Re-evaluation of neuronal P2X7 expression using novel mouse models and a P2X7-specific nanobody.

The P2X7 channel is involved in the pathogenesis of various CNS diseases. An increasing number of studies suggest its presence in neurons where its putative functions remain controversial for more than a decade. To resolve this issue and to provide a model for analysis of P2X7 functions, we generated P2X7 BAC transgenic mice that allow visualization of functional EGFP-tagged P2X7 receptors .

Endogenous Apolipoprotein E (ApoE) Fragmentation Is Linked to Amyloid Pathology in Transgenic Mouse Models of Alzheimer's Disease.

The epsilon 4 allele of the apolipoprotein E (ApoE4) gene is the most important risk factor implicated in Alzheimer's disease (AD) etiology. ApoE4 is more susceptible to proteolysis, and ApoE fragments have been shown to promote tau hyperphosphorylation and exert neurotoxic properties. While a plethora of studies deals with the effect of ApoE and its fragments on amyloid-β peptide (Aβ) deposition and clearance, it is largely unknown whether Aβ in turn influences human or murine ApoE expression and its proteolysis.

Heteromeric assembly of P2X subunits.

Transcripts and/or proteins of P2X receptor (P2XR) subunits have been found in virtually all mammalian tissues. Generally more than one of the seven known P2X subunits have been identified in a given cell type. Six of the seven cloned P2X subunits can efficiently form functional homotrimeric ion channels in recombinant expression systems.

Accelerated tau pathology with synaptic and neuronal loss in a novel triple transgenic mouse model of Alzheimer's disease.

There is pivotal evidence that tau pathology can be triggered by amyloid-β (Aβ) pathology in experimental systems. On the other side, studies on human brain specimen have elucidated that tau pathology may occur before amyloid pathology is present indicating that in principle tau pathology could also trigger Aβ aggregation. To address this question, we have crossed 5XFAD mice coexpressing human mutant APP695 with the Swedish, Florida, and London mutations and human mutant presenilin-1 (PS1) with the M146L and L286V mutations with the PS19 model overexpressing human mutant tau with the P301S mutation.

Abundant pyroglutamate-modified ABri and ADan peptides in extracellular and vascular amyloid deposits in familial British and Danish dementias.

Familial British and familial Danish dementia (FDD) are progressive neurodegenerative disorders characterized by cerebral deposition of the amyloidogenic peptides ABri and ADan, respectively. These amyloid peptides start with an N-terminal glutamate residue, which can be posttranslationally converted into a pyroglutamate (pGlu) modified form, a mechanism which has been extensively described to be relevant for amyloid-beta (Aβ) peptides in Alzheimer's disease. Like pGlu-Aβ peptides, pGlu-ABri peptides have an increased aggregation propensity and show higher toxicity on human neuroblastoma cells as their nonmodified counterparts.