scholarly journals Trem2 Y38C mutation and loss of Trem2 impairs neuronal synapses in adult mice

2020 ◽  
Author(s):  
Vaishnavi S. Jadhav ◽  
Peter BC. Lin ◽  
Taylor Pennington ◽  
Gonzalo Viana Di Prisco ◽  
Asha Jacob Jannu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Late Onset ◽  
Synaptic Proteins ◽  
Synaptic Protein ◽  
Presenile Dementia ◽  
Altered Expression ◽  
Protein Levels

Abstract Background: Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer’s disease (AD), frontotemporal dementia (FTD) and Nasu Hakola Disease (NHD). The Trem2 variant R47H, confers substantially elevated risk of developing late onset Alzheimer’s disease, while NHD-linked Trem2 variants like Y38C, are associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2 species, predisposes individuals to presenile dementia.Methods: To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38C/Y38C and Trem2-/- mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches.Results: While mice harboring the Trem2 Y38C exhibited normal expression levels of TREM2, the pathological outcomes phenocopied Trem2-/- mice at 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. Conclusion: Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38C and Trem2-/- mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like amyloid. This suggests TREM2 impacts neuronal functions providing molecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.

scholarly journals Trem2 Y38C Mutation and Loss of Trem2 Impairs Neuronal Synapses in Adult Mice

2020 ◽  
Author(s):  
Vaishnavi S. Jadhav ◽  
Peter BC. Lin ◽  
Guixiang Xu ◽  
Taylor Pennington ◽  
Gonzalo Viana Di Prisco ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Late Onset ◽  
Synaptic Proteins ◽  
Synaptic Protein ◽  
Presenile Dementia ◽  
Altered Expression ◽  
Protein Levels

Abstract Background:Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer’s disease (AD), frontotemporal dementia (FTD) and NasuHakola Disease (NHD). The Trem2 variantR47H, confers substantially elevated risk of developing late onset Alzheimer’s disease, while NHD-linkedTrem2 variants like Y38Care associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2species predispose individuals to presenile dementia.Methods:To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function, we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38/Y38C and Trem2-/-mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches.Results:While mice harboring Trem2 Y38C exhibited normal expression levels of Trem2, the pathological outcomes phenocopied Trem2-/- miceat 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. Conclusion:Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38Cand Trem2-/- mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like tau or amyloid. This suggests TREM2 impacts neuronal functions and providesmolecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.

scholarly journals Trem2 Y38C mutation and loss of Trem2 impairs neuronal synapses in adult mice

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Vaishnavi S. Jadhav ◽  
Peter B. C. Lin ◽  
Taylor Pennington ◽  
Gonzalo Viana Di Prisco ◽  
Asha Jacob Jannu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Late Onset ◽  
Synaptic Proteins ◽  
Synaptic Protein ◽  
Presenile Dementia ◽  
Altered Expression ◽  
Protein Levels

Abstract Background Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer’s disease (AD), frontotemporal dementia (FTD) and Nasu Hakola Disease (NHD). The Trem2 variant R47H, confers substantially elevated risk of developing late onset Alzheimer’s disease, while NHD-linked Trem2 variants like Y38C, are associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2 species, predisposes individuals to presenile dementia. Methods To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38C/Y38C and Trem2−/− mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches. Results While mice harboring the Trem2 Y38C exhibited normal expression levels of TREM2, the pathological outcomes phenocopied Trem2−/− mice at 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. Conclusion Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38C and Trem2−/− mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like amyloid. This suggests TREM2 impacts neuronal functions providing molecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.

scholarly journals Gga3 deletion and a GGA3 rare variant associated with late onset Alzheimer’s disease trigger BACE1 accumulation in axonal swellings

2020 ◽  
Vol 12 (570) ◽  
pp. eaba1871
Author(s):  
Selene Lomoio ◽  
Rachel Willen ◽  
WonHee Kim ◽  
Kevin Z. Ho ◽  
Edward K. Robinson ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Rare Variant ◽  
Late Onset ◽  
Early Stage ◽  
Loss Of Function ◽  
Axonal Trafficking ◽  
Axonal Swellings

Axonal dystrophy, indicative of perturbed axonal transport, occurs early during Alzheimer’s disease (AD) pathogenesis. Little is known about the mechanisms underlying this initial sign of the pathology. This study proves that Golgi-localized γ-ear-containing ARF binding protein 3 (GGA3) loss of function, due to Gga3 genetic deletion or a GGA3 rare variant that cosegregates with late-onset AD, disrupts the axonal trafficking of the β-site APP-cleaving enzyme 1 (BACE1) resulting in its accumulation in axonal swellings in cultured neurons and in vivo. We show that BACE pharmacological inhibition ameliorates BACE1 axonal trafficking and diminishes axonal dystrophies in Gga3 null neurons in vitro and in vivo. These data indicate that axonal accumulation of BACE1 engendered by GGA3 loss of function results in local toxicity leading to axonopathy. Gga3 deletion exacerbates axonal dystrophies in a mouse model of AD before β-amyloid (Aβ) deposition. Our study strongly supports a role for GGA3 in AD pathogenesis, where GGA3 loss of function triggers BACE1 axonal accumulation independently of extracellular Aβ, and initiates a cascade of events leading to the axonal damage distinctive of the early stage of AD.

[P3-338]: IN VIVO TAU PET IMAGING IN EARLY-ONSET ALZHEIMER's DISEASE AND LATE-ONSET ALZHEIMER's DISEASE

2017 ◽  
Vol 13 (7S_Part_22) ◽  
pp. P1083-P1083
Author(s):  
Young Noh ◽  
Han Kyu Na ◽  
Seongho Seo ◽  
Sang-Yoon Lee ◽  
Hye Jin Jeong ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pet Imaging ◽  
Early Onset ◽  
Late Onset ◽  
Early Onset Alzheimer’S Disease ◽  
Tau Pet ◽  
Tau Pet Imaging

scholarly journals Abi3 regulates microglial ramification and dynamic tissue surveillance in vivo.

2021 ◽  
Author(s):  
Elena Simonazzi ◽  
Ruth Jones ◽  
Fangli Chen ◽  
Adam Ranson ◽  
Joshua Stevenson-Hoare ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Gene Family ◽  
Family Member ◽  
Late Onset ◽  
Gene Family Member ◽  
Surveillance Activity ◽  
Increased Risk ◽  
Microglial Morphology

A rare coding variant of Abelson-interactor gene family member 3 (Abi3) is associated with increased risk of late-onset Alzheimer's Disease (AD). Although Abi3 is recognised as a core microglial gene, its role in microglia is largely unknown. Here we demonstrate that Abi3 is crucial for normal microglial morphology, distribution, and homeostatic tissue surveillance activity in vivo.

Neurochemical Dissection of Synaptic Pathology in Alzheimer's Disease

1998 ◽  
Vol 10 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Pia Davidsson ◽  
Kaj Blennow
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Frontal Cortex ◽  
Late Onset ◽  
Synaptic Proteins ◽  
Presynaptic Membrane ◽  
Control Value ◽  
Postsynaptic Protein ◽  
Post Mortem Brain ◽  
Synaptic Pathology

Synaptic pathology has attained increasing attention as being central in the pathogenesis of Alzheimer's disease (AD). To address the question whether synaptic pathology in AD involves the whole synapse, or is limited to specific components thereof, we studied three different synaptic vesicle proteins (rab3a, synaptotagmin, synaptophysin) and also the presynaptic membrane protein GAP-43 and the postsynaptic protein neurogranin. The material included post-mortem brain tissue (frontal cortex, hippocampus, and cerebellum) from 8 patients with early-onset AD (EAD), 11 patients with late-onset AD (LAD), 6 patients with vascular dementia (VAD), and 9 control subjects. A reduction of all synaptic proteins was found in AD, more pronounced in EAD than in LAD, in both the frontal cortex (EAD 30% to 70% vs. LAD 82% to 88% of control value) and hippocampus (EAD 22% to 82% vs. LAD 76% to 89% of control value), whereas only minor changes were found in VAD. The finding that all synaptic proteins were reduced in AD suggests a degeneration and loss of whole synaptic elements that are more pronounced in EAD than in LAD.

scholarly journals Systemic delivery of a specific antibody targeting the pathological N-terminal truncated tau peptide reduces retinal degeneration in a mouse model of Alzheimer’s Disease

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Valentina Latina ◽  
Giacomo Giacovazzo ◽  
Federica Cordella ◽  
Bijorn Omar Balzamino ◽  
Alessandra Micera ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Retinal Degeneration ◽  
Amyloid Β ◽  
Synaptic Proteins ◽  
Ocular Injury ◽  
Human Beings ◽  
Systemic Delivery ◽  
Model Of Alzheimer’S Disease

AbstractRetina and optic nerve are sites of extra-cerebral manifestations of Alzheimer’s Disease (AD). Amyloid-β (Aβ) plaques and neurofibrillary tangles of hyperphosphorylated tau protein are detected in eyes from AD patients and transgenic animals in correlation with inflammation, reduction of synapses, visual deficits, loss of retinal cells and nerve fiber. However, neither the pathological relevance of other post-translational tau modifications—such as truncation with generation of toxic fragments—nor the potential neuroprotective action induced by their in vivo clearance have been investigated in the context of AD retinal degeneration. We have recently developed a monoclonal tau antibody (12A12mAb) which selectively targets the neurotoxic 20–22 kDa NH2-derived peptide generated from pathological truncation at the N-terminal domain of tau without cross-reacting with its full-length normal protein. Previous studies have shown that 12A12mAb, when intravenously (i.v.)-injected into 6-month-old Tg2576 animals, markedly improves their AD-like, behavioural and neuropathological syndrome. By taking advantage of this well-established tau-directed immunization regimen, we found that 12A12mAb administration also exerts a beneficial action on biochemical, morphological and metabolic parameters (i.e. APP/Aβ processing, tau hyperphosphorylation, neuroinflammation, synaptic proteins, microtubule stability, mitochondria-based energy production, neuronal death) associated with ocular injury in the AD phenotype. These findings prospect translational implications in the AD field by: (1) showing for the first time that cleavage of tau takes part in several pathological changes occurring in vivo in affected retinas and vitreous bodies and that its deleterious effects are successfully antagonized by administration of the specific 12A12mAb; (2) shedding further insights on the tight connections between neurosensory retina and brain, in particular following tau-based immunotherapy. In our view, the parallel response we detected in this preclinical animal model, both in the eye and in the hippocampus, following i.v. 12A12mAb injection opens novel diagnostic and therapeutic avenues for the clinical management of cerebral and extracerebral AD signs in human beings.

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