Interleukin-1 cluster gene polymorphisms and aneurysmal subarachnoid hemorrhage

Updated Trans-Ethnic Meta-Analysis of Associations between Inflammation-Related Genes and Intracranial Aneurysm

OBJECTIVE

We performed an expanded multi-ethnic meta-analysis to identify associations between inflammation-related loci with intracranial aneurysm (IA) susceptibility. This meta-analysis possesses increased statistical power as it is based on the most data ever evaluated.

METHODS

We searched and reviewed relevant literature through electronic search engines up to August 2022. Overall estimates were calculated under the fixed- or random-effect models using pooled odds ratio (OR) and 95% confidence intervals (CIs). Subgroup analyses were performed according to ethnicity.

RESULTS

Our meta-analysis enrolled 15 studies and involved 3070 patients and 5528 controls including European, Asian, Hispanic, and mixed ethnic populations. Of 17 inflammation-related variants, the rs1800796 locus (interleukin [IL]-6) showed the most significant genome-wide association with IA in East-Asian populations, including 1276 IA patients and 1322 controls (OR, 0.65; 95% CI, 0.56-0.75; p=3.24×10-9) under a fixed-effect model. However, this association was not observed in the European population (OR, 1.09; 95% CI, 0.80-1.47; p=0.5929). Three other variants, rs16944 (IL-1β), rs2195940 (IL-12B), and rs1800629 (tumor necrosis factor-α) showed a statistically nominal association with IA in both the overall, as well as East-Asian populations (0.01

CONCLUSION

Our updated meta-analysis with increased statistical power highlights that rs1800796 which maps on the IL-6 gene is associated with IA, and in particular confers a protective effect against occurrence of IA in the East-Asian population.

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Key Words

• Inflammation mediators
• Interleukin-6
• Intracranial aneurysm
• Meta-analysis

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MESH Headings Collapse

Grants

• HURF-2021-35 Hallym University
• Korea Bio Data Station

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Affiliation(s)

Eun Pyo Hong Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea
Sung Min Cho Department of Neurosurgery, Yonsei University Wonju College of Medicine, Wonju, Korea
Jong Kook Rhim Department of Neurosurgery, Jeju National University College of Medicine, Jeju, Korea
Jeong Jin Park Department of Neurology, Konkuk University Medical Center, Seoul, Korea
Jun Hyong Ahn Department of Neurosurgery, Kangwon National University Hospital, Chuncheon, Korea
Dong Hyuk Youn Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea
Jong-Tae Kim Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea
Chan Hum Park Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea
Younghyurk Lee Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea
Jin Pyeong Jeon Department of Neurosurgery, Hallym University College of Medicine, Chuncheon, Korea
on behalf of the First Korean Stroke Genetics Association Research (The FirstKSGAR) Study Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea Department of Neurosurgery, Yonsei University Wonju College of Medicine, Wonju, Korea Department of Neurosurgery, Jeju National University College of Medicine, Jeju, Korea Department of Neurology, Konkuk University Medical Center, Seoul, Korea Department of Neurosurgery, Kangwon National University Hospital, Chuncheon, Korea Department of Neurosurgery, Hallym University College of Medicine, Chuncheon, Korea

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The Role of NLRP3 Inflammasome in Cerebrovascular Diseases Pathology and Possible Therapeutic Targets

Cerebrovascular diseases are pathological conditions involving impaired blood flow in the brain, primarily including ischaemic stroke, intracranial haemorrhage, and subarachnoid haemorrhage. The nucleotide-binding and oligomerisation (NOD) domain-like receptor (NLR) family pyrin domain (PYD)-containing 3 (NLRP3) inflammasome is a protein complex and a vital component of the immune system. Emerging evidence has indicated that the NLRP3 inflammasome plays an important role in cerebrovascular diseases. The function of the NLRP3 inflammasome in the pathogenesis of cerebrovascular diseases remains an interesting field of research. In this review, we first summarised the pathological mechanism of cerebrovascular diseases and the pathological mechanism of the NLRP3 inflammasome in aggravating atherosclerosis and cerebrovascular diseases. Second, we outlined signalling pathways through which the NLRP3 inflammasome participates in aggravating or mitigating cerebrovascular diseases. Reactive oxygen species (ROS)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), ROS/thioredoxin-interacting protein (TXNIP) and purinergic receptor-7 (P2X7R) signalling pathways can activate the NLRP3 inflammasome; activation of the NLRP3 inflammasome can aggravate cerebrovascular diseases by mediating apoptosis and pyroptosis. Autophagy/mitochondrial autophagy, nuclear factor E2-related factor-2 (Nrf2), interferon (IFN)-β, sirtuin (SIRT), and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) reportedly alleviate cerebrovascular diseases by inhibiting NLRP3 inflammasome activation. Finally, we explored specific inhibitors of the NLRP3 inflammasome based on the two-step activation of the NLRP3 inflammasome, which can be developed as new drugs to treat cerebrovascular diseases.

Associations between Inflammatory Cytokine Gene Polymorphisms and Susceptibilities to Intracranial Aneurysm in Chinese Population

Intracranial aneurysm (IA) is a complex disease caused by genetic and environmental factors. Evidence indicates that inflammation plays an important role in IA occurrence. We aimed to explore the associations between inflammatory cytokine gene polymorphisms and IA in a Chinese population. This study enrolled 768 participants of Han ethnicity, including 384 patients with IA and 384 healthy individuals. Sixteen single nucleotide polymorphisms (SNPs) of IL1, IL6, IL12, and TNF-α genes were genotyped using the Sequenom MassARRAY platform. Univariate and multivariate logistic regression analyses were used to analyze the associations. We found IL12B rs3181216 was significantly associated with IA in the recessive and additive models (OR = 0.46, 95% CI = 0.23–0.89, P = 0.022; OR = 0.74, 95% CI = 0.56–0.98, P = 0.034, respectively). TNF-α rs1799964 was associated with IA in dominant and additive models (OR = 0.67, 95% CI = 0.46–0.98, P = 0.041; OR = 0.71, 95% CI = 0.51–0.98, P = 0.034, respectively). IL1A rs17561 was associated with single IA susceptibility (dominant model: OR = 0.52, 95% CI = 0.31–0.85, P = 0.040). The IL12B rs3181216 polymorphism was associated with single IA susceptibility in the recessive model (OR = 0.41, 95% CI = 0.18–0.93, P = 0.033). The IL12B rs2195940 polymorphism was associated with multiple IAs susceptibility (dominant model: OR = 0.28, 95% CI = 0.09–0.89, P = 0.031; additive model: OR = 0.28, 95% CI = 0.09–0.90, P = 0.032). TNF-α rs1799964 was associated with multiple IAs susceptibility in the dominant model (OR = 0.54, 95% CI = 0.30–0.97, P = 0.040). No associations were found between other polymorphisms and IA susceptibility. Therefore, IL1A, IL12B, and TNF-α gene polymorphisms are associated with IA susceptibility in a Chinese population.

Prognostic significance of serum translocator protein in patients with spontaneous intracerebral hematoma：preliminary findings

Background: The aim of this study was to measure the level of translocator protein (TSPO) in patients with intracerebral hematoma (ICH) and to determine whether TSPO can predict ICH outcomes.Method: Patients with ICH were recruited at Wujin Hospital Affiliated with Jiangsu University between January 2018 and May 2020. The level of TSPO and inflammatory factors were analyzed by enzyme-linked immunosorbent assay (ELISA). A receiver operating characteristic curve (ROC) analysis was applied to assess the accuracy of TSPO for predicting patient outcomes.Result: The median of TSPO was 2.26 ng/ml. The lower- (46 cases) and higher-(51 cases) TSPO groups were thus divided based on the median value. The perihematomal edema (PHE) volume in the lower TSPO group was 6.3 ± 1.3 ml which was significantly lower than that in higher-TSPO group (14.8 ± 3.5 ml) (p < 0.05). The serum level of the interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) in the higher-TSPO group was significantly higher than that in the lower TSPO group (p < 0.05). The Spearman's correlation found that TSPO concentrations significantly correlated with PHE volume, modified Rankin Scale score (MRS), IL-1β, IL-6, TNF-α, and CRP concentrations. The area under the ROC (AUC), specificity, sensitivity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and Diagnostic Odds Ratio (DOR) of TSPO was 0.932, 82.1%, 89.9%, 5.02, 0.12, and 40.8, respectively, which was more reliable than other inflammatory factors.Conclusion: The TSPO may a reliable biomarker in predicting the prognosis of ICH patients.

Polymorphisms of Inflammatory Cytokine Genes and Risk for Intracranial Aneurysm: A Systematic Review and Meta-Analysis

PURPOSE

Inflammatory cytokines are thought to be involved in the pathogenesis of intracranial aneurysm (IA), although results among studies in the literature are inconsistent. This article sought to review studies on the associations among polymorphisms in inflammatory cytokine genes and IA risk and to provide recommendations for future research.

MATERIALS AND METHODS

A systematic search of PubMed, Embase, and Web of Science was conducted up to August 4, 2019. The associations between polymorphisms of inflammatory cytokine genes and IA risk were estimated by pooled odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses were performed according to race. Qualitative systematic review was conducted for variants that were studied in only one study. All analyses were performed using STATA 12.0.

RESULTS

13 studies investigating the associations between polymorphisms in five inflammatory cytokine genes (TNF-α, IL-1α, IL-1β, IL6, and IL-12B) and IA were reviewed. Combined results showed that the A allele of TNF-α rs1800629 polymorphism has a protective effect against IA (dominant model: OR=0.65, 95% CI=0.47-0.89, p=0.007). No associations were identified between polymorphisms in IL-1α rs1800587, IL-1β rs16944, IL6 rs1800795 and rs1800796, or IL-12B rs3212227 and IA risk.

CONCLUSION

This review demonstrated an association between TNF-α rs1800629 polymorphism and IA in Caucasians, illustrating the potentially important role of genes involved in inflammation in IA.

Pathogenesis of intracranial aneurysm is mediated by proinflammatory cytokine TNFA and IFNG and through stochastic regulation of IL10 and TGFB1 by comorbid factors

BACKGROUND

Intracranial aneurysm (IA) is often asymptomatic until the time of rupture resulting in subarachnoid hemorrhage (SAH).There is no precise biochemical or phenotype marker for diagnosis of aneurysm. Environmental risk factors that associate with IA can result in modifying the effect of inherited genetic factors and thereby increase the susceptibility to SAH. In addition subsequent to aneurismal rupture, the nature and quantum of inflammatory response might be critical for repair. Therefore, genetic liability to inflammatory response caused by polymorphisms in cytokine genes might be the common denominator for gene and environment in the development of aneurysm and complications associated with rupture.

METHODS

Functionally relevant polymorphisms in the pro- and anti-inflammatory cytokine genes IL-1 complex (IL1A, IL1B, and IL1RN), TNFA, IFNG, IL3, IL6, IL12B, IL1RN, TGFB1, IL4, and IL10] were screened in radiologically confirmed 220 IA patients and 250 controls from genetically stratified Malayalam-speaking Dravidian ethnic population of south India. Subgroup analyses with genetic and environmental variables were also carried out.

RESULTS

Pro-inflammatory cytokines TNFA rs361525, IFNG rs2069718, and anti-inflammatory cytokine IL10 rs1800871 and rs1800872 were found to be significantly associated with IA, independent of epidemiological factors. TGFB1 rs1800469 polymorphism was observed to be associated with IA through co-modifying factors such as hypertension and gender. Functional prediction of all the associated SNPs of TNFA, IL10, and TGFB1 indicates their potential role in transcriptional regulation. Meta-analysis further reiterates that IL1 gene cluster and IL6 were not associated with IA.

CONCLUSIONS

The study suggests that chronic exposure to inflammatory response mediated by genetic variants in pro-inflammatory cytokines TNFA and IFNG could be a primary event, while stochastic regulation of IL10 and TGFB1 response mediated by comorbid factors such as hypertension may augment the pathogenesis of IA through vascular matrix degradation. The implication and interaction of these genetic variants under a specific environmental background will help us identify the resultant phenotypic variation in the pathogenesis of intracranial aneurysm. Identifying genetic risk factors for inflammation might also help in understanding and addressing the posttraumatic complications following the aneurismal rupture.

Mouse models of intracranial aneurysm

Subarachnoid hemorrhage secondary to rupture of an intracranial aneurysm is a highly lethal medical condition. Current management strategies for unruptured intracranial aneurysms involve radiological surveillance and neurosurgical or endovascular interventions. There is no pharmacological treatment available to decrease the risk of aneurysm rupture and subsequent subarachnoid hemorrhage. There is growing interest in the pathogenesis of intracranial aneurysm focused on the development of drug therapies to decrease the incidence of aneurysm rupture. The study of rodent models of intracranial aneurysms has the potential to improve our understanding of intracranial aneurysm development and progression. This review summarizes current mouse models of intact and ruptured intracranial aneurysms and discusses the relevance of these models to human intracranial aneurysms. The article also reviews the importance of these models in investigating the molecular mechanisms involved in the disease. Finally, potential pharmaceutical targets for intracranial aneurysm suggested by previous studies are discussed. Examples of potential drug targets include matrix metalloproteinases, stromal cell-derived factor-1, tumor necrosis factor-α, the renin-angiotensin system and the β-estrogen receptor. An agreed clear, precise and reproducible definition of what constitutes an aneurysm in the models would assist in their use to better understand the pathology of intracranial aneurysm and applying findings to patients.

Vascular endothelial growth factor gene polymorphisms and intracranial aneurysms

BACKGROUND

The exact pathophysiology of the development and rupture of saccular aneurysms is still controversial. Several lines of evidence indicate a role for inflammatory processes. Similarly, abnormal angiogenesis might be related to aneurysm growth. Expression of angiogenesis factors is higher in patients harboring aneurysms. The aim of this study was to verify the association of two functionally active polymorphisms (+ 396 C>T and 18 bp microdeletion) in the vascular endothelial growth factor (VEGF) gene with both susceptibility to and clinical features of aneurysmal subarachnoid hemorrhage (SAH) in an Italian population.

METHOD

Allelic and genotypic frequencies of the + 396 C>T and the 18 bp microdeletion of the VEGF gene were determined in 200 patients and 200 healthy controls.

RESULTS

Both allelic and genotypic frequencies of the examined polymorphisms in the VEGF gene were not significantly different between cases and controls. Furthermore, the different VEGF genotypes did not seem to significantly modify the main clinical features of the disease.

CONCLUSIONS

Our data suggest that the VEGF gene is not a major genetic risk factor for aneurysmal subarachnoid hemorrhage.