Development of P301S tau seeded organotypic hippocampal slice cultures to study potential therapeutics

Abstract

Intracellular tau inclusions are a pathological hallmark of Alzheimer's disease, progressive supranuclear palsy, corticobasal degeneration and other sporadic neurodegenerative tauopathies. Recent in vitro and in vivo studies have shown that tau aggregates may spread to neighbouring cells and functionally connected brain regions, where they can seed further tau aggregation. This process is referred to as tau propagation. Here we describe an ex vivo system using organotypic hippocampal slice cultures (OHCs) which recapitulates aspects of this phenomenon. OHCs are explants of hippocampal tissue which may be maintained in culture for months. They maintain their synaptic connections and multicellular 3D architecture whilst also permitting direct control of the environment and direct access for various analysis types. We inoculated OHCs prepared from P301S mouse pups with brain homogenate from terminally ill P301S mice and then examined the slices for viability and the production and localization of insoluble phosphorylated tau. We show that following seeding, phosphorylated insoluble tau accumulate in a time and concentration dependent manner within OHCs. Furthermore, we show the ability of the conformation dependent anti-tau antibody, MC1, to compromise tau accrual in OHCs, thus showcasing the potential of this therapeutic approach and the utility of OHCs as an ex vivo model system for assessing such therapeutics.

Spreading of P301S Aggregated Tau Investigated in Organotypic Mouse Brain Slice Cultures

“…Moreover, slice cultures have been employed to explore the prion-like propagation of Aβ and tau [ 42 , 43 , 44 ]. Recently, our group has explored the spreading of Aβ and α-Syn using organotypic coronal and sagittal slices, respectively, from wild-type and transgenic mice in an effort to model the transmission of these proteins [ 17 , 45 ].…”

A Combination of Heavy Metals and Intracellular Pathway Modulators Induces Alzheimer Disease-like Pathologies in Organotypic Brain Slices

“…Cells and synapses develop in a manner comparable to the in vivo environment [14]. This system allows direct and repeated manipulation, including the addition of exogenous compounds to the medium or application of collagen hydrogels to achieve a slow, localized protein or peptide release [15][16][17][18][19]. The absence of a blood-brain barrier permits direct investigation of the effects of toxic or therapeutic compounds [20].…”

“…The prion hypothesis postulates systemic aggregation and propagation of Aβ and tau pathologies via interconnected pathways, akin to prion protein transmission [38][39][40][41][42]. Slice cultures have been used to study this pathology transmission [16,17]. Our prior research on postnatal WT animals showed increased spreading of P301S aggregated tau (aggTau) to the ventral areas of slices via neuroanatomically connected pathways [15].…”

Three dimensional and four dimensional live imaging to study mechanisms of progressive neurodegeneration

“…In addition, co-cultures of various brain regions including the nigrostriatal circuit ( 119 ), the cortex, and hippocampus ( 114 , 116 ), as well as entire sagittal and coronal organotypic cultures ( 120 ) have been reported, each of which can be used as a model for neurodegenerative disease. Recent work has shown that organotypic cultures can be prepared from aged mice, providing unique insight into aged neurons ( 121 ), and can be seeded with misfolded pathogenic proteins such as tau to study the propagation of misfolded protein throughout the tissue ( 122 ).…”