Publications by authors named "David Von Schack"

Article Synopsis
  • The brain uses a process called hippocampal neuronal plasticity to help us learn and remember things, which involves changes in how brain cells connect with each other.
  • A protein called midkine (Mdk) is important for the brain's development and memory, and when it's missing, some types of memory can be affected.
  • In experiments with rats, scientists found that learning activities caused Mdk levels to rise quickly and that adding more Mdk helped improve their memory in tests, showing that Mdk plays a helpful role in how we learn and remember.
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Genetic variation in the human leukocyte antigen (HLA) loci is associated with risk of immune-mediated diseases, but the molecular effects of HLA polymorphism are unclear. Here we examined the effects of HLA genetic variation on the expression of 2940 plasma proteins across 45,330 Europeans in the UK Biobank, with replication analyses across multiple ancestry groups. We detected 504 proteins affected by HLA variants (HLA-pQTL), including widespread trans effects by autoimmune disease risk alleles.

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Background And Aims: To define pharmacodynamic and efficacy biomarkers in ulcerative colitis [UC] patients treated with PF-00547659, an anti-human mucosal addressin cell adhesion molecule-1 [MAdCAM-1] monoclonal antibody, in the TURANDOT study.

Methods: Transcriptome, proteome and immunohistochemistry data were generated in peripheral blood and intestinal biopsies from 357 subjects in the TURANDOT study.

Results: In peripheral blood, C-C motif chemokine receptor 9 [CCR9] gene expression demonstrated a dose-dependent increase relative to placebo, but in inflamed intestinal biopsies CCR9 gene expression decreased with increasing PF-00547659 dose.

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Background: The neuropeptide oxytocin (OXT) mediates its actions, including anxiolysis, via its G protein-coupled OXT receptor. Within the paraventricular nucleus of the hypothalamus (PVN), OXT-induced anxiolysis is mediated, at least in part, via activation of the mitogen-activated protein kinase pathway following calcium influx through transient receptor potential cation channel subfamily V member 2 channels. In the periphery, OXT activates eukaryotic elongation factor 2 (eEF2), an essential mediator of protein synthesis.

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Article Synopsis
  • Cytokines play a key role in human diseases and are important for developing therapies by affecting gene regulation and transcription.* -
  • In a clinical trial with anti-IL-6 for systemic lupus erythematosus, researchers found that analyzing gene expression at multiple time points improved the detection of eQTLs related to interferon status and drug exposure.* -
  • The study reveals novel eQTL interactions and identifies potential therapeutic targets by linking transcription factor binding sites with cytokine influences on gene regulation.*
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Background: Transcriptional profiling has been performed on biopsies from ulcerative colitis patients. Limitations in prior studies include the variability introduced by inflammation, anatomic site of biopsy, extent of disease, and medications. We sought to more globally understand the variability of gene expression from patients with ulcerative colitis to advance our understanding of its pathogenesis and to guide clinical study design.

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To allow efficient transcript/gene detection, highly abundant ribosomal RNAs (rRNA) are generally removed from total RNA either by positive polyA+ selection or by rRNA depletion (negative selection) before sequencing. Comparisons between the two methods have been carried out by various groups, but the assessments have relied largely on non-clinical samples. In this study, we evaluated these two RNA sequencing approaches using human blood and colon tissue samples.

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Objective: To define pharmacodynamic biomarkers in the peripheral blood of patients with Crohn's disease [CD] after treatment with PF-00547659, an anti-human mucosal addressin cell adhesion molecule-1 [MAdCAM-1] monoclonal antibody.

Methods: In this Phase 2, randomised, double-blind, controlled study [OPERA], blood samples were analysed from patients with moderate to severe active CD who received placebo or 22.5 mg, 75 mg, or 225 mg of PF-00547659 subcutaneously at baseline and at Weeks 4 and 8, with follow-up at Week 12.

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Background: Genome-wide miRNA expression data can be used to study miRNA dysregulation comprehensively. Although many open-source tools for microRNA (miRNA)-seq data analyses are available, challenges remain in accurate miRNA quantification from large-scale miRNA-seq dataset. We implemented a pipeline called QuickMIRSeq for accurate quantification of known miRNAs and miRNA isoforms (isomiRs) from multiple samples simultaneously.

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Background: Tofacitinib is an oral Janus kinase inhibitor being investigated for psoriasis.

Objective: We sought to elucidate the molecular mechanisms underlying the clinical efficacy of tofacitinib in patients with psoriasis.

Methods: Twelve patients with plaque psoriasis were randomized (3:1) to receive 10 mg of tofacitinib or placebo twice daily for 12 weeks.

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Background: RNA sequencing (RNA-seq), a next-generation sequencing technique for transcriptome profiling, is being increasingly used, in part driven by the decreasing cost of sequencing. Nevertheless, the analysis of the massive amounts of data generated by large-scale RNA-seq remains a challenge. Multiple algorithms pertinent to basic analyses have been developed, and there is an increasing need to automate the use of these tools so as to obtain results in an efficient and user friendly manner.

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Background: While RNA-sequencing (RNA-seq) is becoming a powerful technology in transcriptome profiling, one significant shortcoming of the first-generation RNA-seq protocol is that it does not retain the strand specificity of origin for each transcript. Without strand information it is difficult and sometimes impossible to accurately quantify gene expression levels for genes with overlapping genomic loci that are transcribed from opposite strands. It has recently become possible to retain the strand information by modifying the RNA-seq protocol, known as strand-specific or stranded RNA-seq.

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Regulatory T cells (Tregs) play a central role in counteracting inflammation and autoimmunity. A more complete understanding of cellular heterogeneity and the potential for lineage plasticity in human Treg subsets may identify markers of disease pathogenesis and facilitate the development of optimized cellular therapeutics. To better elucidate human Treg subsets, we conducted direct transcriptional profiling of CD4(+)FOXP3(+)Helios(+) thymic-derived Tregs and CD4(+)FOXP3(+)Helios(-) T cells, followed by comparison with CD4(+)FOXP3(-)Helios(-) T conventional cells.

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Inhibitors of Bruton's tyrosine kinase (BTK) possess much promise for the treatment of oncologic and autoimmune indications. However, our current knowledge of the role of BTK in immune competence has been gathered in the context of genetic inactivation of btk in both mice and man. Using the novel BTK inhibitor PF-303, we model the clinical phenotype of BTK inhibition by systematically examining the impact of PF-303 on the mature immune system in mice.

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Brown adipose tissue (BAT) plays a pivotal role in promoting energy expenditure by the virtue of uncoupling protein-1 (UCP-1) that differentiates BAT from its energy storing white adipose tissue (WAT) counterpart. The clinical implication of "classical" BAT (originates from Myf5 positive myoblastic lineage) or the "beige" fat (originates through trans-differentiation of WAT) activation in improving metabolic parameters is now becoming apparent. However, the inducers and endogenous molecular determinants that govern the lineage commitment and differentiation of classical BAT remain obscure.

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Adult neurogenesis relies on EGF and FGF receptor (EGFR/FGFR) function and endocannabinoid (eCB) signalling. Here we have used a neural stem cell (NSC) line to determine how these systems cooperate to regulate neurogenesis. The results show the EGFR to be solely responsible for maintaining PI3K activation explaining its dominant role in promoting NSC survival.

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Foxp3(+) CD4(+) T helper cells called regulatory T (T reg) cells play a key role in controlling reactivity to self-antigens and onset of autoimmunity. T reg cells either arise in thymus and are called natural T reg (nT reg) cells or are generated in the periphery through induction of Foxp3 and are called inducible T reg (iT reg) cells. The relative contributions of iT reg cells and nT reg cells in peripheral tolerance remain unclear as a result of an inability to separate these two subsets of T reg cells.

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Information storage in the brain depends on the ability of neurons to alter synaptic connectivity within key circuitries such as the hippocampus. Memory-associated synaptic plasticity is mediated by a temporal cascade of de novo protein synthesis and altered protein processing. Here, we have used two-dimensional difference in gel electrophoresis (2-D DIGE) to investigate memory-specific protein changes in the hippocampal dentate gyrus at increasing times following spatial learning.

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Neuropathic pain resulting from nerve lesions or dysfunction represents one of the most challenging neurological diseases to treat. A better understanding of the molecular mechanisms responsible for causing these maladaptive responses can help develop novel therapeutic strategies and biomarkers for neuropathic pain. We performed a miRNA expression profiling study of dorsal root ganglion (DRG) tissue from rats four weeks post spinal nerve ligation (SNL), a model of neuropathic pain.

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The critical sequence of molecular, neurotransmission and synaptic disruptions that underpin the emergence of psychiatric disorders like schizophrenia remain to be established with progress only likely using animal models that capture key features of such disorders. We have related the emergence of behavioural, neurochemical and synapse ultrastructure deficits to transcriptional dysregulation in the medial prefrontal cortex of Wistar rats reared in isolation. Isolation reared animals developed sensorimotor deficits at postnatal day 60 which persisted into adulthood.

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The molecular determinants of Sonic Hedgehog (Shh) signaling in mammalian cells and, in particular, those of the CNS are unclear. Here we report that primary cortical astrocyte cultures are highly responsive to both Shh protein and Hh Agonist 1.6, a selective, small molecule Smoothened agonist.

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Rapamycin is an immunosuppressive immunophilin ligand reported as having neurotrophic activity. We show that modification of rapamycin at the mammalian target of rapamycin (mTOR) binding region yields immunophilin ligands, WYE-592 and ILS-920, with potent neurotrophic activities in cortical neuronal cultures, efficacy in a rodent model for ischemic stroke, and significantly reduced immunosuppressive activity. Surprisingly, both compounds showed higher binding selectivity for FKBP52 versus FKBP12, in contrast to previously reported immunophilin ligands.

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Basic helix-loop-helix PAS domain proteins form a growing family of transcription factors. These proteins are involved in the process of adaptation to cellular stresses and environmental factors such as a change in oxygen concentration. We describe the identification and characterization of a recently cloned PAS domain protein termed Npas4 in ischemic rat brain.

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In order to identify biological processes relevant for cell death and survival in the brain following stroke, the postischemic brain transcriptome was studied by a large-scale cDNA array analysis of three peri-infarct brain regions at eight time points during the first 24 h of reperfusion following middle cerebral artery occlusion in the rat. K-means cluster analysis revealed two distinct biphasic gene expression patterns that contained 44 genes (including 18 immediate early genes), involved in cell signaling and plasticity (i.e.

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Alzheimer's disease is a progressive neurodegenerative disease characterized by senile plaques, neurofibrillary tangles, dystrophic neurites, and reactive glial cells. Activated microglia are found to be intimately associated with senile plaques and may play a central role in mediating chronic inflammatory conditions in Alzheimer's disease. Activation of cultured murine microglial BV2 cells by freshly sonicated Abeta42 results in the secretion of neurotoxic factors that kill primary cultured neurons.

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