Generation of three isogenic, gene-edited iPSC lines carrying the APOE-Christchurch mutation into the three common APOE variants: APOE2Ch, APOE3Ch and APOE4Ch.

Late-onset Alzheimer's disease (AD) has become the paradigm of a non-mendelian complex neurodegenerative disease, for which a major genetic determinant is known, the APOE locus. A rare APOE variant named Christchurch (APOEch) yielding a missense mutation from Arginine to Serine at amino acid 136, has been suggested to exert a protective effect in an individual carrying the most penetrant form of Familial AD (Paisa mutation in PSEN1 gene, E280A). We describe here a new set of induced pluripotent stem cell (iPSC) lines, where the Christchurch mutation (Ch) has been introduced by gene editing into the APOE locus of three isogenic iPSC lines carrying the more common APOE variants (APOE 2/2, APOE 3/3, and an APOE 4/4) in homozygosity.

IP-LC-MSMS Enables Identification of Three Tau -GlcNAcylation Sites as -GlcNAcase Inhibition Pharmacodynamic Readout in Transgenic Mice Overexpressing Human Tau.

-β-linked -acetylglucosaminylation (-GlcNAcylation) modulates tau phosphorylation and aggregation: the pharmacological increase of tau -GlcNAcylation upon treatment with inhibitors of -GlcNAc hydrolase (OGA) constitutes a potential strategy to tackle neurodegenerative diseases. Analysis of tau -GlcNAcylation could potentially be used as a pharmacodynamic biomarker both in preclinical and clinical studies. The goal of the current study was to confirm tau -GlcNAcylation at S400 as a pharmacodynamic readout of OGA inhibition in P301S transgenic mice overexpressing human tau and treated with the OGA inhibitor Thiamet G and to explore if additional -GlcNAcylation sites on tau could be identified.

Scalable expansion of iPSC and their derivatives across multiple lineages.

Induced pluripotent stem cell (iPSC) technology enabled the production of pluripotent stem cell lines from somatic cells from a range of known genetic backgrounds. Their ability to differentiate and generate a wide variety of cell types has resulted in their use for various biomedical applications, including toxicity testing. Many of these iPSC lines are now registered in databases and stored in biobanks such as the European Bank for induced pluripotent Stem Cells (EBiSC), which can streamline the quality control and distribution of these individual lines.

Pharmacological characterization of mutant huntingtin aggregate-directed PET imaging tracer candidates.

Huntington's disease (HD) is caused by a CAG trinucleotide repeat expansion in the first exon of the huntingtin (HTT) gene coding for the huntingtin (HTT) protein. The misfolding and consequential aggregation of CAG-expanded mutant HTT (mHTT) underpin HD pathology. Our interest in the life cycle of HTT led us to consider the development of high-affinity small-molecule binders of HTT oligomerized/amyloid-containing species that could serve as either cellular and in vivo imaging tools or potential therapeutic agents.

Development of a fully human assay combining NGN2-inducible neurons co-cultured with iPSC-derived astrocytes amenable for electrophysiological studies.

Neurogenin 2 encodes a neural-specific transcription factor (NGN2) able to drive neuronal fate on somatic and stem cells. NGN2 is expressed in neural progenitors within the developing central and peripheral nervous systems. Overexpression of NGN2 in human induced pluripotent stem cells (hiPSCs) or human embryonic stem cells has been shown to efficiently trigger conversion to neurons.

SOX9-induced Generation of Functional Astrocytes Supporting Neuronal Maturation in an All-human System.

Astrocytes, the main supportive cell type of the brain, show functional impairments upon ageing and in a broad spectrum of neurological disorders. Limited access to human astroglia for pre-clinical studies has been a major bottleneck delaying our understanding of their role in brain health and disease. We demonstrate here that functionally mature human astrocytes can be generated by SOX9 overexpression for 6 days in pluripotent stem cell (PSC)-derived neural progenitor cells.

Generation of two gene edited iPSC-lines carrying a DOX-inducible NGN2 expression cassette with and without GFP in the AAVS1 locus.

Neurog2 is the gene encoding the neuronal transcription factor NGN2, which can convert stem cells into functional neurons in a fast and efficient way. Here we report the generation of two iPS cell lines, where DOX inducible constructs of neurog2 either without or with T2A-eGFP were inserted into the safe-site locus AAVS1. These iPS cell lines, BIONi010-C-13 and BIONi010-C-15, respectively, stay pluripotent without DOX but differentiate to (GFP positive) neurons when DOX is added without the need of differentiation factors.

Generation of a set of isogenic iPSC lines carrying all APOE genetic variants (Ɛ2/Ɛ3/Ɛ4) and knock-out for the study of APOE biology in health and disease.

APOE genotype is the strongest genetic risk factor for Alzheimer's Disease (AD). The low degree of homology between mouse and human APOE is a concerning issue in preclinical models currently used to study the role of this gene in AD pathophysiology. A key objective of ADAPTED (Alzheimer's Disease Apolipoprotein Pathology for Treatment Elucidation and Development) project was to generate in vitro models that better recapitulate human APOE biology.

Diazaspirononane Nonsaccharide Inhibitors of O-GlcNAcase (OGA) for the Treatment of Neurodegenerative Disorders.

O-GlcNAcylation is a post-translational modification of tau understood to lower the speed and yield of its aggregation, a pathological hallmark of Alzheimer's disease (AD). O-GlcNAcase (OGA) is the only enzyme that removes O-linked -acetyl-d-glucosamine (O-GlcNAc) from target proteins. Therefore, inhibition of OGA represents a potential approach for the treatment of AD by preserving the O-GlcNAcylated tau protein.

The EBiSC iPSC bank for disease studies.

The European Bank for induced Pluripotent Stem Cells (EBiSC), a non-profit repository for storage, banking, Quality Control (QC) and subsequent distribution of research-grade human induced Pluripotent Stem Cell (iPSC) lines, has centralised iPSC lines generated internationally across >35 disease areas and made them available to users via the EBiSC Catalogue, for research use (cells.ebisc.org/).

Imaging Mutant Huntingtin Aggregates: Development of a Potential PET Ligand.

Mutant huntingtin (mHTT) protein carrying the elongated N-terminal polyglutamine (polyQ) tract misfolds and forms protein aggregates characteristic of Huntington's disease (HD) pathology. A high-affinity ligand specific for mHTT aggregates could serve as a positron emission tomography (PET) imaging biomarker for HD therapeutic development and disease progression. To identify such compounds with binding affinity for polyQ aggregates, we embarked on systematic structural activity studies; lead optimization of aggregate-binding affinity, unbound fractions in brain, permeability, and low efflux culminated in the discovery of compound , which exhibited target engagement in autoradiography (ARG) studies in brain slices from HD mouse models and postmortem human HD samples.

Deploying human pluripotent stem cells to treat central nervous system disorders: facts, challenges and realising the potential.

Human pluripotent stem cells (hPSC) represent a unique opportunity to study fundamental biological processes in a human- and cell-specific setting. Its translational potential and the impact on human health makes this technology revolutionary. The possibility to generate stem cells from almost any somatic cell, and their capacity to be differentiated in virtually all cells of the body has been demonstrated extensively during the last decade of research.

Small Molecule Binding to Alzheimer Risk Factor CD33 Promotes Aβ Phagocytosis.

Polymorphism in the microglial receptor CD33 gene has been linked to late-onset Alzheimer disease (AD), and reduced expression of the CD33 sialic acid-binding domain confers protection. Thus, CD33 inhibition might be an effective therapy against disease progression. Progress toward discovery of selective CD33 inhibitors has been hampered by the absence of an atomic resolution structure.

Generation of a set of isogenic, gene-edited iPSC lines homozygous for all main APOE variants and an APOE knock-out line.

Alzheimer's disease (AD) is the most frequent neurodegenerative disease amongst the elderly. The SNPs rs429358 and rs7412 in the APOE gene are the most common risk factor for sporadic AD, and there are three different alleles commonly referred to as APOE-ε2, APOE-ε3 and APOE-ε4. Induced pluripotent stem cells (iPSCs) hold great promise to model AD as such cells can be differentiated in vitro to the required cell type.

Genetically Engineered iPSC-Derived FTDP-17 MAPT Neurons Display Mutation-Specific Neurodegenerative and Neurodevelopmental Phenotypes.

Tauopathies such as frontotemporal dementia (FTD) remain incurable to date, partially due to the lack of translational in vitro disease models. The MAPT gene, encoding the microtubule-associated protein tau, has been shown to play an important role in FTD pathogenesis. Therefore, we used zinc finger nucleases to introduce two MAPT mutations into healthy donor induced pluripotent stem cells (iPSCs).

Generation of a human induced pluripotent stem cell-based model for tauopathies combining three microtubule-associated protein TAU mutations which displays several phenotypes linked to neurodegeneration.

Introduction: Tauopathies are neurodegenerative diseases characterized by TAU protein-related pathology, including frontotemporal dementia and Alzheimer's disease among others. Mutant TAU animal models are available, but none of them faithfully recapitulates human pathology and are not suitable for drug screening.

Methods: To create a new in vitro tauopathy model, we generated a footprint-free triple MAPT-mutant human induced pluripotent stem cell line (N279K, P301L, and E10+16 mutations) using clustered regularly interspaced short palindromic repeats-FokI and piggyBac transposase technology.

Systemic immune-checkpoint blockade with anti-PD1 antibodies does not alter cerebral amyloid-β burden in several amyloid transgenic mouse models.

Chronic inflammation represents a central component in the pathogenesis of Alzheimer's disease (AD). Recent work suggests that breaking immune tolerance by Programmed cell Death-1 (PD1) checkpoint inhibition produces an IFN-γ-dependent systemic immune response, with infiltration of the brain by peripheral myeloid cells and neuropathological as well as functional improvements even in mice with advanced amyloid pathology (Baruch et al., (): Nature Medicine, 22:135-137).

SliceMap: an algorithm for automated brain region annotation.

Summary: Many neurodegenerative disorders, such as Alzheimer's Disease, pertain to or spread from specific sites of the brain. Hence, accurate disease staging or therapy assessment in transgenic model mice demands automated analysis of selected brain regions. To address this need, we have developed an algorithm, termed SliceMap, that enables contextual quantification by mapping anatomical information onto microtome-cut brain slices.

Rapid establishment of the European Bank for induced Pluripotent Stem Cells (EBiSC) - the Hot Start experience.

A fast track "Hot Start" process was implemented to launch the European Bank for Induced Pluripotent Stem Cells (EBiSC) to provide early release of a range of established control and disease linked human induced pluripotent stem cell (hiPSC) lines. Established practice amongst consortium members was surveyed to arrive at harmonised and publically accessible Standard Operations Procedures (SOPs) for tissue procurement, bio-sample tracking, iPSC expansion, cryopreservation, qualification and distribution to the research community. These were implemented to create a quality managed foundational collection of lines and associated data made available for distribution.

Hallmarks of Alzheimer's Disease in Stem-Cell-Derived Human Neurons Transplanted into Mouse Brain.

Human pluripotent stem cells (PSCs) provide a unique entry to study species-specific aspects of human disorders such as Alzheimer's disease (AD). However, in vitro culture of neurons deprives them of their natural environment. Here we transplanted human PSC-derived cortical neuronal precursors into the brain of a murine AD model.

The novel KMO inhibitor CHDI-340246 leads to a restoration of electrophysiological alterations in mouse models of Huntington's disease.

Dysregulation of the kynurenine (Kyn) pathway has been associated with the progression of Huntington's disease (HD). In particular, elevated levels of the kynurenine metabolites 3-hydroxy kynurenine (3-OH-Kyn) and quinolinic acid (Quin), have been reported in the brains of HD patients as well as in rodent models of HD. The production of these metabolites is controlled by the activity of kynurenine mono-oxygenase (KMO), an enzyme which catalyzes the synthesis of 3-OH-Kyn from Kyn.

Development of a Scalable, High-Throughput-Compatible Assay to Detect Tau Aggregates Using iPSC-Derived Cortical Neurons Maintained in a Three-Dimensional Culture Format.

Tau aggregation is the pathological hallmark that best correlates with the progression of Alzheimer's disease (AD). The presence of neurofibrillary tangles (NFTs), formed of hyperphosphorylated tau, leads to neuronal dysfunction and loss, and is directly associated with the cognitive decline observed in AD patients. The limited success in targeting β-amyloid pathologies has reinforced the hypothesis of blocking tau phosphorylation, aggregation, and/or spreading as alternative therapeutic entry points to treat AD.

Characterization of HTT inclusion size, location, and timing in the zQ175 mouse model of Huntington's disease: an in vivo high-content imaging study.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin gene. Major pathological hallmarks of HD include inclusions of mutant huntingtin (mHTT) protein, loss of neurons predominantly in the caudate nucleus, and atrophy of multiple brain regions. However, the early sequence of histological events that manifest in region- and cell-specific manner has not been well characterized.