Survey on the current situation for early diagnosis of dementia and contributing factors in Japan.

BACKGROUND: Early diagnosis of dementia is important for both initiation of non-pharmacological activities to slow cognitive decline as well as the development of disease-modifying drugs; however, it appears there may be a tendency for formal diagnosis to be delayed. Since the current status of diagnosis in Japan is unclear, we conducted a survey with family caregivers of patients with dementia using questionnaires and interviews to investigate the factors regarding the dementia diagnosis process in Japan. METHODS: We distributed questionnaires to family caregivers of people with dementia and conducted additional follow-up interviews with approximately half of them. We calculated odds ratios for the time to diagnosis using logistic regression analysis for each characteristic from the questionnaire data. We also created co-occurrence networks from the interview data in order to provide qualitative context to the questionnaire data. RESULTS: We collected 68 questionnaires and conducted 32 interviews. The median time to diagnosis was 12 months, and logistic regression analysis showed a significant trend toward shorter time to diagnosis in the absence of other caregivers. In addition, there were significant differences in age, relationship with patients and the time from the first visit to the final diagnosis between groups with and without other caregivers. CONCLUSIONS: The results of this study suggest that the presence or absence of other caregivers may affect caregivers' behaviour and the time taken to receive a diagnosis of dementia. These findings indicate it may be beneficial to predict inhibiting factors and change approaches based on caregivers' and patients' background to promote early diagnosis.

Implication of using cognitive function-related simple questions to stratify the risk of long-term care need: population-based prospective study in Kobe, Japan.

BACKGROUND: This study investigated how cognitive function-related simple questions can be used to identify older individuals who are at risk of needing long-term care. METHODS: This cohort study was conducted in Kobe city, Japan. In 2015, the municipal office distributed the Kihon Checklist by post, a 25-item questionnaire including three cognitive function-related questions (questions 18, 19, 20) to citizens aged ≥ 70 years. Need certification is routinely done by Kobe city as part of the national Long-Term Care Insurance Act. The answers to the 2015 questionnaire were merged with need certification data between the questionnaire delivery and the end of December 2019. RESULTS: Of the 77,877 citizens (age: 72.9 ± 2.7 years) who received the questionnaire, 50,154 responded (response rate: 64.4%). During the study period, the cumulative incidence of the need for long-term care was higher in those who did not respond than in those who did (12.5% vs 8.4%; P < 0.001). Among those who responded, the incidence of the need for long-term care was progressively greater as the number of negative answers to cognitive function-related questions increased (5.0%, 8.4%, 15.7% and 30.2% at 4 years' follow-up, for respondents with, respectively, 0, 1, 2 and 3 negative answers). Similarly, when the need certification for long-term care was confined to that accompanied by dementia, the incidence also rose as the number of negative responses to the cognitive function-related questions increased (3.4%, 6.5%, 13.7% and 27.9% for respondents with, respectively, 0, 1, 2 and 3 negative answers). Using multivariate Cox regression analysis, all three cognitive function-related questions were predictive of the need for long-term care, and question 18 (about memory loss) had the highest hazard ratio for predicting the need for long-term care accompanied by dementia. CONCLUSIONS: Use of cognitive function-related simple questions may help identify older adults at risk for needing long-term care, suggesting their potential value for use in administrative and policy approaches aimed at reducing the societal burden of dementia.

Galectin 3-binding protein suppresses amyloid-ß production by modulating ß-cleavage of amyloid precursor protein.

Alzheimer's disease (AD) is the most common type of dementia, and its pathogenesis is associated with accumulation of ß-amyloid (Aß) peptides. Aß is produced from amyloid precursor protein (APP) that is sequentially cleaved by ß- and γ-secretases. Therefore, APP processing has been a target in therapeutic strategies for managing AD; however, no effective treatment of AD patients is currently available. Here, to identify endogenous factors that modulate Aß production, we performed a gene microarray-based transcriptome analysis of neuronal cells derived from human induced pluripotent stem cells, because Aß production in these cells changes during neuronal differentiation. We found that expression of the glycophosphatidylinositol-specific phospholipase D1 (GPLD1) gene is associated with these changes in Aß production. GPLD1 overexpression in HEK293 cells increased the secretion of galectin 3-binding protein (GAL3BP), which suppressed Aß production in an AD model, neuroglioma H4 cells. Mechanistically, GAL3BP suppressed Aß production by directly interacting with APP and thereby inhibiting APP processing by ß-secretase. Furthermore, we show that cells take up extracellularly added GAL3BP via endocytosis and that GAL3BP is localized in close proximity to APP in endosomes where amyloidogenic APP processing takes place. Taken together, our results indicate that GAL3BP may be a suitable target of AD-modifying drugs in future therapeutic strategies for managing AD.

Wide distribution of alpha-synuclein oligomers in multiple system atrophy brain detected by proximity ligation.

Multiple system atrophy (MSA) is a fatal adult-onset neurodegenerative disease that is characterized by varying degrees of cerebellar dysfunction and Parkinsonism. The neuropathological hallmark of MSA is alpha-synuclein (AS)-positive glial cytoplasmic inclusions (GCIs). Although severe neuronal loss (NL) is also observed in MSA, neuronal inclusions (NIs) are rare compared to GCIs, such that the pathological mechanism of NL in MSA is unclear. GCIs and NIs are late-stage pathology features relative to AS oligomers and may not represent early pathological changes in MSA. To reveal the early pathology of MSA, it is necessary to examine the early aggregation of AS, i.e., AS oligomers. Here, we adopted a proximity ligation assay (PLA) to examine the distribution of AS oligomers in brain tissue samples from patients with MSA and other diseases. Surprisingly, MSA brains showed a widespread distribution and abundant accumulation of oligomeric AS in neurons as well as oligodendrocytes of the neocortex. In several regions, oligomeric AS signal intensity was higher in cases with MSA than in cases with Parkinson's disease. In contrast to previous studies, AS-PLA revealed abundant AS oligomer accumulation in Purkinje cells in MSA brains, identifying oligomeric AS accumulation as a possible cause of Purkinje cell loss. This wide distribution of AS oligomers in MSA brain neurons has not been described previously and indicates a pathological mechanism of NL in MSA.

Less Limb Muscle Involvement in Myositis Patients with Anti-Mitochondrial Antibodies.

Recent studies have revealed the clinical, histological, and pathophysiological characteristics in a group of inflammatory myopathies with selected autoantibodies. We retrospectively compared the clinical manifestations and histological features between 8 anti-mitochondrial (anti-M2) antibody-positive and 33 antibody-negative patients. Patients with anti-M2 antibodies have been previously reported to have delayed diagnostic confirmation and frequent cardiopulmonary complications in comparison to those without the antibodies. In our study, clinical characteristics in patients with the antibodies were as follows: lesser degree of limb muscle weakness and atrophy as well as lymphocytic infiltration in muscle biopsy specimens, and frequent paravertebral muscle atrophy. Anti-M2 antibody appeared to be a biomarker related to not only cardiopulmonary complications, but also characteristic -distributions of affected muscles.

Multiple Deep White Matter Hyperintense Lesions on Diffusion-Weighted Imaging: Early Sign of Straight Sinus Thrombosis.

Straight sinus thrombosis (SST) is a rare type of cerebral venous sinus thromboses and is extremely difficult to diagnose, especially at its acute stage. The diagnosis is often delayed in many cases of SST that leads to treatment delay and a poor prognosis. We report the case of a 67-year-old patient who had multiple deep white matter (DWM) hyperintense signals on diffusion-weighted imaging (DWI) immediately after the onset of SST. This DWM hyperintense signal on DWI was the only abnormality at the acute stage, the underlying cause of which was congestive cerebral ischemia. Taken together, DWM hyperintense signals on DWI could be a useful diagnostic imaging marker for the early detection of SST.

Association of the ASCO classification with the executive function subscores of the Montreal cognitive assessment in patients with postischemic stroke.

BACKGROUND: The ASCO classification can evaluate the etiology and mechanisms of ischemic stroke more comprehensively and systematically than conventional stroke classification systems such as Trial of Org 10172 in Acute Stroke Treatment (TOAST). Simultaneously, risk factors for cognitive impairment such as arterial sclerosis, leukoaraiosis, and atrial fibrillation can also be gathered and graded using the ASCO classification. METHODS: Sixty patients with postischemic stroke underwent cognitive testing, including testing by the Japanese version of the Montreal cognitive assessment (MoCA-J) and the mini-mental state examination (MMSE). Ischemic strokes were categorized and graded by the ASCO classification. In this phenotype-based classification, every patient is characterized by the A-S-C-O system (A for Atherosclerosis, S for Small vessel disease, C for Cardiac source, and O for Other cause). Each of the 4 phenotypes is graded 0, 1, 2, or 3, according to severity. The conventional TOAST classification was also applied. Correlations between individual MoCA-J/MMSE scores and the ASCO scores were assessed. RESULTS: The total score of the ASCO classification significantly correlated with the total scores of MoCA-J and MMSE. This correlation was more apparent in MoCA-J than in MMSE, because MoCA-J scores were normally distributed, whereas MMSE scores were skewed toward the higher end of the range (ceiling effect). Results for individual subtests of MoCA-J and MMSE indicated that cognitive function for visuoexecutive, calculation, abstraction, and remote recall significantly correlated with ASCO score. CONCLUSIONS: These results suggest that the ASCO phenotypic classification of stroke is useful not only for assessing the etiology of ischemic stroke but also for predicting cognitive decline after ischemic stroke.

Efficacy of a non-pharmaceutical multimodal intervention program in a group setting for patients with mild cognitive impairment: A single-arm interventional study with pre-post and external control analyses.

Aim: This study aimed to evaluate the efficacy of a non-pharmaceutical multimodal intervention program consisting of physical exercise, cognitive stimulation, and health education in a group setting to slow the progression of mild cognitive impairment (MCI). Methods: A single-arm interventional study was conducted on 27 patients with MCI. To evaluate the efficacy of the intervention program, a pre-post analysis was performed using EuroQol-5 Dimension (EQ-5D), Mini-Mental State Examination (MMSE), Cognitive Function Instrument (CFI), 5 Cog test, depression, and physical performance before and after the 8-month intervention. Additionally, propensity score and the semi-Bayes analyses were performed to compare the intervention program with standard medical care, using the external control patients' data for MMSE scores. Results: Twenty-four patients completed the intervention program. During the study period, although EQ-5D and MMSE scores remained unchanged (mean change 0.02 [95 % confidence interval (CI): -0.004, 0.04], 0.5 [-0.2, 1.3]), CFI and the subcategories of 5Cog (attention and reasoning) improved (mean change -1.23 [-2.24, -0.21], 4.3 [0.9, 7.7], 3.0 [0.4, 5.6]). In the additional analysis comparing changes in MMSE scores, patients who underwent the intervention program had less decline than the external control patients (mean change -1.7 [-2.1, -1.3]) with an observed mean difference of 2.25 [1.46, 3.03], and propensity score-adjusted difference of 2.26 [1.46, 3.05]. The semi-Bayesian approach also suggested that the intervention slowed the progression of MCI. Conclusion: A non-pharmaceutical multimodal intervention program could contribute to slowing cognitive decline in patients with MCI.

Combining plasma Aß and p-tau217 improves detection of brain amyloid in non-demented elderly.

BACKGROUND: Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-ß (Aß)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aß-positron emission tomography (PET) in the preclinical and prodromal AD. METHODS: We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study. J-TRC included 474 non-demented individuals (CDR 0: 331, CDR 0.5: 143). Participants underwent plasma Aß and p-tau217 assessments, and Aß-PET imaging. Findings in J-TRC were replicated in the BioFINDER cohort including 177 participants (cognitively unimpaired: 114, mild cognitive impairment: 63). In both cohorts, plasma Aß(1-42) (Aß42) and Aß(1-40) (Aß40) were measured using immunoprecipitation-MALDI TOF mass spectrometry (Shimadzu), and p-tau217 was measured with an immunoassay on the Meso Scale Discovery platform (Eli Lilly). RESULTS: Aß-PET was abnormal in 81 participants from J-TRC and 71 participants from BioFINDER. Plasma Aß42/Aß40 ratio and p-tau217 individually showed moderate to high accuracies when detecting abnormal Aß-PET scans, which were improved by combining plasma biomarkers and by including age, sex and APOE genotype in the models. In J-TRC, the highest AUCs were observed for the models combining p-tau217/Aß42 ratio, APOE, age, sex in the whole cohort (AUC = 0.936), combining p-tau217, Aß42/Aß40 ratio, APOE, age, sex in the CDR 0 group (AUC = 0.948), and combining p-tau217/Aß42 ratio, APOE, age, sex in the CDR 0.5 group (AUC = 0.955), respectively. Each subgroup results were replicated in BioFINDER, where the highest AUCs were seen for models combining p-tau217, Aß42/40 ratio, APOE, age, sex in cognitively unimpaired (AUC = 0.938), and p-tau217/Aß42 ratio, APOE, age, sex in mild cognitive impairment (AUC = 0.914). CONCLUSIONS: Combination of plasma Aß-related biomarkers and p-tau217 exhibits high performance when predicting Aß-PET positivity. Adding basic clinical information (i.e., age, sex, APOE Îµ genotype) improved the prediction in preclinical AD, but not in prodromal AD. Combination of Aß-related biomarkers and p-tau217 could be highly useful for pre-screening of participants in clinical trials of preclinical and prodromal AD.

Molecular pathology of Sandhoff disease with p.Arg505Gln in HEXB: application of simulation analysis.

Sandhoff disease is a GM2 gangliosidosis caused by mutations in HEXB encoding the ß-subunit of ß-hexosaminidase A. ß-Hexosaminidase A exists as a heterodimer consisting of α- and ß-subunits, and requires a GM2 activator protein to hydrolyze GM2. To investigate the molecular pathology in an adult Sandhoff disease patient with an early disease onset, we performed mutation detection, western blot analysis and molecular simulation analysis. The patient had compound heterozygous mutations p.Arg505Gln and p.Ser341ValfsX30. Western blot analysis showed that the amount of mature form of the α- and ß-subunits was markedly decreased in the patient. We then performed docking simulation analysis of the α- and ß-subunits with p.Arg505Gln, the GM2AP/GM2 complex and ß-hexosaminidase A, and GM2 and ß-hexosaminidase A. Simulation analysis showed that p.Arg505Gln impaired each step of molecular conformation of the α- and ß-subunits heterodimer, the activator protein and GM2. The results indicated that p.Ser341ValfsX30 reduced the amount of ß-subunit, and that p.Arg505Gln hampered the maturation of α- and ß-subunits, and hindered the catalytic ability of ß-hexosaminidase A. In conclusion, various methods including simulation analysis were useful to understand the molecular pathology in Sandhoff disease.

Myositis with antimitochondrial antibodies diagnosed by rectus abdominis muscle biopsy.

INTRODUCTION: Antimitochondrial antibodies are autoantibodies detected in 90% of primary biliary cirrhosis (PBC) patients. Some PBC cases are complicated by myositis, which is difficult to confirm due to minimal histological evidence of inflammation in limb muscles. METHODS: Our aim was to determine the extent of inflammatory changes in a truncal muscle biopsy specimen from a PBC patient. RESULTS: A 48-year-old woman with a 5-year history of atrial fibrillation and chronic heart failure was evaluated for elevated serum creatine kinase level. Antimitochondrial M2 antibodies were detected, and PBC was diagnosed. A biceps brachii biopsy specimen showed mild, non-specific myogenic changes; a second biopsy was performed on the rectus abdominis muscle, which showed typical inflammatory changes. Myositis with antimitochondrial M2 antibodies was confirmed. CONCLUSIONS: In myositis patients with antimitochondrial M2 antibodies, muscles of the extremities are involved to a lesser extent. Radiological and histological examination focusing on truncal muscles, including a biopsy, is important.

Action-rule-based cognitive control enables efficient execution of stimulus-response conflict tasks: a model validation of Simon task performance.

Introduction: The human brain can flexibly modify behavioral rules to optimize task performance (speed and accuracy) by minimizing cognitive load. To show this flexibility, we propose an action-rule-based cognitive control (ARC) model. The ARC model was based on a stochastic framework consistent with an active inference of the free energy principle, combined with schematic brain network systems regulated by the dorsal anterior cingulate cortex (dACC), to develop several hypotheses for demonstrating the validity of the ARC model. Methods: A step-motion Simon task was developed involving congruence or incongruence between important symbolic information (illustration of a foot labeled "L" or "R," where "L" requests left and "R" requests right foot movement) and irrelevant spatial information (whether the illustration is actually of a left or right foot). We made predictions for behavioral and brain responses to testify to the theoretical predictions. Results: Task responses combined with event-related deep-brain activity (ER-DBA) measures demonstrated a key contribution of the dACC in this process and provided evidence for the main prediction that the dACC could reduce the Shannon surprise term in the free energy formula by internally reversing the irrelevant rapid anticipatory postural adaptation. We also found sequential effects with modulated dip depths of ER-DBA waveforms that support the prediction that repeated stimuli with the same congruency can promote remodeling of the internal model through the information gain term while counterbalancing the surprise term. Discussion: Overall, our results were consistent with experimental predictions, which may support the validity of the ARC model. The sequential effect accompanied by dip modulation of ER-DBA waveforms suggests that cognitive cost is saved while maintaining cognitive performance in accordance with the framework of the ARC based on 1-bit congruency-dependent selective control.

The Japan-Multimodal Intervention Trial for Prevention of Dementia PRIME Tamba (J-MINT PRIME Tamba): Study protocol of a randomised controlled multi-domain intervention trial.

The Japan-Multimodal Intervention Trial for Prevention of Dementia PRIME Tamba (J-MINT PRIME Tamba) is a randomised controlled trial to prevent cognitive decline in community-dwelling cognitively ordinary older people at risk of dementia. Participants are aged 65-85 years living in a rural area in Japan, aware of very mild decline in cognitive function or abilities of activities of daily living, have at least one vascular risk (e.g. hypertension or diabetes), and have a Mini-Mental State Examination score of 24 or higher. Approximately 200 participants are randomly divided into two groups, with the intervention group receiving a multi-modal intervention, including lifestyle-related disease management, physical exercise, cognitive training, and nutritional counselling, over 18 months. The primary outcome is change in the composite score of seven neuropsychological tests, including the Free and Cued Selective Reminding Test, Logical Memory I and II subsets of the Wechsler Memory Scale-Revised, and Digit Symbol Substitution Test of the Wechsler Adult Intelligence Scale. In addition, changes in a wide range of other parameters such as physical function, blood test results, sleep, and frailty are also analysed as secondary outcomes. We believe that this study's results will contribute significantly to the development of dementia prevention measures in Japan. Clinical trial registration number: UMIN000041938.

Association between locomotive syndrome and anemia among community-dwelling older adults.

AIM: To investigate the association between locomotive syndrome and anemia among community-dwelling older adults. METHODS: This cross-sectional study was conducted at specific health checkup centers in Japan between 2019 and 2020. We sent a questionnaire to older adults aged ≥65 years who participated in health checkups. A total of 2507 community-dwelling older adults were included in this study (mean age = 72.3 years, 51.4% women). Locomotive syndrome was measured using a 25-question Geriatric Locomotive Function Scale with a score range of 0-100, and was defined as ≥16 points. Anemia was defined using World Health Organization criteria, as a hemoglobin concentration of <13.0 g/dL in men and <12.0 g/dL in women. Logistic regression analyses were performed to investigate the association between locomotive syndrome and anemia, adjusted for age, sex, body mass index, depression symptoms, self-reported comorbidities (cancer, rheumatoid arthritis, knee osteoarthritis, fractures, and spinal disease), hypertension, and renal function. RESULTS: Of all the participants, 11.6% had locomotive syndrome and 12.8% had anemia. Even after adjustment, a relationship between locomotive syndrome and anemia was observed (adjusted odds ratio = 1.9, 95% confidence interval = 1.3-2.7). CONCLUSIONS: Community-dwelling older adults with anemia had a significantly higher prevalence of locomotive syndrome than those without. This finding suggests that older adults with anemia are at risk of locomotive syndrome, and appropriate measures should be taken for prevention. Geriatr Gerontol Int 2023; 23: 426-429.

Tooth Loss as a Predictor of Long-Term Care Requirements in the Elderly: A Study in Kobe City, Japan.

INTRODUCTION: The Kobe project, which utilizes prospective data from the national health insurance system, focuses on early detection and preventive strategies through the Frail Kenshin health check-up program. Previous research has underscored the correlation between tooth loss and the decline in physical and cognitive functions. In this study, using Kobe project data, we examined the link between remaining teeth and long-term care needs in individuals aged 64-65 years, with primary and secondary objectives involving various health parameters and quality of life. METHODS: We analyzed baseline data from a prospective study conducted alongside the Frail Check program for generally healthy individuals aged 64-65 years to examine the relationship between the number of remaining teeth and various health indicators. This study focused on citizens aged 64-65 years to identify those at risk of needing long-term care by the age of 65 years. RESULTS: Data from 1,530 participants were obtained, excluding eight individuals for specific reasons. At the end of the follow-up period, 41 (2.7%) individuals required support and 15 (1.0%) needed long-term care alone. The data revealed a significant association between the number of remaining teeth and the need for long-term care or support, as demonstrated by the Cochran-Armitage trend test (p<0.001). Although trends were noted for nutrition and total Cognitive Functional Instrument Self scores, they did not reach statistical significance. Additionally, a decrease in the number of remaining teeth was significantly associated with worse European Quality of Life Five Dimensions (EQ-5D-5L) visual analog scale scores, mobility, and regular activities (p<0.001). CONCLUSION: Tooth loss indicates the potential long-term care needs of older adults. Monitoring oral health is crucial for addressing care requirements.

Efficacy and Safety of Cilostazol in Mild Cognitive Impairment: A Randomized Clinical Trial.

Importance: Recent evidence indicates the efficacy of ß-amyloid immunotherapy for the treatment of Alzheimer disease, highlighting the need to promote ß-amyloid removal from the brain. Cilostazol, a selective type 3 phosphodiesterase inhibitor, promotes such clearance by facilitating intramural periarterial drainage. Objective: To determine the safety and efficacy of cilostazol in mild cognitive impairment. Design, Setting, and Participants: The COMCID trial (A Trial of Cilostazol for Prevention of Conversion from Mild Cognitive Impairment to Dementia) was an investigator-initiated, double-blind, phase 2 randomized clinical trial. Adult participants were registered between May 25, 2015, and March 31, 2018, and received placebo or cilostazol for up to 96 weeks. Participants were treated in the National Cerebral and Cardiovascular Center and 14 other regional core hospitals in Japan. Patients with mild cognitive impairment with Mini-Mental State Examination (MMSE) scores of 22 to 28 points (on a scale of 0 to 30, with lower scores indicating greater cognitive impairment) and Clinical Dementia Rating scores of 0.5 points (on a scale of 0, 0.5, 1, 2, and 3, with higher scores indicating more severe dementia) were enrolled. The data were analyzed from May 1, 2020, to December 1, 2020. Interventions: The participants were treated with placebo, 1 tablet twice daily, or cilostazol, 50 mg twice daily, for up to 96 weeks. Main Outcomes and Measures: The primary end point was the change in the total MMSE score from baseline to the final observation. Safety analyses included all adverse events. Results: The full analysis set included 159 patients (66 [41.5%] male; mean [SD] age, 75.6 [5.2] years) who received placebo or cilostazol at least once. There was no statistically significant difference between the placebo and cilostazol groups for the primary outcome. The least-squares mean (SE) changes in the MMSE scores among patients receiving placebo were -0.1 (0.3) at the 24-week visit, -0.8 (0.3) at 48 weeks, -1.2 (0.4) at 72 weeks, and -1.3 (0.4) at 96 weeks. Among those receiving cilostazol, the least-squares mean (SE) changes in MMSE scores were -0.6 (0.3) at 24 weeks, -1.0 (0.3) at 48 weeks, -1.1 (0.4) at 72 weeks, and -1.8 (0.4) at 96 weeks. Two patients (2.5%) in the placebo group and 3 patients (3.8%) in the cilostazol group withdrew owing to adverse effects. There was 1 case of subdural hematoma in the cilostazol group, which may have been related to the cilostazol treatment; the patient was successfully treated surgically. Conclusions and Relevance: In this randomized clinical trial, cilostazol was well tolerated, although it did not prevent cognitive decline. The efficacy of cilostazol should be tested in future trials. Trial Registration: ClinicalTrials.gov Identifier: NCT02491268.

FAT10 protein binds to polyglutamine proteins and modulates their solubility.

Expansion of polyglutamine (pQ) chain by expanded CAG repeat causes dominantly inherited neurodegeneration such as Huntington disease, dentatorubral-pallidoluysian atrophy (DRPLA), and numbers of other spinocerebellar ataxias. Expanded pQ disrupts the stability of the pQ-harboring protein and increases its susceptibility to aggregation. Aggregated pQ protein is recognized by the ubiquitin proteasome system, and the enzyme ubiquitin ligase covalently attaches ubiquitin, which serves as a degradation signal by the proteasome. However, accumulation of the aggregated proteins in the diseased brain suggests insufficient degradation machinery. Ubiquitin has several functionally related proteins that are similarly attached to target proteins through its C terminus glycine residue. They are called ubiquitin-like molecules, and some of them are similarly related to the protein degradation pathway. One of the ubiquitin-like molecules, FAT10, is known to accelerate protein degradation through a ubiquitin-independent manner, but its role in pQ aggregate degradation is completely unknown. Thus we investigated its role in a Huntington disease cellular model and found that FAT10 molecules were covalently attached to huntingtin through their C terminus glycine. FAT10 binds preferably to huntingtin with a short pQ chain and completely aggregated huntingtin was FAT10-negative. In addition, ataxin-1,3 and DRPLA proteins were both positive for FAT10, and aggregation enhancement was observed upon FAT10 knockdown. These findings were similar to those for huntingtin. Our new finding will provide a new role for FAT10 in the pathogenesis of polyglutamine diseases.

Self Assessment Memory Scale (SAMS), a new simple method for evaluating memory function.

We have developed a new method for easy self-assessment of changes in memory recall impairment, which can be used during the very early stages of dementia. An 8-picture recall and a 16-word regression were assessed, respectively, and the index was calculated by adding up the ratio of correct responses to both tests. A total of 85 subjects including 12 MCI, 8 AD, and 65 older persons with normal cognitive function were evaluated, and the correlation with the WMS-R Logical Memory II score was examined. The results showed that there was a statistically significant correlation between the 8-picture recall (R = 0.872, p < 0.0001) and the index (R = 0.857, p < 0.0001), respectively, with the Logical Memory score. We have named this index as Self Assessment Memory Scale (SAMS), and are now developing a digital tool to enable easy and self-administered evaluation of recall.