scholarly journals Dendritic spines are lost in clusters in patients with Alzheimer’s disease

2020 ◽  
Author(s):  
Mite Mijalkov ◽  
Giovanni Volpe ◽  
Isabel Fernaud-Espinosa ◽  
Javier DeFelipe ◽  
Joana B. Pereira ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dendritic Spines ◽  
Neurodegenerative Disorder ◽  
Pyramidal Cells ◽  
Memory Deficits ◽  
Memory Storage ◽  
Excitatory Synapses ◽  
Tau Pathology ◽  
Insight Into

SUMMARYAlzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by a deterioration of neuronal connectivity. The pathological accumulation of tau protein in neurons is one of the hallmarks of AD and has been connected to the loss of dendritic spines of pyramidal cells, which are the major targets of cortical excitatory synapses and key elements in memory storage. However, the detailed mechanisms underlying the loss of dendritic spines in patients with AD are still unclear. Here, comparing dendrites with and without tau pathology of AD patients, we show that the presence of tau pathology determines the loss of dendritic spines in blocks, ruling out alternative models where spine loss occurs randomly. Since memory storage has been associated with synaptic clusters, the present results provide a new insight into the mechanisms by which tau drives synaptic damage in AD, paving the way to memory deficits by altering spine organization.

scholarly journals Dendritic spines are lost in clusters in Alzheimer’s disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mite Mijalkov ◽  
Giovanni Volpe ◽  
Isabel Fernaud-Espinosa ◽  
Javier DeFelipe ◽  
Joana B. Pereira ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Dendritic Spines ◽  
Neurodegenerative Disorder ◽  
Pyramidal Cells ◽  
Memory Deficits ◽  
Memory Storage ◽  
Excitatory Synapses ◽  
Tau Pathology ◽  
Insight Into

AbstractAlzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by a deterioration of neuronal connectivity. The pathological accumulation of tau in neurons is one of the hallmarks of AD and has been connected to the loss of dendritic spines of pyramidal cells, which are the major targets of cortical excitatory synapses and key elements in memory storage. However, the detailed mechanisms underlying the loss of dendritic spines in individuals with AD are still unclear. Here, we used graph-theory approaches to compare the distribution of dendritic spines from neurons with and without tau pathology of AD individuals. We found that the presence of tau pathology determines the loss of dendritic spines in clusters, ruling out alternative models where spine loss occurs at random locations. Since memory storage has been associated with synaptic clusters, the present results provide a new insight into the mechanisms by which tau drives synaptic damage in AD, paving the way to memory deficits through alterations of spine organization.

AADVAC1, AN ACTIVE IMMUNOTHERAPY FOR ALZHEIMER’S DISEASE AND NON ALZHEIMER TAUOPATHIES: AN OVERVIEW OF PRECLINICAL AND CLINICAL DEVELOPMENT

2018 ◽  
pp. 1-7
Author(s):  
P. Novak ◽  
N. Zilka ◽  
M. Zilkova ◽  
B. Kovacech ◽  
R. Skrabana ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tau Protein ◽  
Neurodegenerative Disorder ◽  
Therapeutic Potential ◽  
Phase 1 ◽  
Primary Progressive Aphasia ◽  
Tau Proteins ◽  
Active Immunotherapy ◽  
Tau Pathology

Neurofibrillary tau protein pathology is closely associated with the progression and phenotype of cognitive decline in Alzheimer’s disease and other tauopathies, and a high-priority target for disease-modifying therapies. Herein, we provide an overview of the development of AADvac1, an active immunotherapy against tau pathology, and tau epitopes that are potential targets for immunotherapy. The vaccine leads to the production of antibodies that target conformational epitopes in the microtubule-binding region of tau, with the aim to prevent tau aggregation and spreading of pathology, and promote tau clearance. The therapeutic potential of the vaccine was evaluated in transgenic rats and mice expressing truncated, non mutant tau protein, which faithfully replicate of human tau pathology. Treatment with AADvac1 resulted in reduction of neurofibrillary pathology and insoluble tau in their brains, and amelioration of their deleterious phenotype. The vaccine was highly immunogenic in humans, inducing production of IgG antibodies against the tau peptide in 29/30 treated elderly patients with mild-to-moderate Alzheimer’s. These antibodies were able to recognise insoluble tau proteins in Alzheimer patients’ brains. Treatment with AADvac1 proved to be remarkably safe, with injection site reactions being the only adverse event tied to treatment. AADvac1 is currently being investigated in a phase 2 study in Alzheimer’s disease, and a phase 1 study in non-fluent primary progressive aphasia, a neurodegenerative disorder with a high tau pathology component.

scholarly journals Caffeine consumption during pregnancy accelerates the development of cognitive deficits in offspring in a model of tauopathy

2019 ◽  
Author(s):  
Stefania Zappettini ◽  
Emilie Faivre ◽  
Antoine Ghestem ◽  
Sébastien Carrier ◽  
Luc Buée ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Life ◽  
Pyramidal Cells ◽  
Tau Pathology ◽  
Caffeine Consumption ◽  
Early Life Exposure ◽  
Model Of Alzheimer’S Disease ◽  
Electrophysiological Recordings

AbstractPsychoactive drugs used during pregnancy can affect the development of the brain of offspring, directly triggering neurological disorders or increasing the risk for their occurrence. Caffeine is the most widely consumed psychoactive drug, including during pregnancy. In Wild type mice, early life exposure to caffeine renders offspring more susceptible to seizures. Here, we tested the long-term consequences of early life exposure to caffeine in THY-Tau22 transgenic mice, a model of Alzheimer’s disease-like Tau pathology. Caffeine exposed mutant offspring developed cognitive earlier than water treated mutants. Electrophysiological recordings of hippocampal CA1 pyramidal cells in vitro revealed that early life exposure to caffeine changed the way the glutamatergic and GABAergic drives were modified by the Tau pathology. We conclude that early-life exposure to caffeine affects the Tau phenotype and we suggest that caffeine exposure during pregnancy may constitute a risk-factor for early onset of Alzheimer’s disease-like pathology.

scholarly journals Searching for novel cerebrospinal fluid biomarkers of tau pathology in frontotemporal dementia: an elusive quest

2019 ◽  
Vol 90 (7) ◽  
pp. 740-746 ◽  
Author(s):  
Martha S Foiani ◽  
Claudia Cicognola ◽  
Natalia Ermann ◽  
Ione O C Woollacott ◽  
Carolin Heller ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Frontotemporal Dementia ◽  
Neurodegenerative Disorder ◽  
The Novel ◽  
Tau Pathology ◽  
Total Tau ◽  
Significant Difference ◽  
T Tau

BackgroundFrontotemporal dementia (FTD) is a pathologically heterogeneous neurodegenerative disorder associated usually with tau or TDP-43 pathology, although some phenotypes such as logopenic variant primary progressive aphasia are more commonly associated with Alzheimer’s disease pathology. Currently, there are no biomarkers able to diagnose the underlying pathology during life. In this study, we aimed to investigate the potential of novel tau species within cerebrospinal fluid (CSF) as biomarkers for tau pathology in FTD.Methods86 participants were included: 66 with a clinical diagnosis within the FTD spectrum and 20 healthy controls. Immunoassays targeting tau fragments N-123, N-mid-region, N-224 and X-368, as well as a non-phosphorylated form of tau were measured in CSF, along with total-tau (T-tau) and phospho-tau (P-tau(181)). Patients with FTD were grouped based on their Aβ42 level into those likely to have underlying Alzheimer’s disease (AD) pathology (n=21) and those with likely frontotemporal lobar degeneration (FTLD) pathology (n=45). The FTLD group was then subgrouped based on their underlying clinical and genetic diagnoses into those with likely tau (n=7) or TDP-43 (n=18) pathology.ResultsSignificantly higher concentrations of tau N-mid-region, tau N-224 and non-phosphorylated tau were seen in both the AD group and FTLD group compared with controls. However, none of the novel tau species showed a significant difference between the AD and FTLD groups, nor between the TDP-43 and tau pathology groups. In a subanalysis, normalising for total-tau, none of the novel tau species provided a higher sensitivity and specificity to distinguish between tau and TDP-43 pathology than P-tau(181)/T-tau, which itself only had a sensitivity of 61.1% and specificity of 85.7% with a cut-off of <0.109.ConclusionsDespite investigating multiple novel CSF tau fragments, none show promise as an FTD biomarker and so the quest for in vivo markers of FTLD-tau pathology continues.

scholarly journals Effect of plant extracts on Alzheimer’s disease: An insight into therapeutic avenues

2011 ◽  
Vol 02 (01) ◽  
pp. 056-061 ◽  
Author(s):  
M Obulesu ◽  
Dowlathabad Muralidhara Rao
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Treatment Options ◽  
Ache Inhibition ◽  
Melissa Officinalis ◽  
Lemon Balm ◽  
Aggregation Effect ◽  
Insight Into ◽  
Maidenhair Tree

ABSTRACTAlzheimer’s disease (AD) is a devastative neurodegenerative disorder which needs adequate studies on effective treatment options. The extracts of plants and their effect on the amelioration of AD symptoms have been extensively studied. This paper summarizes the mechanisms like acetylcholinesterase (AChE) inhibition, modifi cation of monoamines, antiamyloid aggregation effect, and antioxidant activity which are actively entailed in the process of amelioration of AD symptoms. These effects are induced by extracts of a few plants of different origin like Yizhi Jiannao, Moringaoleifera (Drumstick tree), Ginkgo Biloba (Ginkgo/Maidenhair tree), Cassia obtisufolia (Sicklepod), Desmodium gangeticum (Sal Leaved Desmodium), Melissa officinalis (Lemon Balm), and Salvia officinalis (Garden sage, common sage).

scholarly journals Long Non-coding RNA: Insight Into Mechanisms of Alzheimer's Disease

2022 ◽  
Vol 14 ◽  
Author(s):  
Zhen Lan ◽  
Yanting Chen ◽  
Jiali Jin ◽  
Yun Xu ◽  
Xiaolei Zhu
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Vital Role ◽  
Biological Functions ◽  
Non Coding Rna ◽  
Non Coding Rnas ◽  
Long Non Coding Rna ◽  
Insight Into

Alzheimer's disease (AD), a heterogeneous neurodegenerative disorder, is the most common cause of dementia accounting for an estimated 60–80% of cases. The pathogenesis of AD remains unclear, and no curative treatment is available so far. Increasing evidence has revealed a vital role of non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), in AD. LncRNAs contribute to the pathogenesis of AD via modulating amyloid production, Tau hyperphosphorylation, mitochondrial dysfunction, oxidative stress, synaptic impairment and neuroinflammation. This review describes the biological functions and mechanisms of lncRNAs in AD, indicating that lncRNAs may provide potential therapeutic targets for the diagnosis and treatment of AD.

Apolipoprotein E and Alzheimer's Disease: Findings, Hypotheses, and Potential Mechanisms

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Nicole Koutsodendris ◽  
Maxine R. Nelson ◽  
Antara Rao ◽  
Yadong Huang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Late Onset ◽  
Amyloid Β ◽  
Annual Review ◽  
Complex Nature ◽  
Publication Date ◽  
Molecular Processes ◽  
Tau Pathology

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder that involves dysregulation of many cellular and molecular processes. It is notoriously difficult to develop therapeutics for AD due to its complex nature. Nevertheless, recent advancements in imaging technology and the development of innovative experimental techniques have allowed researchers to perform in-depth analyses to uncover the pathogenic mechanisms of AD. An important consideration when studying late-onset AD is its major genetic risk factor, apolipoprotein E4 (apoE4). Although the exact mechanisms underlying apoE4 effects on AD initiation and progression are not fully understood, recent studies have revealed critical insights into the apoE4-induced deficits that occur in AD. In this review, we highlight notable studies that detail apoE4 effects on prominent AD pathologies, including amyloid-β, tau pathology, neuroinflammation, and neural network dysfunction. We also discuss evidence that defines the physiological functions of apoE and outlines how these functions are disrupted in apoE4-related AD. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Receptor-Interacting Protein Kinase 1 (RIPK1) as a Potential Therapeutic Target: An Overview of Its Possible Role in the Pathogenesis of Alzheimer's Disease

2019 ◽  
Vol 16 (10) ◽  
pp. 907-918
Author(s):  
Hong Hao Chan ◽  
Rhun Yian Koh ◽  
Chooi Ling Lim ◽  
Chee Onn Leong
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Kinase ◽  
Neurodegenerative Disorder ◽  
Psychiatric Symptoms ◽  
Current Treatment ◽  
Interacting Protein ◽  
Amyloid Aβ ◽  
Cognition Impairment ◽  
Insight Into

Alzheimer’s Disease (AD) is an age-dependent neurodegenerative disorder, the most common type of dementia that is clinically characterized by the presence of beta-amyloid (Aβ) extracellularly and intraneuronal tau protein tangles that eventually leads to the onset of memory and cognition impairment, development of psychiatric symptoms and behavioral disorders that affect basic daily activities. Current treatment approved by the U.S Food and Drug Administration (FDA) for AD is mainly focused on the symptoms but not on the pathogenesis of the disease. Recently, receptor-interacting protein kinase 1 (RIPK1) has been identified as a key component in the pathogenesis of AD through necroptosis. Furthermore, genetic and pharmacological suppression of RIPK1 has been shown to revert the phenotype of AD and its mediating pathway is yet to be deciphered. This review is aimed to provide an overview of the pathogenesis and current treatment of AD with the involvement of autophagy as well as providing a novel insight into RIPK1 in reverting the progression of AD, probably through an autophagy machinery.

Role of TREM2 in Alzheimer's Disease and its Consequences on β- Amyloid, Tau and Neurofibrillary Tangles

2020 ◽  
Vol 16 (13) ◽  
pp. 1216-1229 ◽  
Author(s):  
Anurag K. Singh ◽  
Gaurav Mishra ◽  
Anand Maurya ◽  
Rajendra Awasthi ◽  
Komal Kumari ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Tau Pathology ◽  
Functional Roles ◽  
Age Related ◽  
Β Amyloid ◽  
The Impact ◽  
Neuronal Stress

: Alzheimer's Disease (AD) is age-related neurodegenerative disorder recognized by a steadily gradual cognitive decline that has devastating personal and socioeconomic implications. Recently, some genetic factors for AD have been identified which attracted wide attention of researchers in different areas of AD biology and possible new therapeutic targets. Alternative forms of triggering receptor expressed on myeloid cells 2 (TREM2) genes are examples of such risk factors, which contribute higher risk for developing AD. Comprehending TREM2 function pledge to provide salient insight into how neuroinflammation contributes to AD pathology. The dearth of microglial TREM2 shepherd to augmented tau pathology is couple with frequent enhancement of activated neuronal stress kinases. The involvement of TREM2 in the regulation of tau-associated innate immune response of the CNS has clearly demonstrated through these findings. However, whether decrease level of TREM2 assists pathology of tau through changed clearance and pathological escalation of tau or through direct contact between microglia and neuron and any alternative possible mechanisms need to examine. This review briefly summarizes distinct functional roles of TREM2 in AD pathology and highlights the TREM2 gene regulation. We have also addressed the impact of TREM2 on β-amyloid plaques and tau pathology in Alzheimer’s disease.

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