BackgroundMoyamoya disease is an idiopathic vascular disorder of intracranial arteries. Its susceptibility locus has been mapped to 17q25.3 in Japanese families, but the susceptibility gene is unknown.Methodology/Principal FindingsGenome-wide linkage analysis in eight three-generation families with moyamoya disease revealed linkage to 17q25.3 (P<10-4). Fine mapping demonstrated a 1.5-Mb disease locus bounded by D17S1806 and rs2280147. We conducted exome analysis of the eight index cases in these families, with results filtered through Ng criteria. There was a variant of p.N321S in PCMTD1 and p.R4810K in RNF213 in the 1.5-Mb locus of the eight index cases. The p.N321S variant in PCMTD1 could not be confirmed by the Sanger method. Sequencing RNF213 in 42 index cases confirmed p.R4810K and revealed it to be the only unregistered variant. Genotyping 39 SNPs around RNF213 revealed a founder haplotype transmitted in 42 families. Sequencing the 260-kb region covering the founder haplotype in one index case did not show any coding variants except p.R4810K. A case-control study demonstrated strong association of p.R4810K with moyamoya disease in East Asian populations (251 cases and 707 controls) with an odds ratio of 111.8 (P = 10−119). Sequencing of RNF213 in East Asian cases revealed additional novel variants: p.D4863N, p.E4950D, p.A5021V, p.D5160E, and p.E5176G. Among Caucasian cases, variants p.N3962D, p.D4013N, p.R4062Q and p.P4608S were identified. RNF213 encodes a 591-kDa cytosolic protein that possesses two functional domains: a Walker motif and a RING finger domain. These exhibit ATPase and ubiquitin ligase activities. Although the mutant alleles (p.R4810K or p.D4013N in the RING domain) did not affect transcription levels or ubiquitination activity, knockdown of RNF213 in zebrafish caused irregular wall formation in trunk arteries and abnormal sprouting vessels.Conclusions/SignificanceWe provide evidence suggesting, for the first time, the involvement of RNF213 in genetic susceptibility to moyamoya disease.
Background and Purpose-About one half of those who develop adult-onset moyamoya disease experience intracranial hemorrhage. Despite the extremely high frequency of rebleeding attacks and poor prognosis, measures to prevent rebleeding have not been established. The purpose of this study is to determine whether extracranial-intracranial bypass can reduce incidence of rebleeding and improve patient prognosis. Methods-This study was a multicentered, prospective, randomized, controlled trial conducted by 22 institutes in Japan.Adult patients with moyamoya disease who had experienced intracranial hemorrhage within the preceding year were given either conservative care or bilateral extracranial-intracranial direct bypass and were observed for 5 years. Primary and secondary end points were defined as all adverse events and rebleeding attacks, respectively. Results-Eighty patients were enrolled (surgical, 42; nonsurgical, 38). Adverse events causing significant morbidity were observed in 6 patients in the surgical group (14.3%) and 13 patients in the nonsurgical group (34.2%). Kaplan-Meier survival analysis revealed significant differences between the 2 groups (3.2%/y versus 8.2%/y; P=0.048). The hazard ratio of the surgical group calculated by Cox regression analysis was 0.391 (95% confidence interval, 0.148-1.029).Rebleeding attacks were observed in 5 patients in the surgical group (11.9%) and 12 in the nonsurgical group (31.6%), significantly different in the Kaplan-Meier survival analysis (2.7%/y versus 7.6%/y; P=0.042). The hazard ratio of the surgical group was 0.355 (95% confidence interval, 0.125-1.009). Conclusions-Although statistically marginal, Kaplan-Meier analysis revealed the significant difference between surgical and nonsurgical group, suggesting the preventive effect of direct bypass against rebleeding. Clinical Trial Registration
Background and Purpose-The Middle Cerebral Artery Embolism Local Fibrinolytic Intervention Trial (MELT) Japan was organized to determine the safety and clinical efficacy of intraarterial infusion of urokinase (UK) in patients with stroke within 6 hours of onset. Methods-Patients with ischemic stroke presenting within 6 hours of onset and displaying occlusions of the M1 or M2 portion of the middle cerebral artery on carotid angiography were randomized to the UK or control groups. Clinical outcome was assessed by the modified Rankin Scale, National Institutes of Health Stroke Scale, and Barthel Index. Results-The Independent Monitoring Committee recommended stopping the trial after approval of intravenous infusion of recombinant tissue plasminogen activator in Japan. A total of 114 patients underwent randomization, 57 patients in each group. Background characteristics were comparable between the 2 groups. The primary end point of favorable outcome (modified Rankin Scale 0 to 2) at 90 days was somewhat more frequent in the UK group than in the control group (49.1% and 38.6%, OR: 1.54, 95% CI: 0.73 to 3.23) but did not reach a significant level (Pϭ0.345). However, excellent functional outcome (modified Rankin Scale 0 to 1) at 90 days, a preplanned secondary end point, was more frequent in the UK group than in the control group (42.1% and 22.8%, Pϭ0.045, OR: 2.46, 95% CI: 1.09 to 5.54). There were significantly more patients with National Institutes of Health Stroke Scale 0 or 1 at 90 days in the UK group than the control group (Pϭ0.017). The 90-day cumulative mortality was 5.3% in the UK group and 3.5% in the control group (Pϭ1.000), and intracerebral hemorrhage within 24 hours of treatment occurred in 9% and 2%, respectively (Pϭ0.206). Conclusions-The trial was aborted prematurely and the primary end point did not reach statistical significance.Nevertheless, the secondary analyses suggested that intraarterial fibrinolysis has the potential to increase the likelihood of excellent functional outcome.
Background-Oxidized LDL (Ox-LDL) seems to play key roles in atherogenesis. Lectinlike Ox-LDL receptor-1 (LOX-1)is a recently identified cell-surface receptor for Ox-LDL. The relationship of this novel receptor for Ox-LDL to atherogenesis, however, has not yet been clarified. In this study, we explored the expression of LOX-1 in the atherosclerotic lesions of human carotid arteries. Methods and Results-Using carotid endarterectomy specimens obtained from 21 patients and 2 samples of normal human aortas, we examined LOX-1 expression by reverse transcription-polymerase chain reaction and immunohistochemistry. In aortas without atherosclerosis, LOX-1 expression was undetectable by immunohistochemistry and negligible by reverse transcription-polymerase chain reaction. In carotid arteries, luminal endothelial cells covering early atherosclerotic lesions were more frequently positive for LOX-1 expression than those in advanced atherosclerotic lesions. Endothelial cells in the intimal neovasculature of advanced lesions also expressed LOX-1. In addition, macrophages and smooth muscle cells in the intima of advanced atherosclerotic plaques were positive for LOX-1 expression. Conclusions-LOX-1 may play important roles in
BACKGROUND AND PURPOSECerebral aneurysm is a frequent cerebrovascular event and a major cause of fatal subarachnoid haemorrhage, but there is no medical treatment for this condition. Haemodynamic stress and, recently, chronic inflammation have been proposed as major causes of cerebral aneurysm. Nevertheless, links between haemodynamic stress and chronic inflammation remain ill-defined, and to clarify such links, we evaluated the effects of prostaglandin E2 (PGE2), a mediator of inflammation, on the formation of cerebral aneurysms. EXPERIMENTAL APPROACHExpression of COX and prostaglandin E synthase (PGES) and PGE receptors were examined in human and rodent cerebral aneurysm. The incidence, size and inflammation of cerebral aneurysms were evaluated in rats treated with COX-2 inhibitors and mice lacking each prostaglandin receptor. Effects of shear stress and PGE receptor signalling on expression of pro-inflammatory molecules were studied in primary cultures of human endothelial cells (ECs). KEY RESULTSCOX-2, microsomal PGES-1 and prostaglandin E receptor 2 (EP2) were induced in ECs in the walls of cerebral aneurysms. Shear stress applied to primary ECs induced COX-2 and EP2. Inhibition or loss of COX-2 or EP2 in vivo attenuated each other's expression, suppressed nuclear factor kB (NF-kB)-mediated chronic inflammation and reduced incidence of cerebral aneurysm. EP2 stimulation in primary ECs induced NF-kB activation and expression of the chemokine (C-C motif) ligand 2, essential for cerebral aneurysm. CONCLUSIONS AND IMPLICATIONSThese results suggest that shear stress activated PGE2-EP2 pathway in ECs and amplified chronic inflammation via NF-kB. We propose EP2 as a therapeutic target in cerebral aneurysm. BJPBritish Journal of Pharmacology DOI:10.1111DOI:10. /j.1476DOI:10. -5381.2011 British Journal of Pharmacology (2011) IntroductionSubarachnoid haemorrhage is a serious cardiovascular event.It is fatal in 45% of patients within 30 days of onset, whereas 30% suffer from moderate to severe morbidity (van Gijn et al., 2007). The main cause of subarachnoid haemorrhage is a rupture of a pre-existing cerebral aneurysm, which is seen in 1-5% of the general public (Wiebers et al., 2003). Given this high prevalence and susceptibility to subarachnoid haemorrhage, treatment of cerebral aneurysm before rupture is important. Currently, there is no medical treatment that would directly interfere with cerebral aneurysm formation because the pathogenesis of these aneurysms remains unknown. In addition, surgical procedures for cerebral aneurysm have a risk of complication, even though it is low. Therefore, most patients are only given treatments to control some risk factors such as hypertension, rather than any direct treatment for the aneurysm itself.To elucidate the molecular mechanisms of cerebral aneurysm formation, we established a rodent model of cerebral aneurysm (Hashimoto et al., 1978;Morimoto et al., 2002) through inducing haemodynamic stress at bifurcation sites of cerebral arteries. Haemodynamic force is considered ...
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