Publications by authors named "Triest M"

Reactive Oxygen Species (ROS) in the form of HO can act both as physiological signaling molecules as well as damaging agents, depending on their concentration and localization. The downstream biological effects of HO were often studied making use of exogenously added HO, generally as a bolus and at supraphysiological levels. But this does not mimic the continuous, low levels of intracellular HO production by for instance mitochondrial respiration.

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Antimicrobial resistance has become one of the major threats to human health. Therefore, there is a strong need for novel antimicrobials with new mechanisms of action. The kingdom of fungi is an excellent source of antimicrobials for this purpose because it encompasses countless fungal species that harbor unusual metabolic pathways.

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Objectives: Evaluation of the extent and appropriateness of antimicrobial use is a cornerstone of antibiotic stewardship programs, but it is time-consuming. Documentation of the indication at the moment of prescription might be more time-efficient. We investigated the real-life feasibility of mandatory documentation of the indication for all hospital antibiotic prescriptions for quality evaluation purposes.

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Insight into antibiotic prescribing quality is key to general practitioners (GPs) to improve their prescribing behavior and to national antibiotic surveillance and stewardship programs. Additionally to numbers of prescribed antibiotics, quality indicators (QIs) linked to the clinical indication for prescribing are urgently needed. The aim of this proof of concept study was to define indication-linked QIs which can be easily implemented in Dutch primary care by collaborating with data-extraction/processing companies that routinely process patient data for GP practices.

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Aims: Nasal glucagon (NG) is a nasally-administered glucagon powder, absorbed through the nasal mucosa, designed for treatment of severe hypoglycaemia. This study evaluated the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of NG in otherwise healthy participants with common colds and after recovery from cold symptoms, with and without concomitant nasal decongestant.

Materials And Methods: This was a single-centre, open-label study.

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Loss of cellular adhesion leads to the progression of breast cancer through acquisition of anchorage independence, also known as resistance to anoikis. Although inactivation of E-cadherin is essential for acquisition of anoikis resistance, it has remained unclear how metastatic breast cancer cells counterbalance the induction of apoptosis without E-cadherin-dependent cellular adhesion. We report here that E-cadherin inactivation in breast cancer cells induces PI3K/AKT-dependent FOXO3 inhibition and identify FOXO3 as a novel and direct transcriptional activator of the pro-apoptotic protein BMF.

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Background: Glucagon nasal powder (GNP), a novel intranasal formulation of glucagon being developed to treat insulin-induced severe hypoglycemia, contains synthetic glucagon (10% w/w), beta-cyclodextrin, and dodecylphosphocholine. The safety of this formulation was evaluated in four studies in animal models.

Methods: The first study evaluated 28-day sub-chronic toxicology in rats treated intranasally with 1 and 2 mg of GNP/day (0.

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Context: The intranasal route is a promising route of administration for several emergency rescue drugs including naloxone and glucagon. Glucagon nasal powder (GNP) is a novel, needle-free delivery system for intranasal administration of glucagon for the treatment of severe hypoglycemia, an infrequent but serious complication of insulin use in patients with diabetes. The GNP delivery device is a compact, highly portable, single-use nasal powder dosing device constructed of polypropylene that allows for simple, single-step administration.

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Activity of FOXO (forkhead box O) transcription factors is inhibited by growth factor-PI3K (phosphoinositide 3-kinase)-PKB (protein kinase B)/Akt signalling to control a variety of cellular processes including cell cycle progression. Through comparative analysis of a number of microarray datasets we identified a set of genes commonly regulated by FOXO proteins and PI3K-PKB/Akt, which includes CTDSP2 (C-terminal domain small phosphatase 2). We validated CTDSP2 as a genuine FOXO target gene and show that ectopic CTDSP2 can induce cell cycle arrest.

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Article Synopsis
  • FOXO transcription factors are known as tumor suppressors, but they also play a crucial role in tumor survival by activating certain genes.
  • FOXOs enhance the expression of IDH1, which helps maintain important cellular substances like α-ketoglutarate and NADPH.
  • In cancer cells with mutant IDH1, FOXOs still boost IDH1 expression, supporting the production of 2-hydroxyglutarate, a compound that promotes cancer growth and inhibits important enzymes involved in DNA regulation.
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FOXO (forkhead box O) transcription factors are tumor suppressors and increase the life spans of model organisms. Cellular stress, in particular oxidative stress caused by an increase in levels of reactive oxygen species (ROS), activates FOXOs through JNK-mediated phosphorylation. Importantly, JNK regulation of FOXO is evolutionarily conserved.

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Forkhead box O (FOXO) transcription factors are key players in diverse cellular processes affecting tumorigenesis, stem cell maintenance and lifespan. To gain insight into the mechanisms of FOXO-regulated target gene expression, we studied genome-wide effects of FOXO3 activation. Profiling RNA polymerase II changes shows that FOXO3 regulates gene expression through transcription initiation.

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Cellular damage invoked by reactive oxygen species plays a key role in the pathobiology of cancer and aging. Forkhead box class O (FoxO) transcription factors are involved in various cellular processes including cell cycle regulation, apoptosis and resistance to reactive oxygen species, and studies in animal models have shown that these transcription factors are of vital importance in tumor suppression, stem cell maintenance and lifespan extension. Here we report that the activity of FoxO in human cells is directly regulated by the cellular redox state through a unique mechanism in signal transduction.

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FOXO (Forkhead box O) transcription factors are important regulators of cellular metabolism, cell-cycle progression and cell death. FOXO activity is regulated by multiple post-translational modifications, including phosphorylation, acetylation and polyubiquitination. Here, we show that FOXO becomes monoubiquitinated in response to increased cellular oxidative stress, resulting in its re-localization to the nucleus and an increase in its transcriptional activity.

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PDZ-GEF1 (RA-GEF/nRapGEP/CNrasGEF) is a guanine nucleotide exchange factor (GEF) characterised by the presence of a PSD-95/DlgA/ZO-1 (PDZ) domain, a Ras-association (RA) domain and a region related to a cyclic nucleotide binding domain (RCBD). These domains are in addition to a Ras exchange motif (REM) and GEF domain characteristic for GEFs for Ras-like small GTPases. PDZ-GEF1 efficiently exchanges nucleotides of both Rap1 and Rap2, but has also been implicated in mediating cAMP-induced Ras activation through binding of cAMP to the RCBD.

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cAMP is involved in a wide variety of cellular processes that were thought to be mediated by protein kinase A (PKA). However, cAMP also directly regulates Epac1 and Epac2, guanine nucleotide-exchange factors (GEFs) for the small GTPases Rap1 and Rap2 (refs 2,3). Unfortunately, there is an absence of tools to discriminate between PKA- and Epac-mediated effects.

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The lowest energy spin-allowed crystal field band of (Et(4)N)(3)Cr(2)F(9) shows a distinct interference dip at 15,000 cm(-1) with an approximate width of 200 cm(-1). This spectroscopic feature is due to spin-orbit coupling between the (2)E and (4)T(2) excited states and is analyzed with a set of two coupled potential energy surfaces. The minimum of the (4)T(2) potential surface is displaced along at least two normal coordinates.

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Epac1 (cAMP-GEFI) and Epac2 (cAMP-GEFII) are closely related guanine nucleotide exchange factors (GEFs) for the small GTPase Rap1, which are directly regulated by cAMP. Here we show that both GEFs efficiently activate Rap2 as well. A third member of the family, Repac (GFR), which lacks the cAMP dependent regulatory sequences, is a constitutive activator of both Rap1 and Rap2.

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Rap1, a small GTPase of the Ras family, is ubiquitously expressed and particularly abundant in platelets. Previously we have shown that Rap1 is rapidly activated after stimulation of human platelets with alpha-thrombin. For this activation, a phospholipase C-mediated increase in intracellular calcium is necessary and sufficient.

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The small GTPase Rap1 has been implicated in a variety of cellular processes including the control of cell morphology, proliferation, and differentiation. Stimulation of a large variety of cell surface receptors results in the rapid activation of Rap1, i.e.

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