Clavaguera Florence

• University of Basel

Microduplications of the 17q21.31 chromosomal region encompassing the MAPT gene, which encodes the Tau protein, were identified in patients with a progressive disorder initially characterized by severe memory impairment with or without behavioral changes that can clinically mimic Alzheimer disease. The unique neuropathological report showed a prima...

Background Granulovacuolar degeneration bodies (GVBs) are membrane‐bound vacuolar structures harboring a dense core that accumulate in the brains of patients with neurodegenerative disorders, including Alzheimer’s disease and other tauopathies. Insight into the origin of GVBs and their connection to tau pathology has been limited by the lack of sui...

Granulovacuolar degeneration bodies (GVBs) are membrane-bound vacuolar structures harboring a dense core that accumulate in the brains of patients with neurodegenerative disorders, including Alzheimer’s disease and other tauopathies. Insight into the origin of GVBs and their connection to tau pathology has been limited by the lack of suitable exper...

Tauopathies constitute neurodegenerative diseases that are characterized by the intracellular deposition of filaments made of hyperphosphorylated tau protein. The pattern of tau deposition in Alzheimer's disease follows a stereotypical progression, with the first lesions appearing in the locus coeruleus and entorhinal cortex, from where they appear...

Abundant tau inclusions are a defining hallmark of several human neurodegenerative diseases, including Alzheimer's disease. Protein fragmentation is a widely observed event in neurodegenerative proteinopathies. The relevance of tau fragmentation for the neurodegenerative process in tauopathies has yet remained unclear. Here we found that co-express...

Early diagnosis of Alzheimer`s disease (AD) is currently difficult and involves a complex approach including clinical assessment, neuroimaging, and measurement of amyloid-β (Aβ) and tau levels in cerebrospinal fluid (CSF). A better mechanistic understanding is needed to develop more accurate and even presymptomatic diagnostic tools. It has been sho...

Early diagnosis of Alzheimer`s disease (AD) iscurrently difficult and involves acomplex approach including clinical assessment, neuroimaging, and measurement of amyloid-β (Aβ) and tau levelsin cerebrospinal fluid (CSF). A better mechanistic understanding is needed to develop more accurate and even presymptomatic diagnostic tools. It has been shown...

Neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, are characterized by the abnormal aggregation of a small number of intracellular proteins, with tau and α-synuclein being the most commonly affected. Until recently, the events leading to aggregate formation were believed to be entirely cell-autonomous, with protein...

Filaments made of hyperphosphorylated tau protein are encountered in a number of neurodegenerative diseases referred to as “tauopathies”. In the most prevalent tauopathy, Alzheimer's disease, tau pathology progresses in a stereotypical manner with the first lesions appearing in the locus coeruleus and the entorhinal cortex from where they appear to...

Intracellular inclusions composed of hyperphosphorylated filamentous tau are a hallmark of Alzheimer’s disease, progressive supranuclear palsy, Pick’s disease and other sporadic neurodegenerative tauopathies. Recent in vitro and in vivo studies have shown that tau aggregates do not only seed further tau aggregation within neurons, but can also spre...

Filaments made of hyperphosphorylated tau protein are encountered in a group of neurodegenerative disorders termed tauopathies. The most prevalent tauopathy, Alzheimer's disease (AD), additionally presents with extracellular deposits of the amyloid-β peptide (Aβ). Current symptomatic treatments have shown short term benefits in reducing cognitive s...

Filamentous inclusions made of hyperphosphorylated tau are characteristic of numerous human neurodegenerative diseases, including Alzheimer's disease, tangle-only dementia, Pick disease, argyrophilic grain disease (AGD), progressive supranuclear palsy, and corticobasal degeneration. In Alzheimer's disease and AGD, it has been shown that filamentous...

Altered autophagy contributes to the pathogenesis of Alzheimer's disease and other tauopathies, for which curative treatment options are still lacking. We have recently shown that trehalose reduces tau pathology in a tauopathy mouse model by stimulation of autophagy. Here, we studied the effect of the autophagy inducing drug rapamycin on the progre...

Intraperitoneal rapamycin administration resulted in high cerebral rapamycin levels as measured by HPLC. Similar levels were achieved in the forebrain and the brain stem (A; B6 1.5 WT; FB = forebrain, BS: brain stem, BL: blood). Consistent with cerebral mTOR inhibition, Western blotting of forebrain tissue showed significantly reduced phosphorylati...

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Forebrain levels of soluble tau protein remained unchanged after both, 5 months or 6 weeks of rapamycin treatment (A; 5 MT, p = 0.35; 6 WT, p = 0.18). We also analyzed the immediate effects of a short rapamycin treatment of 1.5 weeks duration on forebrain tau levels in pretangle P301S mice. There again was no reduction of soluble tau by rapamycin t...

For the qualitative assessment of astrogliosis in long-term rapamycin treated mice, blinded sets comprising every 5th 20 µm section of 5MT mice were rated from – (A), + (B), ++ (C) to +++ (D) by three independent raters (S.O., K.B., D.W.). The median rating of the GFAP stainings of all sections was listed per brain region and mouse for a qualitativ...

Scheme of the study indicating the treatment schedules of the different groups of rapamycin (R) or vehicle (V) treated P301S mutant tau transgenic mice and non-transgenic C57BL/6J mice. P301S mice were treated twice weekly intraperitoneally with 15 mg rapamycin per kg body weight or vehicle from 3 weeks to 5.5 months of age (group 5-months treatmen...

The soluble microtubule-associated protein tau forms hyperphosphorylated, insoluble and filamentous inclusions in a number of neurodegenerative diseases referred to as "tauopathies." In Alzheimer's disease, tau pathology develops in a stereotypical manner, with the first lesions appearing in the locus coeruleus and entorhinal cortex, from where the...

The soluble microtubule-associated protein tau becomes hyperphosphorylated, insoluble and filamentous in a number of neurodegenerative diseases collectively referred to as tauopathies. In Alzheimer’s disease (AD), tau pathology develops in a stereotypical manner, with the first lesions appearing in the locus coeruleus and the transentorhinal cortex...

The most common neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, are characterized by the misfolding of a small number of proteins that assemble into ordered aggregates in affected brain cells. For many years, the events leading to aggregate formation were believed to be entirely cell-autonomous, with protein misfo...

Hyperphosphorylated tau makes up the filamentous intracellular inclusions of several neurodegenerative diseases, including Alzheimer's disease. In the disease process, neuronal tau inclusions first appear in the transentorhinal cortex from where they seem to spread to the hippocampal formation and neocortex. Cognitive impairment becomes manifest wh...

In this study, we aimed to investigate the interaction between amyloid- and Tau-associated pathologies to gain further insights into the development of Alzheimer's disease. We examined the formation of neurofibrillary tangles (NFT) in adult mouse brain without the prior overexpression of Tau at embryonic or early post-natal stages to dissociate any...

Much of our current understanding of the pathogenic mechanisms in human neurodegenerative disorders has been derived from animal studies. As such, transgenic mouse models have significantly contributed to the development of novel pathogenic concepts underlying human tauopathies, a group of diseases comprising various forms of neurodegenerative diso...

Alzheimer's disease presents morphologically with senile plaques, primarily made of extracellular amyloid-beta (A beta) deposits, and neurofibrillary lesions, which consist of intracellular aggregates of hyperphosphorylated tau protein. To study the in vivo induction of tau pathology, dilute brain extracts from aged A beta-depositing APP23 transgen...

Argyrophilic grain disease (AgD) is a late-onset dementia morphologically characterized by the presence of abundant spindle-shaped argyrophilic grains (ArG) in neuronal processes and coiled bodies in oligodendrocytes. AgD changes consist of the microtubule-associated protein tau in an abnormally and hyperphosphorylated state and are mainly found in...

Argyrophilic grain disease (AgD) is a four-repeat tauopathy that is almost exclusively restricted to allocortical areas. Progressive supranuclear palsy and corticobasal degeneration also show predominant deposition of four-repeat tau filaments, and are associated with the tau H1 haplotype. We investigated a possible association between AgD and the...