Single Nucleotide Polymorphisms of Tissue Inhibitor of Metalloproteinase Genes in Familial Moyamoya Disease

Pediatric Moyamoya Biomarkers: Narrowing the Knowledge Gap

Moyamoya is a progressive cerebrovascular disorder that leads to stenosis of the arteries in the distal internal carotid, proximal middle cerebral and proximal anterior cerebral arteries of the circle of Willis. Typically a network of collaterals form to bypass the stenosis and maintain cerebral blood flow. As moyamoya progresses it affects the anterior circulation more commonly than posterior circulation, and cerebral blood flow becomes increasingly reliant on external carotid supply. Children with moyamoya are at increased risk for ischemic symptoms including stroke and transient ischemic attacks (TIA). In addition, cognitive decline may occur over time, even in the absence of clinical stroke. Standard of care for stroke prevention in children with symptomatic moyamoya is revascularization surgery. Treatment of children with asymptomatic moyamoya with revascularization surgery however remains more controversial. Therefore, biomarkers are needed to assist with not only diagnosis but also with determining ischemic risk and identifying best surgical candidates. In this review we will discuss the current knowledge as well as gaps in research in relation to pediatric moyamoya biomarkers including neurologic presentation, cognitive, neuroimaging, genetic and biologic biomarkers of disease severity and ischemic risk.

Macrohistory of Moyamoya Disease Analyzed Using Artificial Intelligence

INTRODUCTION

Moyamoya disease is characterized by progressive stenotic changes in the terminal segment of the internal carotid artery and the development of abnormal vascular networks called moyamoya vessels. The objective of this review was to provide a holistic view of the epidemiology, etiology, clinical findings, treatment, and pathogenesis of moyamoya disease. A literature search was performed in PubMed using the term "moyamoya disease," for articles published until 2021.

RESULTS

Artificial intelligence (AI) clustering was used to classify the articles into 5 clusters: (1) pathophysiology (23.5%); (2) clinical background (37.3%); (3) imaging (13.2%); (4) treatment (17.3%); and (5) genetics (8.7%). Many articles in the "clinical background" cluster were published from the 1970s. However, in the "treatment" and "genetics" clusters, the articles were published from the 2010s through 2021. In 2011, it was confirmed that a gene called Ringin protein 213 (RNF213) is a susceptibility gene for moyamoya disease. Since then, tremendous progress in genomic, transcriptomic, and epigenetic profiling (e.g., methylation profiling) has resulted in new concepts for classifying moyamoya disease. Our literature survey revealed that the pathogenesis involves aberrations of multiple signaling pathways through genetic mutations and altered gene expression.

CONCLUSION

We analyzed the content vectors in abstracts using AI, and reviewed the pathophysiology, clinical background, radiological features, treatments, and genetic peculiarity of moyamoya disease.

Quantitative Optical Coherence Tomography Angiography in Patients with Moyamoya Vasculopathy: A Pilot Study

Moyamoya (MM) disease is a chronic cerebrovascular disease that can lead to progressive stenosis of the terminal portions of the internal carotid arteries and their proximal branches. We sought to investigate and quantify retinal vascular changes in patients with MM vasculopathy (MMV) using optical coherence tomography angiography (OCTA) compared to healthy controls. Our findings reveal retinal microvascular changes in patients with MMV and highlights the potential of OCTA imaging for the detection of subclinical retinal pathology.

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.

The mechanobiological theory: a unifying hypothesis on the pathogenesis of moyamoya disease based on a systematic review

OBJECTIVE

Moyamoya angiopathy (MMA) affects the distal internal carotid artery and is designated as moyamoya disease (MMD) when predisposing conditions are absent, or moyamoya syndrome (MMS) when it occurs secondary to other causes. The authors aimed to investigate the reason for this anatomical site predilection of MMA. There is compelling evidence to suggest that MMA is a phenomenon that occurs due to stereotyped mechanobiological processes. Literature regarding MMD and MMS was systematically reviewed to decipher a common pattern relating to the development of MMA.

METHODS

A systematic review was conducted to understand the pathogenesis of MMA in accordance with PRISMA guidelines. PubMed MEDLINE and Scopus were searched using "moyamoya" and "pathogenesis" as common keywords and specific keywords related to six identified key factors. Additionally, a literature search was performed for MMS using "moyamoya" and "pathogenesis" combined with reported associations. A progressive search of the literature was also performed using the keywords "matrix metalloprotease," "tissue inhibitor of matrix metalloprotease," "endothelial cell," "smooth muscle cell," "cytokines," "endothelin," and "transforming growth factor" to infer the missing links in molecular pathogenesis of MMA. Studies conforming to the inclusion criteria were reviewed.

RESULTS

The literature search yielded 44 published articles on MMD by using keywords classified under the six key factors, namely arterial tortuosity, vascular angles, wall shear stress, molecular factors, blood rheology/viscosity, and blood vessel wall strength, and 477 published articles on MMS associations. Information obtained from 51 articles that matched the inclusion criteria and additional information derived from the progressive search mentioned above were used to connect the key factors to derive a network pattern of pathogenesis.

CONCLUSIONS

Based on the available literature, the authors have proposed a unifying theory for the pathogenesis of MMA. The moyamoya phenomenon appears to be the culmination of an interplay of vascular anatomy, hemodynamics, rheology, blood vessel wall strength, and a plethora of intricately linked mechanobiological molecular mediators that ultimately results in the mechanical process of occlusion of the blood vessel, stimulating angiogenesis and collateral blood supply in an attempt to perfuse the compromised brain.

Progression in Moyamoya Disease: Clinical Feature, Neuroimaging Evaluation and Treatment

Moyamoya disease (MMD) is a chronic cerebrovascular disease characterized by progressive stenosis of the arteries of the circle of Willis, with the formation of collateral vascular network at the base of the brain. Its clinical manifestations are complicated. Numerous studies have attempted to clarify the clinical features of MMD, including its epidemiology, genetic characteristics, and pathophysiology. With the development of neuroimaging techniques, various neuroimaging modalities with different advantages have deepened the understanding of MMD in terms of structural, functional, spatial, and temporal dimensions. At present, the main treatment for MMD focuses on neurological protection, cerebral blood flow reconstruction, and neurological rehabilitation, such as pharmacological treatment, surgical revascularization, and cognitive rehabilitation. In this review, we discuss recent progress in understanding the clinical features, in the neuroimaging evaluation and treatment of MMD.

Association of Genetic Variants With Moyamoya Disease in 13 000 Individuals: A Meta-Analysis

Background and Purpose- A growing body of evidence indicates genetic components play critical roles in moyamoya disease (MMD). Firm conclusions from studies of this disease have been stymied by small sample sizes and a lack of replicative results. This meta-analysis was conducted to determine whether these genetic polymorphisms are associated with MMD. Methods- PubMed, Google Scholar, Embase, Wanfang, Web of Science, and China National Knowledge Infrastructure databases were used to identify potentially relevant studies published until January 2020. The Review Manager 5.2 and Stata 15.0 software programs were used to perform the statistical analysis. Heterogeneity was assessed using the Cochran Q test and quantified using the I² test. Results- Four thousand seven hundred eleven MMD cases and 8704 controls in 24 studies were included, evaluating 7 polymorphisms in 6 genes. The fixed-effect odds ratios (95% CI) in allelic model of MMP-2 rs243865 were 0.60 (0.41-0.88) (P=0.008). In the country-based subgroup analysis, the fixed-effect odds ratios (95% CI) of RNF213 rs112735431 in allelic model were China, 39.74 (26.63-59.31), Japan, 74.65 (42.79-130.24) and Korea, 50.04 (28.83-86.88; all P<0.00001). In the sensitivity analysis, the fixed-effect odds ratios (95% CI) of allelic and dominant models were the RNF213 rs148731719 variant, 2.17 (1.36-3.48; P=0.001), 2.20 (1.35-3.61; P=0.002), the TIMP-2 rs8179090 variant, 0.33 (0.25-0.43; P<0.00001), 0.88 (0.65-1.21; P=0.440) and the MMP-3 rs3025058 variant, 0.61 (0.47-0.79; P=0.0002), 0.55 (0.41-0.75; P=0.0001), respectively. Conclusions- RNF213 rs112735431 and rs148731719 were positively, and TIMP-2 rs8179090, MMP-2 rs243865, and MMP-3 rs3025058 were inversely associated with MMD using multiple pathophysiologic pathways. Studies in larger population should be conducted to clarify whether and how these variants are associated with MMD.

TIMP2 Polymorphisms Association With Curve Initiation and Progression of Thoracic Idiopathic Scoliosis in the Caucasian Females

Idiopathic scoliosis (IS) etiology remains unclear, but strong genetic background is suggested. Previously reported TIMP2 study indicates an association of genic rs8179090 with IS progression in a Han Chinese population. However, there has been a lack of investigation into intragenic TIMP2 polymorphisms in IS patients. We recruited 100 Caucasian females with IS and 100 controls. Patients were subdivided accordingly to: progression rate, curve severity, joint mobility, and curve pattern. Allele-specific-polymerase chain reaction based on fluorescence resonance energy transfer was applied to evaluate nine TIMP2 polymorphisms. Distribution of genotype and allele frequency in only one polymorphism (rs11658743) differed in case-control study. Four of the polymorphisms (rs2277700, rs11077401, rs2376999, and rs4789934) showed non-equal distributions either in genotype or/and allele distributions in the patients of different progression rates. The rs11077401 was related to curve severity patients distinction and the rs8179090 distinguished patients with different joint mobility level. Two polymorphisms either differed statistically in case of curve patterns subgrouping (rs8068674 and rs8179090) or showed a slight tendency toward significance in the recessive model of allele distributions (rs9916809 and rs8179090). The remaining two polymorphisms (rs2377005, rs11658743) showed no association with either clinical or radiographic IS characteristics. The influence of the G allele of the rs8179090 on the clinical course of IS has not yet been confirmed. We identified four TIMP2 polymorphisms (rs11077401, rs2376999, rs2277700, and rs4789934) that were associated with a higher risk of the progressive IS form. Further genetic association studies based on suggested clinical criteria would be necessary to validate TIMP2 polymorphisms associated with the curve progression. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2217-2225, 2019.

Strong association of tissue inhibitor of metalloproteinase (TIMP)-2 and -3 promoter single nucleotide polymorphisms with risk of colorectal cancer in ethnic Kashmiri population - a case control study

Background: The tissue inhibitors of metalloproteinases (TIMPs) including TIMP2 and TIMP3 are the key physiological inhibitors of matrix metalloproteinases (MMPs) and along with MMPs, TIMPs play a vital role in the coordinated proteolytic breakdown and remodeling of the extracellular matrix (ECM) and the basement membrane that represent the barriers to any malignant tumor invasion and progression. These enzymes are vital for tumor invasion and metastasis and also play a critical role in several other stages of tumor development and progression. The studies on the association of various polymorphisms in human TIMP2 and TIMP3 genes including TIMP2-418G/C and TIMP3-1296T/C single nucleotide polymorphisms (SNPs) and CRC risk are limited, mixed, and inconclusive.Materials and methods: The aim of the present study was to analyze the association of TIMP2-418G/C and TIMP3-1296T/C promoter SNPs with colorectal cancer (CRC) susceptibility and development risk and also to evaluate the modifying effects of possible TIMP2-418G/C and TIMP3-1296T/C SNPs' genotypes on different risk factors of CRC or the reciprocal effect in ethnic population of Kashmir, India through a case-control setup. The genotype frequencies of TIMP2-418G/C and TIMP3-1296T/C promoter SNPs were compared between 142 CRC patients and 184 individually matched healthy controls by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The associations between the TIMP2-418G/C and TIMP3-1296T/C SNPs and CRC risk were examined through conditional logistic regression models adjusted for multiple possible confounding (third) variables. The possible effect measure modification of the association between the relevant SNP genotypes and CRC risk by various CRC risk factors including age, gender, and smoking status was also analyzed. Further, the associations between these SNPs and various clinico-pathological parameters, demographic variables, and environmental factors within the case group subjects with regard to CRC risk were also evaluated.Results: The overall association between the TIMP2-418G/C and TIMP3-1296T/C SNPs and the modulation of CRC risk was found to be highly significant (P=0.019 and P=0.000 for TIMP2 and TIMP3 SNPs, respectively). The heterozygous genotype (GC) of TIMP2-418G/C was significantly associated with an increased risk of colorectal cancer [OR, 1.87 (95%CI, 1.07-3.27); P=0.027] whereas the heterozygous genotype (TC) of TIMP3-1296T/C SNP was significantly associated with a decreased risk of colorectal cancer [OR, 0.53 (95%CI, 0.32-0.86); P=0.011]. The variant genotype (CC) of TIMP3-1296T/C SNP was also significantly associated with a decreased risk of colorectal cancer [OR, 0.18 (95%CI, 0.05-0.65); P=0.009].Conclusion: The present study demonstrates that there is a strong and highly significant association between the TIMP2-418G/C and TIMP3-1296T/C promoter SNPs and the risk of developing CRC in ethnic Kashmiri population. However, in order to substantiate our findings, the present study needs to be replicated with bigger sample size and should involve other ethnically defined populations with high CRC risk.

Childhood Moyamoya: Looking Back to the Future

Moyamoya is a chronic, progressive steno-occlusive arteriopathy that typically affects the anterior circulation arteries of the circle of Willis. A network of deep thalamoperforating and lenticulostriate collaterals develop to by-pass the occlusion giving rise to the characteristic angiographic "puff of smoke" appearance. Moyamoya confers a lifelong risk of stroke and neurological demise, with peak age of presentation in childhood ranging between five and 10 years. Moyamoya disease refers to patients who do not have a comorbid condition, whereas moyamoya syndrome refers to patients in whom moyamoya occurs in association with an acquired or inherited disorder such as sickle cell disease, neurofibromatosis type-1 or trisomy 21. The incidence of moyamoya disease and moyamoya syndrome demonstrates geographic and ethnic variation, with a predominance of moyamoya disease in East-Asian populations. Antiplatelet therapy and surgical revascularization procedures are the mainstay of management, as there are no available treatments to slow the progression of the arteriopathy. Future research is required to address the major gaps that remain in our understanding of the pathologic basis, optimal timing for surgery, and determinants of outcome in this high-stroke risk condition of childhood.

Moyamoya Vasculopathy in Indian Children: Our Experience

Background:

Moyamoya vasculopathy is a chronic progressive vaso-occlusive disease affecting the distal intracranial carotid arteries and their proximal branches. It is an important cause of recurrent strokes in children. Surgical revascularization procedures are now considered as the treatment option for moyamoya vasculopathy. The data from Indian children with moyamoya vasculopathy are limited to a very few studies.

Study Design:

We analyzed the records of children with moyamoya vasculopathy treated at our tertiary care center from 2000 to 2014. Our study population included all patients (aged 0–18 years) with moyamoya disease/syndrome (MMD/MMS). The demographic data, clinical characteristics, imaging, treatment details, and surgical procedures performed were reviewed.

Results:

A total of 41 patients (females-19, males-22) were identified. Thirty-three (80.48%) had MMD and eight (19.5%) had MMS. The mean age (±standard deviation) at presentation was 6.26 ± 3.79 years (range: 6 months–14 years). Majority had ischemic events at onset; none had hemorrhagic manifestations. Twenty-eight (68.29%) patients underwent surgery (a total of 33 surgical procedures, bilateral in five and unilateral in 23) and 13 (31.7%) were managed conservatively. The median duration of follow-up was 2.2 ± 1.85 years (range: 4 months–7 years). Two/thirteen patients (15%), who were managed conservatively, had recurrent strokes as against none (0/28) in the operated patients. No mortality was observed in our cohort.

Conclusion:

We agree with previous studies that Indian patients with moyamoya vasculopathy differ from their Asian and European counterparts. The availability of expertise in revascularization surgeries in various centers should prompt surgery as an efficient and safe treatment option.

The Role of RNF213 4810G>A and 4950G>A Variants in Patients with Moyamoya Disease in Korea

Although a founder variant of RNF213 4810G>A is a major genetic risk factor for moyamoya disease (MMD) in East Asians, the frequency and disease susceptibility of RNF213 variants remain largely unknown. This study investigated the mutation analysis of RNF213 (4448, 4810, 4863, and 4950) between Korean MMD and healthy controls. We performed a polymerase chain reaction-restriction fragment length polymorphism analysis. To identify the association between RNF213 gene polymorphisms and MMD disease, we performed statistical analyses such as multivariable logistic regression and Fisher’s exact test. Genetic data from 117 MMD patients were analyzed and compared with 253 healthy controls. We assessed and compared single nucleotide polymorphisms of RNF213 (4448, 4810, 4863, and 4950) between MMD and control groups. We performed genome-wide association studies to investigate the genetic pathophysiology of MMD. Among the RNF213 variants (4448G>A, 4810G>A, 4863G>A, and 4950G>A), RNF213 4810G>A and 4950G>A variants were more frequent in MMD patients. In a subgroup analysis, the RNF213 4810G>A was more frequent in moyamoya disease, and the comparison with GG+AA genotype was also significantly different in moyamoya patients. These results confirm that RNF213 4810G>A and RNF213 4950G>A were more frequent in MMD patients. We have confirmed that RNF213 4810G>A and 4950G>A are strongly associated with Korean MMD in children and adults as well as for the ischemic and hemorrhagic types.

Integrated Analysis of LncRNA-mRNA Co-Expression Profiles in Patients with Moyamoya Disease

Moyamoya disease (MMD) is an idiopathic disease associated with recurrent stroke. However, the pathogenesis of MMD remains unknown. Therefore, we performed long noncoding RNA (lncRNA) and messenger RNA (mRNA) expression profiles in blood samples from MMD patients (N = 15) and healthy controls (N = 10). A total of 880 differentially expressed lncRNAs (3649 probes) and 2624 differentially expressed mRNAs (2880 probes) were obtained from the microarrays of MMD patients and healthy controls (P < 0.05; Fold Change >2.0). Gene ontology (GO) and pathway analyses showed that upregulated mRNAs were enriched for inflammatory response, Toll-like receptor signaling pathway, chemokine signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway among others, while the downregulated mRNAs were enriched for neurological system process, digestion, drug metabolism, retinol metabolism and others. Our results showed that the integrated analysis of lncRNA-mRNA co-expression networks were linked to inflammatory response, Toll-like signaling pathway, cytokine-cytokine receptor interaction and MAPK signaling pathway. These findings may elucidate the pathogenesis of MMD, and the differentially expressed genes could provide clues to find key components in the MMD pathway.

Chemokine Ligand 5 (CCL5) Derived from Endothelial Colony-Forming Cells (ECFCs) Mediates Recruitment of Smooth Muscle Progenitor Cells (SPCs) toward Critical Vascular Locations in Moyamoya Disease

The etiology and pathogenesis of moyamoya disease (MMD) are still obscure. Previous studies indicated that angiogenic chemokines may play an important role in the pathogenesis of the disease. Recently, it was discovered that peripheral blood-derived endothelial colony-forming cells (ECFCs) and smooth muscle progenitor cells (SPCs) have defective functions in MMD patients. Therefore, the interaction of ECFCs and SPCs, the precursors of two crucial cellular components of vascular walls, with some paracrine molecules is an intriguing subject. In this study, co-culture of ECFCs and SPCs from MMD patients and healthy normal subjects revealed that MMD ECFCs, not SPCs, are responsible for the defective functions of both ECFCs and SPCs. Enhanced migration of SPCs toward MMD ECFCs supported the role for some chemokines secreted by MMD ECFCs. Expression arrays of MMD and normal ECFCs suggested that several candidate cytokines differentially produced by MMD ECFCs. We selected chemokine (C-X-C motif) ligand 6 (CXCR6), interleukin-8 (IL8), chemokine (C-C motif) ligand 2 (CCL2), and CCL5 for study, based on the relatively higher expression of these ligands in MMD ECFCs and their cognate receptors in MMD SPCs. Migration assays showed that only CCL5 significantly augmented the migration activities of SPCs toward ECFCs. Treatment with siRNA for the CCL5 receptor (CCR5) abrogated the effect, confirming that CCL5 is responsible for the interaction of MMD ECFCs and SPCs. These data indicate that ECFCs, not SPCs, are the major players in MMD pathogenesis and that the chemokine CCL5 mediates the interactions. It can be hypothesized that in MMD patients, defective ECFCs direct aberrant SPC recruitment to critical vascular locations through the action of CCL5.

Etiology and pathogenesis of Moyamoya Disease: An update on disease prevalence

Moyamoya disease is a chronic cerebrovascular occlusive disease that is characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches. The occurrence of Moyamoya disease is related to immune, genetic, and other factors. Though the research of Moyamoya disease has made great strides in the past 60 years, the etiology and pathogenesis are largely unknown. This review will focus on the genetic pathogenic and inflammation factors of Moyamoya disease.

A Recent Update of Clinical and Research Topics Concerning Adult Moyamoya Disease

A better understanding of moyamoya disease (MMD), such as natural clinical course, surgical outcomes and research, has been obtained. This review article focuses on an giving an update for adult MMD in the Korean population. In this paper, we mainly discuss the results of our domestic investigations including meta-analysis, and related subjects from other countries.

The Pathophysiology of Moyamoya Disease: An Update

Moyamoya disease (MMD) is a unique cerebrovascular disease characterized by the progressive stenosis of large intracranial arteries and a hazy network of basal collaterals called moyamoya vessels. Because the etiology of MMD is unknown, its diagnosis is based on characteristic angiographic findings. Re-vascularization techniques (e.g., bypass surgery) are used to restore perfusion, and are the primary treatment for MMD. There is no specific treatment to prevent MMD progression. This review summarizes the recent advances in MMD pathophysiology, including the genetic and circulating factors related to disease development. Genetic and environmental factors may play important roles in the development of the vascular stenosis and aberrant angiogenesis in complex ways. These factors include the related changes in circulating endothelial/smooth muscle progenitor cells, cytokines related to vascular remodeling and angiogenesis, and endothelium, such as caveolin which is a plasma membrane protein. With a better understanding of MMD pathophysiology, nonsurgical approaches targeting MMD pathogenesis may be available to stop or slow the progression of this disease. The possible strategies include targeting growth factors, retinoic acid, caveolin-1, and stem cells.

Sonographic findings associated with stenosis progression and vascular complications in moyamoya disease

OBJECT The progression of arterial stenosis in patients with moyamoya disease (MMD) has variable courses and an unclear mechanism. The authors hypothesized that elevated wall shear stress (WSS) at the terminal internal carotid artery (ICA) and proximal middle cerebral artery (MCA) may facilitate MMD progression. They indirectly evaluated the relative magnitude of WSS (WSS value [WSSV]) with MR angiography (MRA) and transcranial Doppler to determine its predictive value for stenosis progression (SP) and the development of vascular complications. METHODS Thirty-one medically treated patients (58 hemispheres and 95 nonoccluded vessels) were analyzed with serial MRA (median follow-up 23 months). The parameters studied were SP, SP rates (SPRs) for individual ICAs/MCAs, and their mean values from the ipsilateral hemispheres as mean SP (MSP) and MSP rates (MSPRs). Significant progression was defined as decrements of ≥ 20% for SP and MSP and ≥ 10%/year for SPR and MSPR. The development of vascular complications in relevant hemispheres was also recorded. The WSSV (dyne/cm(2)) was defined as the shear rate multiplied by blood viscosity. RESULTS After adjusting the initial stenosis degree and MRA stage of MMD, an SP of ≥ 20% and an SPR of ≥ 10%/year were associated with the highest-quartile WSSVs for all individual vessels and for MCAs and ICAs separately. For each hemisphere, an MSP of ≥ 20% and an MSPR of ≥ 10%/year were associated with the highest-quartile mean WSSVs. Furthermore, significant SP was highly correlated with vascular complications, and the highest-quartile mean WSSV was independently associated with vascular complications in relevant hemispheres. CONCLUSIONS An elevated WSSV is an independent predictor for SP and vascular complications in nonoccluded MMD.

Research Progress of Moyamoya Disease in Children

During the onset of Moyamoya disease (MMD), progressive occlusion occurs at the end of the intracranial internal carotid artery, and compensatory net-like abnormal vessels develop in the skull base, generating the corresponding clinical symptoms. MMD can affect both children and adults, but MMD in pediatric patients exhibits distinct clinical features, and the treatment prognoses are different from adult patients. Children are the group at highest risk for MMD. In children, the disease mainly manifests as ischemia, while bleeding is the primary symptom in adults. The pathogenesis of MMD in children is still unknown, and some factors are distinct from those in adults. MMD in children could result in progressive, irreversible nerve functional impairment, and an earlier the onset corresponds to a worse prognosis. Therefore, active treatment at an early stage is highly recommended. The treatment methods for MMD in children mainly include indirect and direct surgeries. Indirect surgeries mainly include multiple burr-hole surgery (MBHS), encephalomyosynangiosis (EMS), and encephaloduroarteriosynangiosis (EDAS); direct surgeries mainly include intra- and extracranial vascular reconstructions that primarily consist of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. Indirect surgery, as a treatment for MMD in children, has shown a certain level of efficacy. However, a standard treatment approach should combine both indirect and direct procedures. Compared to MMD in adults, the treatment and prognosis of MMD in children has higher clinical significance. If the treatment is adequate, a satisfactory outcome is often achieved.

Moyamoya disease and syndromes: from genetics to clinical management

Moyamoya angiopathy is characterized by a progressive stenosis of the terminal portion of the internal carotid arteries and the development of a network of abnormal collateral vessels. This chronic cerebral angiopathy is observed in children and adults. It mainly leads to brain ischemic events in children, and to ischemic and hemorrhagic events in adults. This is a rare condition, with a marked prevalence gradient between Asian countries and Western countries. Two main nosological entities are identified. On the one hand, moyamoya disease corresponds to isolated moyamoya angiopathy, defined as being “idiopathic” according to the Guidelines of the Research Committee on the Pathology and Treatment of Spontaneous Occlusion of the Circle of Willis. This entity is probably multifactorial and polygenic in most patients. On the other hand, moyamoya syndrome is a moyamoya angiopathy associated with an underlying condition and forms a very heterogeneous group with various clinical presentations, various modes of inheritance, and a variable penetrance of the cerebrovascular phenotype. Diagnostic and evaluation techniques rely on magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) conventional angiography, and cerebral hemodynamics measurements. Revascularization surgery can be indicated, with several techniques. Characteristics of genetic moyamoya syndromes are presented, with a focus on recently reported mutations in BRCC3/MTCP1 and GUCY1A3 genes. Identification of the genes involved in moyamoya disease and several monogenic moyamoya syndromes unraveled different pathways involved in the development of this angiopathy. Studying genes and pathways involved in monogenic moyamoya syndromes may help to give insights into pathophysiological models and discover potential candidates for medical treatment strategies.

The GC + CC genotype at position -418 in TIMP-2 promoter and the -1575GA/-1306CC genotype in MMP-2 is genetic predisposing factors for prevalence of moyamoya disease

BACKGROUND

To investigate the association of single-nucleotide polymorphisms (SNPs) in matrix metalloproteinases (MMPs)-2, -3, and -9 and tissue inhibitor of metalloproteinase (TIMP)-2 with moyamoya disease (MMD). We conducted a case-control study of MMD patients by assessing the prevalence of six SNPs of MMP-2 -1575G > A [rs243866], MMP-2 -1306C > T [rs243865], MMP-3 -1171 5a/6a [rs3025058], MMP-9 -1562C > T [rs3918242], MMP-9 Q279R [rs17576], and TIMP-2 -418G > C [rs8179090].

METHODS

Korean patients with MMD (n = 107, mean age, 20.9 ± 15.9 years; 66.4% female) and 243 healthy control subjects (mean age, 23.0 ± 16.1 years; 56.8% female) were included. The subjects were divided into pediatric and adult groups. The genotyping of six well-known SNPs (MMP-2 -1575G > A, MMP-2 -1306C > T, MMP-3 -1171 5a/6a, MMP-9 -1562C > T, MMP-9 Q279R, and TIMP-2 -418G > C) in MMP and TIMP genes was performed by polymerase chain reaction-restriction fragment length polymorphism assays.

RESULTS

A significantly higher frequency of the GC genotype for TIMP-2 -418 G > C was found in MMD patients. The MMP-9 Q279R GA + AA genotype showed a protective effect for MMD. The GA/CC MMP-2 -1575/-1306 genotype was significantly more prevalent in MMD patients.

CONCLUSIONS

Our findings demonstrate that TIMP-2 -418 GC + CC and MMP-2 -1575GA/-1306CC genotypes could be genetic predisposing factors for MMD development.

The roles of methylenetetrahydrofolate reductase 677C>T and 1298A>C polymorphisms in moyamoya disease patients

PURPOSE

The methylenetetrahydrofolate reductase (MTHFR) 677C>T and 1298A>C polymorphisms, which are associated with hyperhomocysteinemia and nitric oxide (NO) deficiency (which is related to atherothrombosis and cerebral ischemia), have not been studied in moyamoya disease. A case-control study was performed to investigate whether the MTHFR 677C>T and 1298A>C polymorphisms contribute to moyamoya disease (MMD).

METHODS

One hundred and seven Korean patients with MMD (mean age, 20.85 ± 15.89 years; 66.4 % female) and 232 healthy control subjects (mean age, 23.99 ± 16.16 years; 56.8 % female) were included. Genotyping for the MTHFR 677C>T and 1298A>C polymorphisms and measurements of homocysteine, folate, vitamin B12, and NO in the cerebrospinal fluid (CSF) were performed. The statistical analysis was performed by multivariate linear regression and logistic regression.

RESULT

The MTHFR 677CT+TT genotype frequency was significantly increased with early-onset MMD (<10 years) compared with late-onset MMD (≥10 years) (adjusted odds ratio, 3.392; 95 % confidence interval, 1.294-8.893, P = 0.013). The MTHFR 677C-1298C/677T-1298A diplotype (1.71 ± 1.23 arbitrary units) presented significantly lower NO levels in the CSF compared with the 677C-1298A/677C-1298A diplotype (11.40 ± 12.24 arbitrary units).

CONCLUSION

The MTHFR 677C>T and 1298A>C polymorphisms have restricted roles in the Korean MMD population. Therefore, further studies involving larger and more heterogeneous cohorts are needed to extend our understanding of the influence of polymorphisms in MTHFR and other thrombophilic genes on MMD.

Normalization of the tumor microenvironment: evidence for tissue inhibitor of metalloproteinase-2 as a cancer therapeutic

Matrix metalloproteinases (MMPs) are members of the Metzincin family of proteases responsible for degrading the extracellular matrix (ECM). In early studies, MMP degradation of the sub-epithelial basement membrane was thought to be tumor cell autonomous and contribute to the invasive behavior of malignant cells. It is now recognized that MMPs have multiple roles that can either promote or inhibit tumor progression and metastasis. The endogenous inhibitors of the MMPs are the tissue inhibitors of metalloproteinases (TIMPs). Early studies on the tumor microenvironment revealed TIMP function to be principally through the inhibition of MMPs, thereby blocking tumor cell migration and invasion. However, data from a number of laboratories are now reporting that TIMPs have direct cellular functions, independent of their MMP inhibitory activity. The TIMPs can modulate normal tissue physiology and development, as well as pathology and progression in a variety of acute and chronic disease states. In this review, we briefly describe the role of MMPs and TIMPs in ECM turnover and formation of the tumor microenvironment. Based on the evidence presented, we postulate that TIMP-2 and other soluble components of the normal ECM may provide a novel therapeutic approach to cancer treatment through "normalization" of the tumor microenvironment.

Vascular remodeling after ischemic stroke: mechanisms and therapeutic potentials

The brain vasculature has been increasingly recognized as a key player that directs brain development, regulates homeostasis, and contributes to pathological processes. Following ischemic stroke, the reduction of blood flow elicits a cascade of changes and leads to vascular remodeling. However, the temporal profile of vascular changes after stroke is not well understood. Growing evidence suggests that the early phase of cerebral blood volume (CBV) increase is likely due to the improvement in collateral flow, also known as arteriogenesis, whereas the late phase of CBV increase is attributed to the surge of angiogenesis. Arteriogenesis is triggered by shear fluid stress followed by activation of endothelium and inflammatory processes, while angiogenesis induces a number of pro-angiogenic factors and circulating endothelial progenitor cells (EPCs). The status of collaterals in acute stroke has been shown to have several prognostic implications, while the causal relationship between angiogenesis and improved functional recovery has yet to be established in patients. A number of interventions aimed at enhancing cerebral blood flow including increasing collateral recruitment are under clinical investigation. Transplantation of EPCs to improve angiogenesis is also underway. Knowledge in the underlying physiological mechanisms for improved arteriogenesis and angiogenesis shall lead to more effective therapies for ischemic stroke.

Review of past research and current concepts on the etiology of moyamoya disease

Research on moyamoya disease has progressed remarkably in the past several decades. Indeed, many new facts concerning the epidemiology of the disease have been revealed and surgical treatments have been drastically improved. However, despite extensive research, the mechanism of moyamoya disease is still unknown. Consequently, the cardinal treatment of this disease has not yet been developed. For further clarification of its etiology, innovative studies are therefore indispensable. The aim of this paper is to review research on the pathogenesis of moyamoya disease to identify milestones in the direction of its true solution. Many hypotheses of the pathogenesis of moyamoya disease have been proposed in the past half century, including infection (viral and bacterial), autoimmune disorders, proteins abnormality, and gene abnormality. Some of these are now considered to be historical achievements. Others, however, can be still subjected to contemporary research. Currently, several genetic abnormalities are considered to offer the most probable hypothesis. In addition, interesting papers have been presented on the role of the endothelial progenitor cell on the pathogenesis of moyamoya disease. Intuitively, however, it appears that a single theory cannot always explain the pathogenesis of this disease adequately. In other words, the complex mechanism of several factors may comprehensively explain the formation of moyamoya disease. The "double hit hypothesis" is probably the best explanation for the complicated pathology and epidemiology of this disease.

Impacts and interactions of PDGFRB, MMP-3, TIMP-2, and RNF213 polymorphisms on the risk of Moyamoya disease in Han Chinese human subjects

Polymorphisms of PDGFRB, MMP-3, TIMP-2, RNF213, TGFB1, Raptor and eNOS genes have been associated with Moyamoya disease (MMD) separately in studies, but their interactions on MMD have never been evaluated in one study. This study enrolled 96 MMD patients and 96 controls to evaluate the contributions and interactions of these polymorphisms on MMD in Chinese Hans. After genotyping, five polymorphisms loci were deemed suitable for analysis, rs3828610 in PDGFRB, rs3025058 in MMP-3, rs8179090 in TIMP-2, rs112735431 and rs148731719 in RNF213. Interactions of different loci on MMD were evaluated by multifactor dimensionality reduction (MDR) method. Significantly higher frequencies of A allele and G/A genotype of rs112735431 in RNF213 were observed in MMD patients compared with controls (P=0.011; P=0.018, respectively). In the dominant model, G/A genotype of rs112735431 was associated with increased risk of MMD (P=0.018). A higher frequency of G allele and G/G genotype of rs148731719 in RNF213 gene in patient than control group (P<0.001; P<0.01, respectively) was also detected. No significant association between MMD and other three loci (P>0.05) was detected. MDR analysis failed to detect any significant interaction among these five loci in the occurrence of MMD (P>0.05), but the combination of three loci (rs112735431 in RNF213, rs3828610 in PDGFRB, rs3025058 in MMP-3) could have the maximum testing accuracy (57.29%) and cross-validation consistency (10/10). The results indicated that RNF213 rs112735431 and rs148731719 may exert a significant influence on MMD occurrence. Compared with this overwhelming effect, the influences of PDGFRB, MMP-3, and TIMP-2 on MMD may be unremarkable in Chinese Hans. There may be no prominent interaction among these five gene polymorphisms on the occurrence of MMD.

Complex chromosome rearrangement of 6p25.3->p23 and 12q24.32->qter in a child with moyamoya

A 7-year-old white girl presented with left hemiparesis and ischemic stroke secondary to moyamoya syndrome, a progressive cerebrovascular occlusive disorder of uncertain but likely multifactorial etiology. Past medical history revealed hearing loss and developmental delay/intellectual disability. Routine karyotype demonstrated extra chromosomal material on 6p. Single nucleotide polymorphism microarray revealed a previously unreported complex de novo genetic rearrangement involving subtelomeric segments on chromosomes 6p and 12q. The duplicated/deleted regions included several known OMIM-annotated genes. This novel phenotype and genotype provides information about a possible association of genomic copy number variation and moyamoya syndrome. Dosage-sensitive genes in the deleted and duplicated segments may be involved in aberrant vascular proliferation. Our case also emphasizes the importance of comprehensive evaluation of both developmental delay and congenital anomalies such as moyamoya.

The role of VEGF and KDR polymorphisms in moyamoya disease and collateral revascularization

We conducted a case-control study to investigate whether vascular endothelial growth factor (VEGF −2578, −1154, −634, and 936) and kinase insert domain containing receptor (KDR −604, 1192, and 1719) polymorphisms are associated with moyamoya disease. Korean patients with moyamoya disease (n = 107, mean age, 20.9±15.9 years; 66.4% female) and 243 healthy control subjects (mean age, 23.0±16.1 years; 56.8% female) were included. The subjects were divided into pediatric and adult groups. Among the 64 surgical patients, we evaluated collateral vessel formation after 2 years and divided patients into good (collateral grade A) or poor (collateral grade B and C) groups. The frequencies and distributions of four VEGF (−2578, −1154, −634, and 936) and KDR (−604, 1192, and 1719) polymorphisms were assessed from patients with moyamoya disease and compared to the control group. No differences were observed in VEGF −2578, −1154, −634, and 936 or KDR −604, 1192, and 1719 polymorphisms between the control group and moyamoya disease group. However, we found the −634CC genotype occurred less frequently in the pediatric moyamoya group (p = 0.040) whereas the KDR −604C/1192A/1719T haplotype increased the risk of pediatric moyamoya (p = 0.024). Patients with the CC genotype of VEGF −634 had better collateral vessel formation after surgery. Our results suggest that the VEGF −634G allele is associated with pediatric moyamoya disease and poor collateral vessel formation.

Association of the miR-146aC>G, miR-196a2C>T, and miR-499A>G polymorphisms with moyamoya disease in the Korean population

Recent evidence has demonstrated associations between the single nucleotide polymorphism (SNP) rs11614913 in miR-196a2C>T and various pathologies. A main target of miRNA-196a is annexin A1 (lipocortin1, ANXA1), which is associated with increased multiple malignant tumors in brain models of ischemia and reperfusion injury. To determine the effects of miRNA SNPs in moyamoya disease, we recruited 107 patients with moyamoya disease and 240 healthy controls from a Korean study population and determined the genotype of each participant from whole blood samples. We compared the patient and the control genotypes and allele frequencies of rs2910164, rs11614913, and rs3746444 and investigated the association of the three SNPs with age and clinical characteristics, such as cerebral hemorrhage or infarction. rs11614913 in miR-196a2C>T was significantly associated with moyamoya disease. The association of this SNP with adult age and cerebral infarction was statistically significant compared to the control group, but the association with hemorrhagic moyamoya disease was not significant. The CT+CC genotype of miR-196a2 was represented at an increased frequency among patients with moyamoya disease. However, the distribution of miR-146aC>G and miR-499A>G genotypes was not statistically different between participants who were healthy and those with moyamoya disease. Thus, the SNP rs11614913 is significantly associated with moyamoya disease, as well as cerebral infarction and adult age in patients with moyamoya disease. This study demonstrates a higher frequency of the CT+CC genotype of the SNP rs11614913 in miR-196a2C>T, which suggests that miR-196a2 may play a role in the pathogenesis of moyamoya disease.

Early diagnosis and surgical revascularization for a predictive case of moyamoya disease in a boy born to a moyamoya mother

Among patients with moyamoya disease, familial occurrence is observed in about 20%, suggesting the involvement of genetic factors. In this report, we describe the first predictive case of moyamoya disease in a boy born to a woman who underwent surgical revascularization for moyamoya disease when she was 3 years old. We educated the mother and her family not to miss his initial signs of the disease. His family could easily notice his brief episode of ischemic attack when he was 6 years old. He underwent superficial temporal artery-to-middle cerebral artery anastomosis and indirect bypass on both sides. The postoperative course was uneventful. In conclusion, it is quite important to educate the family not to miss the initial signs of disease in their offspring, at least when they have a genetic background of the disease, because early diagnosis and effective treatment are essential to improve the long-term outcome in pediatric patients.

Age-specific eNOS polymorphisms in moyamoya disease

OBJECTIVE

We conducted a case-control study to investigate whether polymorphisms in eNOS are related to the age-specific onset of moyamoya disease.

MATERIALS AND METHODS

Ninety-three Korean patients [mean age, 23.0 ± 16.1 years; 59 female (63.4%) and 34 male (36.6%)] with moyamoya disease were consecutively recruited for this study. Three hundred twenty-eight healthy subjects [mean age, 27.7 ± 16.2 years; 217 female (66.2%), 111 male (33.8%)] were consecutively included in the control group. The subjects were divided into pediatric (< 20 years) and adult (≥ 20 years) groups. We further divided the moyamoya group into ischemic and hemorrhagic groups based on clinical and MRI findings. The frequencies and distributions of four eNOS polymorphisms (eNOS -922A>G, -786T>C, 4a4b, and 894G>T) were assessed in pediatric and adult patients with moyamoya disease and compared to the frequencies and distribution in the control group.

RESULTS

No differences in eNOS polymorphisms were observed between control and moyamoya disease group. However, we found that the 4a4b sequences was less frequent in the adult group (p = 0.029). Compared to the control group, there were differences in the haplotype distribution of the study group, specifically the A-4b-G haplotype, which was seen more frequently in the adult patient group.

CONCLUSION

Our results suggest that pediatric and adult-onset moyamoya disease have different genetic backgrounds. These genetic differences can affect age-specific clinical characteristics, such as cerebral ischemia and hemorrhage.

Coronary artery abnormalities in Hyper-IgE syndrome

OBJECTIVE

Hyper-IgE syndrome (HIES) is a rare primary immunodeficiency caused by autosomal dominant STAT3 mutations resulting in recurrent infections and connective tissue abnormalities. Coronary artery abnormalities have been reported infrequently. We aimed to determine the frequency and characteristics of coronary artery abnormalities.

DESIGN

STAT3-mutated HIES patients (n=38), ranging in age from 8 to 57 years, underwent coronary artery imaging by computed tomography or magnetic resonance imaging. Images were evaluated for tortuosity, dilation, and aneurysm. Charts were reviewed for cardiac risk factors. To allow blinded image interpretation, an age- and gender-matched non-HIES group was also evaluated (n=33).

RESULTS

Coronary artery tortuosity or dilation occurred in 70% of HIES patients, with aneurysms present in 37%, incidences much higher than in the literature and in our non-HIES group, in which 21% had tortuosity or dilation and 3% had aneurysms. Hypertension was more common in the HIES group than in the general population and was associated with vessel abnormalities. Atherosclerosis was uncommon and mild.

CONCLUSIONS

Coronary artery aneurysms and tortuosity are common in HIES, despite a paucity of atherosclerosis, suggesting that STAT3 plays an integral role in human vascular remodeling and atherosclerosis.

Analysis of ACTA2 in European Moyamoya disease patients

The discovery of common genetic patterns in different system vascular diseases may provide important insights into the pathogenesis of these severe medical conditions. Recently, the coincidence of mutations in ACTA2 (vascular smooth muscle cell specific isoform of α-actin) in families with thoracic aortic aneurysms and dissections (TAAD) and Moyamoya disease (MMD) was reported in patients of Northern European descent and a positive family history for TAAD and MMD. In this study, we analyzed the nine exons of the ACTA2 gene in central European patients with non-familial MMD, aiming to replicate previously described genetic findings and possibly identify further mutations. DNA sequencing of the nine exons and flanking intronic regions of ACTA2 was performed in 39 MMD patients with no family history for MMD or TAAD and 68 healthy controls of central European descent with custom made primers. One new mutation (R179H, heterozygous) in exon 6 of ACTA2 was found in one patient with MMD. We were not able to detect other previously described mutations. In contrast to a previous report, we did not identify significant sequence variations in ACTA2. Further combined analysis of ACTA2 and other, possibly causative, genes in larger cohorts of MMD and other vascular diseases may identify possible common disease-causing mechanisms.

Common genetic polymorphisms in moyamoya and atherosclerotic disease in Europeans

PURPOSE

Moyamoya is the most common cerebrovascular disease in children in Japan. The disease's etiology is still widely unknown. Several publications describe histopathological changes in the walls of affected vessels similar to those seen in atherosclerosis. In this study, we analyzed the DNA of European patients with Moyamoya disease for single nucleotide polymorphisms associated with atherosclerotic changes.

METHODS

We genotyped 17 SNPs in or adjacent to 11 genes (ELN, LIMK1, CDKN2A/B, CXCL12, Pseudogene ENSG00000197218, PSRC1, MTHFD1L, SMAD3, MIA3, PDGF-B, TIMP2) comparing 40 DNA samples of Moyamoya disease patients to 68 healthy controls from central Europe. The mean age of onset of Moyamoya disease (MMD)-related symptoms was 15.4 years of age. Genotyping was performed by sequencing the SNP containing genetic regions with custom-made primers.

RESULTS

We found strong association of one SNP (rs599839 [A/G], OR = 2.17, 95% CI = 1.17, 4.05; p = 0.01) with the risk allele G located in the 3' UTR region of the PSRC-1 gene. Three further SNPs (rs8326, rs34208922, rs501120) in or adjacent to the genes ELN and CXCL12 showed tendencies towards risk alleles with p values between 0.1 and 0.2 but did not reach statistical significance in our cohort.

CONCLUSIONS

Our results indicate a possible parallel of common processes in the genesis of Moyamoya disease and atherosclerotic disease. Further analyses in larger European cohorts and replication in patients of different ethnicity may lead to possible early detection of patients at risk for developing MMD and subsequently to future causative therapies.

Polymorphisms in TGFB1 and PDGFRB are associated with Moyamoya disease in European patients

BACKGROUND

The etiology of Moyamoya disease (MMD) is still widely unknown. Several publications on Moyamoya describe differences of cytokine and growth factor concentrations in different specimen. We analyzed the DNA of patients with MMD for single nucleotide polymorphisms (SNPs) in and upstream of the genes for previously described associated cytokines and growth factors.

METHOD

Thirteen SNPs were genotyped in or upstream to four genes-basic fibroblast growth factor (BFGF), cellular retinoic acid-binding protein 1 (CRABP1), platelet derived growth factor receptor beta (PDGFRB), and transforming growth factor beta 1 (TGFB1)-comparing 40 DNA samples of MMD patients to 68 healthy controls from central Europe. Genotyping was performed by sequencing the SNP-containing genetic regions with custom made primers.

FINDINGS

We found association of two SNPs: rs382861 [A/C] (p = 0.0373, OR = 1.81, 95% CI = 1.03-3.17) in the promoter region of PDGFRB and rs1800471[C/G] (p = 0.0345, OR = 7.65, 95% CI = 0.97-59.95), located in the first exon of TGFB1.

CONCLUSION

Our results indicate possible genetic risk factors for the genesis of MMD. TGFB1 and PDGFRB are involved in vascular growth and transformation processes which may play a role in the development of MMD. Further analyses in larger European cohorts and replication in patients of different ethnicity, as well as functional studies, may lead to possible early detection of patients at risk for developing MMD and subsequently to future preventive therapies.

Genetics of Moyamoya disease

Moyamoya disease (MMD) is a disease pattern consisting of bilateral stenosis of the intracranial internal carotid arteries (ICA) accompanied by a network of abnormal collateral vessels that bypass the stenosis. Once symptomatic, insufficient cerebral blood flow or rupture of the fragile collaterals may cause stroke or hemorrhage, resulting in severe neurological dysfunction or death. The etiology of MMD is still unknown, although few associations with other diseases and environmental factors have been described. Strong regional differences in epidemiological data, as well as known familial cases, turned the focus to genetics for the insight into the disease's pathogenesis. Thus far, several reports have suggested specific genetic loci and individual genes as predisposing to MMD, but none have demonstrated reproducible results in independent cohorts. Small sample sizes, as well as a likely multifactorial origin, seem to be the most challenging tasks in identifying the disease-causing mechanisms. Once identified, susceptibility genes may allow preventive screening and a possible development of novel therapeutic options.

Comparative analysis of serum proteomes of moyamoya disease and normal controls

OBJECTIVE

The etiology and pathogenesis of moyamoya disease remain unclear. Furthermore, the definitive diagnostic protein-biomarkers for moyamoya disease are still unknown. The present study analyzed serum proteomes from normal controls and moyamoya patients to identify novel serological biomarkers for diagnosing moyamoya disease.

METHODS

We compared the two-dimensional electrophoresis patterns of sera from moyamoya disease patients and normal controls and identified the differentially-expressed spots by matrix-assisted laser desorption/ionization-time-of flight mass spectrometry and electrospray ionization quadruple time-of-flight mass spectrometry.

RESULTS

We found and analyzed 22 differently-expressed proteomes. Two proteins were up-regulated. Twenty proteins were down-regulated. Complement C1 inhibitor protein and apolipoprotein C-III showed predominantly changed expressions (complement C1 inhibitor protein averaged a 7.23-fold expression in moyamoya patients as compared to controls, while apolipoprotein C-III averaged a 0.066-fold expression).

CONCLUSION

Although our study had a small sample size, our proteomic data provide serologic clue proteins for understanding moyamoya disease.

Computational analysis of hemodynamics using a two-dimensional model in moyamoya disease

OBJECT

Bilateral intimal thickening of the distal internal carotid arteries (ICAs) and the development of many collateral vessels in the base of the brain characterize moyamoya disease (MMD). Although the etiology of and the reason why MMD is limited to the major intracranial vessels remain unclear, flow dynamics, such as shear stress, may be related to its smooth-muscle cell migration. Therefore, this study was performed to determine the local hemodynamic factor, which concerns the predominance of specific anatomical sites, such as the distal ICA in the early stage and the proximal posterior cerebral artery (PCA) in the advanced stage of MMD.

METHODS

The authors simulated the hemodynamics in the circle of Willis using computational models of 2D geometries of the distal ICA and PCA. A finite-element commercial package, automatic dynamics incremental nonlinear analysis (ADINA), was used to simulate blood flow in these arteries.

RESULTS

Numerical results demonstrated that shear stress was relatively low at the ICA region. The distribution of shear stress was related to the predisposing area of MMD.

CONCLUSIONS

Diminished shear stress may promote stenosis of the distal ICA, which is a major pathological region in MMD.

Association of HLA-DR and -DQ Genes with Familial Moyamoya Disease in Koreans

OBJECTIVE

Moyamoya disease (MMD) is an uncommon cerebrovascular disorder, characterized by progressive occlusion at the terminal portion of the internal carotid artery. Incidence of the disease is high in East Asia and familial MMD accounts for about 15% of the disease. Although the pathogenesis is unknown, association of HLA class I or II alleles with MMD has been reported with conflicting results. We investigated whether there is a difference in HLA class II association between familial and non-familial forms of the disease.

METHODS

A total of 70 Korean children with MMD, including 16 familial cases (10 probands), and 207 healthy controls were studied. Among familial cases, only 10 probands were used for the HLA frequency analysis. High resolution HLA-DRB1 and DQB1 genotyping was performed using polymerase chain reaction (PCR)-sequence specific oligonucleotide hybridization and PCR-single strand conformation polymorphism methods.

RESULTS

The phenotype frequencies of HLA-DRB1(*)1302 (70.0%) and DQB1(*)0609 (40.0%) were significantly increased in familial MMD compared to both controls [vs. 15.5%, corrected p (p(c)) = 0.008, odds ratio (OR) = 12.76; vs. 4.3%, p(c) = 0.02, OR = 14.67] and non-familial MMD patients (vs. 14.8%, p(c) = 0.02, OR = 13.42; vs. 1.9%, p(c) = 0.02, OR = 35.33). The frequencies of DRB1 and DQB1 alleles in non-familial MMD patients were not significantly different from those in controls.

CONCLUSION

Our findings suggest that the genetic polymorphism of HLA class II genes or other closely linked disease relevant gene(s) could be a genetic predisposing factor for familial MMD.

Pathophysiology and genetic factors in moyamoya disease

Moyamoya disease is an uncommon cerebrovascular condition characterized by progressive stenosis of the bilateral internal carotid arteries with compensatory formation of an abnormal network of perforating blood vessels providing collateral circulation. The etiology and pathogenesis of moyamoya disease remain unclear. Evidence from histological studies, proteomics, and endothelial progenitor cell analyses suggests new theories underlying the cause of vascular anomalies, including moyamoya disease. Familial moyamoya disease has been noted in as many as 15% of patients, indicating an autosomal dominant inheritance pattern with incomplete penetrance. Genetic analyses in familial moyamoya disease and genome-wide association studies represent promising strategies for elucidating the pathophysiology of this condition. In this review, the authors discuss recent studies that have investigated possible mechanisms underlying the etiology of moyamoya disease, including stem cell involvement and genetic factors. They also discuss future research directions that promise not only to offer new insights into the origin of moyamoya disease but to enhance our understanding of new vessel formation in the CNS as it relates to stroke, vascular anomalies, and tumor growth.

A single nucleotide polymorphism on exon-4 of the gene encoding PPARdelta is associated with reduced height in adults and children

CONTEXT

Peroxisome proliferator-activated receptor (PPAR)-delta is a nuclear transcription factor that plays a key role in many metabolic processes, including energy metabolism, and lipid and glucose metabolism. Candidate gene studies have identified a putative functional variant, rs2016520, in the gene encoding PPARdelta (PPARD), which is associated in some studies with metabolic traits. In addition, this single-nucleotide polymorphism was associated with adult height in several whole-genome scans, but this association did not achieve whole genome significance.

OBJECTIVE

This study sought to determine whether PPARD variation influenced height.

DESIGN

Haplotype tagging analysis across PPARD was performed in about 11,000 individuals from the Wellcome Trust U.K. Type 2 Diabetes Case Control Collection (Go-DARTS2).

RESULTS

There was an association between rs2016520 and height in both patients with type 2 diabetes and controls without diabetes (combined P = 5 x 10(-5)). In a metaanalysis using published data from Caucasian cohorts totaling more than 38,000 participants, compelling evidence was found for this locus and its association with height (P = 10(-8)) with an overall effect size of about 0.5 cm per allele. A similar analysis in a group of 2700 prepubescent children also displayed a similar effect size to that seen in the adults.

CONCLUSION

PPARD variation is clearly associated with a phenotype of reduced stature in both adults and children. Because height is an important indicator of metabolic and nutritional status, this provides additional support for a key role for PPARdelta in critical metabolic functions. PPARdelta may affect height through a variety of mechanisms including altered metabolic efficiency or effects on osteoclast function.

Polymorphisms of MMP-3 and TIMP-4 genes affect angiographic coronary plaque progression in non-diabetic and type 2 diabetic patients

BACKGROUND

This study examined whether genetic variants of matrix metallopeptidases (MMPs) and their tissue inhibitors (TIMPs) were associated with angiographic coronary plaque progression (PP) in type 2 diabetic and non-diabetic patients.

METHODS

Four hundred and ninety-nine patients were grouped, who underwent coronary angiography and received repeat examinations after 1-y follow-up. Twelve functional polymorphisms of MMPs and TIMPs were characterized.

RESULTS

Genotype distribution and allele frequency of -1612 5A/6A MMP-3 and 3'UTR C/T TIMP-4 differed between patients with PP and those without in both diabetic and non-diabetic groups after Bonferroni's correction (all P<0.0041667, except for allele frequency of MMP-3 [P=0.007] and genotype/allele frequency of TIMP-4 [P=0.04 and P=0.016, respectively] in diabetes). MMP-3 and TIMP-4 polymorphisms were associated with changes in percent diameter stenosis and minimal lumen diameter in diabetic patients, and changes in cumulative coronary obstruction in both diabetic and non-diabetic patients (all P<0.05). Multivariable regression analysis revealed that hypertension, low HDL-C and genotypes of MMP-3 and TIMP-4 were independent determinants of PP in the whole patients, with these 2 genetic factors being associated with PP in diabetic and non-diabetic subgroups.

CONCLUSION

This study demonstrated that MMP-3 and TIMP-4 polymorphisms affect angiographic coronary PP in type 2 diabetic and non-diabetic patients.

Increased expression of serum Matrix Metalloproteinase-9 in patients with moyamoya disease

BACKGROUND

Moyamoya disease is a chronic occlusive cerebrovascular disease with unknown etiology characterized by an abnormal vascular network at the base of the brain, which can manifest both as ischemic stroke and as cerebral hemorrhage. It was also reported that the patients with moyamoya disease are more vulnerable to cerebral hyperperfusion such as postoperative hemorrhagic complication after extracranial-intracranial bypass surgery despite its low flow revascularization. However, the underlying mechanisms of its pathologic angiogenesis and the occurrence of hemorrhage are undetermined. Excessive degradation of the vascular matrix by MMPs, proteolytic enzymes that degrade all the components of extracellular matrix, can lead to instability of the vascular structure and can thereby cause bleeding. The MMPs also play an important role in tissue remodeling including angiogenesis in both physiologic and pathologic condition.

METHODS

We examined the serum levels of MMP-2 and MMP-9 in 16 cases with definitive moyamoya disease by enzyme-linked immunosorbent assay and compared them with those from healthy controls.

RESULTS

The serum MMP-9 level was significantly higher in moyamoya disease (40.18 ng/mL) than in healthy controls (13.75 ng/mL, P = .0372). There was no difference in serum MMP-2 level between moyamoya disease (646.65 ng/mL) and healthy control (677.60 ng/mL). Immunohistochemistry on the surgical specimens showed significant increase in MMP-9 expression within the arachnoid membrane of moyamoya disease.

CONCLUSION

The increased expression of MMP-9 may contribute to pathologic angiogenesis and/or to the instability of the vascular structure and could thereby cause hemorrhage in moyamoya disease.