Exploring the potential of VGLL3 methylation as a prognostic indicator for intracranial aneurysm with gender-specific considerations.

DNA methylation is widely recognized to play a role in intracranial aneurysm (IA) pathogenesis. We investigated the levels of methylation of vestigial-like 3 (VGLL3) in IA and explored its potential as a prognostic indicator. A total of 48 patients with IA and 48 healthy controls were included in the present study. Methylation levels of CpG sites were assessed using bisulfite pyrosequencing, and levels of VGLL3, TEAD, and YAP in the blood were measured by real-time quantitative polymerase chain reaction testing. VGLL3 methylation was significantly higher in controls than in IA patients (P=0.001), and this phenomenon was more pronounced in females (P<0.001). Compared with the control group, the expression levels of VGLL3 and TEAD in the blood of IA patients were significantly increased, while YAP was significantly decreased. VGLL3 methylation was positively correlated with HDL (P=0.003) and female Lpa concentration (r = 0.426, P=0.03), and was also negatively correlated with age (P=0.003), APOE (P=0.005), and VGLL3 mRNA expression (P<0.001). Methylation and mRNA expression of VGLL3 may serve as indicators of IA risk in females (AUC = 0.810 and 0.809). VGLL3 methylation may participate in the pathogenesis of IA by regulating the expression of the VGLL3/TEAD/YAP pathway, and its gene methylation and expression levels have IA risk prediction value.

Perspective from single-cell sequencing: Is inflammation in acute ischemic stroke beneficial or detrimental?

BACKGROUND: Acute ischemic stroke (AIS) is a common cerebrovascular event associated with high incidence, disability, and poor prognosis. Studies have shown that various cell types, including microglia, astrocytes, oligodendrocytes, neurons, and neutrophils, play complex roles in the early stages of AIS and significantly affect its prognosis. Thus, a comprehensive understanding of the mechanisms of action of these cells will be beneficial for improving stroke prognosis. With the rapid development of single-cell sequencing technology, researchers have explored the pathophysiological mechanisms underlying AIS at the single-cell level. METHOD: We systematically summarize the latest research on single-cell sequencing in AIS. RESULT: In this review, we summarize the phenotypes and functions of microglia, astrocytes, oligodendrocytes, neurons, neutrophils, monocytes, and lymphocytes, as well as their respective subtypes, at different time points following AIS. In particular, we focused on the crosstalk between microglia and astrocytes, oligodendrocytes, and neurons. Our findings reveal diverse and sometimes opposing roles within the same cell type, with the possibility of interconversion between different subclusters. CONCLUSION: This review offers a pioneering exploration of the functions of various glial cells and cell subclusters after AIS, shedding light on their regulatory mechanisms that facilitate the transformation of detrimental cell subclusters towards those that are beneficial for improving the prognosis of AIS. This approach has the potential to advance the discovery of new specific targets and the development of drugs, thus representing a significant breakthrough in addressing the challenges in AIS treatment.

Pathogenic mechanisms and therapeutic implications of extracellular matrix remodelling in cerebral vasospasm.

Cerebral vasospasm significantly contributes to poor prognosis and mortality in patients with aneurysmal subarachnoid hemorrhage. Current research indicates that the pathological and physiological mechanisms of cerebral vasospasm may be attributed to the exposure of blood vessels to toxic substances, such as oxyhaemoglobin and inflammation factors. These factors disrupt cerebral vascular homeostasis. Vascular homeostasis is maintained by the extracellular matrix (ECM) and related cell surface receptors, such as integrins, characterised by collagen deposition, collagen crosslinking, and elastin degradation within the vascular ECM. It involves interactions between the ECM and smooth muscle cells as well as endothelial cells. Its biological activities are particularly crucial in the context of cerebral vasospasm. Therefore, regulating ECM homeostasis may represent a novel therapeutic target for cerebral vasospasm. This review explores the potential pathogenic mechanisms of cerebral vasospasm and the impacts of ECM protein metabolism on the vascular wall during ECM remodelling. Additionally, we underscore the significance of an ECM protein imbalance, which can lead to increased ECM stiffness and activation of the YAP pathway, resulting in vascular remodelling. Lastly, we discuss future research directions.

Nicotinic Acid-Mediated Modulation of Metastasis-Associated Protein 1 Methylation and Inflammation in Brain Arteriovenous Malformation.

We explored metastasis-associated protein 1 (MTA1) promoter methylation in the development of brain arteriovenous malformation (BAVM). The clinical data of 148 sex- and age-matched BAVMs and controls were collected, and the MTA1 DNA methylation in peripheral white blood cells (WBC) was assessed by bisulfite pyrosequencing. Among them, 18 pairs of case-control samples were used for WBC mRNA detection, 32 pairs were used for WBC MTA1 protein measurement, and 50 pairs were used for plasma inflammatory factor analysis. Lipopolysaccharide (LPS) treatment was used to induce an inflammatory injury cell model of human brain microvascular endothelial cells (BMECS). 5-Aza-2'-deoxycytidine (5-AZA), nicotinic acid (NA), and MTA1 siRNAs were used in functional experiments to examine BMECS behaviors. RT-qPCR, Western blot, and ELISA or cytometric bead arrays were used to measure the expression levels of MTA1, cytokines, and signaling pathway proteins in human blood or BMECS. The degree of MTA1 promoter methylation was reduced in BAVM compared with the control group and was inversely proportional to MTA1 expression. Plasma ApoA concentrations in BAVM patients were significantly lower than those in controls and correlated positively with MTA1 promoter methylation and negatively with MTA1 expression. The expression of cytokine was markedly higher in BAVM than in controls. Cell experiments showed that 5-AZA decreased the methylation level of MTA1 and increased the expression of MTA1 protein. LPS treatment significantly increased cytokine concentrations (p < 0.05). NA and MTA1 silencing could effectively reverse the LPS-mediated increase in IL-6 and TNF-α expression through the NF-κB pathway. Our study indicated that NA may regulate MTA1 expression by affecting promoter DNA methylation, improve vascular inflammation through the NF-κB pathway, and alleviate the pathological development of BAVM.

Understanding the pathogenesis of brain arteriovenous malformation: genetic variations, epigenetics, signaling pathways, and immune inflammation.

Brain arteriovenous malformation (BAVM) is a rare but serious cerebrovascular disease whose pathogenesis has not been fully elucidated. Studies have found that epigenetic regulation, genetic variation and their signaling pathways, immune inflammation, may be the cause of BAVM the main reason. This review comprehensively analyzes the key pathways and inflammatory factors related to BAVMs, and explores their interplay with epigenetic regulation and genetics. Studies have found that epigenetic regulation such as DNA methylation, non-coding RNAs and m6A RNA modification can regulate endothelial cell proliferation, apoptosis, migration and damage repair of vascular malformations through different target gene pathways. Gene defects such as KRAS, ACVRL1 and EPHB4 lead to a disordered vascular environment, which may promote abnormal proliferation of blood vessels through ERK, NOTCH, mTOR, Wnt and other pathways. PDGF-B and PDGFR-ß were responsible for the recruitment of vascular adventitial cells and smooth muscle cells in the extracellular matrix environment of blood vessels, and played an important role in the pathological process of BAVM. Recent single-cell sequencing data revealed the diversity of various cell types within BAVM, as well as the heterogeneous expression of vascular-associated antigens, while neutrophils, macrophages and cytokines such as IL-6, IL-1, TNF-α, and IL-17A in BAVM tissue were significantly increased. Currently, there are no specific drugs targeting BAVMs, and biomarkers for BAVM formation, bleeding, and recurrence are lacking clinically. Therefore, further studies on molecular biological mechanisms will help to gain insight into the pathogenesis of BAVM and develop potential therapeutic strategies.

Exploring the role of m6A methylation regulators in glioblastoma multiforme and their impact on the tumor immune microenvironment.

Although the role of N6-Methyladenosine (m6A) methylation factors has been established in multiple cancer types, its involvement in glioblastoma multiforme (GBM) remains limited. This study aims to explore the involvement of m6A regulators in GBM and examine their association with the tumor immune microenvironment (TIME). A comprehensive set of 24 candidate m6A RNA regulators was procured. Consensus clustering was performed based on these regulators to identify distinct GBM clusters. PD-L1 and PD-1 levels, immune cell infiltration, and immune scores were evaluated between two clusters. Prognostic signatures and correlation analysis with TIME were analyzed using Lasso and Spearman's analysis. GBM tissue was collected to verify the correlations. Eighteen m6A regulators (WTAP, YTHDF2, HNRNPC, CAPRIN1, YTHDF3, METTL14, GNL3, ZCCHC4, HNRNPD, YTHDF1, RBM15, PCIF1, RBM27, KIAA1429, MSI2, FTO, ALKBH5, and METTL3), PD-L1, and PD-1 were significantly upregulated in GBM tissue. These regulators were divided into two distinct molecular subtypes (clusters 1 and 2). Cluster 2 exhibited a significant increase in immune score, monocytes, M1 macrophages, activated mast cells, and eosinophils. HNRNPC, YWHAG, and ALKBH5 were significantly associated with TIME and positively correlated with PD-L1. Immune cell invasiveness profiles dynamically changed with copy number changes of these three m6A regulators. Finally, YWHAG and ALKBH5 were found to be independent prognostic indicators of GBM through risk analysis and were experimentally verified with clinical samples. YWHAG and ALKBH5 may be used as prognostic markers for patients with GBM. m6A methylation regulators may play an important role in regulating PD-L1/PD-1 expression and immune infiltration, thus having a significant impact on GBM TIME.

The mechanism of ferroptosis in early brain injury after subarachnoid hemorrhage.

Subarachnoid hemorrhage (SAH) is a cerebrovascular accident with an acute onset, severe disease characteristics, and poor prognosis. Within 72 hours after the occurrence of SAH, a sequence of pathological changes occur in the body including blood-brain barrier breakdown, cerebral edema, and reduced cerebrovascular flow that are defined as early brain injury (EBI), and it has been demonstrated that EBI exhibits an obvious correlation with poor prognosis. Ferroptosis is a novel programmed cell death mode. Ferroptosis is induced by the iron-dependent accumulation of lipid peroxides and reactive oxygen species (ROS). Ferroptosis involves abnormal iron metabolism, glutathione depletion, and lipid peroxidation. Recent study revealed that ferroptosis is involved in EBI and is significantly correlated with poor prognosis. With the gradual realization of the importance of ferroptosis, an increasing number of studies have been conducted to examine this process. This review summarizes the latest work in this field and tracks current research progress. We focused on iron metabolism, lipid metabolism, reduction systems centered on the GSH/GPX4 system, other newly discovered GSH/GPX4-independent antioxidant systems, and their related targets in the context of early brain injury. Additionally, we examined certain ferroptosis regulatory mechanisms that have been studied in other fields but not in SAH. A link between death and oxidative stress has been described. Additionally, we highlight the future research direction of ferroptosis in EBI of SAH, and this provides new ideas for follow-up research.

Lipoprotein(a) and stroke: a two-sample Mendelian randomization study.

Background: To evaluate the causal relationship between lipoprotein(a) Lp(a) and stroke risk. Method: Adopting two grand scale genome-wide association study (GWAS) databases, the instrumental variables were selected on the basis that the genetic loci met the criteria of being independent of each other and closely related to Lp(a). Summary-level data for outcomes, ischemic stroke and its subtypes were acquired from the UK Biobank and MEGASTROKE consortium databases. Two-sample MR analyses were achieved using inverse variance-weighted (IVW) meta-analysis (primary analysis), weighted median analysis, and the MR Egger regression method. Multivariable-adjusted Cox regression models were also used for observational analysis. Result: Genetically predicted Lp(a) was marginally related with higher odds of total stroke (odds ratio (OR) [95% confidence intervals (CI)]: 1.003 [1.001-1.006], p = 0.010), ischemic stroke (OR [95% CI]: 1.004[1.001-1.007], p = 0.004), and large-artery atherosclerotic stroke (OR [95% CI]: 1.012 [1.004-1.019], p = 0.002) when the IVW estimator was used on the MEGASTROKE data. The associations of Lp(a) with stroke and ischemic stroke were also remarkable in the primary analysis using the UK Biobank data. Higher Lp(a) levels were also related with increased total stroke and ischemic stroke risk in the observational research data in the UK Biobank database. Conclusion: Genetically predicted higher Lp(a) perhaps rise the risk of total stroke, ischemic stroke, and large-artery atherosclerotic stroke.

Application of intraoperative infrared thermography in bypass surgery for adult moyamoya syndrome: A preliminary study.

Background and objectives: Cerebral revascularization surgery is the mainstay of treatment for moyamoya syndrome (MMS) today, and intraoperative determination of the patency of the revascularized vessel is a critical factor in the success of the procedure. Currently, major imaging modalities include intraoperative indocyanine green (ICG) videoangiography (ICG-VA), digital subtraction angiography (DSA), and vascular ultrasound Doppler. Infrared thermography is a modern imaging modality with non-contact devices for the acquisition and analysis of thermal data. We aimed to investigate the feasibility and advantages of infrared thermography in determining anastomotic patency during MMS surgery. Methods: Indocyanine green videoangiography and infrared thermography were performed simultaneously in 21 patients with MMS who underwent bypass surgery. The detection result of vessel patency was compared, and the feasibility and advantages of infrared thermography were assessed. Results: The patency of the anastomosis was accurately determined in 21 patients using either ICG angiography or infrared thermography. In 20 patients, the results of infrared thermography showed that the vascular anastomosis was unobstructed, and there was an agreement with the subsequent results of ICG-VA. In one patient, we suspected inadequate patency after testing the anastomosis with infrared thermography, and the results of ICG-VA evaluation of the anastomosis confirmed that there was indeed an anastomotic obstruction. Conclusion: Compared with ICG-VA, infrared thermography might offer an alternative non-invasive, contrast-free option in assessing anastomosis patency compared with ICG-VA, and it is likely to become more widely used in the clinic in the near future.

A Novel Necroptosis-Related Prognostic Signature of Glioblastoma Based on Transcriptomics Analysis and Single Cell Sequencing Analysis.

Background: Glioblastoma (GBM) is the most common and deadly brain tumor. The clinical significance of necroptosis (NCPS) genes in GBM is unclear. The goal of this study is to reveal the potential prognostic NCPS genes associated with GBM, elucidate their functions, and establish an effective prognostic model for GBM patients. Methods: Firstly, the NCPS genes in GBM were identified by single-cell analysis of the GSE182109 dataset in the GEO database and weighted co-expression network analysis (WGCNA) of The Cancer Genome Atlas (TCGA) data. Three machine learning algorithms (Lasso, SVM-RFE, Boruta) combined with COX regression were used to build prognostic models. The subsequent analysis included survival, immune microenvironments, and mutations. Finally, the clinical significance of NCPS in GBM was explored by constructing nomograms. Results: We constructed a GBM prognostic model composed of NCPS-related genes, including CTSD, AP1S1, YWHAG, and IER3, which were validated to have good performance. According to the above prognostic model, GBM patients in the TCGA and CGGA groups could be divided into two groups according to NCPS, with significant differences in survival analysis between the two groups and a markedly worse prognostic status in the high NCPS group (p < 0.001). In addition, the high NCPS group had higher levels of immune checkpoint-related gene expression, suggesting that they may be more likely to benefit from immunotherapy. Conclusions: Four genes (CTSD, AP1S1, YWHAG, and IER3) were screened through three machine learning algorithms to construct a prognostic model for GBM. These key and novel diagnostic markers may become new targets for diagnosing and treating patients with GBM.

DNA methylation and mRNA expression of glutathione S-transferase alpha 4 are associated with intracranial aneurysms in a gender-dependent manner.

Objective: We performed a case-control study to investigate the correlation between DNA methylation and mRNA expression of the glutathione S-transferase alpha 4 (GSTA4) gene and the risk of intracranial aneurysm (IA) in the Chinese Han population. Methods: After propensity score matching, 44 pairs of cases and controls were collected in this study. Fasting blood samples were collected for DNA and RNA extraction within 24 h of admission. Nine CpG dinucleotides were selected from the GSTA4 promoter region for DNA methylation pyrosequencing. mRNA expression of GSTA4 was measured by quantitative real-time polymerase chain reaction (RT-qPCR). In vitro cell experiments were conducted to verify the association between 5-aza-2'-deoxycytidine induced DNA hypomethylation and GSTA4 mRNA expression. Results: The mean methylation level of GSTA4 was much lower in IA patients, especially in IA patients, especially in unruptured IA (UIA), than that in controls (IA vs. Control, p < .001; ruptured IA (RIA) vs. Control, p = .005; UIA vs. Control, p < .001). With sex stratification, we further found that the association between GSTA4 methylation and IA risk presented only in women (mean methylation level: IA vs. Control, p < .001; RIA vs. Control, p = .009; UIA vs. Control, p < .001). GSTA4 mRNA expression was significantly higher in the IA group than in the control group (p < .01) and negatively correlated with DNA methylation in all individuals (r = -.746, p < .001). DNA hypomethylation can increase GSTA4 mRNA expression in human primary artery smooth muscle cells. The receiver operating characteristic (ROC) curve showed that GSTA4 mean methylation (AUC = .80, p < .001) was a reliable predictor of women intracranial aneurysm, among which CpG 1 exhibited the best predictive value (AUC = .89, p < .001). In addition, GSTA4 expression levels could also predict the risk of IA in women (AUC = .87, p = .005). Conclusion: Decreased DNA methylation and increased mRNA expression of the GSTA4 gene are associated with the risk of IA in women.