A pathogenic PSEN1 Trp165Cys mutation associated with early-onset Alzheimers disease

Background Presenilin-1 (PSEN1) is one of the causative genes for early onset Alzheimers disease (EOAD). Recently, emerging studies reported several novel PSEN1 mutations among Asian. We describe a male with EOAD had a pathogenic PSEN1 mutation. Case presentation A 53-year-old male presented with memory decline, followed by difficulty in finding ways. Patient had positive family history, since his mother and one of his brother was also affected with dementia. Brain magnetic resonance imaging (MRI) scan showed mild degree of atrophy of bilateral hippocampus and parietal lobe. 18F-Florbetaben-PET (FBB-PET) revealed increased amyloid deposition in bilateral frontal, parietal, temporal lobe and precuneus. Whole exome analysis revealed a heterozygous, probably pathogenic PSEN1 (c.695G > T, p.W165C) mutation. Interestingly, Trp165Cys mutation is located in trans membrane (TM)-III region, which is conserved between PSEN1/PSEN2. In vitro studies revealed that PSEN1 Trp165Cys could result in disturbances in amyloid metabolism. This prediction was confirmed by structure predictions and previous in vitro studies that the p.Trp165Cys could result in decreased Aβ42/Aβ40 ratios. Conclusion We report a case of EOAD having a pathogenic PSEN1 (Trp165Cys) confirmed with in silico and in vitro predictions.This work was supported by a National Research Foundation of Korea (NRF) Grants, awarded by the Korean government (MEST, No. 2017R1A2B4012636 & 2017R1C1B5017807). Dr. An SS receives the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST, No. 2017R1A2B4012636). Dr. Eva Bagyinszky receives the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST, No. 2017R1C1B5017807). Dr. Giau VV reports no disclosure. Dr. Pyun JM reports no disclosure. Dr. Suh J reports no disclosure. Dr. Kim SY reports no disclosure

Novel PSEN1 G209A mutation in early-onset Alzheimer dementia supported by structural prediction

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Abstract Background Three main genes are described as causative genes for early-onset Alzheimer dementia (EOAD): APP, PSEN1 and PSEN2. We describe a woman with EOAD had a novel PSEN1 mutation. Case report A 54-year-old right-handed woman presented 12-year history of progressive memory decline. She was clinically diagnosed as familial Alzheimer's disease due to a PSEN1 mutation. One of two daughters also has the same mutation, G209A in the TM-IV of PS1 protein. Her mother had unspecified dementia that began at the age of 40s. PolyPhen2 and SIFT prediction suggested that G209A might be a damaging variant with high scores. 3D modeling revealed that G209A exchange could result significant changes in the PS1 protein. Conclusion We report a case of EOAD having probable novel PSEN1 (G209A) mutation verified with structural prediction

Blood amyloid-β oligomerization associated with neurodegeneration of Alzheimers disease

Introduction Oligomeric amyloid-ß is a major toxic species associated with Alzheimers disease pathogenesis. Methods used to measure oligomeric amyloid-β in the blood have increased in number in recent years. The Multimer Detection System-Oligomeric Amyloid-β (MDS-OAβ) is a specific method to measure oligomerization tendencies in the blood. The objective of this study was to determine the association between amyloid-ß oligomerization in the plasma and structural changes of the brain. Methods We studied 162 subjects composed of 92 community-based normal healthy subjects, 17 with subjective cognitive decline, 14 with mild cognitive impairment and 39 with Alzheimers disease dementia. All subjects underwent MDS-OAβ and three-dimensional T1 magnetic resonance imaging. To determine the structural changes of the brain that are statistically correlated with MDS-OAβ level, we used voxel-based morphometry with corrections for age and total intracranial volume covariates. Results We found brain volume reduction in the bilateral temporal, amygdala, parahippocampal and lower parietal lobe and left cingulate and precuneus regions (family-wise error, p < 0.05). Reduction was also found in white matter in proximity to the left temporal and bilateral lower parietal lobes and posterior corpus callosum (family-wise error, p < 0.05). Brain volume increment was not observed in any regions within grey or white matter. Discussion Findings suggest that substantial correlation exists between amyloid ß oligomerization in the blood and brain volume reduction in the form of Alzheimers disease despite of uncertainty in the casual relationship.This work was supported by a grant of the Korea Healthcare Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HI14C1251)

Decreased Exosomal Acetylcholinesterase Activity in the Plasma of Patients With Parkinson’s Disease

Exosomes, which are small extracellular vesicles produced from various cell types, contain a variety of molecular constituents, such as proteins, lipids, and RNA. Recently, exosomal biomarkers have been investigated to probe the understanding and diagnosis of neurodegenerative disorders. Previous reports have demonstrated increased exosomal α-synuclein (α-syn) in patients with Parkinson’s disease (PD) in comparison to healthy controls (HC). Interestingly, the cholinergic loss was revealed in the central and peripheral nervous systems in histopathology and molecular neuroimaging. Thereby, we simultaneously examined acetylcholinesterase (AChE) with α-syn as exosomal markers. Exosomes were isolated from the plasma of 34 FP-CIT PET proven patients with PD and 29 HC. Exosomal α-syn and AChE activity were quantified andthe relationship with clinical parameters was analyzed. Remarkably, exosomal AChE activity was significantly decreased in PD compared to HC (P = 0.002). Moreover, exosomal AChE activity in PD revealed a strong negative correlation with disease severity, including H&amp;Y (P = 0.007) and UPDRS part III (P = 0.047) scores. By contrast, no significant difference in exosomal α-syn concentration was observed between groups. These results support the occurrence of cholinergic dysfunction in PD, and they could be implicated with disease progression, especially motor deficits. Exosomal AChE activity with advanced exosome isolation techniques may be a reliable biomarker for the early diagnosis and prognosis of PD