Assembly of α-synuclein and neurodegeneration in the central nervous system of heterozygous M83 mice following the peripheral administration of α-synuclein seeds.

Peripheral administration (oral, intranasal, intraperitoneal, intravenous) of assembled A53T α-synuclein induced synucleinopathy in heterozygous mice transgenic for human mutant A53T α-synuclein (line M83). The same was the case when cerebellar extracts from a case of multiple system atrophy with type II α-synuclein filaments were administered intraperitoneally, intravenously or intramuscularly. We observed abundant immunoreactivity for pS129 α-synuclein in nerve cells and severe motor impairment, resulting in hindlimb paralysis and shortened lifespan.

Synthesis and Assessment of Novel Probes for Imaging Tau Pathology in Transgenic Mouse and Rat Models.

Aggregated tau protein is a core pathology present in several neurodegenerative diseases. Therefore, the development and application of positron emission tomography (PET) imaging radiotracers that selectively bind to aggregated tau in fibril form is of importance in furthering the understanding of these disorders. While radiotracers used in human PET studies offer invaluable insight, radiotracers that are also capable of visualizing tau fibrils in animal models are important tools for translational research into these diseases.

Neuropathological changes and cognitive deficits in rats transgenic for human mutant tau recapitulate human tauopathy.

The assembly of tau protein into abnormal filaments and brain cell degeneration are characteristic of a number of human neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia and parkinsonism linked to chromosome 17. Several murine models have been generated to better understand the mechanisms contributing to tau assembly and neurodegeneration. Taking advantage of the more elaborate central nervous system and higher cognitive abilities of the rat, we generated a model expressing the longest human tau isoform (2N4R) with the P301S mutation.

Assembly of transgenic human P301S Tau is necessary for neurodegeneration in murine spinal cord.

A pathological pathway leading from soluble monomeric to insoluble filamentous Tau is characteristic of many human neurodegenerative diseases, which also exhibit dysfunction and death of brain cells. However, it is unknown how the assembly of Tau into filaments relates to cell loss. To study this, we first used a mouse line transgenic for full-length human mutant P301S Tau to investigate the temporal relationship between Tau assembly into filaments, assessed using anti-Tau antibody AT100, and motor neuron numbers, in the lumbar spinal cord.

Analysis of mouse brain microvascular endothelium using laser capture microdissection coupled with proteomics.

The blood-brain barrier (BBB) has been well studied in terms of its pharmacological properties. However, for a better understanding of the molecular mechanisms regulating these activities, means to thoroughly investigate the BBB at the genomic and proteomic levels are essential. Global gene expression analysis platforms have, in fact, provided a venue for cataloguing the BBB transcriptome.

Endothelial cell heterogeneity of blood-brain barrier gene expression along the cerebral microvasculature.

The blood-brain barrier (BBB) refers to the network of microvessels that selectively restricts the passage of substances between the circulation and the central nervous system (CNS). This microvascular network is comprised of arterioles, capillaries and venules, yet the respective contribution of each of these to the BBB awaits clarification. In this regard, it has been postulated that brain microvascular endothelial cells (BMEC) from these different tributaries might exhibit considerable heterogeneity in form and function, with such diversity underlying unique roles in physiological and pathophysiological processes.

Validation of immuno-laser capture microdissection coupled with quantitative RT-PCR to probe blood-brain barrier gene expression in situ.

Laser capture microdissection (LCM) holds great potential for analyzing gene expression profiles in situ. Most recently, this laboratory employed a novel immunostain-based LCM protocol (immuno-LCM) to selectively retrieve brain microvascular endothelial cells (BMEC) from intimately associated perivascular cells. However, before this protocol can be confidently coupled to downstream analytical platforms, it must be demonstrated that any variability associated with it is minimal, so as not to obscure data interpretation.

Analysis of mouse brain microvascular endothelium using immuno-laser capture microdissection coupled to a hybrid linear ion trap with Fourier transform-mass spectrometry proteomics platform.

The purpose of this study was to identify the protein profile of the mouse brain microvascular endothelium in situ. This involved coupling of a double-label, immuno-laser capture microdissection (LCM) process with LTQ-FT mass spectrometry to perform the in situ proteomic analysis. LCM was utilized to isolate cells from frozen mouse brain tissue sections.