Katsunobu Takenaka

Autosomal dominant moyamoya disease maps to chromosome 17q25.3.

Background: Moyamoya disease (MMD) is an idiopathic steno-occlusive cerebrovascular disease that represents an important cause of stroke. However, etiology of the disease has remained largely unknown. Methods: We previously showed that the inheritance pattern of MMD is autosomal dominant with incomplete penetrance. Here, we report the genome-wide parametric linkage analysis for MMD in 15 extended Japanese families. We conducted linkage analyses under two diagnostic classifications: narrow and broad. Affected member-only analysis was applied due to incomplete and age-dependent penetrance of the disease. Results: Under both classifications, significant evidence of linkage was only observed on chromosome 17q25.3, with maximum multipoint logarithm of odds (lod) scores of 6.57 (under the narrow classification) and 8.07 (under the broad classification) at D17S704. Haplotype analysis revealed segregation of a disease haplotype in all families but one, and informative crossovers enabled mapping of the MMD locus to a 3.5-Mb region between D17S1806 and the telomere of 17q, encompassing 94 annotated genes. Conclusions: Our data suggest that there is a major gene locus for autosomal dominant moyamoya disease on chromosome 17q25.3.

Inheritance pattern of familial moyamoya disease: autosomal dominant mode and genomic imprinting

Background: Although the aetiology of moyamoya disease (MMD) has not been fully clarified, genetic analysis of familial MMD (F-MMD) has considerable potential to disclose it. Objective: To determine the inheritance pattern and clinical characteristics of F-MMD to enable precise genetic analyses of the disease. Methods: 15 highly aggregated Japanese families (52 patients; 38 women and 14 men) with three or more affected members were examined. The difference in categories of age at onset (child onset, adult onset and asymptomatic) between paternal and maternal transmission was compared by χ2 statistics. Results: In all families there had been three or more generations without consanguinity, and all types of transmission, including father-to-son, were observed. Among a total of 135 offspring of affected people, 59 (43.7%) were patients with MMD or obligatory carriers. Affected mothers were more likely to produce late-onset (adult-onset or asymptomatic) female offspring (p = 0.007). Conclusions: The mode of inheritance of F-MMD is autosomal dominant with incomplete penetrance. Thus, in future genetic studies on F-MMD, parametric linkage analyses using large families with an autosomal dominant mode of inheritance are recommended. Genomic imprinting may be associated with the disease.

Genome-Wide Scan for Japanese Familial Intracranial Aneurysms Linkage to Several Chromosomal Regions

Background—Genetic factors have an important role in the pathogenesis of intracranial aneurysm (IA). The results of previous studies have suggested several loci. Methods and Results—From 29 IA families with ≥3 individuals affected by IA, we used nonparametric (model-free) methods for linkage analyses, using GENEHUNTER and Merlin software. Genome-wide linkage analyses revealed 3 regions on chromosomes 17cen (maximum nonparametric logarithm of the odds score [MNS] = 3.00, nominal P=0.001), 19q13 (MNS=2.15, nominal P=0.020), and Xp22 (MNS=2.16, nominal P=0.019). We tested 4 candidate genes in these regions: the microfibril-associated protein 4 gene (MFAP4) and the promoter polymorphism of the inducible nitric oxide synthase gene (NOS2A) on chromosome 17cen, the epsilon genotypes of the apolipoprotein E gene (APOE) on chromosome 19q13, and the angiotensin I converting enzyme 2 gene (ACE2) on chromosome Xp22. Associations of their polymorphisms with IA were evaluated by a case-control study (100 cases: 29 probands from IA families and 71 unrelated subjects with IAs, 100 unrelated control subjects [unaffected members with IAs and absence of family history of IAs]). However, the case-control study showed that none of the polymorphisms of the examined genes had associations with IA. Conclusions—A genome-wide scan in 29 Japanese families with a high degree of familial clustering revealed 1 suggestive linkage region on chromosome 17cen and 2 potentially interesting regions on chromosomes 19q13 and Xp22. These regions were consistent with previous findings in various populations.

Influence of Bax or Bcl-2 overexpression on the ceramide-dependent apoptotic pathway in glioma cells

Ceramide has recently been regarded as a potential mediator of apoptosis. In the present study, the effects of Bcl-2 and Bax on the ceramide-mediated apoptotic pathways were examined in glioma cells overexpressing Bcl-2 or Bax. Etoposide, cisplatin and tumor necrosis factor-α induced apoptosis of C6 rat glioma cells which was associated with ceramide formation due to activation of neutral sphingomyelinase, followed by release of mitochondrial cytochrome c into the cytosol and activation of caspases-9 and -3. The growth of C6 cells stably overexpressing either Bcl-2 or Bax was almost equal to that of the vector-transfected cells. Bax overexpression enhanced etoposide-induced apoptosis through acceleration of cytochrome c release and caspases activation. However, Bax had no effect on ceramide formation. Similar findings were obtained in C6 cells and U87-MG human glioblastoma cells which were transiently overexpressed with Bax. In contrast, Bcl-2 overexpression resulted in a retardation of the apoptotic process via prevention of cytochrome c release and caspases activation, and ceramide formation was also blocked when Bcl-2 was highly overexpressed in glioma cells. In addition, transient overexpression of Bcl-xL also exerted inhibitory effects on ceramide formation and apoptotic cell death induced by etoposide. These results indicate that Bax promotes apoptosis regardless of ceramide formation and that Bcl-2 or Bcl-xL prevents ceramide formation by repressing neutral sphingomyelinase as well as ceramide-induced cytochrome c release.

Levels of perfluorooctane sulfonate and perfluorooctanoic acid in female serum samples from Japan in 2008, Korea in 1994–2008 and Vietnam in 2007–2008

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have recently received attention owing to their widespread contamination in the environment. One of major manufacturers, 3M Company voluntarily phased out PFOS production in 2002. We measured the PFOS and PFOA concentrations in serum samples from Japan (Sendai, Takayama and Osaka), Korea (Busan and Seoul) and Vietnam (Hanoi) to evaluate the possible effects of the phase-out on the serum levels. There were spatial differences in both the serum PFOS and PFOA concentrations. The serum PFOS concentrations (ngmL(-1)) evaluated as the geometric mean (geometric standard deviation) in 2007-2008 ranged from 4.86 (1.45) in Sendai, Japan, to 9.36 (1.42) in Busan, Korea. The serum PFOA concentrations ranged from 0.575 (2.32) in Hanoi, Vietnam, to 14.2 (1.73) in Osaka, Japan. Historically archived samples collected from Korea in 1994-2008 revealed that the serum PFOA concentrations increased by 1.24-fold in Busan from 2000 to 2008 and 1.41-fold in Seoul from 1994 to 2007. On the other hand, the serum PFOS concentrations did not change from 1994 to 2007/2008. The serum PFOS levels in Japan in 2008 were significantly decreased compared with previously reported values (22.3-66.7% of the values in 2003/2004). However, the serum PFOA levels showed a clear decline from 2003 to 2008 in a high-exposed area, Osaka, but not in low-exposed areas in Japan. The trends toward decreases were not uniformly observed in Asian countries, unlike the case for the United States, suggesting that local factors associated with the production and introduction histories in each country overwhelm the effects of the phase-out.

Search on Chromosome 17 Centromere Reveals TNFRSF13B as a Susceptibility Gene for Intracranial Aneurysm A Preliminary Study

Background— Our previous studies have shown a significant linkage of intracranial aneurysms (IAs) to chromosome 17. Methods and Results— Nine genes (TNFRSF13B, M-RIP, COPS3, RAI1, SREBF1, GRAP, MAPK7, MFAP4, and AKAP10) were selected from 108 genes that are located between D17S1857 and D17S1871 by excluding 99 genes that were pseudogenes, hypothetical genes, or well-characterized genes but not likely associated with IA. Direct sequencing of all coding and regulatory regions in 58 cases (29 pedigree probands and 29 unrelated nonpedigree cases) was performed. Deleterious changes were found only in TNFRSF13B, K154X, and c.585 to 586insA in exon4. The association of IA with TNFRSF13B was further studied in 304 unrelated cases and 332 control subjects. Rare nonsynonymous changes, a splicing acceptor site change and a frame shift, were found in unrelated cases (2.3%; 14 of 608) more frequently than in control subjects (0.8%; 5 of 664; P=0.035). The association study using single-nucleotide polymorphisms in an unrelated case-control cohort revealed a protective haplotype (odds ratio 0.69, 95% confidence interval 0.52 to 0.92, P=0.012) compared with the major haplotype after adjustment for covariates. Conclusions— We propose that TNFRSF13B is one of the susceptibility genes for IA.

The relationship between Moyamoya disease and bacterial infection

To examine the relationship between Moyamoya disease and bacterial infections, authors studied the serum of 85 cases of Moyamoya disease and the influence of Propionibacterium acnes (P. acnes) infection on intracranial arteries in rats. The serum levels of P. acnes antibody, IgM, transferrin (Tf), alpha 2-macroglobulin (alpha 2M) were significantly higher in Moyamoya disease than in normal volunteers. Moyamoya-like changes of the intracranial internal carotid arteries were histopathologically demonstrated in P. acnes infectious rats. These findings suggest that P. acnes and immunological factors might play a role in the pathogenesis of Moyamoya disease.

Angiotensin I-converting enzyme gene polymorphism in intracranial saccular aneurysm individuals

A polymorphism in the angiotensin I-converting enzyme (ACE) gene has been associated with cerebrovascular diseases as a new potent risk factor. The purpose of this study was to investigate an association of the gene polymorphism with intracranial saccural aneurysmal patients. The study population consisted of 83 aneurysmal patients (age range 41-85 years) (the AN group) and 104 matched control subjects (age range 30-81 years) (the Control group). For detection of the ACE gene polymorphism, the standard PCR method was performed by using genomic DNA isolated from peripheral blood leukocytes. The PCR products were a 490-bp in the presence of the insertion (I) and a 190-bp fragment in the absence of the insertion (D). The ACE gene polymorphism was classified into three genotypes: I/I genotype (a 490-bp band); D/D genotype (a 190-bp band); or I/D genotype (both a 490-bp and a 190-bp band). The number of subjects with I/I, I/D, and D/D genotypes was 38, 40, and 5 in the AN group and 43, 45, and 16 in the Control group, respectively. The frequency of the D/D genotype in the AN group was significantly lower (5/83 = 0.06) than that in the Control group (16/104 = 0.15) (chi 2 = 4.06; p = 0.044). There was no significant difference between the genotype sof hypertensive patients and normotensive patients in the AN group. Thus, this present study suggests that genetic heterogeneity of the ACE gene may be correlated with the etiology of intracranial aneurysms.

THE CHARACTERIZATION OF HUMAN BRAIN TUMOR USING MAGNETIZATION TRANSFER TECHNIQUE IN MAGNETIC RESONANCE IMAGING

The clinical applicability of magnetization transfer (MT) technique in magnetic resonance imaging (MRI) for the estimation of the histological and constitutional feature of brain tumors was investigated. MT effect was evaluated by measuring the MT ratio (MTR). The parameters in 1.5-tesla MRI system were as follows: TR, 50 msec; TE, 5 msec; flip angle, 30 degree; offset frequency of off-resonance MT pulse, 1000 Hz. The sequence was performed in 20 normal volunteers and 45 patients with brain tumors which were characterized histologically and surgically. The MTR for brain tumors was significantly lower than that for normal brain tissue (p < 0.05). The MTR for meningioma was higher than that for the other brain tumors (p < 0.05). In the meningiomas, MTR for fibrous type was higher than that for meningothelial type, but there was no statistical significance. Regarding the physical consistency for the brain tumors, as classified by surgery, there was a statistically significant difference in MTR between the soft tumor group (0.22 +/- 0.03, n = 6) and the hard tumor group (0.36 +/- 0.04, n = 10) (p < 0.01). This study suggested that the MT technique for patients with brain tumor may be useful to understand the characteristics of the tumors presurgically, based on the degree of intermolecular interaction of macromolecule such as protein.

Absence of Linkage of Familial Intracranial Aneurysms to 7q11 in Highly Aggregated Japanese Families

Background and Purpose— We sought to test the linkage of familial intracranial aneurysms (FIAs) to the ELN (elastin) locus in chromosome 7q11 reported previously. Methods— Intracranial aneurysm (IA) probands were searched from patient records or neurosurgeons’ recalls in collaborating hospitals. Members of the participating probands’ families who had unknown affection status were screened by MR angiography and diagnosed by digital subtraction angiography. Inclusion criteria of families for genetic analyses were as follows: at least 3 alive affected members or 2 alive affected members with at least 1 unaffected member (≥60 years). Linkage to the ELN locus was tested with the use of GENEHUNTER by parametric and nonparametric methods. To exclude false-negatives in the linkage analysis, the lowest 5% limits of logarithms of the odds (LOD) and nonparametric LOD (NPL) scores for individual families and for the total set of families were simulated on assumption that the ELN locus is linked to FIAs. Results— Questionnaires were sent to 885 patients, and 563 responded. Seventy-nine probands were positive for family history. One hundred thirty-four family members of unknown affection status were screened. A total of 14 families with 64 members met the criteria. Linkage to the ELN locus was discarded in 11 families and was inconclusive for 3 families. The total LOD and total NPL scores for 14 families were −8.04 and −0.643, respectively. Our conclusion did not change even when the values of penetrance were changed or only affected members were analyzed. Conclusions— The majority of aggregated IA Japanese families may not have a genetic linkage to chromosome 7q11.