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

Recent Advances in Genetics of Moyamoya Disease: Insights into the Different Pathogenic Pathways

Moyamoya disease (MMD) is a rare yet clinically significant cerebrovascular disorder characterized by progressive stenosis of the distal internal carotid artery and/or its principal branches, accompanied by the development of characteristic collateral vessel networks. This disease demonstrates a complex multifactorial etiology with strong genetic determinants, as evidenced by its distinct geographical distribution patterns and familial clustering. Recent genetic researches have identified multiple pathogenic mutations contributing to MMD development through three principal mechanisms: progressive vascular stenosis, abnormal angiogenesis, and dysregulated inflammatory responses. Furthermore, moyamoya syndrome frequently occurs as a secondary vascular complication in various monogenic disorders. This review provides a comprehensive analysis of recent genetic advances in MMD in view of diverse pathogenic pathways, offering valuable perspectives on the molecular mechanisms underlying disease development and potential therapeutic targets.

Lipidomic profiling of the cerebrospinal fluid in moyamoya angiopathy patients

BACKGROUND

Moyamoya angiopathy (MA) is a rare cerebrovascular disorder which can occur in both children and young adults, characterized by progressive occlusion of the intracranial carotid arteries, leading patients to ischemic and haemorrhagic strokes. Despite decades of research, the mechanisms underlying MA remain poorly clarified and current gaps in the understanding of pathogenesis have hampered the development of suitable preventive strategies and therapeutic options. Moreover, clinically approved biomarkers for MA patients' stratification are missing. The unknown pathophysiology and the lack of reliable biomarkers prompted us to investigate cerebrospinal fluid (CSF) lipidome through state-of-the-art lipidomics.

METHODS

Intraoperative CSF from a subgroup of MA patients in comparison to age/sex matched controls (CTRL) was analysed through LC-MS/MS, by an untargeted lipidomic approach. Receiver operating characteristic (ROC) curve and simple linear regression analyses were performed for diagnostic use. We searched for simultaneously altered lipids in plasma and CSF of MA patients.

RESULTS

Overall, we observed a significant increase of sphingolipids (p < 0.05) and phospholipids (p < 0.05) in MA CSF. A partial least squares discriminant analysis clearly separated MA and CTRL by 64% on Principal Component 1. We identified lipid classes (n = 12) with a Variance Importance in Projection score ≥ 1.5, within those lipids highly correlated with MA (n = 70). A significant increase in acylcarnitines, sphingolipids (sphingomyelins and ceramides), phospholipids (lysophosphatidylcholines; phosphatidylcholines; phosphatidylethanolamines; ether-phosphatidylethanolamines; ether-phosphatidylcholines) and cholesterol esters was found by multivariate and univariate analyses. Monoacylglycerols were the only lipid class displaying a markedly significant (p < 0.001) decrease in CSF of MA patients as compared to CTRL subjects. The ROC curve and simple linear regression analysis identified 10 out of 12 lipid classes as reliable MA biomarkers, mainly dealing with phospholipids. We then compared current and previous data on plasma lipidomic profile. The discriminant analysis returned n = 175 (in plasma) and n = 70 (in CSF) simultaneously altered lipids respectively, and phosphatidylcholines (n = 10) resulted as commonly decreased in plasma and increased in CSF.

CONCLUSIONS

Our findings highlighted a strong pro-inflammatory environment in MA CSF. These preliminary hallmarks could be helpful to decipher the complex MA pathogenesis, by supplying candidate biomarkers for patient stratification.

A Child With Moyamoya Disease-A Case Study

Pediatric palliative care is a narrow subspeciality dealing with specialized comprehensive care approach for children living with chronic life-limiting illness and their families. Moyamoya disease with extracranial involvement is one such rare disease, where the most appropriate curative treatment is not yet determined. It is a vaso-occlusive disorder affecting intracranial vessels commonly, and rarely extracranial vessels. It is considered as one of the infrequent causes of acute stroke in children. We report a severe case of Moyamoya disease in a child, affecting both cerebral and extra-cranial vessels. The child had renal vessel involvement, which led to renovascular hypertension and end-stage renal disease. Considering the intricacies of complicated transplant outcomes, parents opted for pediatric palliative care. Bearing in mind the poor outcome of the extensive disease and need for regular follow-up, periodic counselling is imperative in successful management of children with Moyamoya disease. Given the progressive and relentless nature of the child's disease, a coordinated, multifaceted management is required to optimize the physical, psychological and social functioning of these children and their families.

Safety analysis of STA-MCA bypass combined with EDAS in the treatment of patients with moyamoya disease

This study evaluates the clinical efficacy and safety of superficial temporal artery to middle cerebral artery (STA-MCA) bypass combined with encephalo-duro-arterio-synangiosis (EDAS) in the treatment of moyamoya disease. A total of 80 patients with moyamoya disease who were treated at our institution between January 2022 and January 2024 were enrolled and randomly assigned to 2 groups: a control group (n = 40) and an observation group (n = 40). The control group underwent EDAS, while the observation group received STA-MCA bypass in addition to EDAS. Surgical success rates, cerebral blood flow (CBF) efficacy markers, neurological function scores, and surgical safety were comprehensively assessed in both groups. The surgical success rate in the observation group was 95.00%, significantly higher than 75.00% in the control group (P < .05). Three days postoperatively, the observation group exhibited significantly higher CBF and cerebral blood volume compared to the control group, with reduced time to peak and mean transit time (P < .05). One month after surgery, the observation group had significantly lower modified Rankin Scale and National Institutes of Health Stroke Scale scores, and higher mini-mental state examination scores compared to the control group (P < .05). The incidence of perioperative complications was 15.00% in the observation group and 17.50% in the control group, with no significant difference between the groups (P > .05). STA-MCA bypass combined with EDAS significantly improves surgical success rates, cerebral hemodynamic parameters, and neurological function outcomes in patients with moyamoya disease without increasing the incidence of surgical complications, indicating favorable safety.

Collateral blood vessels in stroke and ischemic disease: Formation, physiology, rarefaction, remodeling

Collateral blood vessels are unique, naturally occurring endogenous bypass vessels that provide alternative pathways for oxygen delivery in obstructive arterial conditions and diseases. Surprisingly however, the capacity of the collateral circulation to provide protection varies greatly among individuals, resulting in a significant fraction having poor collateral circulation in their tissues. We recently reviewed evidence that the presence of naturally-occurring polymorphisms in genes that determine the number and diameter of collaterals that form during development (ie, genetic background), is a major contributor to this variation. The purpose of this review is to summarize current understanding of the other determinants of collateral blood flow, drawing on both animal and human studies. These include the level of smooth muscle tone in collaterals, hemodynamic forces, how collaterals form during development (collaterogenesis), de novo formation of additional new collaterals during adulthood, loss of collaterals with aging and cardiovascular risk factor presence (rarefaction), and collateral remodeling (structural lumen enlargement). We also review emerging evidence that collaterals not only provide protection in ischemic conditions but may also serve a physiological function in healthy individuals. Primary focus is on studies conducted in brain, however relevant findings in other tissues are also reviewed, as are questions for future investigation.

Integrated bulk RNA sequencing and mass cytometry analysis reveal the circulating immune landscape in ischemic and hemorrhagic Moyamoya disease

BACKGROUND

Moyamoya disease (MMD) is increasingly recognized as being influenced by chronic inflammation, with circulating immune cells playing a role in its progression. However, research on the immune characteristics of different MMD subtypes is limited. This study aims to compare the peripheral immune profiles of ischemic and hemorrhagic MMD patients.

METHODS

Peripheral immune profiles were analyzed using transcriptome sequencing and mass cytometry. Data preprocessing was followed by functional and gene set enrichment analyses, as well as the construction of immune-related gene sets and protein-protein interaction networks. High-dimensional data analysis was performed using the PhenoGraph and t-SNE algorithms.

RESULTS

The study involved 9 ischemic and 6 hemorrhagic MMD patients for transcriptome analysis, and 20 ischemic and 16 hemorrhagic patients for mass cytometry. Hemorrhagic MMD patients exhibited upregulated genes associated with inflammation, hypoxia, and bacterial responses and downregulated genes related to immune response regulation. The results of mass cytometry analysis showed that, compared to ischemic MMD, patients with hemorrhagic MMD had reduced CD3 expression levels in T cells and their specific subsets, as well as impaired chemotactic capacity of DPT cells. The function of the B03 subset in B cells was diminished, while the proportion of NK cells increased and that of monocytes decreased. Additionally, the proportions of the D03 and D07 subsets in dendritic cells (DCs) were elevated.

CONCLUSIONS

This study reveals distinct immune profiles in ischemic and hemorrhagic MMD, emphasizing the need for subtype-specific therapeutic strategies.

Emerging role of mesenchymal cells in cardiac and cerebrovascular diseases: Physiology, pathology, and therapeutic implications

In recent years, the therapeutic utility of mesenchymal stem cells (MSCs) has received substantial attention from investigators, owing to their pleiotropic properties. The emerging insights from the developments in tissue engineering provide perspectives for the repair of damaged tissue and the replacement of failing organs. Perivascular cells including MSC-like pericytes, vascular smooth muscles, and other cells located around blood vessels, have been acknowledged to contribute to in situ angiogenesis and repair process. MSCs offer a wide array of therapeutic applications in different pathological states. However, in the current article, we have highlighted the recent updates on MSCs and their key applications in cardiac and cerebrovascular diseases, evident in different preclinical and clinical studies. We believe the present article would assist the investigators in understanding the recent advances of MSCs and exploring their therapeutic potential in varied ailments, especially cardiac and cerebrovascular diseases.

Stroke-Related Outcomes in Moyamoya Disease Compared with Moyamoya Syndromes: A Propensity-Matched Analysis

OBJECTIVE

Moyamoya syndrome (MMS) is a subset of moyamoya disease (MMD) with a systemic comorbidity. Due to the lack of direct comparisons between various MMS subgroups and their MMD counterparts, we aimed to analyze differences in stroke-related outcomes between MMS subgroups and patients with MMD through propensity score matching (PSM).

METHODS

We analyzed the National Inpatient Sample (NIS) from 2011 to 2020 for patients with MMD and common MMS-related comorbidities: Down syndrome (DS), sickle-cell disease (SCD), and type 1 neurofibromatosis (NF1). PSM was performed to match patients of each MMS subgroup to patients with MMD only, controlling for stroke risk factors. Rates of ischemic strokes, hemorrhagic strokes, and transient ischemic attacks (TIAs) were evaluated after matching.

RESULTS

A total of 10,652 patients with a moyamoya diagnosis were identified: 7971 with MMD only, 2202 with MMS-SCD, 162 with MMS-NF1, and 317 with MMS-DS. PSM for MMD only and MMS-SCD resulted in 630 matched pairs. After matching, univariate analysis showed that patients with MMS-SCD had significantly lower rates of ischemic strokes (8.9% vs. 17.9%; P = 0.001), hemorrhagic strokes (5.1% vs. 8.1%; P = 0.031), and TIAs (2.2% vs. 4.6%; P = 0.020) than did patients with MMD only. For the MMS-DS subgroup, 92 matched pairs showed significantly lower rates of TIAs than did patients with MMD only (0% vs. 6.5%; P = 0.013). Comparing 54 matched pairs of patients with MMD only and patients with MMS-NF1 showed no significant differences in stroke-related outcomes.

CONCLUSIONS

Patients with MMS-SCD had significantly lower rates of acute ischemic stroke, hemorrhagic stroke, and TIA compared with patients with MMD only. Future research should consider the source of these differences in improving stroke prevention in patients with MMD.

Moyamoya disease manifesting with bilateral involvement of the proximal vertebral arteries: A case report

Moyamoya disease (MMD) is a cerebrovascular disorder characterized by progressive occlusion of intracranial arteries, often leading to stroke and intracerebral hemorrhage. While MMD classically affects the intracranial vasculature, we present an unusual case of bilateral vertebral steno-occlusion, resulting in vertebrobasilar insufficiency in a 37-year-old man with MMD and treated with angioplasty and stenting of the dominant vertebral artery. Review of the literature demonstrates proximal vertebral artery involvement to be a rare manifestation of moyamoya disease. This report contributes to the understanding of the clinical spectrum of MMD and emphasizes the need for vigilance and awareness of the possibility of extracranial vascular complications in affected individuals.

Characterizing Revascularization After Encephalo-Duro-Arterio-Synangiosis (EDAS) in Adult Patients With Moyamoya Disease Using the Orbital Grading System

BACKGROUND

The Matsushima grade has traditionally been used to evaluate vessel ingrowth from the superficial temporal artery after encephalo-duro-arterio-synangiosis (EDAS) for Moyamoya disease (MMD) patients. However, this grading is subjective and prone to measurement variability. Herein, we propose the orbital grading system quantifying leptomeningeal and burr hole-related vessel-ingrowth from the superficial temporal artery and/or middle meningeal artery to the middle and anterior cerebral arteries post EDAS in MMD patients.

METHODS

An anatomical classification was developed by reference to 2 parallel vertical lines from the bony landmarks of the orbit, categorized from Grade 0-3. Regression models were used to compare clinical and functional outcomes of our grading system with the Matsushima scale.

RESULTS

Forty MMD patients, with median age of 48 years, mostly females (72.5%), underwent 56 EDAS procedures. Presentation included ischemic events (65.0%), hemorrhage (22.5%), and seizures (7.5%). Most patients were categorized as Suzuki ≥ IV (69.5%). Fifty EDAS (89.9%) had concurrent burr holes placed (parietal and frontal regions). At a median follow-up of 13.7 months, collateral growth was graded as follows: grade 0 (6; 10.8%), grade 1 (12; 21.4%), grade 2 (23; 41.1%), and grade 3 (15; 26.8%). Linear regression showed similarities in the distribution between the orbital grading system and Matsushima grading (r = 0.86; P < 0.01). Ischemic events were fewer in hemispheres categorized as grade 2-3 compared to grade 0-1 (P = 0.047) as well as in Matsushima grading A or B compared to C (P = 0.047).

CONCLUSIONS

The orbital grading system demonstrated agreement in identifying postoperative ischemic events as the Matsushima grade and provides a more practical and objective evaluation of collateral vessel ingrowth after EDAS with and without burr holes.

Mass cytometry revealed the circulating immune cell landscape across different Suzuki stages of Moyamoya disease

Moyamoya disease (MMD) is a cerebrovascular disorder marked by progressive arterial narrowing, categorized into six stages known as Suzuki stages based on angiographic features. Growing evidence indicates a pivotal role of systemic immune and inflammatory responses in the initiation and advancement of MMD. This study employs high-dimensional mass cytometry to reveal the immunophenotypic characteristics of peripheral blood immune cells (PBMCs) at various Suzuki stages, offering insights into the progression of MMD. PBMC samples from eight patients with early-stage MMD (Suzuki stages II and III) and eight patients with later-stage MMD (Suzuki stages IV, V, and VI) were analyzed using high-dimensional mass cytometry to evaluate the frequency and phenotype of immune cell subtypes. We identified 15 cell clusters and found that the immunological features of early-stage MMD and later-stage MMD are composed of cluster variations. In this study, we confirmed that, compared to later-stage MMD, the early-stage MMD group exhibits an increase in non-classical monocytes. As the Suzuki stage level increases, the proportions of plasmacytoid DCs and monocyte-derived DCs decrease. Furthermore, T cells, monocytes, DCs, and PMN-MDSCs in the early-stage MMD group show activation of the canonical NF-κB signaling pathway. We summarized and compared the similarities and differences between early-stage MMD patients and later-stage MMD patients. There is a potential role of circulating immune dysfunction and inflammatory responses in the onset and development of MMD.