Loss of BRCC3 deubiquitinating enzyme leads to abnormal angiogenesis and is associated with syndromic moyamoya

Moyamoya is a cerebrovascular angiopathy characterized by a progressive stenosis of the terminal part of the intracranial carotid arteries and the compensatory development of abnormal and fragile collateral vessels, also called moyamoya vessels, leading to ischemic and hemorrhagic stroke. Moyamoya angiopathy can either be the sole manifestation of the disease (moyamoya disease) or be associated with various conditions, including neurofibromatosis, Down syndrome, TAAD (autosomal-dominant thoracic aortic aneurysm), and radiotherapy of head tumors (moyamoya syndromes). Its prevalence is ten times higher in Japan than in Europe, and an estimated 6%-12% of moyamoya disease is familial in Japan. The pathophysiological mechanisms of this condition remain obscure. Here, we report on three unrelated families affected with an X-linked moyamoya syndrome characterized by the association of a moyamoya angiopathy, short stature, and a stereotyped facial dysmorphism. Other symptoms include an hypergonadotropic hypogonadism, hypertension, dilated cardiomyopathy, premature coronary heart disease, premature hair graying, and early bilateral acquired cataract. We show that this syndromic moyamoya is caused by Xq28 deletions removing MTCP1/MTCP1NB and BRCC3. We also show that brcc3 morphant zebrafish display angiogenesis defects that are rescued by endothelium-specific expression of brcc3. Altogether, these data strongly suggest that BRCC3, a deubiquitinating enzyme that is part of the cellular BRCA1 and BRISC complexes, is an important player in angiogenesis and that BRCC3 loss-of-function mutations are associated with moyamoya angiopathy.     

Moyamoya disease: A clinical spectrum, literature review and case series from a tertiary care hospital in Pakistan

Background  

Moyamoya is a rare cerebrovascular disease of unknown etiology. The data on moyamoya disease from Pakistan is sparse. We report a case series of 13 patients who presented with moyamoya disease to a tertiary care hospital in Pakistan with a national referral base.     

Diagnosing moyamoya syndrome using ultrasound - a case report

Background

Moyamoya syndrome is a vasculopathy characterised by progressive occlusion of the cerebral arteries resulting in the development of abnormal collateral circulation. To diagnose this syndrome, imaging of the cerebral arteries is required including CT- or MR-angiography and conventional angiography. We present a case of moyamoya disease with typical findings detected in the sonography. The diagnosis was suspected after reviewing the initial ultrasound images of the cerebral arteries with evidence for obliterated intracranial arteries and the detection of an existing collateral circulation network.

Case presentation

A 62 years old male patient presented in the hospital’s emergency department with symptoms indicating a subacute cerebrovascular event. Immediate sonographic studies showed a right-sided pulsatile Doppler-signal in the common and internal carotid arteries, suggestive of distal stenoses. In addition, the transcranial examination indicated obliteration of both middle cerebral arteries. Numerous arterial vessels suggestive of leptomeningeal collateral arteries revealed a strong arterial leptomeningeal flow. At this stage of the diagnostic work-up, the collateral circulation network, characteristic of moyamoya disease, was indicated by sonography. Moyamoya syndrome was verified by conventional angiography. The aetiological work remained empty, so the diagnosis of moyamoya disease was established.

Conclusion

Our case report indicates that sonography can be a useful tool for detecting the vaculopathy in moyamoya syndrome. In case routine procedures, such as the CT- or MR-angiography, with evidence for obliterated intracerebral arteries, ultrasound studies might provide important information regarding an existing collateral network in the scope of a moyamoya syndrome.

     

Loss of α1β1 Soluble Guanylate Cyclase,the Major Nitric Oxide Receptor,Leads to Moyamoya and Achalasia

Moyamoya is a cerebrovascular condition characterized by a progressive stenosis of the terminal part of the internal carotid arteries (ICAs) and the compensatory development of abnormal “moyamoya” vessels. The pathophysiological mechanisms of this condition, which leads to ischemic and hemorrhagic stroke, remain unknown. It can occur as an isolated cerebral angiopathy (so-called moyamoya disease) or in association with various conditions (moyamoya syndromes). Here, we describe an autosomal-recessive disease leading to severe moyamoya and early-onset achalasia in three unrelated families. This syndrome is associated in all three families with homozygous mutations in GUCY1A3, which encodes the α1 subunit of soluble guanylate cyclase (sGC), the major receptor for nitric oxide (NO). Platelet analysis showed a complete loss of the soluble α1β1 guanylate cyclase and showed an unexpected stimulatory role of sGC within platelets. The NO-sGC-cGMP pathway is a major pathway controlling vascular smooth-muscle relaxation, vascular tone, and vascular remodeling. Our data suggest that alterations of this pathway might lead to an abnormal vascular-remodeling process in sensitive vascular areas such as ICA bifurcations. These data provide treatment options for affected individuals and strongly suggest that investigation of GUCY1A3 and other members of the NO-sGC-cGMP pathway is warranted in both isolated early-onset achalasia and nonsyndromic moyamoya.     

Kinetics of 125I-PDGF binding and down-regulation of PDGF receptor in arterial smooth muscle cells derived from patients with moyamoya disease

Progressive stenosis or occlusion of bilateral internal carotid arteries by fibrocellular intimal thickening results in cerebral ischemia in moyamoya disease. We recently found that cultured smooth muscle cells (SMC) derived from arteries of patients with moyamoya disease responded poorly to serum mitogens, especially to platelet-derived growth factor (PDGF). In the present study, we investigated further the binding and processing of ¹²⁵I-PDGF, as well as down-regulation of the PDGF receptors in arterial SMC derived from patients with moyamoya disease. The specific binding sites of ¹²⁵I-PDGF were reduced significantly at both 4°C and 22°C on SMC from moyamoya disease compared with those from controls (4.78 vs. 11.92 × 10⁴/cell at 4°C), though the apparen dissociation constant (Kd) were the same. Kinetics of ¹²⁵I-PDGF binding at 37°C in cells from moyamoya disease showed fewer binding sites (less than 1/3 of controls) and lower degradation per cell than in those from controls, though no difference was observed in either internalization or degradation of each receptor. When SMC were exposed to lower concentrations of nonlabeled PDGF at 37°C, the percentage of remaining binding sites on cells from moyamoya disease was significantly less than that from controls. This excess down-regulation of PDGF receptor in SMC from moyamoya disease may be interpreted as insufficent recycling or a decreased intracellular pool of the PDGF receptor. These results are closely correlated with the diminished proliferation responses to PDGF in SMC from moyamoya disease and provide evidence that functional alterations in vascular cells are involved in the mechanism of development of intimal thickening in moyamoya disease. © 1993 Wiley-Liss, Inc.     

烟雾病5例临床分析

目的：研究烟雾病（moyamoya disease,MMD）的临床及影像学特征。方法：回顾性分析5例烟雾病患者,分析其临床及影像学特点。结果：本组病例既往均无阳性病史,中、青年起病,男性居多,均以缺血性脑血管病起病,肢体瘫痪不重,经颅多普勒（TCD）及头颅核磁改变明显,数字减影血管造影（DSA）检查均存在血管闭塞及侧支开放,烟雾血管网形成,1例MRA证实烟雾血管网形成。结论：对于无既往史的中、青年脑卒中患者,要考虑MMD的可能,需完善TCD、头核磁检寻找证据,最后完善数字减影血管造影确诊。     

烟雾病5 例临床分析

目的:研究烟雾病(moyamoya disease,MMD)的临床及影像学特征。方法:回顾性分析5例烟雾病患者,分析其临床及影像学特点。结果:本组病例既往均无阳性病史,中、青年起病,男性居多,均以缺血性脑血管病起病,肢体瘫痪不重,经颅多普勒(TCD)及头颅核磁改变明显,数字减影血管造影(DSA)检查均存在血管闭塞及侧支开放,烟雾血管网形成,1例MRA证实烟雾血管网形成。结论:对于无既往史的中、青年脑卒中患者,要考虑MMD的可能,需完善TCD、头核磁检寻找证据,最后完善数字减影血管造影确诊。     

The gene encoding nicastrin, a major gamma-secretase component, modifies risk for familial early-onset Alzheimer disease in a Dutch population-based sample

Nicastrin regulates gamma-secretase cleavage of the amyloid precursor protein by forming complexes with presenilins, in which most mutations causing familial early-onset Alzheimer disease (EOAD) have been found. The gene encoding nicastrin (NCSTN) maps to 1q23, a region that has been linked and associated with late-onset Alzheimer disease (LOAD) in various genome screens. In 78 familial EOAD cases, we found 14 NCSTN single-nucleotide polymorphisms (SNPs): 10 intronic SNPs, 3 silent mutations, and 1 missense mutation (N417Y). N417Y is unlikely to be pathogenic, since it did not alter amyloid beta secretion in an in vitro assay and its frequency was similar in case and control subjects. However, SNP haplotype estimation in two population-based series of Dutch patients with EOAD (n=116) and LOAD (n=240) indicated that the frequency of one SNP haplotype (HapB) was higher in the group with familial EOAD (7%), compared with the LOAD group (3%) and control group (3%). In patients with familial EOAD without the APOE epsilon4 allele, the HapB frequency further increased, to 14%, resulting in a fourfold increased risk (odds ratio = 4.1; 95% confidence interval 1.2-13.3; P=.01). These results are compatible with an important role of gamma-secretase dysfunction in the etiology of familial EOAD.     

Neuronal sodium-channel alpha1-subunit mutations in generalized epilepsy with febrile seizures plus

Generalized epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome characterized by the presence of febrile and afebrile seizures. The first gene, GEFS1, was mapped to chromosome 19q and was identified as the sodium-channel beta1-subunit, SCN1B. A second locus on chromosome 2q, GEFS2, was recently identified as the sodium-channel alpha1-subunit, SCN1A. Single-stranded conformation analysis (SSCA) of SCN1A was performed in 53 unrelated index cases to estimate the frequency of mutations in patients with GEFS+. No mutations were found in 17 isolated cases of GEFS+. Three novel SCN1A mutations-D188V, V1353L, and I1656M-were found in 36 familial cases; of the remaining 33 families, 3 had mutations in SCN1B. On the basis of SSCA, the combined frequency of SCN1A and SCN1B mutations in familial cases of GEFS+ was found to be 17%.     

Molecular genetics of Alzheimer's disease: presenilin 1 gene analysis in a cohort of patients from the Poznań region

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory loss and personality changes. Pathological hallmarks of AD are: deposition of amyloid plaques and neurofibrillary tangles in the brain, accompanied by neuronal and synaptic loss. The genetic background of AD is heterogeneous and strongly depends on the form of the disease. In most of the families with early-onset AD (EOAD) (10% of the total population of patients), the disease segregates as an autosomal dominant fully penetrant trait. To date, some missense mutations in three genes encoding the amyloid precursor protein, presenilin 1 (PS1) and 2 (PS2) have been found to cause familial EOAD. We screened for mutations in the presenilin genes in a sample of 55 patients with familial or sporadic form of EOAD from the Poznan region. We found 4 missense mutations in the PS1 gene: A246E in exon 7, P267L in exon 8, E318G in exon 9, and L424R in exon 12 among 5 unrelated patients. The frequency of PS1 mutations was 11% (5 of 55) in the whole sample of the patients with EOAD or 50% (3 of 6) if the analysis was restricted to familial cases with a positive history of dementia in the patient's family.     

Altered cellular responses to serum mitogens, including platelet-derived growth factor, in cultured smooth muscle cells derived from arteries of patients with moyamoya disease

Progressive stenosis or occlusion of bilateral internal carotid arteries by fibrocellular intimal thickening results in cerebral ischemia in moyamoya disease. The etiology is unknown. We examined cultured arterial smooth muscle cells (SMC) from scalp arteries of five patients with moyamoya disease. In this study we investigated the responsiveness of the cells in culture to serum mitogens including platelet-derived growth factor (PDGF), a major mitogen of SMC, and compared the response to that of cells derived from age-matched control patients. SMC from patients with moyamoya disease proliferated less rapidly in a medium with 15% serum than did control SMC and responded poorly to the addition of PDGF to 5% serum. PDGF alone did not stimulate SMC in a quiescent state to initiate DNA synthesis in moyamoya disease, without serum factors other than bovine serum albumin, though it significantly stimulated the controls. Simultaneous additions of epidermal growth factor, insulin-like growth factor-I, and PDGF stimulated initiation of DNA synthesis in cells from moyamoya disease, but not as much as PDGF alone did in the controls. Although direct correlations with the pathogenesis of the disease remain to be clarified, the results indicate altered interrelations between serum factors and the cellular responses in vessels of moyamoya disease.     

<Emphasis Type="Italic">PHEX</Emphasis> analysis in 118 pedigrees reveals new genetic clues in hypophosphatemic rickets

Familial hypophosphatemic rickets is a rare disease, which is mostly transmitted as an X-linked dominant trait, and mutations on the phosphate regulating gene with homologies to endopeptidases on the X-chromosome (PHEX) gene are responsible for the disease in most familial cases. In this study we analyzed PHEX in a large cohort of 118 pedigrees representing 56 familial cases and 62 sporadic cases. The high-resolution melting curves technique was tested as a screening method, along with classical sequencing. PHEX mutations have been found in 87% of familial cases but also in 72% of sporadic cases. Missense mutations were found in 16 probands, two of which being associated with other PHEX mutations resulting into truncated proteins. By plotting missense mutations described so far on a 3D model of PHEX we observed that these mutations focus on two regions located in the inner part of the PHEX protein. Family members of 13 sporadic cases were analyzed and a PHEX mutation was detected in one of the apparently healthy mother. These results highlight the major role of PHEX in X-linked dominant hypophosphatemic rickets, and give new clues regarding the genetic analysis of the disease. A screening of the different family members should be mandatory when a PHEX mutation is assessed in a sporadic case and the search for another PHEX mutation should be systematically proceed when facing a missense mutation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Voxel Based Analysis of Surgical Revascularization for Moyamoya Disease: Pre- and Postoperative SPECT Studies

Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disease that causes abnormal enlargement of collateral pathways (moyamoya vessels) in the region of the basal ganglia and thalamus. Cerebral revascularization procedures remain the preferred treatment for patients with MMD, improving the compromised cerebral blood flow (CBF). However, voxel based analysis (VBA) of revascularization surgery for MMD based on data from pre- and postoperative data has not been established. The latest algorithm called as Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) has been introduced for VBA as the function of statistical parametric mapping (SPM8), and improved registration has been achieved by SPM8 with DARTEL. In this study, VBA was conducted to evaluate pre- and postoperative single photon emission computed tomography (SPECT) images for MMD by SPM8 with DARTEL algorithm, and the results were compared with those from SPM8 without DARTEL (a conventional method). Thirty-two patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery as the first surgery were included and all patients underwent pre- and postoperative 3D T1-weighted imaging and SPECT. Pre- and postoperative SPECT images were registered to 3D T1-weighted images, then VBA was conducted. Postoperative SPECT showed more statistically increased CBF areas in the bypassed side cerebral hemisphere by using SPM8 with DARTEL (58,989 voxels; P<0.001), and increased ratio of CBF after operation was less than 15%. Meanwhile, postoperative SPECT showed less CBF increased areas by SPM8 without DARTEL. In conclusion, VBA was conducted for patients with MMD, and SPM8 with DARTEL revealed that postoperative SPECT showed statistically significant CBF increases over a relatively large area and with at most 15% increase ratio.     

Mutations in Smooth Muscle Alpha-Actin (ACTA2) Cause Coronary Artery Disease, Stroke, and Moyamoya Disease, Along with Thoracic Aortic Disease

The vascular smooth muscle cell (SMC)-specific isoform of α-actin (ACTA2) is a major component of the contractile apparatus in SMCs located throughout the arterial system. Heterozygous ACTA2 mutations cause familial thoracic aortic aneurysms and dissections (TAAD), but only half of mutation carriers have aortic disease. Linkage analysis and association studies of individuals in 20 families with ACTA2 mutations indicate that mutation carriers can have a diversity of vascular diseases, including premature onset of coronary artery disease (CAD) and premature ischemic strokes (including Moyamoya disease [MMD]), as well as previously defined TAAD. Sequencing of DNA from patients with nonfamilial TAAD and from premature-onset CAD patients independently identified ACTA2 mutations in these patients and premature onset strokes in family members with ACTA2 mutations. Vascular pathology and analysis of explanted SMCs and myofibroblasts from patients harboring ACTA2 suggested that increased proliferation of SMCs contributed to occlusive diseases. These results indicate that heterozygous ACTA2 mutations predispose patients to a variety of diffuse and diverse vascular diseases, including TAAD, premature CAD, ischemic strokes, and MMD. These data demonstrate that diffuse vascular diseases resulting from either occluded or enlarged arteries can be caused by mutations in a single gene and have direct implications for clinical management and research on familial vascular diseases.     

Association of apolipoprotein E but not B with Alzheimer's disease

In our studies apolipoprotein E4 (APOE4) is associated with both early- and late-onset Alzheimer's disease. Alzheimer's patients from West Texas were screened for the APOE4 allele, which was found at frequencies of 0.43 and 0.59 in familial late- and early-onset cases. Sporadic cases had lower frequencies, but they still were 2–4 times higher than control spouses. To determine whether the APOE association may be a risk factor for coronary disease as well, we examined two APOB gene restriction sites that have previously been found to be associated with coronary artery disease, especially myocardial infarctions. The APOB alleles were found at similar frequencies in Alzheimer's patients and control spouses.     

Changes to the geometry and fluid mechanics of the carotid siphon in the pediatric Moyamoya disease

Background: The Moyamoya disease is a cerebrovascular disease that causes occlusion of the distal end of the internal carotid artery, leading to the formation of multiple tiny collateral arteries. To date, the pathogenesis of Moyamoya is unknown. Improved understanding of the changes to vascular geometry and fluid mechanics of the carotid siphon during disease may improve understanding of the pathogenesis, prognosis techniques and disease management. Methods: A retrospective analysis of Magnetic Resonance Angiography (MRA) images was performed for Moyamoya pediatric patients (MMD) (n = 23) and control (Ctrl) pediatric patients (n = 20). The Ctrl group was composed of patients who complained of headache and had normal MRA. We performed segmentation of MRA images to quantify geometric parameters of the artery. Computational fluid dynamics (CFD) was performed to quantify the hemodynamic parameters. Results: MMD internal carotid and carotid siphons were smaller in cross-sectional areas, and shorter in curved vascular length. Vascular curvature remained constant over age and vascular size and did not change between Ctrl and MMD, but MMD carotid siphon had lower tortuosity in the posterior bend, and higher torsion in the anterior bend. Wall shear stress and secondary flows were significantly lower in MMD, but the ratio of secondary flow kinetic energy to primary flow kinetic energy were similar between MMD and Ctrl. Conclusion: There were alterations to both the geometry and the flow mechanics of the carotid siphons of Moyamoya patients but it is unclear whether hemodynamics is the cause or the effect of morphological changes observed.     

Targeted Exon Capture and Sequencing in Sporadic Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that results in progressive degeneration of motor neurons, ultimately leading to paralysis and death. Approximately 10% of ALS cases are familial, with the remaining 90% of cases being sporadic. Genetic studies in familial cases of ALS have been extremely informative in determining the causative mutations behind ALS, especially as the same mutations identified in familial ALS can also cause sporadic disease. However, the cause of ALS in approximately 30% of familial cases and in the majority of sporadic cases remains unknown. Sporadic ALS cases represent an underutilized resource for genetic information about ALS; therefore, we undertook a targeted sequencing approach of 169 known and candidate ALS disease genes in 242 sporadic ALS cases and 129 matched controls to try to identify novel variants linked to ALS. We found a significant enrichment in novel and rare variants in cases versus controls, indicating that we are likely identifying disease associated mutations. This study highlights the utility of next generation sequencing techniques combined with functional studies and rare variant analysis tools to provide insight into the genetic etiology of a heterogeneous sporadic disease.     

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.     

Clinical and immunopathological features of Moyamoya disease

Background

Moyamoya disease (MMD) is a cerebrovascular disease characterized by progressive stenosis or occlusion of the terminal portion of internal carotid arteries and the formation of a vascular network at the base of the brain. The pathogenesis of MMD is still unclear.

Methodology/Principal Findings

We retrospectively analyzed clinical data for 65 consecutive patients with MMD in our institutions and evaluated the histopathological and immunohistochemical findings of intracranial vessels from 3 patients. The onset age distribution was found to have 1 peak at 40–49 year-old age group, no significant difference was observed in the female-to-male ratio (F/M = 1.2). Intracranial hemorrhage was the predominant disease type (75%). Positive family history was observed in 4.6% of patients. Histopathological findings were a narrowed lumen due to intimal fibrous thickening without significant inflammatory cell infiltration, and the internal elastic lamina was markedly tortuous and stratified. All 3 autopsy cases showed vacuolar degeneration in the cerebrovascular smooth muscle cells. Immunohistochemical study showed the migration of smooth muscle cells in the thickened intima, and aberrant expression of IgG and S100A4 protein in vascular smooth muscle cells. The Complement C3 immunoreactivity was negative.

Conclusion/Significance

This study indicated that aberrant expression of IgG and S100A4 protein in intracranial vascular wall of MMD patients, which suggested that immune-related factors may be involved in the functional and morphological changes of smooth muscle cells, and finally caused the thickened intima. A possible mechanism is that deposits of IgG in the damaged internal elastic lamina may underlie the disruption of internal elastic lamina, which facilitated S100A4 positive SMCs migrated into intima through broken portions of the internal elastic lamina, resulting in lumen stenosis or occlusion, leading to compensatory small vessels proliferation.