Assessment of thrombocytopenia, sleep apnea, and cardiac involvement in GNE myopathy patients.

INTRODUCTION: We previously identified UDP-N-acetylglucosamine 2-epimerase (GNE) myopathy patients with sleep apnea and a past history of thrombocytopenia, but without disease-specific cardiac involvement. This study aimed to clarify the occurrence, severity, and serial changes of these complications. METHODS: Thirty-three genetically confirmed GNE myopathy patients who participated in a 5-y longitudinal observational history study underwent platelet count and platelet-associated immunoglobulin G (PA-IgG) measurements, a sleep study, and electrocardiography (ECG), Holter ECG, and echocardiogram examinations. RESULTS: Among the 33 patients, three had low platelet counts and 17 out of 26 were PA-IgG positive. No patient exhibited bleeding tendencies, and 3 out of 28 had low platelet counts. Muscle weakness was more pronounced, and summed MMT and grip power significantly lower, in PA-IgG-positive patients than in PA-IgG-negative patients. Of 19 patients, 7, 4, and 3 who underwent a sleep study had mild, moderate, and severe sleep apnea, respectively, and three started continuous positive airway pressure (CPAP). The respiratory disturbance index was not significantly correlated with physical evaluation items or forced vital capacity. All patients underwent ECG, 32 underwent cardiac ultrasound, and 25 underwent Holter ECG. No disease-specific cardiac involvement was noted, no serial changes during the follow-up period were observed for ECG and echocardiography, and none of the patients required therapy for cardiac abnormalities. DISCUSSION: PA-IgG is a potential disease biomarker in GNE myopathy patients, although its significance needs to be clarified. While none of the patients in this study experienced cardiomyopathy or arrythmia due to myopathy, sleep apnea was identified as a frequent complication.

Alternative Selection of ß-Site APP-Cleaving Enzyme 1 (BACE1) Cleavage Sites in Amyloid ß-Protein Precursor (APP) Harboring Protective and Pathogenic Mutations within the Aß Sequence.

ß-Site APP-cleaving enzyme 1 (BACE1) cleaves amyloid ß-protein precursor (APP) at the bond between Met671 and Asp672 (ß-site) to generate the carboxyl-terminal fragment (CTFß/C99). BACE1 also cleaves APP at another bond between Thr681 and Gln682 (ß'-site), yielding CTFß'/C89. Cleavage of CTFß/C99 by γ-secretase generates Aß(1-XX), whereas cleavage of CTFß'/C89 generates Aß(11-XX). Thus, ß'-site cleavage by BACE1 is amyloidolytic rather than amyloidogenic. ß' cleavage of mouse APP is more common than the corresponding cleavage of human APP. We found that the H684R substitution within human Aß, which replaces the histidine in the human protein with the arginine found at the corresponding position in mouse, facilitated ß' cleavage irrespective of the species origin of BACE1, thereby significantly increasing the level of Aß(11-XX) and decreasing the level of Aß(1-XX). Thus, amino acid substitutions within the Aß sequence influenced the selectivity of alternative ß- or ß'-site cleavage of APP by BACE1. In familial Alzheimer's disease (FAD), the APP gene harbors pathogenic variations such as the Swedish (K670N/M671L), Leuven (E682K), and A673V mutations, all of which decrease Aß(11-40) generation, whereas the protective Icelandic mutation (A673T) increases generation of Aß(11-40). Thus, A673T promotes ß' cleavage of APP and protects subjects against AD. In addition, CTFß/C99 was cleaved by excess BACE1 activity to generate CTFß'/C89, followed by Aß(11-40), even if APP harbored pathogenic mutations. The resultant Aß(11-40) was more metabolically labile in vivo than Aß(1-40). Our analysis suggests that some FAD mutations in APP are amyloidogenic and/or amyloidolytic via selection of alternative BACE1 cleavage sites.

Facilitation of brain mitochondrial activity by 5-aminolevulinic acid in a mouse model of Alzheimer's disease.

The activities of mitochondrial enzymes, which are essential for neural function, decline with age and in age-related disease. In particular, the activity of cytochrome c oxidase (COX/complex IV) decreases in patients with Alzheimer's disease (AD). COX, a mitochondrial inner membrane protein complex that contains heme, plays an essential role in the electron transport chain that generates ATP. Heme synthesis begins with 5-aminolevulinic acid (5-ALA) in mitochondria. 5-ALA synthetase is the rate-limiting enzyme in heme synthesis, suggesting that supplementation with 5-ALA might help preserve mitochondrial activity in the aged brain. We administered a diet containing 5-ALA to triple-transgenic AD (3xTg-AD) model mice for 6 months, starting at 3 months of age. COX activity and protein expression, as well as mitochondrial membrane potential, were significantly higher in brains of 5-ALA-fed mice than in controls. Synaptotagmin protein levels were also significantly higher in 5-ALA-fed mice, suggesting improved preservation of synapses. Although brain Aß levels tended to decrease in 5-ALA-fed mice, we observed no other significant changes in other biochemical and pathological hallmarks of AD. Nevertheless, our study suggests that daily oral administration of 5-ALA could preserve mitochondrial enzyme activities in the brains of aged individuals, thereby contributing to the preservation of neural activity.

Cytoplasmic fragment of Alcadein α generated by regulated intramembrane proteolysis enhances amyloid ß-protein precursor (APP) transport into the late secretory pathway and facilitates APP cleavage.

The neural type I membrane protein Alcadein α (Alcα), is primarily cleaved by amyloid ß-protein precursor (APP) α-secretase to generate a membrane-associated carboxyl-terminal fragment (Alcα CTF), which is further cleaved by γ-secretase to secrete p3-Alcα peptides and generate an intracellular cytoplasmic domain fragment (Alcα ICD) in the late secretory pathway. By association with the neural adaptor protein X11L (X11-like), Alcα and APP form a ternary complex that suppresses the cleavage of both Alcα and APP by regulating the transport of these membrane proteins into the late secretory pathway where secretases are active. However, it has not been revealed how Alcα and APP are directed from the ternary complex formed largely in the Golgi into the late secretory pathway to reach a nerve terminus. Using a novel transgenic mouse line expressing excess amounts of human Alcα CTF (hAlcα CTF) in neurons, we found that expression of hAlcα CTF induced excess production of hAlcα ICD, which facilitated APP transport into the nerve terminus and enhanced APP metabolism, including Aß generation. In vitro cell studies also demonstrated that excess expression of Alcα ICD released both APP and Alcα from the ternary complex. These results indicate that regulated intramembrane proteolysis of Alcα by γ-secretase regulates APP trafficking and the production of Aß in vivo.

Cats Did Not Change Their Problem-Solving Behaviours after Human Demonstrations.

Humans learn by observing the behaviour of others, which can lead to more efficient problem-solving than by trial-and-error learning. Numerous studies have shown that animals, other than humans, are also capable of social learning. Dogs, as humans' closest companion animals, can learn to obtain rewards following behavioural demonstrations by humans. However, it is not known whether cats, who also live with humans, can learn how to solve problems by observing human behaviours. Three experiments were used to investigate whether cats could change their behaviour and gain rewards efficiently by observing a human demonstrating how to obtain food. In Experiment 1, a human demonstrated how to open a transparent drawer and take out the reward inside, but cats did not significantly follow the same method as the human. In Experiment 2a, a transparent tube device was used to make the operation easier for cats. However, cats were not influenced by the human behaviour. As the devices used in these experiments were transparent, meaning that the cats could see the food inside directly, they might have required strong inhibitory control. Therefore, in Experiment 2b the tube device was made opaque, and cats again observed the human demonstration. Nevertheless, the cats were not influenced by the human's behaviour. The results of these experiments indicate a lack of social learning, including imitation, from human behaviours in cats, at least in these experimental settings with food rewards. Other than their inherent ability, cats' biological characteristics and the experimental context may have contributed towards the negative results.

Treatment of sleep-related eating disorder with suvorexant: A case report on the potential benefits of replacing benzodiazepines with orexin receptor antagonists.

Background: Nocturnal eating behavior in patients with sleep-related eating disorder (SRED) is difficult to control and can become chronic, causing weight gain and psychological distress. Here, we report a case of SRED comorbid with major depressive disorder successfully treated by switching from brotizolam to suvorexant, that is, from a benzodiazepine to an orexin receptor antagonist. Case Presentation: A 25-year-old woman complained of night snacking with partial/complete amnesia and sleepwalking for 1 year. She had a diagnosis of major depressive disorder at age 20 and was on paroxetine and brotizolam for depression and insomnia. At 24 years of age, she experienced her second depressive episode, then her amnestic nocturnal eating became prominent. Even after improvement in depressive symptoms, she experienced uncontrollable nocturnal eating episodes every 2 days, resulting in weight gain of over 10 kg. After a partial amnestic eating episode following an awakening from stage N2 sleep was confirmed through video polysomnography, she was diagnosed with SRED. Considering her strong desire to resolve involuntary eating, we instructed her to discontinue brotizolam and start suvorexant. Subsequently, her nocturnal eating completely disappeared. She experienced rebound insomnia, which improved within 1 month. She was then continued on 10 mg of suvorexant and has not experienced nocturnal eating for 2 years. Conclusion: This case highlights the importance of discontinuing benzodiazepines in the treatment of SRED, but also suggests the potential benefit of orexin receptor antagonists in the treatment of SRED. The efficacy of orexin receptor antagonists in idiopathic SRED should be tested in future studies.

A simple method to evaluate the pentagon copy test of the Mini-Mental State Examination for the differentiation of dementia with Lewy bodies.

There are many commonalities between the clinical symptoms of dementia with Lewy bodies (DLB) and those of Alzheimer's disease (AD). The accurate differentiation of these two diseases is an important neuropsychological issue. The Mini-Mental State Examination (MMSE) is often used as a screening test for dementing disorders. We created evaluation items for the pentagon copy test of MMSE and developed a simple, highly accurate evaluation method for differentiating DLB in combination with conventional evaluation items such as the Qualitative Scoring MMSE Pentagon Test (QSPT). Subjects were divided into three groups: DLB (n = 119), AD (n = 50), and Normal (n = 26). The severities of DLB and AD ranged from mild cognitive impairment (MCI) to mild dementia. We compared the results of the pentagon copy test. We found that the rates of patients with abnormalities in "motor incoordination" and "gestalt destruction" were higher in the DLB group than the AD group. Furthermore, receiver operating characteristic curve analysis suggested the differentiation of DLB with high accuracy (sensitivity: 0.70, specificity: 0.78) using the criterion of patients meeting one of the following three characteristics: "the number of angles on QSPT: scores other than 4," "major tremor (Parkinsonism-related tremor) is present," and "gestalt destruction (distortion in overall coherence) is present." This evaluation method may be clinically useful for evaluating MCI to mild DLB patients because the burden on patients is low.

The use of a scented face mask in pediatric patients may facilitate mask acceptance before anesthesia induction.

Background: Scented face masks are commonly used during the induction phase of anesthesia. The present study investigated whether the use of a scented mask improved mask acceptance before the slow induction of anesthesia in pediatric patients. Methods: This prospective, randomized controlled trial enrolled patients aged 2-10 years who were scheduled to undergo surgery under general anesthesia. Patients were randomly assigned to either of regular unscented (control group) or scented (experimental group) face masks before anesthesia induction with a parent. The primary outcome was the mask acceptance score, rated on a validated 4-point from 1 point (not afraid; easily accepts the mask) to 4 points (afraid of a mask; crying or struggling). The secondary outcome was heart rate assessed by pulse oximetry in the pediatric ward before transfer to the operating room (OR), at the entrance to the OR, at the patient notification of mask fitting by the anesthesiologist, and after mask fitting. Results: Seventy-seven patients were accessed for eligibility, with 67 enrolled in the study: 33 in the experimental group and 34 in the control group. Mask acceptance was significantly greater among patients aged 2-3 years in the experimental than in the control group (p < 0.05). Conclusion: The use of a scented mask can improve mask acceptance before anesthesia induction with a parental presence in pediatric patients aged 2-3 years.Clinical Trial Registration: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000040819.

Brain p3-Alcß peptide restores neuronal viability impaired by Alzheimer's amyloid ß-peptide.

We propose a new therapeutic strategy for Alzheimer's disease (AD). Brain peptide p3-Alcß37 is generated from the neuronal protein alcadein ß through cleavage of γ-secretase, similar to the generation of amyloid ß (Aß) derived from Aß-protein precursor/APP. Neurotoxicity by Aß oligomers (Aßo) is the prime cause prior to the loss of brain function in AD. We found that p3-Alcß37 and its shorter peptide p3-Alcß9-19 enhanced the mitochondrial activity of neurons and protected neurons against Aßo-induced toxicity. This is due to the suppression of the Aßo-mediated excessive Ca2+ influx into neurons by p3-Alcß. Successful transfer of p3-Alcß9-19 into the brain following peripheral administration improved the mitochondrial viability in the brain of AD mice model, in which the mitochondrial activity is attenuated by increasing the neurotoxic human Aß42 burden, as revealed through brain PET imaging to monitor mitochondrial function. Because mitochondrial dysfunction is common in the brain of AD patients alongside increased Aß and reduced p3-Alcß37 levels, the administration of p3-Alcß9-19 may be a promising treatment for restoring, protecting, and promoting brain functions in patients with AD.

Sleep disturbance and health-related quality of life in Parkinson's disease: A clear correlation between health-related quality of life and subjective sleep quality.

INTRODUCTION: Comorbid insomnia and poor sleep quality in Parkinson's disease (PD) are associated with a poor health-related quality of life (HRQoL). However, the relationship between HRQoL and sleep measures obtained using polysomnography (PSG) remains unclear. We aimed to examine the association between various sleep measures and HRQoL in PD patients. METHODS: We retrospectively included patients with PD who underwent PSG and responded to self-administered questionnaires including the Pittsburgh Sleep Quality Index (PSQI) and Medical Outcomes Study 36-Item Short-Form Health Survey. RESULTS: The patients' (n = 120) mean age was 67.06 (SD = 8.77) years, and their mean Hoehn and Yahr stage was 2.25 (SD = 0.78). A higher PSQI score (worse subjective sleep quality) was correlated in PSG with shorter sleep latency, less N1 sleep, and more N2 sleep. Multiple regression analysis showed that the total PSQI score correlated with both physical and mental HRQoL (p < 0.001 in both cases). However, neither type of HRQoL studied correlated with objective sleep measures, including indicators of sleep architecture, sleep-disordered breathing, and sleep related movement disorders. CONCLUSION: Despite the association between subjective sleep quality and HRQoL, the associations between objective measures and HRQoL were negligible. Objective sleep fragmentation may not be perceived as a sleep disturbance in patients with PD, and therefore may not adversely affect their subjective health, given the paradoxical correlation between PSQI score and sleep architecture.

Decrease in p3-Alcß37 and p3-Alcß40, products of Alcadein ß generated by γ-secretase cleavages, in aged monkeys and patients with Alzheimer's disease.

INTRODUCTION: Neuronal p3-Alcß peptides are generated from the precursor protein Alcadein ß (Alcß) through cleavage by α- and γ-secretases of the amyloid ß (Aß) protein precursor (APP). To reveal whether p3-Alcß is involved in Alzheimer's disease (AD) contributes for the development of novel therapy and/or drug targets. METHODS: We developed new sandwich enzyme-linked immunosorbent assay (sELISA) systems to quantitate levels of p3-Alcß in the cerebrospinal fluid (CSF). RESULTS: In monkeys, CSF p3-Alcß decreases with age, and the aging is also accompanied by decreased brain expression of Alcß. In humans, CSF p3-Alcß levels decrease to a greater extent in those with AD than in age-matched controls. Subjects carrying presenilin gene mutations show a significantly lower CSF p3-Alcß level. A cell study with an inverse modulator of γ-secretase remarkably reduces the generation of p3-Alcß37 while increasing the production of Aß42. DISCUSSION: Aging decreases the generation of p3-Alcß, and further significant decrease of p3-Alcß caused by aberrant γ-secretase activity may accelerate pathogenesis in AD.

Stabilization of intracellular trafficking and metabolism of amyloid ß-protein precursor and Alcadein ß by apolipoprotein E.

Intracellular metabolism of amyloid ß-protein precursor (APP) is important for the pathogenesis of Alzheimer's disease (AD). Alcadeins (Alcα, Alcß, and Alcγ) are neural membrane proteins similar to APP in their localization, metabolism, and cellular function. Isoform ε4 of apolipoprotein E (ApoE) is a major risk factor for AD. We found that ApoE expression attenuated intracellular trafficking of APP and Alcß, resulting in metabolic stabilization of both proteins. By contrast, Alcα intracellular proteolysis was facilitated by ApoE expression, which was not due to an increase in the primary cleavage of Alcα. This difference may result from binding of ApoE to membrane proteins.

Mechanism of intramembrane cleavage of alcadeins by γ-secretase.

BACKGROUND: Alcadein proteins (Alcs; Alcα, Alcßand Alcγ) are predominantly expressed in neurons, as is Alzheimer's ß-amyloid (Aß) precursor protein (APP). Both Alcs and APP are cleaved by primary α- or ß-secretase to generate membrane-associated C-terminal fragments (CTFs). Alc CTFs are further cleaved by γ-secretase to secrete p3-Alc peptide along with the release of intracellular domain fragment (Alc ICD) from the membrane. In the case of APP, APP CTFß is initially cleaved at the ε-site to release the intracellular domain fragment (AICD) and consequently the γ-site is determined, by which Aß generates. The initial ε-site is thought to define the final γ-site position, which determines whether Aß40/43 or Aß42 is generated. However, initial intracellular ε-cleavage sites of Alc CTF to generate Alc ICD and the molecular mechanism that final γ-site position is determined remains unclear in Alcs. METHODOLOGY: Using HEK293 cells expressing Alcs plus presenilin 1 (PS1, a catalytic unit of γ-secretase) and the membrane fractions of these cells, the generation of p3-Alc possessing C-terminal γ-cleavage site and Alc ICD possessing N-terminal ε-cleavage site were analysed with MALDI-TOF/MS. We determined the initial ε-site position of all Alcα, Alcß and Alcγ, and analyzed the relationship between the initially determined ε-site position and the final γ-cleavage position. CONCLUSIONS: The initial ε-site position does not always determine the final γ-cleavage position in Alcs, which differed from APP. No additional γ-cleavage sites are generated from artificial/non-physiological positions of ε-cleavage for Alcs, while the artificial ε-cleavage positions can influence in selection of physiological γ-site positions. Because alteration of γ-secretase activity is thought to be a pathogenesis of sporadic Alzheimer's disease, Alcs are useful and sensitive substrate to detect the altered cleavage of substrates by γ-secretase, which may be induced by malfunction of γ-secretase itself or changes of membrane environment for enzymatic reaction.