Ichiro Yabe

Mutations in COQ2 in familial and sporadic multiple-system atrophy the multiple-system atrophy research collaboration

BACKGROUND Multiple-system atrophy is an intractable neurodegenerative disease characterized by autonomic failure in addition to various combinations of parkinsonism, cerebellar ataxia, and pyramidal dysfunction. Although multiple-system atrophy is widely considered to be a nongenetic disorder, we previously identified multiplex families with this disease, which indicates the involvement of genetic components. METHODS In combination with linkage analysis, we performed whole-genome sequencing of a sample obtained from a member of a multiplex family in whom multiple-system atrophy had been diagnosed on autopsy. We also performed mutational analysis of samples from members of five other multiplex families and from a Japanese series (363 patients and two sets of controls, one of 520 persons and one of 2383 persons), a European series (223 patients and 315 controls), and a North American series (172 patients and 294 controls). On the basis of these analyses, we used a yeast complementation assay and measured enzyme activity of parahydroxybenzoate-polyprenyl transferase. This enzyme is encoded by the gene COQ2 and is essential for the biosynthesis of coenzyme Q10. Levels of coenzyme Q10 in lymphoblastoid cells and brain tissue were measured on high-performance liquid chromatography. RESULTS We identified a homozygous mutation (M78V-V343A/M78V-V343A) and compound heterozygous mutations (R337X/V343A) in COQ2 in two multiplex families. Furthermore, we found that a common variant (V343A) and multiple rare variants in COQ2, all of which are functionally impaired, are associated with sporadic multiple-system atrophy. The V343A variant was exclusively observed in the Japanese population. CONCLUSIONS Functionally impaired variants of COQ2 were associated with an increased risk of multiple-system atrophy in multiplex families and patients with sporadic disease, providing evidence of a role of impaired COQ2 activities in the pathogenesis of this disease. (Funded by the Japan Society for the Promotion of Science and others.).

Efficacy and safety of leuprorelin in patients with spinal and bulbar muscular atrophy (JASMITT study): a multicentre, randomised, double-blind, placebo-controlled trial

BACKGROUND Spinal and bulbar muscular atrophy is a hereditary motor neuron disease caused by the expansion of a polyglutamine tract in the androgen receptor. At present there are no treatments for spinal and bulbar muscular atrophy, although leuprorelin suppressed the accumulation of pathogenic androgen receptors in a phase 2 trial. We aimed to assess the efficacy and safety of leuprorelin for spinal and bulbar muscular atrophy. METHODS The Japan SBMA Interventional Trial for TAP-144-SR (JASMITT) was a 48-week, randomised, double-blind, placebo-controlled trial done at 14 hospitals between August, 2006, and March, 2008. Patients with spinal and bulbar muscular atrophy were randomly assigned (1:1) by minimisation to subcutaneous 11.25 mg leuprorelin or identical placebo every 12 weeks. Patients and investigators were masked to treatment allocation. The primary endpoint was pharyngeal barium residue, which indicates incomplete bolus clearance, measured at week 48 by videofluorography. All patients who were randomly assigned and who were assessed with videofluorography at least once were included in the analyses. This study is registered with the JMACCT clinical trials registry, number JMA-IIA00009, and the UMIN clinical trials registry, number UMIN000000465. FINDINGS 204 patients were randomly assigned and 199 started treatment: 100 with leuprorelin and 99 with placebo. At week 48, the pharyngeal barium residue after initial swallowing had changed by -5.1% (SD 21.0) in the leuprorelin group and by 0.2% (18.2) in the placebo group (difference between groups -5.3%; 95% CI -10.8 to 0.3; p=0.063). The mean difference in pharyngeal barium residue after piecemeal deglutition at week 48 was -3.2% (-6.4 to 0.0; p=0.049), but there was no significant difference between the groups after covariate adjustment for the baseline data (-4.1 to 1.6; p=0.392). In a predefined subgroup analysis, leuprorelin treatment was associated with a greater reduction in barium residue after initial swallowing than was placebo in patients with a disease duration less than 10 years (difference between groups -9.8, -17.1 to -2.5; p=0.009). There were no significant differences in the number of drug-related adverse events between groups (57 of 100 in the leuprorelin group and 54 of 99 in the placebo group; p=0.727). INTERPRETATION 48 weeks of treatment with leuprorelin did not show significant effects on swallowing function in patients with spinal and bulbar muscular atrophy, although it was well tolerated. Disease duration might influence the efficacy of leuprorelin and thus further clinical trials with sensitive outcome measures should be done in subpopulations of patients. FUNDING Large Scale Clinical Trial Network Project, Japan and Takeda Pharmaceuticals.

A novel locus for dominant cerebellar ataxia (SCA14) maps to a 10.2-cM interval flanked by D19S206 and D19S605 on chromosome 19q13.4-qter.

Dominantly inherited, late‐onset pure cerebellar ataxia is a group of genetically heterogeneous neurodegenerative disorders. Approximately half of these disorders in the Japanese population are caused by moderate expansion of a CAG repeat in the coding region of the CACNA1A gene on chromosome 19p13 (SCA6). However, neither the loci nor the specific mutations for the remaining disorders have been determined. We performed systematic linkage analysis in a three‐generation Japanese family with a locus or mutation that differed from those of known spinocerebellar ataxias. The family members with a late onset (≥39 years old) exhibited pure cerebellar ataxia, whereas those with an early onset (≤27 years old) first showed intermittent axial myoclonus followed by ataxia. Other neurological signs were sparse, and neuroimaging studies revealed that atrophy was confined to the cerebellum. Multipoint analysis and haplotype reconstruction ultimately traced this novel spinocerebellar ataxia locus (SCA14) to a 10.2‐cM interval flanked by D19S206 and D19S605 on chromosome 19q13.4‐qter (Zmax = 4.08, corrected for age‐dependent penetrance). Ann Neurol 2000;48:156–163

Vitamin D receptor gene polymorphism in multiple sclerosis and the association with HLA class II alleles

We have previously reported that the association between Bsm I polymorphism, one of the vitamin D receptor genes (VDRG) polymorphism, and multiple sclerosis (MS). In this report, we investigated the further possible role or relevance of VDRG in the pathogenesis of MS. Apa I polymorphism was detected by PCR-RFLP from the DNA of 77 conventional MS patients and 95 healthy controls. The study of the Bsm I and Apa I haplotypes was carried out by employing previously reported Bsm I data. The AA genotype and the [A] allele in the profiles were significantly more prevalent in MS patients than in controls (P=0.0070 and P=0.0321, respectively). In the [A] allele-positive MS patients, the positive rate of DPB1*0501 in HLA was significantly higher than that of the [A] allele-positive controls and that of the [A] allele-negative MS patients even when the corrected P value (P(corr)) was applied (P(corr)=0.0220 and P(corr)=0.0077, respectively). The frequency of DRB1*1501 was higher in the [A] allele-positive patients than in the [A] allele-positive controls and the [A] allele-negative patients (P(uncorr)=0.0431 and P(uncorr)=0.0089, respectively), but the P values did not reach statistical significance after P corrections. The rate of Bsm I and Apa I haplotypes was much higher in bA/bA-positive MS patients than in the controls (P=0.0003), and in the bA positive MS patients, the positive rate of DPB1*0501 was higher than that of the bA-positive controls and that of the bA-negative MS patients (P(corr)=0.0308 and P(corr)=0.0033, respectively). These results indicate that VDRG polymorphism may be associated with susceptibility to MS, and HLA alleles may correlate with risk for MS together with VDRG.

Neuropathological and molecular studies of spinocerebellar ataxia type 6 (SCA6)

Abstract SCA6 is an autosomal dominant spinocerebellar ataxia (SCA) caused by a small CAG repeat expansion of the gene encoding an α-1a-voltage-dependent Ca channel gene subunit on chromosome 19p13. A Japanese woman with SCA6, with a 7-year history of progressive pure cerebellar ataxia, died of malignant lymphoma. Systematic neuropathological examination showed that neuronal degeneration was confined to the cerebellar Purkinje cells and, to a lesser degree, the granular cells, without any involvement of other central nervous system structures. Such pathological selectivity correlates with the localized expression of the responsible gene, and coincides with the neurological manifestation. These findings might contribute to establishing the phenotype of the SCA6 via comparison with other dominant ataxias.

MSA-C is the predominant clinical phenotype of MSA in Japan: Analysis of 142 patients with probable MSA

We investigated the clinical features and mode of disease progression in 142 patients with probable multiple system atrophy (MSA) according to the Consensus Criteria. The subjects included 84 men and 58 women with a mean age at onset of 58.2+/-7.1 years (range: 38-79 years). Cerebellar signs were detected in 87.3% of these patients at the time of initial examination, and were found in 95.1% of them at latest follow-up. MSA-C was diagnosed in 83.8% of the patients at their first examination. Parkinsonism was initially detected in 28.9% of the patients, increasing to 51.4% at the latest follow-up. Among all of the subjects, only 16.2% were classified as having MSA-P on initial examination. At the latest follow-up, parkinsonian features had become predominant over cerebellar features in 24.6% of the 65 patients with MSA-C who were followed for more than 3 years. Although parkinsonism usually masked the signs of cerebellar involvement in MSA-C patients, none of the patients with MSA-P at an early stage showed predominance of cerebellar features at the latest follow-up. Parkinsonism is the predominant feature of MSA among Western patients, even at an early stage, but this study showed that cerebellar deficits are the main feature in Japanese patients. This difference of disease manifestations between ethnic groups suggests that genetic factors may influence the clinical phenotype of MSA.

CTLA-4 gene polymorphism may modulate disease in Japanese multiple sclerosis patients

Multiple sclerosis (MS) is widely believed to have a T-cell-mediated autoimmune etiology. The CTLA-4 gene is a strong candidate for involvement in autoimmune diseases because it plays an important role in the termination of T-cell activation. To examine the genetic association of the CTLA-4 gene locus with MS, we analyzed the CTLA-4 gene exon 1 A/G polymorphism in 74 Japanese MS patients and 93 controls. We also investigated the possible interactions of the CTLA-4 gene polymorphism with clinical course and severity, with MRI findings, with another genetic marker-HLA antigens, and with oligoclonal bands (OCB) in the cerebrospinal fluid (CSF). The CTLA-4 exon 1 polymorphism was similar between MS patients and controls. Conversely, clinical disability was significantly more severe in AA homozygous patients than in the other patients, and the allele frequency and the phenotype frequency of the A allele were significantly higher in patients with severe-grade MRI findings of cerebral white matter than in patients with mild-grade MRI findings. The allele frequency and the phenotype frequency of the A allele were significantly higher in patients with OCB than in patients without. This CTLA-4 polymorphism may modulate the prognosis of patients with MS and may be relevant to generation of OCB in the CSF.

Safety and efficacy of edaravone in well defined patients with amyotrophic lateral sclerosis: a randomised, double-blind, placebo-controlled trial

BACKGROUND In a previous phase 3 study in patients with amyotrophic lateral sclerosis (ALS), edaravone did not show a significant difference in the Revised ALS Functional Rating Scale (ALSFRS-R) score compared with placebo. Post-hoc analysis of these data revealed that patients in an early stage with definite or probable diagnosis of ALS, defined by the revised El Escorial criteria, who met a select set of inclusion criteria showed a greater magnitude of effect than did the full study population. We aimed to substantiate this post-hoc result and assess safety and efficacy of edaravone in a phase 3 trial that focused on patients with early stage ALS who met the post-hoc analysis inclusion criteria. METHODS In this phase 3, randomised, double-blind, parallel-group study, patients aged 20-75 years with ALS of grade 1 or 2 in the Japan ALS Severity Classification, scores of at least 2 points on all 12 items of ALSFRS-R, forced vital capacity of 80% or more, definite or probable ALS according to the revised El Escorial criteria, and disease duration of 2 years or less were recruited from 31 hospitals in Japan. Eligible patients also had a decrease of 1-4 points in the ALSFRS-R score during a 12-week observation period before randomisation. Patients meeting all criteria were then randomly assigned 1:1 to receive 60 mg intravenous edaravone or intravenous saline placebo for 6 cycles (4 weeks per cycle with 2 weeks on, 2 weeks off) for a total treatment duration of 24 weeks. In cycle 1, the study drug or placebo was administered once per day for 14 days within a 14 day period, followed by the drug-free period. In cycle 2 and thereafter, the study drug or placebo was administered for 10 days within a 14 day period, followed by a 2 week drug-free period. Participants and investigators, including those assessing outcomes, were masked to treatment allocation. The primary efficacy outcome was the change in ALSFRS-R score from the baseline to 24 weeks (or at discontinuation if this was after the third cycle) after randomisation. The primary outcome was assessed in all patients who had received at least one treatment infusion, had at least one assessment post-baseline, and reached the end of cycle 3. For patients with missing values at the end of cycle 6, data were imputed by the last observation carried forward (LOCF) method, provided the patients had completed at least cycle 3. Safety was assessed in all patients who had received at least one treatment infusion and had at least one assessment post-baseline. This trial is registered with ClinicalTrials.gov, NCT01492686. FINDINGS Between Nov 28, 2011, and Sept 3, 2014, we screened 213 patients, and enrolled 192 as potential participants. Of these, 137 patients completed the observation period: 69 were randomly assigned to receive edaravone, and 68 were randomly assigned to receive placebo. 68 patients taking edaravone and 66 taking placebo were included in the primary efficacy analysis. For the primary outcome, the change in ALSFRS-R score was -5·01 (SE 0·64) in the edavarone group and -7·50 (0·66) in the placebo group. The least-squares mean difference between groups was 2·49 (SE 0·76, 95% CI 0·99-3·98; p=0·0013) in favour of edaravone. Treatment-emergent adverse events were reported in 58 (84%) patients receiving edaravone and 57 (84%) patients receiving placebo. 11 (16%) patients taking edaravone and 16 (24%) taking placebo had serious adverse events, and one (1%) patient receiving edaravone and four (6%) patients receiving placebo had adverse events (one dysphagia in edaravone group and one dyspnoea, two respiratory disorder, and one rash in the placebo group) that led to withdrawal. INTERPRETATION Edaravone showed efficacy in a small subset of people with ALS who met criteria identified in post-hoc analysis of a previous phase 3 study, showing a significantly smaller decline of ALSFRS-R score compared with placebo. There is no indication that edaravone might be effective in a wider population of patients with ALS who do not meet the criteria. FUNDING Mitsubishi Tanabe Pharma Corporation.Summary Background In a previous phase 3 study in patients with amyotrophic lateral sclerosis (ALS), edaravone did not show a significant difference in the Revised ALS Functional Rating Scale (ALSFRS-R) score compared with placebo. Post-hoc analysis of these data revealed that patients in an early stage with definite or probable diagnosis of ALS, defined by the revised El Escorial criteria, who met a select set of inclusion criteria showed a greater magnitude of effect than did the full study population. We aimed to substantiate this post-hoc result and assess safety and efficacy of edaravone in a phase 3 trial that focused on patients with early stage ALS who met the post-hoc analysis inclusion criteria. Methods In this phase 3, randomised, double-blind, parallel-group study, patients aged 20–75 years with ALS of grade 1 or 2 in the Japan ALS Severity Classification, scores of at least 2 points on all 12 items of ALSFRS-R, forced vital capacity of 80% or more, definite or probable ALS according to the revised El Escorial criteria, and disease duration of 2 years or less were recruited from 31 hospitals in Japan. Eligible patients also had a decrease of 1–4 points in the ALSFRS-R score during a 12-week observation period before randomisation. Patients meeting all criteria were then randomly assigned 1:1 to receive 60 mg intravenous edaravone or intravenous saline placebo for 6 cycles (4 weeks per cycle with 2 weeks on, 2 weeks off) for a total treatment duration of 24 weeks. In cycle 1, the study drug or placebo was administered once per day for 14 days within a 14 day period, followed by the drug-free period. In cycle 2 and thereafter, the study drug or placebo was administered for 10 days within a 14 day period, followed by a 2 week drug-free period. Participants and investigators, including those assessing outcomes, were masked to treatment allocation. The primary efficacy outcome was the change in ALSFRS-R score from the baseline to 24 weeks (or at discontinuation if this was after the third cycle) after randomisation. The primary outcome was assessed in all patients who had received at least one treatment infusion, had at least one assessment post-baseline, and reached the end of cycle 3. For patients with missing values at the end of cycle 6, data were imputed by the last observation carried forward (LOCF) method, provided the patients had completed at least cycle 3. Safety was assessed in all patients who had received at least one treatment infusion and had at least one assessment post-baseline. This trial is registered with ClinicalTrials.gov, NCT01492686. Findings Between Nov 28, 2011, and Sept 3, 2014, we screened 213 patients, and enrolled 192 as potential participants. Of these, 137 patients completed the observation period: 69 were randomly assigned to receive edaravone, and 68 were randomly assigned to receive placebo. 68 patients taking edaravone and 66 taking placebo were included in the primary efficacy analysis. For the primary outcome, the change in ALSFRS-R score was −5·01 (SE 0·64) in the edavarone group and −7·50 (0·66) in the placebo group. The least-squares mean difference between groups was 2·49 (SE 0·76, 95% CI 0·99–3·98; p=0·0013) in favour of edaravone. Treatment-emergent adverse events were reported in 58 (84%) patients receiving edaravone and 57 (84%) patients receiving placebo. 11 (16%) patients taking edaravone and 16 (24%) taking placebo had serious adverse events, and one (1%) patient receiving edaravone and four (6%) patients receiving placebo had adverse events (one dysphagia in edaravone group and one dyspnoea, two respiratory disorder, and one rash in the placebo group) that led to withdrawal. Interpretation Edaravone showed efficacy in a small subset of people with ALS who met criteria identified in post-hoc analysis of a previous phase 3 study, showing a significantly smaller decline of ALSFRS-R score compared with placebo. There is no indication that edaravone might be effective in a wider population of patients with ALS who do not meet the criteria. Funding Mitsubishi Tanabe Pharma Corporation.

Secretion of DJ-1 into the serum of patients with Parkinson's disease.

DJ-1 was initially identified by us as a novel oncogene and has later been found to be a causative gene for familial Parkinsons disease PARK7. DJ-1 plays role in transcriptional regulation and in oxidative stress function, and loss of its function is thought to be related to onset age, mode of progression and clinical severity of both familial and sporadic forms of Parkinsons disease (PD). DJ-1 is localized both in the cytoplasm and nucleus, and it has been reported to be secreted into the serum or plasma of patients with breast cancer, melanoma, familial amyloidotic polyneuropathy and stroke. In this study, levels of DJ-1 secreted into the serum of healthy controls and patients with sporadic PD were examined by using a DJ-1 ELISA kit, and the level of oxidative stress in the serum was also measured. The results showed that DJ-1 was secreted into the serum of both healthy controls and PD patients. There was no significant difference between the levels of secreted DJ-1 in two groups, and correlations of levels of secreted DJ-1 with age, clinical severity of PD and level of oxidative stress were not found.

Genetic polymorphisms of osteopontin in association with multiple sclerosis in Japanese patients

Osteopontin (OPN) exhibits pleiotropic functions and abundant transcripts for OPN are present in brains of patients with multiple sclerosis (MS). The aim of this study was to investigate the role of OPN genes in the pathogenesis of MS. Polymorphisms at the 8090th, 9250th and 9583rd positions in OPN were detected by PCR-RFLP from DNAs of 116 MS Japanese patients and 124 healthy controls. The C/C genotype at the 8090th position in exon 6 was more prevalent in MS than in control (p<0.0001), and C allele was more prevalent in MS than in control (p<0.0001, OR=2.57, 95% CI=1.65-4.00). For the 9583rd position polymorphism in exon 7, patients with G/G genotype (age; 32.1+/-12.5 years, mean+/-S.D.) showed a later disease onset than G/A (age; 25.9+/-7.8 years, p=0.01) and A/A (age; 25.2+/-8.9 years, p=0.01) genotypes. There were no significant correlations between OPN gene polymorphisms and disease progression. Our results suggest that the 8090th polymorphism might be associated with susceptibility to MS, while the 9583rd polymorphism might be associated with age of onset of MS.