Genetics and Epigenetics of Spontaneous Intracerebral Hemorrhage

The association between TLR2/4 and clinical outcome in intracerebral hemorrhage

BACKGROUND AND PURPOSE

Toll-like receptors (TLRs) are involved in innate immunity and inflammatory responses in various diseases. Our study aimed to investigate the association between the levels of soluble TLR4 (sTLR4) and soluble TLR2 (sTLR2) and clinical outcomes following intracerebral hemorrhage (ICH).

METHODS

Patients admitted to department of Neurology with acute ICH were included. Plasma levels of sTLR4 and sTLR2 after ICH were measured by enzyme-linked immunosorbent assay. Poor clinical outcome was defined as a modified Rankin score (mRS) of 3-6 at 3-month and 12-month after onset.

RESULTS

All 207 patients with ICH and 100 non-stroke controls were included in our analysis. The mean sTLR4 level was 4.53±1.51 ng/ml and mean sTLR2 level was 3.65±0.72 ng/ml. There was significant trend towards worse clinical outcomes with increasing sTLR4 and sTLR2 terciles at 3 and 12 months. According to receiver operating curve (ROC), the sTLR4 was reliable predictor for poor clinical outcome at 3 months (ROC=0.75) and 12 months (ROC=0.74). The sTLR2 was less reliable predictor for poor clinical outcome at 3 months (ROC=0.64) and 12 months (ROC=0.65). The level of sTLR4 was an independent predictor of poor clinical outcome at 12-month (OR 1.24, 95 % CI 1.16-1.80; P=0.019).

CONCLUSIONS

The sTLR4 quantification may provide accurate prognostic information after ICH.

Examining Transcriptomic Alterations in Rat Models of Intracerebral Hemorrhage and Severe Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a life-threatening condition associated with significant morbidity and mortality. This study investigates transcriptomic alterations in rodent models of ICH and severe ICH to shed light on the genetic pathways involved in hemorrhagic brain injury. We performed principal component analysis, revealing distinct principal component segments of normal rats compared to ICH and severe ICH rats. We employed heatmaps and volcano plots to identify differentially expressed genes and utilized bar plots and KEGG pathway analysis to elucidate the molecular pathways involved. We identified a multitude of differentially expressed genes in both the ICH and severe ICH models. Our results revealed 5679 common genes among the normal, ICH, and severe ICH groups in the upregulated genes group, and 1196 common genes in the downregulated genes, respectively. A volcano plot comparing these groups further highlighted common genes, including PDPN, TIMP1, SERPINE1, TUBB6, and CD44. These findings underscore the complex interplay of genes involved in inflammation, oxidative stress, and neuronal damage. Furthermore, pathway enrichment analysis uncovered key signaling pathways, including the TNF signaling pathway, protein processing in the endoplasmic reticulum, MAPK signaling pathway, and Fc gamma R-mediated phagocytosis, implicated in the pathogenesis of ICH.

Epigenetics and the neurodegenerative process

Neurological diseases are multifactorial, genetic and environmental. Environmental factors such as diet, physical activity and emotional state are epigenetic factors. Environmental markers are responsible for epigenetic modifications. The effect of epigenetic changes is increased inflammation of the nervous system and neuronal damage. In recent years, it has been shown that epigenetic changes may cause an increased risk of neurological disorders but, currently, the relationship between epigenetic modifications and neurodegeneration remains unclear. This review summarizes current knowledge about neurological disorders caused by epigenetic changes in diseases such as Alzheimer's disease, Parkinson's disease, stroke and epilepsy. Advances in epigenetic techniques may be key to understanding the epigenetics of central changes in neurological diseases.

MiRNAs as potential therapeutic targets and biomarkers for non-traumatic intracerebral hemorrhage

Non-traumatic intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke, most often occurring between the ages of 45 and 60. Hypertension is most often the cause of ICH. Less often, atherosclerosis, blood diseases, inflammatory changes in cerebral vessels, intoxication, vitamin deficiencies, and other reasons cause hemorrhages. Cerebral hemorrhage can occur by diapedesis or as a result of a ruptured vessel. This very dangerous disease is difficult to treat, requires surgery and can lead to disability or death. MicroRNAs (miRNAs) are a class of non-coding RNAs (about 18-22 nucleotides) that are involved in a variety of biological processes including cell differentiation, proliferation, apoptosis, etc., through gene repression. A growing number of studies have demonstrated miRNAs deregulation in various cardiovascular diseases, including ICH. In addition, given that computed tomography (CT) and/or magnetic resonance imaging (MRI) are either not available or do not show clear signs of possible vessel rupture, accurate and reliable analysis of circulating miRNAs in biological fluids can help in early diagnosis for prevention of ICH and prognosis patient outcome after hemorrhage. In this review, we highlight the up-to-date findings on the deregulated miRNAs in ICH, and the potential use of miRNAs in clinical settings, such as therapeutic targets and non-invasive diagnostic/prognostic biomarker tools.

Gender Predicts Differences in Acute Ischemic Cardioembolic Stroke Profile: Emphasis on Woman-Specific Clinical Data and Early Outcome-The Experience of Sagrat Cor Hospital of Barcelona Stroke Registry

Background and Objectives: Acute ischemic cardioembolic stroke (CS) is a clinical condition with a high risk of death, and can lead to dependence, recurrence, and dementia. Materials and Methods: In this study, we evaluated gender differences and female-specific clinical data and early outcomes in 602 women diagnosed with CS from a total of 4600 consecutive acute stroke patients in a single-center hospital stroke registry over 24 years. A comparative analysis was performed in women and men in terms of demographics, cerebrovascular risk factors, clinical data, and early outcomes. Results: In a multivariate analysis, age, hypertension, valvular heart disease, obesity, and internal capsule location were independent variables associated with CS in women. The overall in-hospital mortality rate was similar, but the group of women had a greater presence of neurological deficits and a higher percentage of severe limitation at hospital discharge. After the multivariate analysis, age, altered consciousness, limb weakness, and neurological, respiratory, gastrointestinal, renal, cardiac and peripheral vascular complications were independent predictors related to early mortality in women. Conclusions: Women with CS showed a differential demographic and clinical profile and worse early outcomes than men. Advanced age, impaired consciousness, and medical complications were predictors of stroke severity in women with CS.

Identification of key genes in spontaneous cerebral hemorrhage and prevention of disease damage: LASSO and SVM regression

Prevention is more important than treatment, and the incidence of intracerebral hemorrhage can be effectively reduced by intervening on the risk factors of intracerebral hemorrhage. By studying the risk factors of spontaneous intracerebral hemorrhage, we can identify the risk factors to achieve the target of treatment and prevention. Through the use of the Least Absolute Shrinkage and Selection Operator (LASSO) and the Support Vector Machine (SVM), the two essential SICH-related genes, NUAK1 and ERO1L, were eliminated from consideration. A Venn analysis was performed, and based on the two important modules, it found that SICH was related with four critical genes: VCM1, CRNDE, COL6A2, and HSPB6. One gene (NUAK1) was dramatically downregulated in the illness group compared to the control group, whereas three essential genes (ERO1L, VCAM1, and COL6A2) were significantly upregulated in the disease group. In the end, the genes ERO1L, VCAM1, COL6A2, and NUAK1 were shown to be the most important ones for SICH. It is anticipated that these genes will become novel biomarkers as well as targets for the development of new pharmacotherapies for SICH.

Curcumin preconditioning enhances the neuroprotective effects of olfactory mucosa-derived mesenchymal stem cells on experimental intracerebral hemorrhage

Oxidative stress is essential in brain injury after intracerebral hemorrhage (ICH). Ferroptosis, iron-dependent oxidative cell death, overwhelms the antioxidant system. Recently, Olfactory mucosa-derived mesenchymal stem cells (OM-MSCs) hold great potential for treating ferroptosis-mediated oxidative brain damage after ICH. However, massive grafted cell death, possibly caused by a hostile host brain microenvironment, lessens the effectiveness of OM-MSCs. Therefore, it is necessary to develop strategies to upregulate the therapeutic efficacy of OM-MSCs in ICH. Curcumin, a well-established traditional herbal substance, has potent antioxidant property. In the present study, curcumin preconditioning might enhance the anti-oxidative activity of OM-MSCs, thereby augmenting the therapeutic efficacy of OM-MSCs in ICH. In vitro model of ICH, we demonstrated that curcumin-preconditioned OM-MSCs co-culture is more effective in attenuating the cell injury, oxidative stress, and ferroptosis of neuronal cells compared to the native OM-MSCs treatment. In vivo model of ICH, transplantation of curcumin-preconditioned OM-MSCs also showed better neuroprotective effects. Moreover, curcumin pretreatment promoted the survival of OM-MSCs under a conditioned medium from hemin-insulted neurons by improving the anti-oxidative capacities of OM-MSCs. Collectively, our investigation suggested that curcumin preconditioning effectively enhanced the survival and neuroprotective effects of OM-MSCs in the ICH model by upregulating the anti-oxidative capacities of OM-MSCs. Curcumin-preconditioned OM-MSCs might be taken as a novel therapeutic strategy for treating ICH.

Small-vessel disease in the brain

Cerebral small-vessels are generally located in the brain at branch points from major cerebral blood vessels and perfuse subcortical structures such as the white matter tracts, basal ganglia, thalamus, and pons. Cerebral small-vessel disease (CSVD) can lead to several different clinical manifestations including ischemic lacunar stroke, intracerebral hemorrhage, and vascular dementia. Risk factors for CSVD overlap with conventional vascular risk factors including hypertension, diabetes mellitus, and hypercholesterolemia, as well as genetic causes. As in cardiovascular disease, treatment of CSVD involves both primary and secondary prevention. Aspirin has not been established as a primary prevention strategy for CSVD among the general population; however, long-term antiplatelet therapy with aspirin alone continues to be the mainstay of secondary stroke prevention for non-cardioembolic ischemic stroke and high-risk TIA.

Acute Spontaneous Lobar Cerebral Hemorrhages Present a Different Clinical Profile and a More Severe Early Prognosis than Deep Subcortical Intracerebral Hemorrhages-A Hospital-Based Stroke Registry Study

Acute spontaneous intracerebral hemorrhage (ICH) is the most severe stroke subtype, with a high risk of death, dependence, and dementia. Knowledge about the clinical profile and early outcomes of ICH patients with lobar versus deep subcortical brain topography remains limited. In this study, we investigated the effects of ICH topography on demographics, cerebrovascular risk factors, clinical characteristics, and early outcomes in a sample of 298 consecutive acute ICH patients (165 with lobar and 133 with subcortical hemorrhagic stroke) available in a single-center-based stroke registry over 24 years. The multiple logistic regression analysis shows that variables independently associated with lobar ICH were early seizures (OR 6.81, CI 95% 1.27−5.15), chronic liver disease (OR 4.55, 95% CI 1.03−20.15), hemianopia (OR 2.55, 95% CI 1.26−5.15), headaches (OR 1.90, 95% CI 1.90, 95% IC 1.06−3.41), alcohol abuse (>80 gr/day) (OR 0−10, 95% CI 0.02−0,53), hypertension (OR 0,41, 95% CI 0.23−0−70), sensory deficit (OR 0.43, 95% CI 0.25−0.75), and limb weakness (OR: 0.47, 95% CI 0.24−0.93). The in-hospital mortality was 26.7% for lobar and 16.5% for subcortical ICH. The study confirmed that the clinical spectrum, prognosis, and early mortality of patients with ICH depend on the site of bleeding, with a more severe early prognosis in lobar intracerebral hemorrhage.

Association of candidate genetic variants and circulating levels of ApoE/ApoJ with common neuroimaging features of cerebral amyloid angiopathy

Introduction

Cerebral amyloid angiopathy (CAA) is characterized by the accumulation of amyloid-β (Aβ) in brain vessels and is a main cause of lobar intracerebral hemorrhage (ICH) in the elderly. CAA is associated with magnetic resonance imaging (MRI) markers of small vessel disease (SVD). Since Aβ is also accumulated in Alzheimer's disease (AD) in the brain parenchyma, we aimed to study if several single nucleotide polymorphisms (SNPs) previously associated with AD were also associated with CAA pathology. Furthermore, we also studied the influence of APOE and CLU genetic variants in apolipoprotein E (ApoE) and clusterin/apolipoprotein J (ApoJ) circulating levels and their distribution among lipoproteins.

Methods

The study was carried out in a multicentric cohort of 126 patients with lobar ICH and clinical suspicion of CAA.

Results

We observed several SNPs associated with CAA neuroimaging MRI markers [cortical superficial siderosis (cSS), enlarged perivascular spaces in the centrum semiovale (CSO-EPVS), lobar cerebral microbleeds (CMB), white matter hyperintensities (WMH), corticosubcortical atrophy and CAA-SVD burden score]. Concretely, ABCA7 (rs3764650), CLU (rs9331896 and rs933188), EPHA1 (rs11767557), and TREML2 (rs3747742) were significantly associated with a CAA-SVD burden score. Regarding circulating levels of apolipoproteins, protective AD SNPs of CLU [rs11136000 (T) and rs9331896 (C)] were significantly associated with higher HDL ApoJ content in the lobar ICH cohort. APOEε2 carriers presented higher plasma and LDL-associated ApoE levels whereas APOEε4 carriers presented lower plasma ApoE levels. Additionally, we observed that lower circulating ApoJ and ApoE levels were significantly associated with CAA-related MRI markers. More specifically, lower LDL-associated ApoJ and plasma and HDL-associated ApoE levels were significantly associated with CSO-EPVS, lower ApoJ content in HDL with brain atrophy and lower ApoE content in LDL with the extent of cSS.

Discussion

This study reinforces the relevance of lipid metabolism in CAA and cerebrovascular functionality. We propose that ApoJ and ApoE distribution among lipoproteins may be associated with pathological features related to CAA with higher ApoE and ApoJ levels in HDL possibly enhancing atheroprotective, antioxidative, and anti-inflammatory responses in cerebral β-amyloidosis.

Vertigo in Acute Stroke Is a Predictor of Brain Location but Is Not Related to Early Outcome: The Experience of Sagrat Cor Hospital of Barcelona Stroke Registry

BACKGROUND

Vertigo is an uncommon symptom among acute stroke victims. Knowledge about the clinical profile, the brain location, and the early outcome in stroke patients with cerebrovascular diseases and vertigo remains limited.

OBJECTIVES

In this study, the effects of vertigo on cerebral topography and early prognosis in cerebrovascular diseases were investigated.

METHODS

A comparative analysis in terms of demographics, risk factors, clinical characteristics, stroke subtypes, cerebral and vascular topography, and early outcome was performed between patients with presence or absence of vertigo on a sample of 3743 consecutive acute stroke patients available from a 24-year ongoing single-center hospital-based stroke registry.

RESULTS

Vertigo was present in 147 patients (3.9%). Multiple logistic regression analysis showed that variables independently associated with vertigo were: location in the cerebellum (OR 5.59, CI 95% 3.24-9.64), nausea or vomiting (OR 4.48, CI 95% 2.95-6.82), medulla (OR 2.87, CI 95% 1.31-6.30), pons (OR 2.39, CI 95% 1.26-4.51), basilar artery (OR 2.36, CI 95% 1.33-4.17), ataxia (OR 2.33, CI 95% 1.41-3.85), and headache (OR 2.31, CI 95% 1.53-3.49).

CONCLUSION

The study confirmed that the presence of vertigo was not related with increased in-hospital mortality or poor prognosis at hospital discharge. Vertigo is mainly related to non-lacunar vertebrobasilar stroke with topographic localization in the cerebellum and/or brainstem.