Perampanel Inhibits α‐Synuclein Transmission in Parkinson's Disease Models

パーキンソン病モデルへのペランパネルの有効性を確認 --パーキンソン病の進行抑制治療への期待--. 京都大学プレスリリース. 2021-04-05.[Background]: The intercellular transmission of pathogenic proteins plays a key role in the clinicopathological progression of neurodegenerative diseases. Previous studies have demonstrated that this uptake and release process is regulated by neuronal activity. [Objective]: The objective of this study was to examine the effect of perampanel, an antiepileptic drug, on α‐synuclein transmission in cultured cells and mouse models of Parkinson's disease.Methods: Mouse primary hippocampal neurons were transduced with α‐synuclein preformed fibrils to examine the effect of perampanel on the development of α‐synuclein pathology and its mechanisms of action. An α‐synuclein preformed fibril‐injected mouse model was used to validate the effect of oral administration of perampanel on the α‐synuclein pathology in vivo. [Results]: Perampanel inhibited the development of α‐synuclein pathology in mouse hippocampal neurons transduced with α‐synuclein preformed fibrils. Interestingly, perampanel blocked the neuronal uptake of α‐synuclein preformed fibrils by inhibiting macropinocytosis in a neuronal activity‐dependent manner. We confirmed that oral administration of perampanel ameliorated the development of α‐synuclein pathology in wild‐type mice inoculated with α‐synuclein preformed fibrils.[Conclusion]: Modulation of neuronal activity could be a promising therapeutic target for Parkinson's disease, and perampanel could be a novel disease‐modifying drug for Parkinson's disease

Impact of Gba2 on neuronopathic Gaucher’s disease and α-synuclein accumulation in medaka (Oryzias latipes)

Homozygous mutations in the lysosomal glucocerebrosidase gene, GBA1, cause Gaucher's disease (GD), while heterozygous mutations in GBA1 are a strong risk factor for Parkinson's disease (PD), whose pathological hallmark is intraneuronal α-synuclein (asyn) aggregates. We previously reported that gba1 knockout (KO) medaka exhibited glucosylceramide accumulation and neuronopathic GD phenotypes, including short lifespan, the dopaminergic and noradrenergic neuronal cell loss, microglial activation, and swimming abnormality, with asyn accumulation in the brains. A recent study reported that deletion of GBA2, non-lysosomal glucocerebrosidase, in a non-neuronopathic GD mouse model rescued its phenotypes. In the present study, we generated gba2 KO medaka and examined the effect of Gba2 deletion on the phenotypes of gba1 KO medaka. The Gba2 deletion in gba1 KO medaka resulted in the exacerbation of glucosylceramide accumulation and no improvement in neuronopathic GD pathological changes, asyn accumulation, or swimming abnormalities. Meanwhile, though gba2 KO medaka did not show any apparent phenotypes, biochemical analysis revealed asyn accumulation in the brains. gba2 KO medaka showed a trend towards an increase in sphingolipids in the brains, which is one of the possible causes of asyn accumulation. In conclusion, this study demonstrated that the deletion of Gba2 does not rescue the pathological changes or behavioral abnormalities of gba1 KO medaka, and GBA2 represents a novel factor affecting asyn accumulation in the brains

Repurposing bromocriptine for Aβ metabolism in Alzheimer’s disease (REBRAnD) study : randomised placebo-controlled double-blind comparative trial and open-label extension trial to investigate the safety and efficacy of bromocriptine in Alzheimer’s disease with presenilin 1 (PSEN1) mutations

Introduction Alzheimer’s disease (AD) is one of the most common causes of dementia. Pathogenic variants in the presenilin 1 (PSEN1) gene are the most frequent cause of early-onset AD. Medications for patients with AD bearing PSEN1 mutation (PSEN1-AD) are limited to symptomatic therapies and no established radical treatments are available. Induced pluripotent stem cell (iPSC)-based drug repurposing identified bromocriptine as a therapeutic candidate for PSEN1-AD. In this study, we used an enrichment strategy with iPSCs to select the study population, and we will investigate the safety and efficacy of an orally administered dose of bromocriptine in patients with PSEN1-AD. Methods and analysis This is a multicentre, randomised, placebo-controlled trial. AD patients with PSEN1 mutations and a Mini Mental State Examination-Japanese score of ≤25 will be randomly assigned, at a 2:1 ratio, to the trial drug or placebo group (≥4 patients in TW-012R and ≥2 patients in placebo). This clinical trial consists of a screening period, double-blind phase (9 months) and extension phase (3 months). The double-blind phase for evaluating the efficacy and safety is composed of the low-dose maintenance period (10 mg/day), high-dose maintenance period (22.5 mg/day) and tapering period of the trial drug. Additionally, there is an open-labelled active drug extension period for evaluating long-term safety. Primary outcomes are safety and efficacy in cognitive and psychological function. Also, exploratory investigations for the efficacy of bromocriptine by neurological scores and biomarkers will be conducted. Ethics and dissemination The proposed trial is conducted according to the Declaration of Helsinki, and was approved by the Institutional Review Board (K070). The study results are expected to be disseminated at international or national conferences and published in international journals following the peer-review process

Idiopathic rapid eye movement sleep behavior disorder in Japan: An observational study.

Introduction:Idiopathic rapid eye movement sleep behavior disorder (iRBD) is one of the most specific prodromal symptoms of synucleinopathies, including Parkinson\u27s disease (PD) and multiple system atrophy. The Japan Parkinson\u27s Progression Markers Initiative (J-PPMI) was a prospective cohort study conducted in Japanese patients with iRBD to investigate biomarkers for prodromal synucleinopathies. We carried out an initial assessment of the J-PPMI study to reveal the factors correlated with dopamine transporter single-photon emission computed tomography (DaT) and 123I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy.Methods:This cross-sectional study was conducted in 108 patients with iRBD, selected from the J-PPMI study. We divided the patients into four groups based on the MIBG and DaT results. We also recorded the patients\u27 demographics and clinical data. Following PD probability calculation, we examined the biomarkers associated with DaT and MIBG.Results:Ninety-five of the enrolled patients (88%) met the diagnostic criteria for prodromal PD based on the probability score. Only five patients had normal MIBG and DaT. We identified 29 cases with decreased DaT and MIBG, all of whom met the above diagnostic criteria. Both DaT and MIBG were significantly correlated with the Japanese version of the Montreal Cognitive Assessment (MoCA-J) score.Conclusion:Both DaT and MIBG are important biomarkers for confirming synucleinopathies and/or staging disease progression. Although 95% of iRBD patients were consistent with the body-first subtype concept, alpha-synuclein pathologies of iRBD might have widespread systemic involvement rather than being confined to the lower brainstem, particularly in patients with reduced MoCA-J scores