Novel Susceptibility Loci for Moyamoya Disease Revealed by a Genome-Wide Association Study

RNF213 Variants, Vasospastic Angina, and Risk of Fatal Myocardial Infarction

Importance

Vasospastic angina (VSA) is vasospasm of the coronary artery and is particularly prevalent in East Asian populations. However, the specific genetic architecture for VSA at genome-wide levels is not fully understood.

Objective

To identify genetic factors associated with VSA.

Design, Setting, and Participants

This was a case-control genome-wide association study of VSA. Data from Biobank Japan (BBJ; enrolled patients from 2002-2008 and 2013-2018) were used, and controls without coronary artery disease (CAD) were enrolled. Patients from the BBJ were genotyped using arrays or a set of arrays. Patients recruited between 2002 and 2005 were classified within the first dataset, and those recruited between 2006 and 2008 were classified within the second dataset. To replicate the genome-wide association study in the first and second datasets, VSA cases and control samples from the latest patients in the BBJ recruited between 2013 and 2018 were analyzed in a third dataset.

Exposures

Single-nucleotide variants associated with VSA.

Main Outcomes and Measures

Cases with VSA and controls without CAD.

Results

A total of 5720 cases (mean [SD] age, 67 [10] years; 3672 male [64.2%]) and 153 864 controls (mean [SD] age, 62 [15] years; 77 362 male [50.3%]) in 3 datasets were included in this study. The variants at the RNF213 locus showed the strongest association with VSA across the 3 datasets (odds ratio [OR], 2.34; 95% CI, 1.99-2.74; P = 4.4 × 10-25). Additionally, rs112735431, an Asian-specific rare deleterious variant (p.Arg4810Lys) experimentally shown to be associated with reduced angiogenesis and a well-known causal risk for Moyamoya disease was the most promising candidate for a causal variant explaining the association. The effect size of rs112735431 on VSA was distinct from that of other CADs. Furthermore, homozygous carriers of rs112735431 showed an association with VSA characterized by a large effect estimate (OR, 18.34; 95% CI, 5.15-65.22; P = 7.0 × 10-6), deviating from the additive model (OR, 4.35; 95% CI, 1.18-16.05; P = .03). Stratified analyses revealed that rs112735431 exhibited a stronger association in males (χ21 = 7.24; P = .007) and a younger age group (OR, 3.06; 95% CI, 2.24-4.19), corresponding to the epidemiologic features of VSA. In the registry, carriers without CAD of the risk allele rs112735431 had a strikingly high mortality rate due to acute myocardial infarction during the follow-up period (hazard ratio, 2.71; 95% CI, 1.57-4.65; P = 3.3 × 10-4). As previously reported, a possible overlap between VSA and Moyamoya disease was not found.

Conclusions and Relevance

Results of this study suggest that vascular cell dysfunction mediated by variants in the RNF213 locus may promote coronary vasospasm, and the presence of the risk allele could serve as a predictive factor for the prognosis.

Knockdown the moyamoya disease susceptibility gene, RNF213, upregulates the expression of basic fibroblast growth factor and matrix metalloproteinase-9 in bone marrow derived mesenchymal stem cells

Moyamoya disease (MMD) is a chronic, progressive cerebrovascular occlusive disease. Ring finger protein 213 (RNF213) is a susceptibility gene of MMD. Previous studies have shown that the expression levels of angiogenic factors increase in MMD patients, but the relationship between the susceptibility gene RNF213 and these angiogenic mediators is still unclear. The aim of the present study was to investigate the pathogenesis of MMD by examining the effect of RNF213 gene knockdown on the expression of matrix metalloproteinase-9 (MMP-9) and basic fibroblast growth factor (bFGF) in rat bone marrow-derived mesenchymal stem cells (rBMSCs). Firstly, 40 patients with MMD and 40 age-matched normal individuals (as the control group) were enrolled in the present study to detect the levels of MMP-9 and bFGF in serum by ELISA. Secondly, Sprague-Dawley male rat BMSCs were isolated and cultured using the whole bone marrow adhesion method, and subsequent phenotypic analysis was performed by flow cytometry. Alizarin red and oil red O staining methods were used to identify osteogenic and adipogenic differentiation, respectively. Finally, third generation rBMSCs were transfected with lentivirus recombinant plasmid to knockout expression of the RNF213 gene. After successful transfection was confirmed by reverse transcription-quantitative PCR and fluorescence imaging, the expression levels of bFGF and MMP-9 mRNA in rBMSCs and the levels of bFGF and MMP-9 protein in the supernatant of the culture medium were detected on the 7th and 14th days after transfection. There was no significant difference in the relative expression level of bFGF among the three groups on the 7th day. For the relative expression level of MMP-9, there were significant differences on the 7th day and 14th day. In addition, there was no statistically significant difference in the expression of bFGF in the supernatant of the RNF213 shRNA group culture medium, while there was a significant difference in the expression level of MMP-9. The knockdown of the RNF213 gene affects the expression of bFGF and MMP-9. However, further studies are needed to determine how they participate in the pathogenesis of MMD. The findings of the present study provide a theoretical basis for clarifying the pathogenesis and clinical treatment of MMD.

High Level of Serum Complement C3 Expression is Associated with Postoperative Vasculopathy Progression in Moyamoya Disease

Background

The immune system plays an important role in the onset and development of moyamoya disease (MMD), but the specific mechanisms remain unclear. This study aimed to explore the relationship between the expression of complements and immunoglobulin in serum and progression of MMD.

Methods

A total of 84 patients with MMD and 70 healthy individuals were enrolled. Serum immunoglobulin and complement C3 and C4 expression were compared between healthy individuals and MMD patients. Follow-up was performed at least 6 months post-operation. Univariate and multivariate analysis after adjusting different covariates were performed to explore predictive factors associated with vasculopathy progression. A nomogram basing on the results of multivariate analysis was established to predict vasculopathy progression.

Results

Compared to healthy individuals, MMD patients had significantly lower expression of serum complements C3 (P = 0.003*). Among MMD patients, C3 was significantly lower in those with late-stage disease (P = 0.001*). Of 84 patients, 27/84 (32.1%) patients presented with vasculopathy progression within a median follow-up time of 13.0 months. Age (P=0.006*), diastolic blood pressure (P=0.004*) and serum complement C3 expression (P=0.015*) were associated with vasculopathy progression after adjusting different covariables.

Conclusion

Complement C3 is downregulated in moyamoya disease and decreases even further in late-Suzuki stage disease. Age, diastolic blood pressure and serum complement C3 expression are associated with vasculopathy progression, suggesting that the complement might be involved in the development of moyamoya disease.

Isolated anterior cerebral artery occlusion: an atypical form of moyamoya disease

BACKGROUND

The relationship between anterior cerebral artery (ACA) occlusion and moyamoya disease (MMD) has rarely been studied. In this study, we focused on a special type of MMD: isolated ACA-occlusive MMD. We investigated clinical attributes, genotypes and progression risk factors in patients with ACA-occlusive MMD, providing initial insights into the relationship between ACA occlusion and MMD.

METHODS

We retrospectively analysed digital subtraction angiography (DSA) from 2486 patients and diagnosed 139 patients with ACA-occlusive MMD. RNF213 p.R4810K (rs112735431) mutation analysis was performed. Patients were categorised into progression and non-progression groups based on whether they progressed to typical MMD. Differences in clinical characteristics, neuropsychological assessment, radiological findings and genotypes were evaluated. Logistic regression analyses identified risk factors for ACA-occlusive MMD progression.

RESULTS

The median age of patients with ACA-occlusive MMD was 36 years, and the primary symptom was transient ischaemic attack (TIA). 72.3% of ACA-occlusive MMD patients had cognitive decline. Of 116 patients who underwent RNF213 gene mutation analysis, 90 patients (77.6%) carried the RNF213 p.R4810K GG allele and 26 (22.4%) carried the GA allele. Of 102 patients with follow-up DSA data, 40 patients (39.2%) progressed. Kaplan-Meier curve estimates indicated a higher incidence of ischaemic stroke in the progression group during follow-up (p=0.035). Younger age (p=0.041), RNF213 p.R4810K GA genotype (p=0.037) and poor collateral compensation from the middle cerebral artery (MCA) to ACA (p<0.001) were risk factors of ACA-occlusive MMD progression to typical MMD.

CONCLUSIONS

Cognitive decline and TIA might be the main manifestations of ACA-occlusive MMD. Isolated ACA occlusion may be an early signal of MMD. The initial lesion site of MMD is not strictly confined to the terminal portion of the internal carotid artery. Younger patients, patients with RNF213 p.R4810K GA genotype or those with inadequate MCA-to-ACA compensation are more likely to develop typical MMD.

Clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease: Longitudinal and Cross-Sectional Study

Objective

This study aimed to explore the long-term outcome of unilateral moyamoya disease and predict the clinical and genetic factors associated with contralateral progression in unilateral moyamoya disease.

Methods

We retrospectively recruited unilateral moyamoya disease patients with available genetic data who underwent encephaloduroarteriosynangiosis (EDAS) surgery at our institution from January 2009 to November 2017. Long-term follow-up data, including clinical outcomes, angiographic features, and genetic information, were analyzed.

Results

A total of 83 unilateral moyamoya disease patients with available genetic data were enrolled in our study. The mean duration of clinical follow-up was 7.9 ± 2.0 years. Among all patients, 19 patients demonstrated contralateral progression to bilateral disease. Heterozygous Ring Finger Protein 213 p.R4810K mutations occurred significantly more frequently in unilateral moyamoya disease patients with contralateral progression. Furthermore, patients with contralateral progression typically demonstrated an earlier age of onset than those with non-progressing unilateral moyamoya disease. In the contralateral progression group, posterior circulation involvement was observed in 11 (11/19, 57.9%) patients compared to 12 (12/64, 18.8%) in the non-contralateral progression group (P = 0.001). The time to peak of cerebral perfusion and neurological status showed significant postoperative improvement.

Conclusion

Long-term follow-up revealed that the EDAS procedure might provide benefits for unilateral moyamoya disease patients. Ring Finger Protein 213 p.R4810K mutations, younger age, and posterior circulation involvement might predict the contralateral progression of unilateral moyamoya disease.

Multiomics and blood-based biomarkers of moyamoya disease: protocol of Moyamoya Omics Atlas (MOYAOMICS)

BACKGROUND

Moyamoya disease (MMD) is a rare and complex cerebrovascular disorder characterized by the progressive narrowing of the internal carotid arteries and the formation of compensatory collateral vessels. The etiology of MMD remains enigmatic, making diagnosis and management challenging. The MOYAOMICS project was initiated to investigate the molecular underpinnings of MMD and explore potential diagnostic and therapeutic strategies.

METHODS

The MOYAOMICS project employs a multidisciplinary approach, integrating various omics technologies, including genomics, transcriptomics, proteomics, and metabolomics, to comprehensively examine the molecular signatures associated with MMD pathogenesis. Additionally, we will investigate the potential influence of gut microbiota and brain-gut peptides on MMD development, assessing their suitability as targets for therapeutic strategies and dietary interventions. Radiomics, a specialized field in medical imaging, is utilized to analyze neuroimaging data for early detection and characterization of MMD-related brain changes. Deep learning algorithms are employed to differentiate MMD from other conditions, automating the diagnostic process. We also employ single-cellomics and mass cytometry to precisely study cellular heterogeneity in peripheral blood samples from MMD patients.

CONCLUSIONS

The MOYAOMICS project represents a significant step toward comprehending MMD's molecular underpinnings. This multidisciplinary approach has the potential to revolutionize early diagnosis, patient stratification, and the development of targeted therapies for MMD. The identification of blood-based biomarkers and the integration of multiple omics data are critical for improving the clinical management of MMD and enhancing patient outcomes for this complex disease.

High-resolution MRI vessel wall enhancement in moyamoya disease: risk factors and clinical outcomes

OBJECTIVES

Intracranial vessel wall enhancement (VWE) on high-resolution magnetic resonance imaging (HRMRI) is associated with the progression and poor prognosis of moyamoya disease (MMD). This study assessed potential risk factors for VWE in MMD.

METHODS

We evaluated MMD patients using HRMRI and traditional angiography examinations. The participants were divided into VWE and non-VWE groups based on HRMRI. Logistic regression was performed to compare the risk factors for VWE in MMD. The incidence of cerebrovascular events of the different subgroups according to risk factors was compared using Kaplan-Meier survival and Cox regression.

RESULTS

We included 283 MMD patients, 84 of whom had VWE on HRMRI. The VWE group had higher modified Rankin Scale scores at admission (p = 0.014) and a higher incidence of ischaemia and haemorrhage (p = 0.002) than did the non-VWE group. Risk factors for VWE included the ring finger protein 213 (RNF213) p.R4810K variant (odds ratio [OR] 2.01, 95% confidence interval [CI] 1.08-3.76, p = 0.028), hyperhomocysteinaemia (HHcy) (OR 5.08, 95% CI 2.34-11.05, p < 0.001), and smoking history (OR 3.49, 95% CI 1.08-11.31, p = 0.037). During the follow-up of 63.9 ± 13.2 months (median 65 months), 18 recurrent stroke events occurred. Cox regression showed that VWE and the RNF213 p.R4810K variant were risk factors for stroke.

CONCLUSION

The RNF213 p.R4810K variant is strongly associated with VWE and poor prognosis in MMD. HHcy and smoking are independent risk factors for VWE.

CLINICAL RELEVANCE STATEMENT

Vessel wall enhancement in moyamoya disease is closely associated with poor prognosis, especially related to the ring finger protein 213 p.R4810K variant, hyperhomocysteinaemia, and smoking, providing crucial risk assessment information for the clinic.

KEY POINTS

• The baseline presence of vessel wall enhancement is significantly associated with poor prognosis in moyamoya disease. • The ring finger protein 213 p.R4810K variant is strongly associated with vessel wall enhancement and poor prognosis in moyamoya disease. • Hyperhomocysteinaemia and smoking are independent risk factors for vessel wall enhancement in moyamoya disease.

Genetics in Ischemic Stroke: Current Perspectives and Future Directions

Ischemic stroke is a heterogeneous condition influenced by a combination of genetic and environmental factors. Recent advancements have explored genetics in relation to various aspects of ischemic stroke, including the alteration of individual stroke occurrence risk, modulation of treatment response, and effectiveness of post-stroke functional recovery. This article aims to review the recent findings from genetic studies related to various clinical and molecular aspects of ischemic stroke. The potential clinical applications of these genetic insights in stratifying stroke risk, guiding personalized therapy, and identifying new therapeutic targets are discussed herein.

RNF213 loss-of-function promotes pathological angiogenesis in moyamoya disease via the Hippo pathway

Moyamoya disease is an uncommon cerebrovascular disorder characterized by steno-occlusive changes in the circle of Willis and abnormal vascular network development. Ring finger protein 213 (RNF213) has been identified as an important susceptibility gene for Asian patients, but researchers have not completely elucidated whether RNF213 mutations affect the pathogenesis of moyamoya disease. Using donor superficial temporal artery samples, whole-genome sequencing was performed to identify RNF213 mutation types in patients with moyamoya disease, and histopathology was performed to compare morphological differences between patients with moyamoya disease and intracranial aneurysm. The vascular phenotype of RNF213-deficient mice and zebrafish was explored in vivo, and RNF213 knockdown in human brain microvascular endothelial cells was employed to analyse cell proliferation, migration and tube formation abilities in vitro. After bioinformatics analysis of both cell and bulk RNA-seq data, potential signalling pathways were measured in RNF213-knockdown or RNF213-knockout endothelial cells. We found that patients with moyamoya disease carried pathogenic mutations of RNF213 that were positively associated with moyamoya disease histopathology. RNF213 deletion exacerbated pathological angiogenesis in the cortex and retina. Reduced RNF213 expression led to increased endothelial cell proliferation, migration and tube formation. Endothelial knockdown of RNF213 activated the Hippo pathway effector Yes-associated protein (YAP)/tafazzin (TAZ) and promoted the overexpression of the downstream effector VEGFR2. Additionally, inhibition of YAP/TAZ resulted in altered cellular VEGFR2 distribution due to defects in trafficking from the Golgi apparatus to the plasma membrane and reversed RNF213 knockdown-induced angiogenesis. All these key molecules were validated in ECs isolated from RNF213-deficient animals. Our findings may suggest that loss-of-function of RNF213 mediates the pathogenesis of moyamoya disease via the Hippo pathway.

Integrated analysis of the association between methionine cycle and risk of moyamoya disease

OBJECTIVE

The role of methionine (Met) cycle in the pathogenesis and progression of cardiovascular and cerebrovascular diseases has been established, but its association with moyamoya disease (MMD) has rarely been studied. This study aimed to analyze the levels of Met cycle-related metabolites and constructed a risk model to explore its association with the risk of MMD.

METHODS

In this prospective study, a total of 302 adult MMD patients and 88 age-matched healthy individuals were consecutively recruited. The serum levels of Met cycle-related metabolites were quantified by liquid chromatography-mass spectrometry (LC-MS). Participants were randomly divided into training set and testing set at a ratio of 1:1. The training set was used to construct the risk score model by LASSO regression. The association between Met cycle-related risk score and the risk of MMD was analyzed using logistic regression and assessed by ROC curves. The testing set was used for validation.

RESULTS

The levels of methionine sulfoxide and homocysteine were significantly increased, while the levels of betaine and choline were significantly decreased in MMD and its subtypes compared to healthy controls (p < 0.05 for all). The training set was used to construct the risk model and the risk score of each participant has been calculated. After adjusting for potential confounders, the risk score was independently associated with the risk of MMD and its subtypes (p < 0.05 for all). We then divided the participants into low-risk and high-risk groups, the high-risk score was significantly associated with the risk of MMD and its subtypes (p < 0.05 for all). The risk scores were further assessed as tertiles, the highest tertile was significantly associated with a higher risk of MMD and its subtypes compared to the lowest (p < 0.05 for all). The results were validated in the testing set.

CONCLUSION

This study has constructed and validated a risk model based on Met cycle-related metabolites, which was independently associated with the risk of MMD and its subtypes. The findings provided a new perspective on the risk evaluation and prevention of MMD.

Adult Moyamoya Disease and Syndrome: Current Perspectives and Future Directions: A Scientific Statement From the American Heart Association/American Stroke Association

Adult moyamoya disease and syndrome are rare disorders with significant morbidity and mortality. A writing group of experts was selected to conduct a literature search, summarize the current knowledge on the topic, and provide a road map for future investigation. The document presents an update in the definitions of moyamoya disease and syndrome, modern methods for diagnosis, and updated information on pathophysiology, epidemiology, and both medical and surgical treatment. Despite recent advancements, there are still many unresolved questions about moyamoya disease and syndrome, including lack of unified diagnostic criteria, reliable biomarkers, better understanding of the underlying pathophysiology, and stronger evidence for treatment guidelines. To advance progress in this area, it is crucial to acknowledge the limitations and weaknesses of current studies and explore new approaches, which are outlined in this scientific statement for future research strategies.

Genome-wide association study identifies novel susceptibilities to adult moyamoya disease

Genome-wide association study has limited to discover single-nucleotide polymorphisms (SNPs) in several ethnicities. Here, we investigated an initial GWAS to identify genetic modifiers predicting with adult moyamoya disease (MMD) in Koreans. GWAS was performed in 216 patients with MMD and 296 controls using the large-scale Asian-specific Axiom Precision Medicine Research Array. A subsequent fine-mapping analysis was conducted to assess the causal variants associated with adult MMD. A total of 489,966 out of 802,688 SNPs were subjected to quality control analysis. Twenty-one SNPs reached a genome-wide significance threshold (p = 5 × 10-8) after pruning linkage disequilibrium (r2 < 0.8) and mis-clustered SNPs. Among these variants, the 17q25.3 region including TBC1D16, CCDC40, GAA, RNF213, and ENDOV genes was broadly associated with MMD (p = 3.1 × 10-20 to 4.2 × 10-8). Mutations in RNF213 including rs8082521 (Q1133K), rs10782008 (V1195M), rs9913636 (E1272Q), rs8074015 (D1331G), and rs9674961 (S2334N) showed a genome-wide significance (1.9 × 10-8 < p < 4.3 × 10-12) and were also replicated in the East-Asian populations. In subsequent analysis, RNF213 mutations were validated in a fine-mapping outcome (log10BF > 7). Most of the loci associated with MMD including 17q25.3 regions were detected with a statistical power greater than 80%. This study identifies several novel and known variations predicting adult MMD in Koreans. These findings may good biomarkers to evaluate MMD susceptibility and its clinical outcomes.

The Progression of Pathophysiology of Moyamoya Disease

Moyamoya disease (MMD) is a chronic steno-occlusive cerebrovascular disease that often leads to hemorrhagic and ischemic strokes; however, its etiology remains elusive. Surgical revascularization by either direct or indirect bypass techniques to restore cerebral hypoperfusion is the treatment of choice to date. This review aims to provide an overview of the current advances in the pathophysiology of MMD, including the genetic, angiogenic, and inflammatory factors related to disease progression. These factors may cause MMD-related vascular stenosis and aberrant angiogenesis in complex manners. With a better understanding of the pathophysiology of MMD, nonsurgical approaches that target the pathogenesis of MMD may be able to halt or slow the progression of this disease.

Factors Influencing Collateral Circulation Formation After Indirect Revascularization for Moyamoya Disease: a Narrative Review

Indirect revascularization is one of the main techniques for the treatment of Moyamoya disease. The formation of good collateral circulation is a key measure to improve cerebral blood perfusion and reduce the risk of secondary stroke, and is the main method for evaluating the effect of indirect revascularization. Therefore, how to predict and promote the formation of collateral circulation before and after surgery is important for improving the success rate of indirect revascularization in Moyamoya disease. Previous studies have shown that vascular endothelial growth factor, endothelial progenitor cells, Caveolin-1, and other factors observed in patients with Moyamoya disease may play a key role in the generation of collateral vessels after indirect revascularization through endothelial hyperplasia and smooth muscle migration. In addition, mutations in the genetic factor RNF213 have also been associated with this process. This study summarizes the factors and mechanisms influencing collateral circulation formation after indirect revascularization in Moyamoya disease.

Surgical outcomes following encephaloduroarteriosynangiosis in moyamoya disease associated with hyperhomocysteinemia

INTRODUCTION

This study investigated the effect of indirect revascularization surgery in adult patients with moyamoya disease (MMD) complicated with hyperhomocysteinemia (HHcy), and the effect of HHcy on the progression of adult MMD.

METHODS

A retrospective case-control study was conducted in patients with MMD, with or without HHcy (n = 123). Postoperative collateral angiogenesis was evaluated using the Matsushima grading system and disease progression using the Suzuki staging system. Cerebral blood flow was evaluated before and after surgery using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and neurological function prognosis using the improved Rankin score (mRS). Univariate and multivariate logistic regression analyses were performed to determine risk factors for the clinical outcomes.

RESULTS

There was no significant difference in the Suzuki stage composition ratios between the HHcy group and the non-HHcy group before and after surgery. Non-HHcy patients were more likely to grow new collateral circulating vessels after encephaloduroarteriosynangiosis (EDAS). Moreover, postoperative DSC-MRI indicated that the time to peak significantly improved.

CONCLUSIONS

HHcy level may be a specific predictor of adverse clinical outcomes after EDAS in patients with MMD and a risk factor for poor collateral circulation and poor prognosis. Patients with MMD complicated with HHcy need to strictly control homocysteine levels before EDAS surgery.

The genetic landscape and clinical implication of pediatric Moyamoya angiopathy in an international cohort

Pediatric Moyamoya Angiopathy (MMA) is a progressive intracranial occlusive arteriopathy that represents a leading cause of transient ischemic attacks and strokes in childhood. Despite this, up to now no large, exclusively pediatric MMA cohort has been subjected to systematic genetic investigation. In this study, we performed molecular karyotyping, exome sequencing and automated structural assessment of missense variants on a series of 88 pediatric MMA patients and correlated genetic, angiographic and clinical (stroke burden) findings. The two largest subgroups in our cohort consisted of RNF213 and neurofibromatosis type 1 (NF1) patients. While deleterious RNF213 variants were associated with a severe MMA clinical course with early symptom onset, frequent posterior cerebral artery involvement and higher stroke rates in multiple territories, NF1 patients had a similar infarct burden compared to non-NF1 individuals and were often diagnosed incidentally during routine MRIs. Additionally, we found that MMA-associated RNF213 variants have lower predicted functional impact compared to those associated with aortic disease. We also raise the question of MMA as a feature of recurrent as well as rare chromosomal imbalances and further support the possible association of MMA with STAT3 deficiency. In conclusion, we provide a comprehensive characterization at the genetic and clinical level of a large exclusively pediatric MMA population. Due to the clinical differences found across genetic subgroups, we propose genetic testing for risk stratification as part of the routine assessment of pediatric MMA patients.

Heart-brain connections: Phenotypic and genetic insights from magnetic resonance images

Cardiovascular health interacts with cognitive and mental health in complex ways, yet little is known about the phenotypic and genetic links of heart-brain systems. We quantified heart-brain connections using multiorgan magnetic resonance imaging (MRI) data from more than 40,000 subjects. Heart MRI traits displayed numerous association patterns with brain gray matter morphometry, white matter microstructure, and functional networks. We identified 80 associated genomic loci (P < 6.09 × 10-10) for heart MRI traits, which shared genetic influences with cardiovascular and brain diseases. Genetic correlations were observed between heart MRI traits and brain-related traits and disorders. Mendelian randomization suggests that heart conditions may causally contribute to brain disorders. Our results advance a multiorgan perspective on human health by revealing heart-brain connections and shared genetic influences.

Advances in Management of the Stroke Etiology One-Percenters

PURPOSE OF REVIEW

Uncommon causes of stroke merit specific attention; when clinicians have less common etiologies of stoke in mind, the diagnosis may come more easily. This is key, as optimal management will in many cases differs significantly from "standard" care.

RECENT FINDINGS

Randomized controlled trials (RCT) on the best medical therapy in the treatment of cervical artery dissection (CeAD) have demonstrated low rates of ischemia with both antiplatelet and vitamin K antagonism. RCT evidence supports the use of anticoagulation with vitamin K antagonism in "high-risk" patients with antiphospholipid antibody syndrome (APLAS), and there is new evidence supporting the utilization of direct oral anticoagulation in malignancy-associated thrombosis. Migraine with aura has been more conclusively linked not only with increased risk of ischemic and hemorrhagic stroke, but also with cardiovascular mortality. Recent literature has surprisingly not provided support the utilization of L-arginine in the treatment of patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS); however, there is evidence at this time that support use of enzyme replacement in patients with Fabry disease. Additional triggers for reversible cerebral vasoconstriction syndrome (RCVS) have been identified, such as capsaicin. Imaging of cerebral blood vessel walls utilizing contrast-enhanced MRA is an emerging modality that may ultimately prove to be very useful in the evaluation of patients with uncommon causes of stroke. A plethora of associations between cerebrovascular disease and COVID-19 have been described. Where pertinent, authors provide additional tips and guidance. Less commonly encountered conditions with updates in diagnosis, and management along with clinical tips are reviewed.

Meta-analysis of the association between RNF213 polymorphisms and clinical features of moyamoya disease in Asian population

BACKGROUND

We performed this study to explore the relationship between ring finger protein 213 (RNF213) gene polymorphisms and clinical features in moyamoya disease (MMD).

METHODS

Electronic databases (PubMed, Google Scholar, Embase, Scopus, Cochrane Library) were conducted from inception to May 15th, 2022. Odds ratios (ORs) with 95 % confidence intervals (CIs) were generated as effect size for binary variants. Subgroup analyses were performed by the RNF213 polymorphisms. Sensitivity was used to examine the robustness of associations.

RESULTS

A total of 16 articles and 3061 MMD patients were included and the association of five RNF213 polymorphisms on 9 clinical features of MMD were identified. Patients under 18 years of age at onset, familial MMD, cerebral ischemic stroke and posterior cerebral artery involvement (PCi) were significantly more common in mutant type compared with wild type of RNF213. Compared with each wild type, subgroup analysis showed that rs11273543 and rs9916351 remarkably increased risk of MMD on early onset, but rs371441113 evidently delayed the onset of MMD. Rs112735431 in mutant type was significantly higher than wild type in patients with PCi. Subgroup analysis in mutant type showed that rs112735431 conspicuously decreased intracerebral/ intraventricular hemorrhage (ICH/IVH) risk and yet rs148731719 obviously increased the risk in ICH/IVH.

CONCLUSION

More attention should be paid to patients on whom the ischemic MMD occurs younger than 18 years old. RNF213 polymorphism screening and cerebrovascular imaging examination should be performed to evaluate intracranial vascular involvement, to achieve early detection and early treatment and avoid more serious cerebrovascular events.

Physiological and pathophysiological mechanisms of the molecular and cellular biology of angiogenesis and inflammation in moyamoya angiopathy and related vascular diseases

Rationale

The etiology and pathophysiological mechanisms of moyamoya angiopathy (MMA) remain largely unknown. MMA is a progressive, occlusive cerebrovascular disorder characterized by recurrent ischemic and hemorrhagic strokes; with compensatory formation of an abnormal network of perforating blood vessels that creates a collateral circulation; and by aberrant angiogenesis at the base of the brain. Imbalance of angiogenic and vasculogenic mechanisms has been proposed as a potential cause of MMA. Moyamoya vessels suggest that aberrant angiogenic, arteriogenic, and vasculogenic processes may be involved in the pathophysiology of MMA. Circulating endothelial progenitor cells have been hypothesized to contribute to vascular remodeling in MMA. MMA is associated with increased expression of angiogenic factors and proinflammatory molecules. Systemic inflammation may be related to MMA pathogenesis.

Objective

This literature review describes the molecular mechanisms associated with cerebrovascular dysfunction, aberrant angiogenesis, and inflammation in MMA and related cerebrovascular diseases along with treatment strategies and future research perspectives.

Methods and results

References were identified through a systematic computerized search of the medical literature from January 1, 1983, through July 29, 2022, using the PubMed, EMBASE, BIOSIS Previews, CNKI, ISI web of science, and Medline databases and various combinations of the keywords "moyamoya," "angiogenesis," "anastomotic network," "molecular mechanism," "physiology," "pathophysiology," "pathogenesis," "biomarker," "genetics," "signaling pathway," "blood-brain barrier," "endothelial progenitor cells," "endothelial function," "inflammation," "intracranial hemorrhage," and "stroke." Relevant articles and supplemental basic science articles almost exclusively published in English were included. Review of the reference lists of relevant publications for additional sources resulted in 350 publications which met the study inclusion criteria. Detection of growth factors, chemokines, and cytokines in MMA patients suggests the hypothesis of aberrant angiogenesis being involved in MMA pathogenesis. It remains to be ascertained whether these findings are consequences of MMA or are etiological factors of MMA.

Conclusions

MMA is a heterogeneous disorder, comprising various genotypes and phenotypes, with a complex pathophysiology. Additional research may advance our understanding of the pathophysiology involved in aberrant angiogenesis, arterial stenosis, and the formation of moyamoya collaterals and anastomotic networks. Future research will benefit from researching molecular pathophysiologic mechanisms and the correlation of clinical and basic research results.

Eye-brain connections revealed by multimodal retinal and brain imaging genetics in the UK Biobank

As an anatomical extension of the brain, the retina of the eye is synaptically connected to the visual cortex, establishing physiological connections between the eye and the brain. Despite the unique opportunity retinal structures offer for assessing brain disorders, less is known about their relationship to brain structure and function. Here we present a systematic cross-organ genetic architecture analysis of eye-brain connections using retina and brain imaging endophenotypes. Novel phenotypic and genetic links were identified between retinal imaging biomarkers and brain structure and function measures derived from multimodal magnetic resonance imaging (MRI), many of which were involved in the visual pathways, including the primary visual cortex. In 65 genomic regions, retinal imaging biomarkers shared genetic influences with brain diseases and complex traits, 18 showing more genetic overlaps with brain MRI traits. Mendelian randomization suggests that retinal structures have bidirectional genetic causal links with neurological and neuropsychiatric disorders, such as Alzheimer's disease. Overall, cross-organ imaging genetics reveals a genetic basis for eye-brain connections, suggesting that the retinal images can elucidate genetic risk factors for brain disorders and disease-related changes in intracranial structure and function.

The complex genetic basis of fibromuscular dysplasia, a systemic arteriopathy associated with multiple forms of cardiovascular disease

Artery stenosis is a common cause of hypertension and stroke and can be due to atherosclerosis accumulation in the majority of cases and in a small fraction of patients to arterial fibromuscular dysplasia (FMD). Artery stenosis due to atherosclerosis is widely studied with known risk factors (e.g. increasing age, male gender, and dyslipidemia) to influence its etiology, including genetic factors. However, the causes of noninflammatory and nonatherosclerotic stenosis in FMD are less understood. FMD occurs predominantly in early middle-age women, a fraction of the population where cardiovascular risk is different and understudied. FMD arteriopathies are often diagnosed in the context of hypertension and stroke and co-occur mainly with spontaneous coronary artery dissection, an atypical cause of acute myocardial infarction. In this review, we provide a comprehensive overview of the recent advances in the understanding of molecular origins of FMD. Data were obtained from genetic studies using complementary methodological approaches applied to familial, syndromic, and sporadic forms of this intriguing arteriopathy. Rare variation analyses point toward mechanisms related to impaired prostacyclin signaling and defaults in fibrillar collagens. The study of common variation, mainly through a recent genome-wide association study, describes a shared genetic link with blood pressure, in addition to point at potential risk genes involved in actin cytoskeleton and intracellular calcium homeostasis supporting impaired vascular contraction as a key mechanism. We conclude this review with future strategies and approaches needed to fully understand the genetic and molecular mechanisms related to FMD.

Circulating choline pathway nutrients and risk of moyamoya disease

Background

Circulating choline pathway nutrients play a critical role in first stroke and recurrent stroke. However, there is limited information available on the effects of choline pathway nutrients on the risk of moyamoya disease (MMD) and its subtypes. We investigated the association between circulating choline and betaine and the incident risk of MMD and its subtypes.

Methods

The case-control study enrolled 385 patients with MMD [i.e., 110 transient ischemic attack (TIA)-type MMD, 157 infarction-type MMD, and 118 hemorrhagic-type MMD] and 89 matched healthy controls.

Results

Serum choline and betaine were inversely related to the risk of MMD and its subtypes. The risk of MMD was decreased with each increment in choline level [per 1 μmol increase: odds ratio (OR), 0.756; 95% CI, 0.678–0.843] and betaine level (per 1 μmol increase: OR, 0.952; 95% CI, 0.932–0.972), respectively. When choline and betaine were assessed as quartiles, compared with the lowest quartile of serum choline and betaine levels, those in the highest quartile had a significantly decreased risk of MMD (choline, Q4 vs. Q1: OR, 0.023; 95% CI, 0.005–0.118; betaine, Q4 vs. Q1: OR, 0.058; 95% CI, 0.018–0.184).

Conclusions

Serum choline and betaine were associated with the decreased risk of MMD and its subtypes.

Mystery(n) Phenotypic Presentation in Europeans: Report of Three Further Novel Missense RNF213 Variants Leading to Severe Syndromic Forms of Moyamoya Angiopathy and Literature Review

Moyamoya angiopathy (MMA) is a rare cerebral vasculopathy in some cases occurring in children. Incidence is higher in East Asia, where the heterozygous p.Arg4810Lys variant in RNF213 (Mysterin) represents the major susceptibility factor. Rare variants in RNF213 have also been found in European MMA patients with incomplete penetrance and are today a recognized susceptibility factor for other cardiovascular disorders, from extracerebral artery stenosis to hypertension. By whole exome sequencing, we identified three rare and previously unreported missense variants of RNF213 in three children with early onset of bilateral MMA, and subsequently extended clinical and radiological investigations to their carrier relatives. Substitutions all involved highly conserved residues clustered in the C-terminal region of RNF213, mainly in the E3 ligase domain. Probands showed a de novo occurring variant, p.Phe4120Leu (family A), a maternally inherited heterozygous variant, p.Ser4118Cys (family B), and a novel heterozygous variant, p.Glu4867Lys, inherited from the mother, in whom it occurred de novo (family C). Patients from families A and C experienced transient hypertransaminasemia and stenosis of extracerebral arteries. Bilateral MMA was present in the proband’s carrier grandfather from family B. The proband from family C and her carrier mother both exhibited annular figurate erythema. Our data confirm that rare heterozygous variants in RNF213 cause MMA in Europeans as well as in East Asian populations, suggesting that substitutions close to positions 4118–4122 and 4867 of RNF213 could lead to a syndromic form of MMA showing elevated aminotransferases and extracerebral vascular involvement, with the possible association of peculiar skin manifestations.

Transcriptomic Profiling of Intracranial Arteries in Adult Patients With Moyamoya Disease Reveals Novel Insights Into Its Pathogenesis

Moyamoya disease (MMD) is a rare, progressively steno-occlusive cerebrovascular disorder of unknown etiology. Here, we revealed the gene expression profile of the intracranial arteries in MMD via the RNA-sequencing (RNA-seq). We identified 556 differentially expressed genes (DEGs) for MMD, including 449 and 107 significantly upregulated or downregulated genes. Compared with atherosclerosis-associated intracranial artery stenosis/occlusion (AS-ICASO) controls, upregulated genes were mainly involved in extracellular matrix (ECM) organization, whereas downregulated genes were primarily associated with mitochondrial function and oxidative phosphorylation in MMD. Moreover, we found that a separate sex analysis uncovers more DEGs (n = 1.022) compared to an combined sex analysis in MMD. We identified 133 and 439 sex-specific DEGs for men and women in MMD, respectively. About 95.6% of sex-specific DEGs were protein-coding genes and 3% of the genes belonged to long non-coding RNAs (lncRNA). Sex-specific DEGs were observed on all chromosomes, of which 95.49 and 96.59% were autosomal genes in men and women, respectively. These sex-specific DEGs, such as aquaporin-4 (AQP4), superoxide dismutase 3 (SOD3), and nuclear receptor subfamily 4 group A member 1 (NR4A1), may contribute to sex differences in MMD. This transcriptomic study highlighted that ECM and mitochondrial function are the central molecular mechanisms underlying MMD, and revealed sex differences in the gene expression in the intracranial arteries, thereby providing new insights into the pathogenesis of MMD.

MicroRNA Expression in Circulating Leukocytes and Bioinformatic Analysis of Patients With Moyamoya Disease

Objective: MicroRNAs (miRNAs) in exosomes had been implicated differentially expressed in patient with moyamoya disease (MMD), but the miRNAs expression in circulating leukocytes remains unclear. This study was investigated on the differential expression of miRNAs in peripheral leukocytes between MMD patients and healthy adults, and among patients with subtypes of MMD.

Materials and methods: A total of 30 patients with MMD and 10 healthy adults were enrolled in a stroke center from October 2017 to December 2018. The gene microarray was used to detect the differential expression profiles of miRNA in leukocytes between MMD patients and controls, and the differentially expressed miRNAs were verified by the method of real-time PCR. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore the key signaling pathways and possible pathogenesis of MMD.

Results: The microarray results showed 12 differentially expressed miRNAs in leukocytes of MMD patients compared with controls (fold change &gt;2.0, p &lt; 0.05 and FDR &lt;0.05), of which 8 miRNAs were upregulated (miRNA-142-5p, miRNA-29b-3p, miRNA-424-5p, MiRNA-582-5p, miRNA-6807-5p, miRNA-142-3p, miRNA-340-5p, miRNA-4270), and 4 miRNAs were downregulated (miRNA-144-3p, miRNA-451a, miRNA-486-5p, miRNA-363-3p). The real-time PCR confirmed seven differentially expressed miRNAs (p &lt; 0.05), of which 4 miRNAs (miRNA-29b-3p, miRNA-142-3p, miRNA-340-5p, miRNA-582-5p) were upregulated, and 3 miRNAs (miRNA-363-3p, miRNA-451a and miRNA-486-5p) were downregulated. Both GO and KEGG analysis suggested that the Wnt signaling pathway may be involved in the pathogenesis of MMD. In addition, miRNAs were also differentially expressed among patients with subtypes of MMD.

Conclusion: This study indicated that miRNAs are differentially expressed in peripheral leukocytes between MMD patients and healthy adults, and among patients with subtypes of MMD. The Wnt signaling pathway is probably involved in the pathogenesis of MMD.

The Potential Mechanism Behind Native and Therapeutic Collaterals in Moyamoya

Background and Purpose

To explore the genetic basis and molecular mechanism of native arteriogenesis and therapeutic synangiosis in moyamoya disease (MMD).

Methods

An angiography-based study using patients from a prospective trial of encephaloduroarteriosynangiosis (EDAS) surgery was performed. The spontaneous collaterals grades were evaluated according to the system described by a new grading system. Blood samples were collected from all the recruited patients before EDAS and during the second hospitalization 3 months post-EDAS. We performed Boolean analysis using a combination of specific cell surface markers of CD34^briCD133⁺CD45^dimKDR⁺. Genotyping of p.R4810K was also performed. The correlation of age, sex, initial symptoms at diagnosis, collateral grade, Suzuki stages, the RNF213 genotype, time to peak (TTP), and endothelial progenitor cell (EPC) count with good collateral circulation was evaluated.

Results

Eighty-five patients with MMD were included in this study. The mutation rate of RNF213 p.R4810K in our study was 25.9% (22/85). The heterozygous mutations were occurred significantly more frequently in the cases that were presented with infarction, worse neurological status, severe posterior cerebral artery (PCA) stenosis, and longer TTP delay. Further, the heterozygous mutations occurred significantly more frequently in the poor collateral stage group. Lower grades were significantly correlated with severe ischemia symptoms, worse neurological status, and a longer TTP delay. The post-operative angiographic findings showed that a good Matsushima grade was correlated with heterozygous mutations, a lower collateral stage, and a longer TTP delay. The CD34^briCD133⁺CD45^dimKDR⁺ cell count in patients 3 months post-EDAS was significantly higher as compared to the count before EDAS in the good Matsushima grade group. However, this change was not observed in the poor Matsushima grade group.

Conclusions

These data imply that mutations of RNF213 p.R4810K affect the establishment of spontaneous collateral circulation, and EPCs are involved in the process of formation of new EDAS collaterals.

Epigenome-Wide Association Study Reveals Differential Methylation Sites and Association of Gene Expression Regulation with Ischemic Moyamoya Disease in Adults

Background

The association of DNA methylation with the pathogenesis of adult ischemic moyamoya disease (MMD) is unknown. Here, we investigated the genome-wide DNA methylation profiles in patients with MMD and identified the genes related to the pathogenesis of MMD.

Methods

Whole blood samples were collected from 20 individuals, including 10 patients with ischemic moyamoya disease without any underlying disease and 10 healthy individuals. Genome-wide DNA methylation analysis was performed using Illumina 850K microarrays. Transcriptional correlation was verified using quantitative reverse transcription-polymerase chain reaction. In vitro experiments were used to analyze the association of functional defects with candidate epigenetic markers.

Results

The genome-wide methylation level in the whole blood of adults with ischemic MMD was higher than that in the healthy individuals. In total, 759 methylation probes differed significantly between the case and control. The hypermethylated regions were mostly concentrated in the gene spacer regions. Among genes with the highest degree of the differential expression, KCNMA1 and GALNT2 were upregulated, whereas SOX6 and RBM33 were downregulated.

Conclusions

This is the first study showing that the low expression of genes associated with epigenetic regulation, such as SOX6 and RBM33, may be related to vascular occlusion in MMD, whereas the overexpression of KCNMA1 and GALNT2 may be related to the vascular hyperplasia. The results suggest that DNA methylation was involved in the pathogenesis of MMD, and new pathogenic genes were proposed as biological markers.

Calcification of the abdominal aorta is an under-appreciated cardiovascular disease risk factor in the general population

Calcification of large arteries is a high-risk factor in the development of cardiovascular diseases, however, due to the lack of routine monitoring, the pathology remains severely under-diagnosed and prevalence in the general population is not known. We have developed a set of machine learning methods to quantitate levels of abdominal aortic calcification (AAC) in the UK Biobank imaging cohort and carried out the largest to-date analysis of genetic, biochemical, and epidemiological risk factors associated with the pathology. In a genetic association study, we identified three novel loci associated with AAC (FGF9, NAV9, and APOE), and replicated a previously reported association at the TWIST1/HDAC9 locus. We find that AAC is a highly prevalent pathology, with ~ 1 in 10 adults above the age of 40 showing significant levels of hydroxyapatite build-up (Kauppila score > 3). Presentation of AAC was strongly predictive of future cardiovascular events including stenosis of precerebral arteries (HR~1.5), myocardial infarction (HR~1.3), ischemic heart disease (HR~1.3), as well as other diseases such as chronic obstructive pulmonary disease (HR~1.3). Significantly, we find that the risk for myocardial infarction from elevated AAC (HR ~1.4) was comparable to the risk of hypercholesterolemia (HR~1.4), yet most people who develop AAC are not hypercholesterolemic. Furthermore, the overwhelming majority (98%) of individuals who develop pathology do so in the absence of known pre-existing risk conditions such as chronic kidney disease and diabetes (0.6% and 2.7% respectively). Our findings indicate that despite the high cardiovascular risk, calcification of large arteries remains a largely under-diagnosed lethal condition, and there is a clear need for increased awareness and monitoring of the pathology in the general population.

Identification and Functional Characterization of a Novel Susceptibility Locus for Small Vessel Vasculitis with MPO-ANCA

OBJECTIVE

To identify and characterize genetic loci associated with the risk of developing anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV).

METHODS

Genetic association analyses were performed after Illumina sequencing of 1,853 genes and subsequent replication with genotyping of selected SNPs in a total cohort of 1110 Scandinavian cases with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) and 1589 controls. A novel AAV-associated SNP was analysed for allele-specific effects on gene expression using luciferase reporter assay.

RESULTS

Proteinase 3 ANCA positive (PR3-ANCA+) AAV was significantly associated with two independent loci in the HLA-DPB1/A1 region (rs1042335, p= 6.3 x 1 0 -61, Odds ratio (OR)= 0.10; rs9277341, p= 1.5 x 1 0 -44, OR = 0.22) and with rs28929474 in the SERPINA1 gene (p= 2.7 x 1 0 -10, OR = 2.9). Myeloperoxidase (MPO)-ANCA+ AAV was significantly associated with the HLA-DQB1/HLA-DQA2 locus (rs9274619, p= 5.4 x 1 0 -25, OR = 3.7) and with a rare variant in the BACH2 gene (rs78275221, p= 7.9 x 1 0 -7, OR = 3.0), the latter a novel susceptibility locus for MPO-ANCA+ GPA/MPA. The rs78275221-A risk allele reduced luciferase gene expression in endothelial cells, specifically, as compared with the non-risk allele.

CONCLUSION

We identified a novel susceptibility locus for MPO-ANCA+ AAV and propose that the associated variant is of mechanistic importance, exerting a regulatory function on gene expression in specific cell types.

The association between the Moyamoya disease susceptible gene RNF213 variant and incident cardiovascular disease in a general population: the Nagahama study

OBJECTIVE

An association between the Moyamoya disease susceptible gene ring finger protein 213 (RNF213) variant and ischemic stroke and coronary artery disease has been suggested in case-control studies. We aimed to investigate the possible association between the RNF213 variant and the incidence of cardiovascular disease in a general population.

METHODS

The study participants consisted of 9153 Japanese community residents without history of cardiovascular disease. The clinical parameters employed in this analysis were observed at baseline between 2008 and 2010. The RNF213 p.R4859K variant was determined by TaqMan probe assay and then confirmed by Sanger sequencing.

RESULTS

During 8.52 years follow-up period, we observed 214 incident cases of cardiovascular diseases (99 total stroke cases, 119 major adverse cardiac event cases, including 4 cases of both). The incidence rate was higher for the variant allele carriers (120 cases; incidence rate, 71.0 per 10 000 person-years) than for the homozygotes of the wild-type allele (26.9), and the group differences achieved statistical significance (P = 0.009). Although the RNF213 variant was also associated with systolic blood pressure (dominant model: coefficient of 8.19 mmHg; P < 0.001), the Cox regression analysis adjusted for major covariates including systolic blood pressure identified the RNF213 variant as an independent determinant for cardiovascular disease (hazard ratio of 3.41, P = 0.002) and major adverse cardiac event (hazard ratio of 3.80, P = 0.010) but not with total stroke (P = 0.102).

CONCLUSION

The Moyamoya disease susceptible RNF213 variant was associated with blood pressure and the incidence of cardiovascular disease in a Japanese general population.

Dysregulation of Rnf 213 gene contributes to T cell response via antigen uptake, processing, and presentation

Growing evidence suggest the association between Moyamoya disease (MMD) and immune systems, such as antigen presenting cells in particular. Rnf213 gene, a susceptibility gene for MMD, is highly expressed in immune tissues, however, its function remains unclear. In addition, the physiological role of RNF213 gene polymorphism c.14576G > A (rs112735431), susceptibility variant for MMD, is also poorly understood. By studying Rnf213-knockout (Rnf213-KO) mice with deletion of largest exon32 and Rnf213-knockin (Rnf213-KI) mice with insertion of single-nucleotide polymorphism corresponding to c.14576G > A mutation in MMD patients, we aimed to investigate the role of RNF213 in dendritic cell development, and antigen processing and presentation. First, we found a high level of Rnf213 gene expression in conventional DCs and monocytes. Second, flow cytometric and confocal microscopic analysis revealed ovalbumin protein-pulsed Rnf213-KO and Rnf213-KI DCs showed impaired antigen uptake, proteolysis and reduced numbers of endosomes and lysosomes, and thereby failed to activate and proliferate antigen-specific T cells efficiently. In addition, Rnf213-KI DCs showed a similar phenotype to that of Rnf213-KO BMDCs. In conclusion, our findings suggest the critical role of RNF213 in antigen uptake, processing and presentation.

Genetic investigation of fibromuscular dysplasia identifies risk loci and shared genetics with common cardiovascular diseases

Fibromuscular dysplasia (FMD) is an arteriopathy associated with hypertension, stroke and myocardial infarction, affecting mostly women. We report results from the first genome-wide association meta-analysis of six studies including 1556 FMD cases and 7100 controls. We find an estimate of SNP-based heritability compatible with FMD having a polygenic basis, and report four robustly associated loci (PHACTR1, LRP1, ATP2B1, and LIMA1). Transcriptome-wide association analysis in arteries identifies one additional locus (SLC24A3). We characterize open chromatin in arterial primary cells and find that FMD associated variants are located in arterial-specific regulatory elements. Target genes are broadly involved in mechanisms related to actin cytoskeleton and intracellular calcium homeostasis, central to vascular contraction. We find significant genetic overlap between FMD and more common cardiovascular diseases and traits including blood pressure, migraine, intracranial aneurysm, and coronary artery disease.

The Genetic Basis of Moyamoya Disease

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive spontaneous bilateral occlusion of the intracranial internal cerebral arteries (ICA) and their major branches with compensatory capillary collaterals resembling a “puff of smoke” (Japanese: Moyamoya) on cerebral angiography. These pathological alterations of the vessels are called Moyamoya arteriopathy or vasculopathy and a further distinction is made between primary and secondary MMD. Clinical presentation depends on age and population, with hemorrhage and ischemic infarcts in particular leading to severe neurological dysfunction or even death. Although the diagnostic suspicion can be posed by MRA or CTA, cerebral angiography is mandatory for diagnostic confirmation. Since no therapy to limit the stenotic lesions or the development of a collateral network is available, the only treatment established so far is surgical revascularization. The pathophysiology still remains unknown. Due to the early age of onset, familial cases and the variable incidence rate between different ethnic groups, the focus was put on genetic aspects early on. Several genetic risk loci as well as individual risk genes have been reported; however, few of them could be replicated in independent series. Linkage studies revealed linkage to the 17q25 locus. Multiple studies on the association of SNPs and MMD have been conducted, mainly focussing on the endothelium, smooth muscle cells, cytokines and growth factors. A variant of the RNF213 gene was shown to be strongly associated with MMD with a founder effect in the East Asian population. Although it is unknown how mutations in the RNF213 gene, encoding for a ubiquitously expressed 591 kDa cytosolic protein, lead to clinical features of MMD, RNF213 has been confirmed as a susceptibility gene in several studies with a gene dosage-dependent clinical phenotype, allowing preventive screening and possibly the  development of new therapeutic approaches. This review focuses on the genetic basis of primary MMD only.

Multi-omics approaches for revealing the complexity of cardiovascular disease

The development and progression of cardiovascular disease (CVD) can mainly be attributed to the narrowing of blood vessels caused by atherosclerosis and thrombosis, which induces organ damage that will result in end-organ dysfunction characterized by events such as myocardial infarction or stroke. It is also essential to consider other contributory factors to CVD, including cardiac remodelling caused by cardiomyopathies and co-morbidities with other diseases such as chronic kidney disease. Besides, there is a growing amount of evidence linking the gut microbiota to CVD through several metabolic pathways. Hence, it is of utmost importance to decipher the underlying molecular mechanisms associated with these disease states to elucidate the development and progression of CVD. A wide array of systems biology approaches incorporating multi-omics data have emerged as an invaluable tool in establishing alterations in specific cell types and identifying modifications in signalling events that promote disease development. Here, we review recent studies that apply multi-omics approaches to further understand the underlying causes of CVD and provide possible treatment strategies by identifying novel drug targets and biomarkers. We also discuss very recent advances in gut microbiota research with an emphasis on how diet and microbial composition can impact the development of CVD. Finally, we present various biological network analyses and other independent studies that have been employed for providing mechanistic explanation and developing treatment strategies for end-stage CVD, namely myocardial infarction and stroke.

RNF213 and GUCY1A3 in Moyamoya Disease: Key Regulators of Metabolism, Inflammation, and Vascular Stability

Moyamoya disease is an idiopathic chronically progressive cerebrovascular disease, which causes both ischemic and hemorrhagic stroke. Genetic studies identified RNF213/Mysterin and GUCY1A3 as disease-causing genes. They were also known to be associated with non-moyamoya intracranial large artery disease, coronary artery disease and pulmonary artery hypertension. This review focused on these two molecules and their strong linker, calcineurin/NFAT signaling and caveolin to understand the pathophysiology of moyamoya disease and related vascular diseases. They are important regulators of lipid metabolism especially lipotoxicity, NF-κB mediated inflammation, and nitric oxide-mediated vascular protection. Although intimal thickening with fibrosis and damaged vascular smooth muscle cells are the distinguishing features of moyamoya disease, origin of the fibrous tissue and the mechanism of smooth muscle cell damages remains not fully elucidated. Endothelial cells and smooth muscle cells have long been a focus of interest, but other vascular components such as immune cells and extracellular matrix also need to be investigated in future studies. Molecular research on moyamoya disease would give us a clue to understand the mechanism preserving vascular stability.

Association of HLA-DQA2 and HLA-B With Moyamoya Disease in the Chinese Han Population

Objective

An HLA imputation was conducted to explore the relationship between HLA and patients with moyamoya disease (MMD) in the Chinese Han population.

Methods

In this study, we performed an association analysis of the major histocompatibility complex region in 2,786 individuals of Chinese Han ancestry (2,031 controls and 755 patients with MMD), through a widely used HLA imputation method.

Results

We identified that the variant rs3129731 (odds ratio [OR] = 1.79, p = 3.69 × 10⁻¹⁶) located between the MTCO3P1 and HLA-DQA2 is a major genetic risk factor for MMD. In addition to this variant, found in the conditional association analysis, we also detected another independent signal, rs1071817 (OR = 0.62, p = 1.20 × 10⁻¹¹), in HLA-B.

Conclusions

Our research suggests that the genetic polymorphism of HLA-DQA2 and HLA-B could be a genetic predisposing factor for MMD in Chinese Han. This may provide some evidence for further HLA-related studies of patients with MMD of Chinese Han ethnicity and indicates that MMD is an immune-related disease.

Genetic and Proteomic Contributions to the Pathophysiology of Moyamoya Angiopathy and Related Vascular Diseases

Rationale

This literature review describes the pathophysiological mechanisms of the current classes of proteins, cells, genes, and signaling pathways relevant to moyamoya angiopathy (MA), along with future research directions and implementation of current knowledge in clinical practice.

Objective

This article is intended for physicians diagnosing, treating, and researching MA.

Methods and Results

References were identified using a PubMed/Medline systematic computerized search of the medical literature from January 1, 1957, through August 4, 2020, conducted by the authors, using the key words and various combinations of the key words “moyamoya disease,” “moyamoya syndrome,” “biomarker,” “proteome,” “genetics,” “stroke,” “angiogenesis,” “cerebral arteriopathy,” “pathophysiology,” and “etiology.” Relevant articles and supplemental basic science articles published in English were included. Intimal hyperplasia, medial thinning, irregular elastic lamina, and creation of moyamoya vessels are the end pathologies of many distinct molecular and genetic processes. Currently, 8 primary classes of proteins are implicated in the pathophysiology of MA: gene-mutation products, enzymes, growth factors, transcription factors, adhesion molecules, inflammatory/coagulation peptides, immune-related factors, and novel biomarker candidate proteins. We anticipate that this article will need to be updated in 5 years.

Conclusion

It is increasingly apparent that MA encompasses a variety of distinct pathophysiologic conditions. Continued research into biomarkers, genetics, and signaling pathways associated with MA will improve and refine our understanding of moyamoya’s complex pathophysiology. Future efforts will benefit from multicenter studies, family-based analyses, comparative trials, and close collaboration between the clinical setting and laboratory research.

Association of single nucleotide polymorphisms of MTHFR, TCN2, RNF213 with susceptibility to hypertension and blood pressure

Methylenetetrahydrofolate reductase gene (MTHFR), transcobalaminII (TCN2) and ring finger protein 213 (RNF213) are related to homocysteine (Hcy) level and are of great significance for hypertension. We aimed to evaluate the associations of MTHFR (rs1801133, rs1801131, rs9651118), TCN2 (rs117353193) and RNF213 (rs9916351) with hypertension and blood pressure (BP). A total of 953 patients with hypertension and 1103 controls were enrolled. Genotyping was performed by Taqman. Logistic regression analysis indicated that A allele of TCN2 rs117353193 under the dominant model had a significantly protective effect (P=0.045) after adjustment, which showed that AA+GA genotype has a lower risk than GG. Additionally, the average diastolic BP (DBP) (P=0.044) and mean arterial pressure (MAP) (P=0.035) levels were significantly different between genotypes of RNF213 rs9916351. Further pairwise comparison showed that the average systolic BP (SBP) level of the TT genotype carriers were significantly higher than in CC (P=0.024), and the average DBP and MAP levels of the TT genotype carriers were higher than in CT (P=0.044, P=0.012, respectively) and CC (P=0.048, P=0.010, respectively). In the recessive model, the average SBP (P=0.043), DBP (P=0.018) and MAP (P=0.017) levels with the TT genotype carriers were significantly higher than in CT+CC. Multiple linear regression analysis suggested that RNF213 rs9916351 in the recessive model had significant effects on SBP (P=0.025), DBP (P=0.017) and MAP (P=0.010) as a risk factor. However, no associations were observed between MTHFR and hypertension. TCN2 rs117353193 might serve as a protective factor in hypertension, and RNF213 rs9916351 might be a risk factor that is linked to increase BP level in Northeast Chinese population.

RNF213 gene polymorphism rs9916351 and rs8074015 significantly associated with moyamoya disease in Chinese population

Background

Gene polymorphism especially Ring Finger Protein 213 (RNF213) p.R4810K is one of the main cause of moyamoya disease (MMD) in Asian populations, especially among Japanese people. However, missense mutation may not explain the reduced frequency of MMD in Chinese patients. We performed a hospital based case-control study in a Chinese population to elucidate the possible underlying reasons.

Methods

Five gene polymorphism loci, namely, rs35692831, rs9916351, rs9913636, rs8074015 and rs112735431, were included. A total of 98 patients and 114 healthy controls were enrolled in the study. Genomic DNA was genotyped by Mass Array methods.

Results

A significant difference was observed between patients and healthy controls in rs9916351, rs9913636, and rs8074015 loci under three genotypes and allelic models (P<0.01). Logistic regression analysis revealed the significant differences under the dominant, recessive and additional model in rs9916351 [odds ratio (OR) =4.173, 95% confidence interval (CI): 2.290-7.606, P<0.001; OR =3.152, 95% CI: 1.585-6.267, P=0.001; OR =0.199, 95% CI: 1.727-3.764, P<0.001; respectively] and rs8074015 (OR =0.359, 95% CI: 0.206-0.627, P<0.001; OR =0.348, 95% CI: 0.148-0.81, P=0.015; OR =0.208, 95% CI: 0.311-0.703, P<0.001; respectively), even adjusting for age and gender. In addition, the haplotype rs9913636-rs8074015 under "GACG" showed significant association with MMD.

Conclusions

Our results had revealed the polymorphism of RNF213 rs9916351 and rs8074015 were significantly associated with MMD especially in Chinese population.

Modifiable Risk Factors Associated With Moyamoya Disease: A Case-Control Study

BACKGROUND AND PURPOSE

The cause of moyamoya disease (MMD) remains unknown. We aimed to investigate the association between modifiable risk factors and MMD in a prospective, case-control study.

METHODS

Clinical and laboratory characteristics were evaluated in consecutively recruited adult patients with MMD and age-matched healthy control individuals. The potential risk factors for MMD were estimated by logistic regression analysis.

RESULTS

Our prospective study included 138 adult patients and 138 healthy control subjects. Logistic regression analyses showed that increased body mass index (odds ratio [OR], 1.121 [95% CI, 1.018-1.234]; P=0.020) and homocysteine (OR, 1.201 [95% CI, 1.081-1.334]; P=0.001) were associated with higher risk of MMD. Whereas increased albumin (OR, 1.043 [95% CI, 1.004-1.082]; P=0.028) and high-density lipoprotein cholesterol (OR, 1.043 [95% CI, 1.004-1.082]; P=0.028) were correlated with a lower risk of MMD. Furthermore, homocysteine (OR, 1.070 [95% CI, 1.010-1.134]; P=0.023) was significantly related to unilateral lesions.

CONCLUSIONS

Increased body mass index and homocysteine were associated with a higher risk of MMD. In contrast, increased albumin and high-density lipoprotein cholesterol were correlated with a lower risk of MMD. Furthermore, increased homocysteine was related to a higher prevalence of unilateral MMD. More attention should be paid to the modifiable risk factors of MMD, as these might help us finding its cause and new therapeutic regimen. Registration: URL: http://www.chictr.org. Unique identifier: ChiCTR2000031412.

PHACTR1 is associated with disease progression in Chinese Moyamoya disease

Moyamoya disease (MMD) is a progressive stenosis at the terminal portion of internal carotid artery and frequently occurs in East Asian countries. The etiology of MMD is still largely unknown. We performed a case-control design with whole-exome sequencing analysis on 31 sporadic MMD patients and 10 normal controls with matched age and gender. Patients clinically diagnosed with MMD was determined by digital subtraction angiography (DSA). Twelve predisposing mutations on seven genes associated with the sporadic MMD patients of Chinese ancestry (CCER2, HLA-DRB1, NSD-1, PDGFRB, PHACTR1, POGLUT1, and RNF213) were identified, of which eight single nucleotide variants (SNVs) were deleterious with CADD PHRED scaled score > 15. Sanger sequencing of nine cases with disease progression and 22 stable MMD cases validated that SNV (c.13185159G>T, p.V265L) on PHACTR1 was highly associated with the disease progression of MMD. Finally, we knocked down the expression of PHACTR1 by transfection with siRNA and measured the cell survival of human coronary artery endothelial cell (HCAEC) cells. PHACTR1 silence reduced the cell survival of HCAEC cells under serum starvation cultural condition. Together, these data identify novel predisposing mutations associated with MMD and reveal a requirement for PHACTR1 in mediating cell survival of endothelial cells.

Moyamoya vasculopathy in a young Caucasian woman with significant methamphetamine use

Background

Moyamoya is a rare cerebrovascular disorder seen predominantly in Asian populations. Methamphetamine use is a recognised cause of stroke in young people, but its pathophysiology is not fully understood. The incidence of moyamoya vasculopathy in methamphetamine-associated stroke is unknown due to a lack of sufficient data. We present a rare case of moyamoya syndrome in a young Caucasian woman with methamphetamine-associated stroke.

Case

A 31-year-old Caucasian woman presented with progressive right arm weakness, speech disturbance and seizures on a background of escalating methamphetamine use in the 9 months prior to admission. She did not have a personal or family history of stroke. MRI revealed both embolic and watershed infarcts in bilateral frontal regions and CT angiography showed development of new lenticulostriate collateral vessels. Digital subtraction angiography confirmed steno-occlusive disease of the bilateral anterior circulations and a ‘puff of smoke’ appearance.

Conclusion

In young patients who present with stroke with unclear aetiology, it is important to obtain a thorough substance use history. Moyamoya vasculopathy should be considered when evaluating the pathophysiology of stroke in young people.

Loss of mitochondrial ClpP, Lonp1, and Tfam triggers transcriptional induction of Rnf213, a susceptibility factor for moyamoya disease

Human RNF213, which encodes the protein mysterin, is a known susceptibility gene for moyamoya disease (MMD), a cerebrovascular condition with occlusive lesions and compensatory angiogenesis. Mysterin mutations, together with exposure to environmental trigger factors, lead to an elevated stroke risk since childhood. Mysterin is induced during cell stress, to function as cytosolic AAA+ ATPase and ubiquitylation enzyme. Little knowledge exists, in which context mysterin is needed. Here, we found that genetic ablation of several mitochondrial matrix factors, such as the peptidase ClpP, the transcription factor Tfam, as well as the peptidase and AAA+ ATPase Lonp1, potently induces Rnf213 transcript expression in various organs, in parallel with other components of the innate immune system. Mostly in mouse fibroblasts and human endothelial cells, the Rnf213 levels showed prominent upregulation upon Poly(I:C)-triggered TLR3-mediated responses to dsRNA toxicity, as well as upon interferon gamma treatment. Only partial suppression of Rnf213 induction was achieved by C16 as an antagonist of PKR (dsRNA-dependent protein kinase). Since dysfunctional mitochondria were recently reported to release immune-stimulatory dsRNA into the cytosol, our results suggest that mysterin becomes relevant when mitochondrial dysfunction or infections have triggered RNA-dependent inflammation. Thus, MMD has similarities with vasculopathies that involve altered nucleotide processing, such as Aicardi-Goutières syndrome or systemic lupus erythematosus. Furthermore, in MMD, the low penetrance of RNF213 mutations might be modified by dysfunctions in mitochondria or the TLR3 pathway.

Angiographic characteristics in Moyamoya disease with the p.R4810K variant: a propensity score-matched analysis

BACKGROUND AND PURPOSE

The p.R4810K variant was identified as a strong susceptibility in patients with Moyamoya disease (MMD). The aim of this study was to investigate the angiographic characteristics in MMD with the p.R4810K variant.

METHODS

Angiographic characteristics were compared between patients with wild-type p.R4810K variant (GG) and patients with heterozygous p.R4810K variant (GA) after 1:1 propensity score matching, including Suzuki stage, collateral circulation and external carotid artery (ECA) collateral. Collateral circulation was graded with scores ranging from 0 to 12: posterior collateral circulation from the posterior cerebral artery to the middle cerebral artery and anterior cerebral artery was scored from 0 to 6; anterior collateral circulation was scored as 6 to 0 corresponding to Suzuki stages 0 to 6.

RESULTS

A total of 489 patients were screened; 133 pairs were obtained after 1:1 propensity score matching. Compared with the patients in the GA group, unilateral MMD was more frequent in the GG group (P = 0.026). Hemispheres in the GA group (86/266) had more posterior cerebral artery involvement than hemispheres in the GG group (48/266) (P < 0.001). Hemispheres in the GA group had a lower grade in collateral circulation than hemispheres in the GG group (P = 0.011), but ECA collateral was more frequently observed in the GA group than in the GG group (53.4% vs. 39.8%, P = 0.002). Superficial temporal artery and occipital artery collateral was more frequently observed in the GA group than in the GG group (P < 0.05).

CONCLUSIONS

Patients in the GA group had lower grades in collateral circulation than patients in the GG group, but ECA collateral was more frequently observed in the GA group than in the GG group.

Xq28 copy number gain causing moyamoya disease and a novel moyamoya syndrome

BACKGROUND

The molecular anomalies causing moyamoya disease (MMD) and moyamoya syndromes (MMS) are unknown in most patients.

OBJECTIVE

This study aimed to identify de novo candidate copy number variants (CNVs) in patients with moyamoya.

METHODS

Rare de novo CNVs screening was performed in 13 moyamoya angiopathy trios using whole exome sequencing (WES) reads depth data and whole genome high density SNP array data. WES and SNP array data from an additional cohort of 115 unrelated moyamoya probands were used to search for recurrence of these rare de novo CNVs.

RESULTS

Two de novo CNVs were identified in two unrelated probands by both methods and confirmed by qPCR. One of these CNVs, located on Xq28, was detected in two additional families. This interstitial Xq28 CNV gain is absent from curated gold standard database of control genomic variants and gnomAD databases. The critical region contains five genes, including MAMLD1, a major NOTCH coactivator. Typical MMD was observed in the two families with a duplication, whereas in the triplicated patients of the third family, a novel MMS associating moyamoya and various systemic venous anomalies was evidenced.

CONCLUSION

The recurrence of this novel Xq28 CNV, its de novo occurrence in one patient and its familial segregation with the affected phenotype in two additional families strongly suggest that it is pathogenic. In addition to genetic counselling application, its association with pulmonary hypertension is of major importance for clinical care. These data also provide new insights into the genomic architecture of this emblematic, non-atherosclerotic, large vessel disease.

Genomic profiling of human vascular cells identifies TWIST1 as a causal gene for common vascular diseases

Genome-wide association studies have identified multiple novel genomic loci associated with vascular diseases. Many of these loci are common non-coding variants that affect the expression of disease-relevant genes within coronary vascular cells. To identify such genes on a genome-wide level, we performed deep transcriptomic analysis of genotyped primary human coronary artery smooth muscle cells (HCASMCs) and coronary endothelial cells (HCAECs) from the same subjects, including splicing Quantitative Trait Loci (sQTL), allele-specific expression (ASE), and colocalization analyses. We identified sQTLs for TARS2, YAP1, CFDP1, and STAT6 in HCASMCs and HCAECs, and 233 ASE genes, a subset of which are also GTEx eGenes in arterial tissues. Colocalization of GWAS association signals for coronary artery disease (CAD), migraine, stroke and abdominal aortic aneurysm with GTEx eGenes in aorta, coronary artery and tibial artery discovered novel candidate risk genes for these diseases. At the CAD and stroke locus tagged by rs2107595 we demonstrate colocalization with expression of the proximal gene TWIST1. We show that disrupting the rs2107595 locus alters TWIST1 expression and that the risk allele has increased binding of the NOTCH signaling protein RBPJ. Finally, we provide data that TWIST1 expression influences vascular SMC phenotypes, including proliferation and calcification, as a potential mechanism supporting a role for TWIST1 in CAD.