoid hemorrhage

Ox-LDL Induces Neuron Apoptosis and Worsens Neurological Outcomes in aSAH via Fas/FADD Pathway

The aim of this study was to assess the role of Ox-LDL (oxidized low-density lipoprotein) in the clinical prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH) and to investigate the underlying mechanisms in a mouse model of aSAH. Plasma Ox-LDL levels were measured in 50 aSAH patients and in 20 control patients via ELISA. Analysis of the associations between Ox-LDL levels and neurological function was carried out 1 year after discharge. The effects of Ox-LDL on aSAH model behavior and neurological damage were studied via Nissl staining and brain assessments. qRT‒PCR, Western blotting, and FITC/PI apoptosis detection were performed in an aSAH cell model to reveal the effects of Ox-LDL on neurons. Protein docking and Fas knockdown were used to explore the role of the Fas/FADD pathway in the Ox-LDL-induced exacerbation of neuron dysfunction. Among aSAH patients, those with lower Ox-LDL levels (1.755 ± 0.2107 mmol/L) had an mRS score ≤ 2 after one year, whereas those with higher Ox-LDL levels (2.532 ± 0.1860 mmol/L) had an mRS score > 2. Mice that were injected twice weekly with 0.2 ml of Ox-LDL, seven times, experienced increased neurological damage and neuronal apoptosis, activating the Fas/FADD pathway, an effect that was mirrored in the 20 µg/ml Ox-LDL-treated cell model. Blocking Fas/FADD with 170 µg of C75 or siRNA inhibited the apoptotic phenotype both in vivo and in vitro. Ox-LDL promoted neuronal apoptosis via Fas/FADD pathway after aSAH. The inhibition of Ox-LDL could serve as a therapeutic strategy to prevent neuronal damage after aSAH and improve prognostic outcomes.

Cross-disease transcriptomic analysis reveals DOK3 and PAPOLA as therapeutic targets for neuroinflammatory and tumorigenic processes

Objective

Subarachnoid hemorrhage (SAH) and tumorigenesis share numerous biological complexities; nevertheless, the specific gene expression profiles and underlying mechanisms remain poorly understood. This study aims to identify differentially expressed genes (DEGs) that could serve as biomarkers for diagnosis and prognosis.

Methods

Gene expression datasets (GSE122063, GSE13353, GSE161870) were analyzed using machine learning algorithms and logistic regression to identify DEGs associated with both SAH and tumorigenesis. Lasso regression and receiver operating characteristic (ROC) curve analysis were employed to evaluate the classification accuracy of these genes. Validation of critical DEGs was performed through pan-cancer analysis and experimental studies, focusing on the role of DOK3 in modulating inflammation and oxidative stress in U251MG glioblastoma and BV2 microglia cells.

Results

Fifteen common DEGs were identified, with DOK3 and PAPOLA highlighted as crucial genes implicated in SAH and neurodegenerative processes. Experimental validation demonstrated that DOK3 overexpression significantly reduced pro-inflammatory cytokine levels and oxidative stress markers while enhancing antioxidant enzyme activity. Additionally, DOK3 influenced tumorigenic processes such as apoptosis, cell cycle regulation, and proliferation, effectively mitigating LPS-induced cytotoxicity and inflammation in BV2 microglial cells.

Conclusions

DOK3 and PAPOLA play critical roles in both SAH and related neurodegeneration, presenting themselves as potential prognostic biomarkers and therapeutic targets. Notably, DOK3 exhibits potential as an antitumor agent with anti-inflammatory and antioxidative properties, offering therapeutic benefits for both cancer and neuroinflammatory conditions.

High levels of blood lipid and glucose predict adverse prognosis in patients with aneurysmal subarachnoid hemorrhage

Objective

We conducted a retrospective study on the prognostic factors of aneurysmal subarachnoid hemorrhage (aSAH) patients in the author's Hospital from January 2019 to May 2023. To discuss the association of the blood lipid and glucose levels of patients with the prognosis of aSAH, and verify that high blood lipid and glucose levels are important factors affecting adverse prognosis.

Methods

All patients with aSAH were collected as the case group, which was divided into two groups according to the modified Rankin Scores (mRS), the good prognosis group (Group A, mRS ＜ 3) and the adverse prognosis group (Group B,mRS ≥3). The clinical data of age, gender, accompanied chronic diseases (hypertension, diabetes), smoking, drinking, Glasgow Coma Scale (GCS), Hunt-Hess (H-H) grade, Modified Fisher grade, total cholesterol (TC) , triglyceride (TG) , high-density cholesterol lipoprotein (HDL-C) , low-density cholesterol lipoprotein (LDL-C) , blood glucose (BG) , responsible aneurysm diameter and location were recorded too. Correlations between blood lipid and glucose levels and Modified Fisher grade were assessed by the Spearman correlation analysis. The receiver operating characteristic (ROC) curve was utilized to evaluate the diagnostic efficacy. The effect of blood lipid and glucose levels on adverse prognosis was analyzed by Logistic regression models.

Result

A total of 259 patients with aSAH were enrolled. The average age of all patients is (56.54 ± 10.52) years, including 96 males and 163 females. They were divided into Group A (n = 146) and Group B (n = 113). Univariate analysis results show that age, the levels of TC, TG, LDL-C, and BG were higher in Group B (P < 0.05). Besides, Group B had more severe GCS, H-H grade, and Modified Fisher grade than Group A, and a higher proportion of intracranial aneurysms with larger diameter (P < 0.05). Correlation analysis showed that TC, TG, LDL-C, and BG levels were positively correlated with Modified Fisher grade (P < 0.05) and H-H grade (P < 0.05). Multivariate logistic regression model analysis showed that high level of Modified Fisher grade (OR = 0.079, 95%CI: 0.027-0.230) , high level of H-H grade (OR = 0.204, 95%CI: 0.067-0.622) , TC (OR = 10.711, 95%CI: 2.457-46.700) , LDL-C (OR = 0.178, 95%CI: 0.039-0.823) and BG (OR = 1.273, 95%CI: 1.012-1.602) increased the risk of adverse prognosis. The AUC of "H-H grade", "Modified Fisher grade", "TC level", "LDL-C level" and "BG level" was 0.822, 0.885, 0.860, 0.772, and 0.721, respectively, in the ROC curve.

Conclusion

Modified Fisher grade, H-H grade, TC, LDL-C, and BG levels at admission were independent predictors of adverse prognosis of aSAH. Besides, TC, LDL-C, and BG levels were positively correlated with Modified Fisher grade and Hunt-Hess grade. What's more, high levels of TC, LDL-C, and BG combined with Modified Fisher grade and H-H grade can identify high-risk groups with adverse prognoses in aSAH patients.

MicroRNA-195-5p Inhibits Intracerebral Hemorrhage-Induced Inflammatory Response and Neuron Cell Apoptosis

Intracerebral hemorrhage (ICH) is a severe condition characterized by bleeding within brain tissue. Primary brain injury in ICH results from a mechanical insult caused by blood accumulation, whereas secondary injury involves inflammation, oxidative stress, and disruption of brain physiology. miR-195-5p may participate in ICH pathology by regulating cell proliferation, oxidative stress, and inflammation. Therefore, we assessed the performance of miR-195-5p in alleviating ICH-induced secondary brain injury. ICH was established in male Sprague-Dawley rats (7 weeks old, 200-250 g) via the stereotaxic intrastriatal injection of type IV bacterial collagenase, after which miR-195-5p was administered intravenously. Neurological function was assessed using corner turn and forelimb grip strength tests. Protein expression was assessed by western blotting and ELISA. The miR-195-5p treatment significantly improved neurological function; modulated macrophage polarization by promoting anti-inflammatory marker (CD206 and Arg1) production and inhibiting pro-inflammatory marker (CD68 and iNOS) production; enhanced Akt signalling, reduced oxidative stress by increasing Sirt1 and Nrf2 levels, and attenuated inflammation by decreasing NF-κB activation; inhibited apoptosis via increased Bcl-2 and decreased cleaved caspase-3 levels; and regulated synaptic plasticity by modulating NMDAR2A, NMDAR2B, BDNF, and TrkB expression and ERK and CREB phosphorylation. In conclusion, miR-195-5p exerts neuroprotective effects in ICH by reducing inflammation and oxidative stress, inhibiting apoptosis, and restoring synaptic plasticity, ultimately restoring behavioral recovery, and represents a promising therapeutic agent that warrants clinical studies.

ATF2/BAP1 Axis Mediates Neuronal Apoptosis After Subarachnoid Hemorrhage via P53 Pathway

BACKGROUND

Neuronal apoptosis plays an essential role in the pathogenesis of brain injury after subarachnoid hemorrhage (SAH). BAP1 (BRCA1-associated protein 1) is considered to exert pro-apoptotic effects in multiple diseases. However, evidence supporting the effect of BAP1 on the apoptotic response to SAH is lacking. Therefore, we aimed to confirm the role of BAP1 in SAH-induced apoptosis.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to detect BAP1 expression in the cerebrospinal fluid. Endovascular perforation was performed in mice to induce SAH. Lentiviral short hairpin RNA targeting BAP1 mRNA was transduced into the ipsilateral cortex of mice with SAH to investigate the role of BAP1 in neuronal damage. Luciferase and coimmunoprecipitation assays were performed to investigate the mechanism through which BAP1 participates in hemin-induced SAH.

RESULTS

First, BAP1 expression was upregulated in the cerebrospinal fluid of patients with SAH and positively associated with unfavorable outcomes. ATF2 (activating transcription factor-2) then regulated BAP1 expression by binding to the BAP1 promoter. In addition, BAP1 overexpression enhanced P53 activity and stability by reducing P53 proteasome-mediated degradation. Subsequently, elevated P53 promoted neuronal apoptosis via the P53 pathway. Inhibition of the neuronal BAP1/P53 axis significantly reduced neurological deficits and neuronal apoptosis and improved neurological dysfunction in mice after SAH.

CONCLUSIONS

Our results suggest that the neuronal ATF2/BAP1 axis exerts a brain-damaging effect by modulating P53 activity and stability and may be a novel therapeutic target for SAH.

GSK-126 Attenuates Cell Apoptosis in Ischemic Brain Injury by Modulating the EZH2-H3K27me3-Bcl2l1 Axis

Whether epigenetic modifications participate in the cell apoptosis after ischemic stroke remains unclear. Histone 3 tri-methylation at lysine 27 (H3K27me3) is a histone modification that leads to gene silencing and is involved in the pathogenesis of ischemic stroke. Since the expression of many antiapoptotic genes is inhibited in the ischemic brains, here we aimed to offer an epigenetic solution to cell apoptosis after stroke by reversing H3K27me3 levels after ischemia. GSK-126, a specific inhibitor of enhancer of zeste homolog 2 (EZH2), significantly decreased H3K27me3 levels and inhibited middle cerebral artery occlusion (MCAO) induced and oxygen glucose deprivation (OGD) induced cell apoptosis. Moreover, GSK-126 attenuated the apoptosis caused by oxidative stress, excitotoxicity, and excessive inflammatory responses in vitro. The role of H3K27me3 in regulating of the expression of the antiapoptotic molecule B cell lymphoma-2 like 1 (Bcl2l1) explained the antiapoptotic effect of GSK-126. In conclusion, we found that GSK-126 could effectively protect brain cells from apoptosis after cerebral ischemia, and this role of GSK-126 is closely related to an axis that regulates Bcl2l1 expression, beginning with the regulation of EZH2-dependent H3K27me3 modification.

Machine learning predictors of risk of death within 7 days in patients with non-traumatic subarachnoid hemorrhage in the intensive care unit: A multicenter retrospective study

Non-traumatic subarachnoid hemorrhage (SAH) is a critical neurosurgical emergency with a high mortality rate, imposing a significant burden on both society and families. Accurate prediction of the risk of death within 7 days in SAH patients can provide valuable information for clinicians, enabling them to make better-informed medical decisions. In this study, we developed six machine learning models using the MIMIC III database and data collected at our institution. These models include Logistic Regression (LR), AdaBoosting (AB), Multilayer Perceptron (MLP), Bagging (BAG), Gradient Boosting Machines (GBM), and Extreme Gradient Boosting (XGB). The primary objective was to identify predictors of death within 7 days in SAH patients admitted to intensive care units. We employed univariate and multivariate logistic regression as well as Pearson correlation analysis to screen the clinical variables of the patients. The initially screened variables were then incorporated into the machine learning models, and the performance of these models was evaluated. Furthermore, we compared the performance differences among the six models and found that the MLP model exhibited the highest performance with an AUC of 0.913. In this study, we conducted risk factor analysis using Shapley values to identify the factors associated with death within 7 days in patients with SAH. The risk factors we identified include Gcsmotor, bicarbonate, wbc, spo2, heartrate, age, nely, glucose, aniongap, GCS, rbc, sysbp, sodium, and gcseys. To provide clinicians with a useful tool for assessing the risk of death within 7 days in SAH patients, we developed a web calculator based on the MLP machine learning model.

Advances of nanotechnology for intracerebral hemorrhage therapy

Intracerebral hemorrhage (ICH), the most devastating subtype of stoke, is of high mortality at 5 years and even those survivors usually would suffer permanent disabilities. Fortunately, various preclinical active drugs have been approached in ICH, meanwhile, the therapeutic effects of these pharmaceutical ingredients could be fully boosted with the assistance of nanotechnology. In this review, besides the pathology of ICH, some ICH therapeutically available active drugs and their employed nanotechnologies, material functions, and therapeutic principles were comprehensively discussed hoping to provide novel and efficient strategies for ICH therapy in the future.

The Critical Role of Sirt1 in Subarachnoid Hemorrhages: Mechanism and Therapeutic Considerations

The subarachnoid hemorrhage (SAH) is an important cause of death and long-term disability worldwide. As a nicotinamide adenine dinucleotide-dependent deacetylase, silent information regulator 1 (Sirt1) is a multipotent molecule involved in many pathophysiological processes. A growing number of studies have demonstrated that Sirt1 activation may exert positive effects on SAHs by regulating inflammation, oxidative stress, apoptosis, autophagy, and ferroptosis. Thus, Sirt1 agonists may serve as potential therapeutic drugs for SAHs. In this review, we summarized the current state of our knowledge on the relationship between Sirt1 and SAHs and provided an updated overview of the downstream molecules of Sirt1 in SAHs.

Inhibition of CCR2 attenuates neuroinflammation and neuronal apoptosis after subarachnoid hemorrhage through the PI3K/Akt pathway

BACKGROUND

Neuroinflammation and neuronal apoptosis are closely associated with a poor prognosis in patients with subarachnoid hemorrhage (SAH). We investigated the role of C-C motif chemokine receptor 2 (CCR2) in SAH.

METHODS

Pre-processed RNA-seq transcriptome datasets GSE167110 and GSE79416 from the Gene Expression Omnibus (GEO) database were screened for genes differentially expressed between mice with SAH and control mice, using bioinformatics analysis. The endovascular perforation model was performed to establish SAH. RS504393 (a CCR2 antagonist) and LY294002 (PI3K inhibitor) were administered to explore the mechanism of neuroinflammation after SAH. SAH grading, neurological scoring, brain water content and blood-brain barrier (BBB) permeability determination, enzyme-linked immunosorbent assay (ELISA), western blotting, and immunofluorescence were performed. An in vitro model of SAH was induced in H22 cells by hemin treatment. The protective mechanism of CCR2 inhibition was studied by adding RS504393 and LY294002. Clinical cerebrospinal fluid (CST) samples were detected by ELISA.

RESULTS

Expression of CCR2 was upregulated in both datasets and was identified as a hub gene. CCR2 expression was significantly upregulated in the cytoplasm of neurons after SAH, both in vitro and in vivo. RS significantly reduced the brain water content and blood-brain barrier permeability, alleviated neuroinflammation, and reduced neuronal apoptosis after SAH. Additionally, the protective effects of CCR2 inhibition were abolished by LY treatment. Finally, the levels of CCR2, inflammatory factors, and apoptotic factors were elevated in the CSF of patients with SAH. CCR2 levels were associated with patient outcomes at the 6-month follow-up.

CONCLUSION

CCR2 expression was upregulated in both in vitro and in vivo SAH models. Additionally, inhibition of CCR2, at least partly through the PI3K/AKT pathway, alleviated neuroinflammation and neuronal apoptosis in vivo and in vitro. CCR2 levels in the CSF have a moderate diagnostic value for 6-month outcome prediction in patients with SAH.