A tubulin binding molecule drives differentiation of acute myeloid leukemia cells.

Despite much progress in developing better drugs, many patients with acute myeloid leukemia (AML) still die within a year of diagnosis. This is partly because it is difficult to identify therapeutic targets that are effective across multiple AML subtypes. One common factor across AML subtypes is the presence of a block in differentiation.

A call for better understanding of target engagement in Tau antibody development.

Significant efforts have been channeled into developing antibodies for the treatment of CNS indications. Disappointment with the first generation of clinical Tau antibodies in Alzheimer's disease has highlighted the challenges in understanding whether an antibody can reach or affect the target in the compartment where it is involved in pathological processes. Here, we highlight different aspects essential for improving translatability of Tau-based immunotherapy.

Unbound Brain-to-Plasma Partition Coefficient, K-a Game Changing Parameter for CNS Drug Discovery and Development.

Purpose: More than 15 years have passed since the first description of the unbound brain-to-plasma partition coefficient (K) by Prof. Margareta Hammarlund-Udenaes, which was enabled by advancements in experimental methodologies including cerebral microdialysis. Since then, growing knowledge and data continue to support the notion that the unbound (free) concentration of a drug at the site of action, such as the brain, is the driving force for pharmacological responses.

Differentiation of Human Induced Pluripotent Stem Cells (hiPSC) into Endothelial-Type Cells and Establishment of an In Vitro Blood-Brain Barrier Model.

Development of central nervous system (CNS) therapeutics and their brain delivery is impeded by the presence of the blood-brain barrier (BBB). In vitro BBB models, in particular human in vitro BBB models, are critical tools for CNS drug research and development. However, the availability of primary human microvascular endothelial cells is very limited for in vitro modeling.

Strategies for delivering therapeutics across the blood-brain barrier.

Achieving sufficient delivery across the blood-brain barrier is a key challenge in the development of drugs to treat central nervous system (CNS) disorders. This is particularly the case for biopharmaceuticals such as monoclonal antibodies and enzyme replacement therapies, which are largely excluded from the brain following systemic administration. In recent years, increasing research efforts by pharmaceutical and biotechnology companies, academic institutions and public-private consortia have resulted in the evaluation of various technologies developed to deliver therapeutics to the CNS, some of which have entered clinical testing.

Trafficking of JC virus-like particles across the blood-brain barrier.

Hollow viral vectors, such as John Cunningham virus-like particles (JC VLPs), provide a unique opportunity to deliver drug cargo into targeted cells and tissue. Current understanding of the entry of JC virus in brain cells has remained insufficient. In particular, interaction of JC VLPs with the blood-brain barrier (BBB) has not been analyzed in detail.

Combining experimental strategies for successful target deconvolution.

Investment in phenotypic drug discovery has led to increased demand for rapid and robust target deconvolution to aid successful drug development. Although methods for target identification and mechanism of action (MoA) discovery are flourishing, they typically lead to lists of putative targets. Validating which target(s) are involved in the therapeutic mechanism of a compound poses a significant challenge, requiring direct binding, target engagement, and functional studies in relevant physiological contexts.

Generating Human iPSC-Derived Astrocytes with Chemically Defined Medium for In Vitro Disease Modeling.

To better understand and model neurological, in particular neurodegenerative diseases, human induced pluripotent stem cells (hiPSCs) offer a great source for generation of neural cells. We provide a protocol for the differentiation of hiPSc-derived astrocytes in vitro. This protocol not only is chemically defined, that is, it does not use serum, but also allows for the expansion of astrocyte progenitor cells and mature astrocytes.

Development of Human in vitro Brain-blood Barrier Model from Induced Pluripotent Stem Cell-derived Endothelial Cells to Predict the in vivo Permeability of Drugs.

An in vitro blood-brain barrier (BBB) model is critical for enabling rapid screening of the BBB permeability of the drugs targeting on the central nervous system. Though many models have been developed, their reproducibility and renewability remain a challenge. Furthermore, drug transport data from many of the models do not correlate well with the data for in vivo BBB drug transport.

Reproducibility of Molecular Phenotypes after Long-Term Differentiation to Human iPSC-Derived Neurons: A Multi-Site Omics Study.

Reproducibility in molecular and cellular studies is fundamental to scientific discovery. To establish the reproducibility of a well-defined long-term neuronal differentiation protocol, we repeated the cellular and molecular comparison of the same two iPSC lines across five distinct laboratories. Despite uncovering acceptable variability within individual laboratories, we detect poor cross-site reproducibility of the differential gene expression signature between these two lines.

Prediction of brain:blood unbound concentration ratios in CNS drug discovery employing in silico and in vitro model systems.

Recent years have seen a paradigm shift away from optimizing the brain:blood concentration ratio toward the more relevant brain:blood unbound concentration ratio (K) in CNS drug discovery. Here, we review the recent developments in the in silico and in vitro model systems to predict the K of discovery compounds with special emphasis on the in-vitro-in-vivo correlation. We also discuss clinical 'translation' of rodent K and highlight the future directions for improvement in brain penetration prediction.

Drug Distribution into Peripheral Nerve.

Little is known about the impact of the blood-nerve barrier (BNB) on drug distribution into peripheral nerves. In this study, we examined the peripheral nerve penetration in rats of 11 small-molecule drugs possessing diverse physicochemical and transport properties and ProTx-II, a tarantula venom peptide with molecular mass of 3826 Daltons. Each drug was administered as constant rate intravenous infusion for 6 hours (small molecules) or 24 hours (ProTx-II).

Quantitative Algorithm-Based Paired Imaging Measurement for Antibody-Triggered Endocytosis in Cultured Cells.

Antibody-triggered endocytosis (ATE) is a biological mechanism on which many therapeutic strategies are grounded, such as delivery of antibody-drug conjugates (ADCs). Current methods monitoring ATE include confocal Z-stack analysis, acid wash, antibody quenching, and pH-sensitive dye labeling. However, those generate less quantifiable results with low throughput.

Brain delivery research in public-private partnerships: The IMI-JU COMPACT consortium as an example.

The Blood-Brain Barrier (BBB) represents a major hurdle in the development of treatments for CNS disorders due to the fact that it very effectively keeps drugs, especially biological macromolecules, out of the brain. Concomitantly with the increasing importance of biologics research on the BBB and, more specifically, on brain delivery technologies has intensified in recent years. Public-Private Partnerships (PPPs) represent an innovative opportunity to address such complex challenges as they bring together the best expertise from both industry and academia.

Label-free detection of small-molecule binding to a GPCR in the membrane environment.

Evaluation of drug-target interaction kinetics is becoming increasingly important during the drug-discovery process to investigate selectivity of a drug and predict in vivo target occupancy. To date, it remains challenging to obtain kinetic information for interactions between G-protein-coupled receptors (GPCRs) and small-molecule ligands in a label-free manner. Often GPCRs need to be solubilized or even stabilized by mutations which can be difficult and is time consuming.

Targeting mutant huntingtin for the development of disease-modifying therapy.

Huntington's disease (HD) is a progressive and fatal neurodegenerative disease, and the most common inherited CAG repeat disorder. A polyglutamine expansion in the N-terminus of the huntingtin protein (HTT) leads to protein misfolding and downstream pathogenic processes culminating in widespread functional impairment and neurodegeneration in the striatum, cortex and other brain areas. To date, only symptomatic treatments are available that address motor, psychiatric and cognitive deficits.

Heterocomplex formation of 5-HT2A-mGlu2 and its relevance for cellular signaling cascades.

Dopamine, serotonin and glutamate play a role in the pathophysiology of schizophrenia. In the brain a functional crosstalk between the serotonin receptor 5-HT(2A) and the metabotropic glutamate receptor mGlu(2) has been demonstrated. Such a crosstalk may be mediated indirectly through neuronal networks or directly by receptor oligomerization.

Development and validation of a fluorescence-based HTS assay for the identification of P/Q-type calcium channel blockers.

Dysfunction of P/Q-type calcium channels is thought to underlie a variety of neurological diseases. There is evidence that migraine, Alzheimer's disease, and epilepsy involve a gain-of-function of the channel, leading to abnormal presynaptic vesicle release. P/Q-channel blockers may normalize current flow and consequently lead to an alleviation of disease symptoms.

Preclinical assessment of an adjunctive treatment approach for cognitive impairment associated with schizophrenia using the alpha7 nicotinic acetylcholine receptor agonist WYE-103914/SEN34625.

Rationale: α7 nicotinic acetylcholine receptor (nAChR) agonists are proposed as candidate agents for the adjunctive treatment of cognitive deficits associated with schizophrenia. Despite the pursuit of such an approach clinically, it is surprising that the preclinical profile of pro-cognitive agents in conjunction with antipsychotic drugs is currently unexplored.

Objectives: We determined if the memory-enhancing effects of the selective α7 nAChR agonist WYE-103914 were preserved in the presence of the atypical antipsychotic drug risperidone, and if the antipsychotic-like profile of risperidone was preserved in the presence of WYE-103914.

Screening technologies for ion channel drug discovery.

For every movement, heartbeat and thought, ion channels need to open and close. It is therefore not surprising that their malfunctioning leads to serious diseases. Currently, only approximately 10% of drugs, with a market value in excess of US$10 billion, act on ion channels.

VSTM2L is a novel secreted antagonist of the neuroprotective peptide Humanin.

Humanin (HN) is a 24-residue peptide displaying a protective activity in vitro against a range of cytotoxic and neurotoxic insults, as well as mediating in vivo amelioration of Alzheimer disease (AD)-related memory impairment in experimental models. Published evidence suggests that the mechanisms through which HN exerts its cyto- and neuroprotective activity may include its secretion and binding to membrane-associated receptors. Here, we describe the identification of a new modulator of HN neuroprotective activity, V-set and transmembrane domain containing 2 like (VSTM2L), previously known as C20orf102.

Novel alpha-7 nicotinic acetylcholine receptor agonists containing a urea moiety: identification and characterization of the potent, selective, and orally efficacious agonist 1-[6-(4-fluorophenyl)pyridin-3-yl]-3-(4-piperidin-1-ylbutyl) urea (SEN34625/WYE-103914).

Alpha-7 nicotinic acetylcholine receptor (alpha7 nAChR) agonists are promising therapeutic candidates for the treatment of cognitive impairment. We report a series of novel, potent small molecule agonists (4-18) of the alpha7 nAChR deriving from our continuing efforts in the areas of Alzheimer's disease and schizophrenia. One of the compounds of the series containing a urea moiety (16) was further shown to be a selective agonist of the alpha7 nAChR with excellent in vitro and in vivo profiles, brain penetration, and oral bioavailability and demonstrated in vivo efficacy in multiple behavioral cognition models.

Endothelial cell adhesion to the extracellular matrix induces c-Src-dependent VEGFR-3 phosphorylation without the activation of the receptor intrinsic kinase activity.

Rationale: Integrins cooperate with growth factor receptors to promote downstream signaling for cell proliferation and migration. However, the mechanism of receptor activation is still unknown.

Objective: To analyze the mechanism of phosphorylation of the vascular endothelial growth factor receptor (VEGFR)-3 by cell adhesion.

Increased Dickkopf-1 expression in transgenic mouse models of neurodegenerative disease.

To investigate the role of the Wnt inhibitor Dickkopf-1 (DKK-1) in the pathophysiology of neurodegenerative diseases, we analysed DKK-1 expression and localization in transgenic mouse models expressing familial Alzheimer's disease mutations and a frontotemporal dementia mutation. A significant increase of DKK-1 expression was found in the diseased brain areas of all transgenic lines, where it co-localized with hyperphosphorylated tau-bearing neurons. In TgCRND8 mice, DKK-1 immunoreactivity was detected in neurons surrounding amyloid deposits and within the choline acetyltransferase-positive neurons of the basal forebrain.

A primer on screening data management.

A drug discovery startup company or academic lab entering the screening arena faces numerous challenges as it tries to manage the large quantity of data generated by a typical drug discovery screening campaign. Although there are sophisticated off-the-shelf software solutions available, their use requires substantial forethought and attention to detail if the data they capture are to be of sufficient quality to serve the various purposes to which it will be put. For newcomers to the field of screening data management in particular, the problem is compounded by a lack of literature covering the practical aspects of managing screening data.