Ring Finger Protein 213 Research Articles

Transient Global Cerebral Ischemia Induces RNF213, a Moyamoya Disease Susceptibility Gene, in Vulnerable Neurons of the Rat Hippocampus CA1 Subregion and Ischemic Cortex

The RING finger protein 213 (RNF213) is an important susceptibility gene for moyamoya disease (MMD) and is also implicated in other types of intracranial major artery stenosis/occlusion (ICAS); however, the role of RNF213 in the development of ICAS including MMD is unclear. The constitutive expression of the RNF213 gene is relatively weak in brain tissue, while information regarding the expression patterns of the RNF213 gene under cerebral ischemia, which is one of characteristic pathologies associated with ICAS, is currently limited. Our objective was to address this critical issue, and we investigated Rnf213 mRNA expression in rat brains after 5 minutes of transient global cerebral ischemia (tGCI) by occluding the common carotid arteries coupled with severe hypotension. Rnf213 gene expression patterns were investigated with in situ RNA hybridization and a real-time polymerase chain reaction (PCR) from 1 to 72 hours after tGCI. In situ RNA hybridization revealed a significant increase in Rnf213 mRNA levels in the hippocampus CA1 sub-region 48 hours after tGCI. The significant induction of the Rnf213 gene was also evident in the ischemic cortex. Double staining of Rnf213 mRNA with NeuN immunohistochemistry revealed Rnf213 hybridization signal expression exclusively in neurons. The real-time PCR analysis confirmed the induction of the Rnf213 gene after tGCI. The up-regulation of the Rnf213 gene in vulnerable neurons in the hippocampus CA1 after tGCI suggests its involvement in forebrain ischemia, which is an underlying pathology of MMD. Further investigations are needed to elucidate its exact role in the pathophysiology of ICAS including MMD.

Abstract WP151: Genetic Variant RNF213 in non-MMD Intracranial Major Artery Stenosis/Occlusion in Chinese Han Population and HR-MRI Findings

Introduction: Ring finger protein 213 (RNF213) gene R4810K variant,a susceptibility locus for moyamoya disease disease (MMD) in eastern Asian, has also recently been identified as a susceptibility locus for non-MMD Intracranial Major Artery Stenosis/Occlusion (non-MMD ICASO). Due to genetic heterogeneity, further studies are needed to verify whether the R4810K variant of RNF213 is associated with ICASO in other populations. Methods: RNF213 gene R4810K variant was genotyped in 114 patients with non-MMD ICASO (male, 78.9%) and 268 healthy controls(male, 73.5%)from the Chinese Han population. Association between RNF213 gene R4810K variant and non-MMD ICASO was analyzed in a case-control study. Patients with RNF213 variant-related ICASO were scanned High resolution (HR)-MRI, and the presumptive diagnosis of these patients was made based on the HR-MRI characteristics. Results: The RNF213 R4810K variant was observed in 8 (7.0%, including 5 females) patients with non-MMD ICASO and only in 1 (0.4%) healthy control. The RNF213 R4810K variant was associated with non-MMD ICASO and increased the risk for non-MMD ICASO (P<0.01; OR, 20.2; 95% confidence interval, 2.5-163.1) (Figure 1A). Presumptive MMD based on HR-MRI findings was diagnosed in all female patients with RNF213 variant-related ICASO. However, presumptive intracranial atherosclerotic stenosis was diagnosed based on HR-MRI findings in one of three males harboring the RNF213 variant (Figure 1B). Conclusions: RNF213 R4810K appears to be a genetic risk variant for non-MMD ICASO among the Chinese Han population. HR-MRI supported that RNF213 variant-related ICASO should be identified as MMD in female patients. However, a similar relationship could not be established among male patients. Our data suggest that detection of R4810K in female patients with ICASO is a useful biomarker to differentiate MMD from other ICASO.

Smaller outer diameter of atherosclerotic middle cerebral artery associated with RNF213 c.14576G>A Variant (rs112735431).

Background:Intracranial atherosclerosis (ICAS) involves diverse histologies and several remodeling patterns. Ring finger protein 213 (RNF213) c.14576G>A variant (rs112735431), recently reported to be associated with ICAS, may be linked with negative remodeling (outer diameter – reducing morphological alteration) of intracranial arteries. This study investigated the outer diameter of atherosclerotic middle cerebral artery (MCA).Methods:Patients with unilateral atherosclerotic MCA stenosis/occlusion were enrolled in this single-hospital-based case-control study at The University of Tokyo Hospital. The patients were divided into two groups by the presence of RNF213 c.14576G>A (variant group and wild-type group) and the outer diameter of the MCA was measured with high-resolution magnetic resonance imaging.Results:Twenty-eight patients with the wild type and 19 patients with the variant type were included. The outer diameter of the stenotic side MCA was smaller in the variant group than in the wild-type group (P = 8.3 × 10-6). The outer diameter of the normal side MCA was also smaller in the variant group than in the wild-type group (P = 5.2 × 10-3). The ratio of stenotic side to normal side was also smaller in the variant group than in the wild-type group (P = 1.5 × 10-5).Conclusions:This study indicates that RNF213 c.14576G>A is associated with negative remodeling of ICAS.

Role of Ring Finger Protein 213 in Moyamoya Disease.

Objective:The aim of this study was to help people comprehensively understand the research advances related to ring finger protein 213 (RNF213) in moyamoya disease (MMD) and to understand the disease at the molecular level to provide a new perspective of the diagnosis of the disease.Data Sources:This review was based on data in articles published between 2005 and 2015 that were retrieved from the PubMed database. The search terms included RNF213, MMD, intracranial major artery stenosis/occlusion (ICASO), genotype, phenotype, mutant and variants, and the combinations of these terms.Study Selection:Articles related to MMD and RNF213 were selected for review, and we also reviewed publications related to ICASO.Results:RNF213 is not only associated with MMD but also associated with intracranial major artery stenosis. In addition, RNF213 variants exhibit apparent ethnic diversity; specifically, the c.14576G>A variant is mainly detected in Korean, Chinese, and Japanese populations, particularly the latter population. The genotypes of RNF213 correlate with the phenotypes of MMD; for example, the homozygous c.14576G>A variant is associated with early-onset, severe symptoms, and an unfavorable prognosis. Furthermore, the RNF213 c.14576G>A variant should be considered during the diagnosis of MMD because no patients with quasi-MMD have been reported to carry the RNF213 c.14576G>A variant whereas 66 of 78 patients with definite MMD have been found to carry this variant.Conclusions:The growing literature demonstrates that MMD is primarily caused by the synergy of genetic and environmental factors, and unknown genetic modifiers might play roles in the etiology of MMD. Further research should be conducted to clarify the pathogenic mechanism of MMD.

RNF213 Is Associated with Intracranial Aneurysms in the French-Canadian Population

Intracranial aneurysms (IAs) are the result of focal weakness in the artery wall and have a complex genetic makeup. To date, genome-wide association and sequencing studies have had limited success in identifying IA risk factors. Distinct populations, such as the French-Canadian (FC) population, have increased IA prevalence. In our study, we used exome sequencing to prioritize risk variants in a discovery cohort of six FC families affected by IA, and the analysis revealed an increased variation burden for ring finger protein 213 (RNF213). We resequenced RNF213 in a larger FC validation cohort, and association tests on further identified variants supported our findings (SKAT-O, p = 0.006). RNF213 belongs to the AAA+ protein family, and two variants (p.Arg2438Cys and p.Ala2826Thr) unique to affected FC individuals were found to have increased ATPase activity, which could lead to increased risk of IA by elevating angiogenic activities. Common SNPs in RNF213 were also extracted from the NeuroX SNP-chip genotype data, comprising 257 FC IA-affected and 1,988 control individuals. We discovered that the non-ancestral allele of rs6565666 was significantly associated with the affected individuals (p = 0.03), and it appeared as though the frequency of the risk allele had changed through genetic drift. Although RNF213 is a risk factor for moyamoya disease in East Asians, we demonstrated that it might also be a risk factor for IA inthe FC population. It therefore appears that the function of RNF213 can be differently altered to predispose distinct populations to dissimilar neurovascular conditions, highlighting the importance of a population's background in genetic studies of heterogeneous disease.

Association between the rs112735431 polymorphism of the RNF213 gene and moyamoya disease: A case-control study and meta-analysis

Ring finger protein 213 (RNF213) gene polymorphisms are thought to be significant in the etiology and pathogenesis of moyamoya disease (MMD). Due to the rarity of MMD patients, their ethnic diversity, and the use of varying methodologies, studies of the association between these polymorphisms and MMD have not been repeatable. This lack of reproducibility affects the strength of the conclusions drawn from their results. We conducted the present case-control study and meta-analysis to provide more precise estimates of the association between the rs112735431 (c.14576G>A) polymorphism and the risk of MMD. A total of 81 MMD patients and 100 healthy controls were enrolled in our case-control study. The RNF213 rs112735431 (c.14576G>A) polymorphism was genotyped using Sanger sequencing after amplification with polymerase chain reaction (PCR). The genetic algorithm (GA) genotype and A allele frequencies of RNF213 rs112735431 (c.14576G>A) (odds ratio, OR=7.10, 95% confidence interval, CI=1.51–33.43, p=0.006; OR=9.37, 95% CI=2.10–41.84, p<0.001, respectively) were significantly higher in the MMD group than those in the control group. In our meta-analysis, we assessed a total of eight case-control studies, including 985 patients and 2335 controls. Pooled ORs indicated a significant association between the presence of the rs112735431 (c.14576G>A) polymorphism and MMD risk (dominant model: OR=74.55, 95% CI=35.86–154.98, p<0.00001). Subgroup analysis based on country and sensitivity analysis verified these results. Our case-control study and meta-analysis both provide evidence of an association between the rs112735431(c.14576G>A) polymorphism in the RNF213 gene and MMD risk.

Caveolin-1, Ring finger protein 213, and endothelial function in Moyamoya disease.

Moyamoya disease is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for Moyamoya disease in East Asian countries. However, the pathogenesis of Moyamoya disease remains unclear. We prospectively analyzed clinical data for 139 patients with Moyamoya disease (108 bilateral Moyamoya disease, 31 unilateral Moyamoya disease), 61 patients with intracranial atherosclerotic stroke, and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor (VEGF) and receptor (VEGFR2), and antagonizing cytokine (endostatin)) and endothelial dysfunction (asymmetric dimethylarginine (ADMA), and nitric oxide and its metabolites (nitrite and nitrate)) between patients with Moyamoya disease and intracranial atherosclerotic stroke. We then performed path analysis to evaluate whether a certain protein biomarker mediates the association between genes and Moyamoya disease. Caveolin-1 level was decreased in patients with Moyamoya disease and markedly decreased in RNF213 variant carriers. Circulating factors such as VEGF and VEGFR2 did not differ among the groups. Markers for endothelial dysfunction were significantly higher in patients with intracranial atherosclerotic stroke but normal in those with Moyamoya disease. Path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 levels that could lead to Moyamoya disease. The level of combined marker of Moyamoya disease (caveolin-1) and intracranial atherosclerotic stroke (ADMA, an endothelial dysfunction marker) predicted Moyamoya disease with good sensitivity and specificity. Our results suggest that Moyamoya disease is a caveolae disorder but is not related to endothelial dysfunction or dysregulation of circulating cytokines.

The association between the ring finger protein 213 (RNF213) polymorphisms and moyamoya disease susceptibility: a meta-analysis based on case-control studies.

A number of studies assessed the association of ring finger protein 213 (RNF213) gene polymorphisms with moyamoya disease (MMD), but the results were not entirely consistent. This meta-analysis was performed to explore the relationship between RNF213 polymorphisms and moyamoya disease in Asian population. A systematic search from the PubMed, MEDLINE, EMBASE, ISI web of science, CNKI, China CBM and WANFANG DATA databases was conducted to retrieve published studies until March 2015. Statistical analyses were performed using the STATA12.0 software. Fixed or random effects model, subgroup analysis, sensitivity analysis, and publication bias were used to improve the comprehensive analysis. Eight papers including 904 MMD patients and 2258 controls were recruited in the meta-analysis. rs112735431 was closely associated with the risk of MMD among Asian population in all genetic models (dominant model: OR 103.39, 95% CI 52.25-204.55, P=1.69e-40; recessive model: OR 16.45, 95% CI 6.00-45.10, P=5.33e-08; additive model: OR 61.49, 95% CI 22.07-171.33, P=3.32e-15), especially in the Japanese population. Subgroup analysis revealed highly statistically significant higher risk in the patients with family histories. Although another polymorphism rs148731719 showed no significant association with the MMD, rs138130613 was found to be related to the higher risk in Chinese population (dominant model: OR 8.34, 95% CI 1.72-40.47, P=0.008). Our meta-analysis strengthens RNF213 rs112735431 is closely associated with the increased risk of MMD in Japanese, and the screening combined with rs112735431 and rs138130613may improve the detection rate for MMD in China.

Abstract WP280: Caveolin-1, Ring Finger Protein 213, and Endothelial Function in Moyamoya Disease

Background: Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for MMD in East Asian. However, the pathogenesis of MMD is still unclear. Methods: We prospectively analyzed clinical data for 139 patients with MMD (108 definite MMD, 31 probable MMD) and 61 patients with intracranial atherosclerotic stroke (ICAS), and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor [VEGF] and receptor [VEGFR2], and antagonizing cytokine [endostatin]) and endothelial dysfunction (asymmetric dimethylarginine [ADMA], nitric oxide and its metabolites [nitrite and nitrate]), between patients with MMD and ICAS. We then performed the path analysis to evaluate whether a certain protein biomarker mediates the association the genetic and MMD. Results: Caveolin-1 level was decreased in patients with MMD and this level was markedly decreased in RNF213 variant carriers. Circulating factor such as VEGF and receptor were not different among the groups. Markers for endothelial dysfunction were significantly higher in patients with ICAS, but normal in MMD. The path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 level that led to MMD. The level of combined marker of MMD (caveolin-1) and ICAS (ADMA, marker for endothelial dysfunction) predicted MMD with a good sensitivity and specificity. Conclusions: Our results indicate that MMD is primarily caveolae disorder, dysregulation of endothelial vesicular trafficking and signal transduction, but not related to endothelial dysfunction or dysregulation of circulating cytokines.

Transient middle cerebral artery occlusion in mice induces neuronal expression of RNF213, a susceptibility gene for moyamoya disease

Although recent genome-wide and locus-specific association studies revealed that the RING finger protein 213 (RNF213) gene is an important susceptibility gene for moyamoya disease (MMD), the exact mechanism by which the genetic alteration of RNF213 contributes to the development of MMD has not yet been elucidated. A quantitative reverse transcription polymerase chain reaction (PCR) analysis revealed that the constitutive expression of the RNF213 gene was very low in adult and embryonic brain tissue. However, information regarding the temporal and spatial expression patterns of the RNF213 gene under the condition of cerebral ischemia, which is one of characteristic pathologies associated with MMD, is currently limited. In order to address this critical issue, Rnf213 mRNA expression was investigated in mouse brains subjected to 60min of transient middle cerebral artery occlusion (tMCAO). Male C57BL6/j mice underwent tMCAO through the intraluminal blockade of MCA. Expression of the Rnf213 gene in the tMCAO brain was investigated with in situ RNA hybridization and a real-time PCR analysis from 1 to 72h after tMCAO. In situ RNA hybridization revealed a significant increase in Rnf213 mRNA levels in the cerebral cortex supplied by the affected MCA, especially at the penumbra area, as early as 6h after tMCAO, and these levels had increased further by 24h. Rnf213 gene expression remained unchanged in the non-ischemic hemisphere or control specimens. Double staining of Rnf213 mRNA with NeuN immunohistochemistry revealed Rnf213 hybridization signal expression mostly in neurons. The real-time PCR analysis confirmed induction of the Rnf213 gene after tMCAO. Therefore, the Rnf213 gene was up-regulated in the ischemic brain, especially at the penumbra area, 6h after tMCAO. Early increases in RNF213 gene expression in neurons after tMCAO indicate its involvement in cerebral ischemia, which is an underlying pathology of MMD. Further investigation is required to clarify its exact role in the pathophysiology of MMD.

Adult Moyamoya Disease: A Burden of Intracranial Stenosis in East Asians?

BackgroundBoth Moyamoya disease (MMD) and intracranial atherosclerotic stenosis (ICAS) are more prevalent in Asians than in Westerners. We hypothesized that a substantial proportion of patients with adult-onset MMD were misclassified as having ICAS, which may in part explain the high prevalence of intracranial atherosclerotic stroke in Asians.MethodWe analyzed 352 consecutive patients with ischemic events within the MCA distribution and relevant intracranial arterial stenosis, but no demonstrable carotid or cardiac embolism sources. Conventional angiography was performed in 249 (70.7%) patients, and the remains underwent MRA. The occurrence of the c.14429G>A (p.Arg4810Lys) variant in ring finger protein 213 (RNF213) was analyzed. This gene was recently identified as a susceptibility gene for MMD in East Asians.ResultsThe p.Arg4810Lys variant was observed in half of patients with intracranial stenosis (176 of 352, 50.0%), in no healthy control subjects (n = 51), and in 3.2% of stroke control subjects (4 of 124 patients with other etiologies). The presence of basal collaterals, bilateral involvement on angiography, and absence of diabetes were independently associated with the presence of the RNF213 variant. Among 131 patients who met all three diagnostic criteria and were diagnosed with MMD, three-fourths (75.6%) had this variant. However, a significant proportion of patients who met two criteria (57.7%), one criterion (28.6%), or no criteria (20.0%) also had this variant. Some of them developed typical angiographic findings of MMD on follow-up angiography.ConclusionsCareful consideration of MMD is needed when diagnosing ICAS because differential therapeutic strategies are required for these diseases and due to the limitations of the current diagnostic criteria for MMD.

Review of past and present research on experimental models of moyamoya disease

Moyamoya disease (MMD) is characterized by a progressive steno-occlusive disease affecting the terminal portions of the cerebral internal carotid artery (ICA) and by formation of an abnormal vascular network at the base of the brain. Several pathogeneses, including inflammation, immune complex, upregulation of angiogenic factors, and abnormality of endothelial progenitor cells (EPCs) have been hypothesized. However, the mechanisms of MMD are largely unknown, and in vivo and in vitro models of MMD have not yet been established. Previously, inflammation- and immune-complex-related animal models have been reported but failed to reproduce severe stenotic lesions in the terminal portion of ICA. Thereafter, several clinical studies revealed that angiogenic activity of circulating EPCs was defective in MMD patients. These results suggested that the function and quantity of EPCs could be useful as a cellular model of MMD. Very recently, RING finger protein 213 (RNF213) was identified as an MMD susceptibility gene, a discovery that led to the efforts to generate gene mutation-based animal models. Although RNF213 knockout animal models have not yet successfully represented the phenotype of MMD, they have provided new insights into the role of RNF213 in remodeling after vascular injury and postischemic angiogenesis. Furthermore, the use of induced pluripotent stem cells (iPSCs) and an appropriate differentiation protocol have made it possible to obtain abundant quantities of MMD-specific vascular cells. In summary, studies have shown that endothelial cells derived from MMD-iPSCs have impaired angiogenic activity, which is a finding consistent with the results of EPC studies. Further studies are needed to create true MMD-specific experimental models to promote understanding of MMC pathogenesis and aid drug development.

Analysis of t(9;17)(q33.2;q25.3) chromosomal breakpoint regions and genetic association reveals novel candidate genes for bipolar disorder.

Breakpoints of chromosomal abnormalities facilitate identification of novel candidate genes for psychiatric disorders. Genome-wide significant evidence supports the linkage between chromosome 17q25.3 and bipolar disorder (BD). Co-segregation of translocation t(9;17)(q33.2;q25.3) with psychiatric disorders has been reported. We aimed to narrow down these chromosomal breakpoint regions and to investigate the associations between single nucleotide polymorphisms within these regions and BD as well as schizophrenia (SZ) in large genome-wide association study samples. We cross-linked Danish psychiatric and cytogenetic case registers to identify an individual with both t(9;17)(q33.2;q25.3) and BD. Fluorescent in situ hybridization was employed to map the chromosomal breakpoint regions of this proband. We accessed the Psychiatric Genomics Consortium BD (n=16,731) and SZ (n=21,856) data. Genetic associations between these disorders and single nucleotide polymorphisms within these breakpoint regions were analysed by BioQ, FORGE, and RegulomeDB programmes. Four protein-coding genes [coding for (endonuclease V (ENDOV), neuronal pentraxin I (NPTX1), ring finger protein 213 (RNF213), and regulatory-associated protein of mammalian target of rapamycin (mTOR) (RPTOR)] were found to be located within the 17q25.3 breakpoint region. NPTX1 was significantly associated with BD (p=0.004), while ENDOV was significantly associated with SZ (p=0.0075) after Bonferroni correction. Prior linkage evidence and our findings suggest NPTX1 as a novel candidate gene for BD.

Genomewide association study identifies no major founder variant in Caucasian moyamoya disease

Moyamoya disease (MMD) is an idiopathic cerebrovascular occlusive-stenosis disorder at the terminal portion of internal carotid arteries and its main branches, accompanied by collateral vascular networks at the base of the circle of Willis (Takeuchi and Shimizu 1957; Suzuki and Takaku 1969). MMD has the highest prevalence in East Asian countries and a low prevalence in European countries (Goto and Yonekawa 1992; Kuroda and Houkin 2008). We have found that the p.R4810K variant in the ring finger protein 213 (RNF213) is a major founder susceptibility gene for East Asian MMD (Liu et al. 2010, 2011). In this study, we aimed to test whether there is a major founder susceptibility gene for Caucasian MMD using a genomewide association study (GWAS). We demonstrated that there was no major founder variant in Caucasian MMD as it is in East Asian MMD. We identified several suggestive association regions for Caucasian MMD.

Genetic Variant RNF213 c.14576G&gt;A in Various Phenotypes of Intracranial Major Artery Stenosis/Occlusion

Recently, we reported a common genetic variant, ring finger protein 213 (RNF213) c.14576G>A variant, a susceptibility gene for moyamoya disease (MMD), among patients with intracranial major artery stenosis/occlusion (ICASO) in a selected Japanese population. The aim of this 2-center-based case-control study was to confirm our previous finding in a larger population. Study participants were recruited from The University of Tokyo Hospital and Kanto Neurosurgical Hospital. The occurrence rate of c.14576G>A variant was investigated in 323 patients, 22 with definite MMD, 8 with unilateral MMD, 84 with ICASO in the absence of MMD (non-MMD ICASO), 34 with extracranial carotid atherosclerosis, 44 with cerebral aneurysm, 21 with intracerebral hemorrhage, and 110 control subjects. RNF213 c.14576G>A variant was found in 1.8% (2/110) of the normal control group and had significant associations with definite MMD (P<0.0001; odds ratio, 144.0; 95% confidence interval, 26.7-775.9), unilateral MMD (P=0.0001; odds ratio, 54.0; 95% confidence interval, 7.5-386.8), and non-MMD ICASO (P<0.0001; odds ratio, 16.8; 95% confidence interval, 3.81-74.5). There was no significant association with extracranial carotid atherosclerosis, cerebral aneurysm, or intracerebral hemorrhage. This result replicated our previous findings. A particular subset of patients with various phenotypes of ICASO has a common genetic variant, RNF213 c.14576G>A, indicating that RNF213 c.14576G>A variant is a high-risk allele for ICASO.

Identification of a novel gene fusion RNF213-SLC26A11 in chronic myeloid leukemia by RNA-Seq

Chronic myeloid leukemia (CML) was the first hematological malignancy to be associated with a specific genetic lesion. The Philadelphia translocation, producing a BCR‑ABL hybrid oncogene, is the most common mechanism of CML development. However, in the present study, b3a2, b2a2 and ela2 fusion junctions of the breakpoint cluster region (BCR)-V-abl Abelson murine leukemia viral oncogene homolog 1 (ABL) gene were not detected in patients diagnosed with CML three and four years previously. RNA-Seq technology, with an average coverage of ~30‑fold, was used to detect gene fusion events in a patient with a 6-year history of CML, identified to be in the chronic phase of the disease. Using deFuse and TopHat‑fusion programs with improved filtering methods, we identified two reliable gene fusions in a blood sample obtained from the CML patient, including extremely low expression levels of the classic BCR‑ABL1 gene fusion. In addition, a novel gene fusion involving the ring finger protein 213 (RNF213)-solute carrier family 26, member 11 (SLC26A11) was identified and validated by reverse transcription polymerase chain reaction. Further bioinformatic analysis revealed that specific domains of SLC26A11 were damaged, which may affect the function of sulfate transportation of the normal gene. The present study demonstrated that, in specific cases, alternative gene fusions, besides BCR‑ABL, may be associated with the development of CML.

Identification of a Genetic Variant Common to Moyamoya Disease and Intracranial Major Artery Stenosis/Occlusion

The c.14576G>A variant in ring finger protein 213 (RNF213) was recently identified as a susceptibility gene variant for moyamoya disease (MMD). The occurrence of c.14576G>A variant was evaluated in patients with intracranial major artery stenosis/occlusion (ICASO) without signs of MMD (non-MMD ICASO), as well as in patients with MMD and other cerebrovascular diseases as controls. This single-hospital-based case-control study was completed in 7 months (from October 2011-April 2012) at Department of Neurosurgery, The University of Tokyo Hospital. The occurrence of c.14576G>A variant was analyzed in 41 patients with non-MMD ICASO, in 48 with MMD, in 21 with cervical disease, in 61 with cerebral aneurysm, and in 25 normal subjects. Nine of 41 patients (21.9%) with non-MMD ICASO and 41 of 48 (85.4%) with MMD had the c.14576G>A variant. One of 61 patients (1.6%) with cerebral aneurysm and no patients with cervical disease or normal subjects had the variant. Comparison of each phenotype group with the normal subjects showed that presence of c.14576G>A variant had significant associations with MMD (odds ratio [OR], 292.8; 95% confidence interval [CI], 15.4-5153.0; P<0.0001) and with non-MMD ICASO (OR, 14.9; 95% CI, 0.82-268.4; P=0.01), but no association with either cerebral aneurysm (OR, 1.2; 95% CI, 0.04-32.0; P=1.00) or cervical disease (OR, 1.1; 95% CI, 0.02-62.3; P=1.00). The present study indicates that a particular subset of Japanese patients with non-MMD ICASO has a genetic variant associated with MMD. Therefore, we propose the existence of a new entity of ICASO caused by the c.14576G>A variant in RNF213.

P-5-575 - Cell differentiation and prognostic factors in pineal parenchymal tumors

The RING finger protein 213 (RNF213) is an important susceptibility gene for moyamoya disease (MMD) and is also implicated in other types of intracranial major artery stenosis/occlusion (ICAS); however, the role of RNF213 in the development of ICAS including MMD is unclear. The constitutive expression of the RNF213 gene is relatively weak in brain tissue, while information regarding the expression patterns of the RNF213 gene under cerebral ischemia, which is one of characteristic pathologies associated with ICAS, is currently limited. Our objective was to address this critical issue, and we investigated Rnf213 mRNA expression in rat brains after 5 minutes of transient global cerebral ischemia (tGCI) by occluding the common carotid arteries coupled with severe hypotension. Rnf213 gene expression patterns were investigated with in situ RNA hybridization and a real-time polymerase chain reaction (PCR) from 1 to 72 hours after tGCI. In situ RNA hybridization revealed a significant increase in Rnf213 mRNA levels in the hippocampus CA1 sub-region 48 hours after tGCI. The significant induction of the Rnf213 gene was also evident in the ischemic cortex. Double staining of Rnf213 mRNA with NeuN immunohistochemistry revealed Rnf213 hybridization signal expression exclusively in neurons. The real-time PCR analysis confirmed the induction of the Rnf213 gene after tGCI. The up-regulation of the Rnf213 gene in vulnerable neurons in the hippocampus CA1 after tGCI suggests its involvement in forebrain ischemia, which is an underlying pathology of MMD. Further investigations are needed to elucidate its exact role in the pathophysiology of ICAS including MMD.