Search results for "LEM"
showing 10 items of 23327 documents
Modulation of Intracellular O-2 Concentration in Escherichia coli Strains Using Oxygen Consuming Devices
2018
International audience; The use of cell factories for the production of bulk and value-added compounds is nowadays an advantageous alternative to the traditional petrochemical methods. Nevertheless, the efficiency and productivity of several of these processes can improve with the implementation of micro-oxic or anoxic conditions. In the industrial setting, laccases are appealing catalysts that can oxidize a wide range of substrates and reduce O-2 to H2O. In this work, several laccase-based devices were designed and constructed to modulate the intracellular oxygen concentration in bacterial chassis. These oxygen consuming devices (OCDs) included Escherichia coil's native laccase (CueO) and …
Co-regulation of paralog genes in the three-dimensional chromatin architecture.
2016
Paralog genes arise from gene duplication events during evolution, which often lead to similar proteins that cooperate in common pathways and in protein complexes. Consequently, paralogs show correlation in gene expression whereby the mechanisms of co-regulation remain unclear. In eukaryotes, genes are regulated in part by distal enhancer elements through looping interactions with gene promoters. These looping interactions can be measured by genome-wide chromatin conformation capture (Hi-C) experiments, which revealed self-interacting regions called topologically associating domains (TADs). We hypothesize that paralogs share common regulatory mechanisms to enable coordinated expression acco…
A Basic Architecture of an Autonomous Adaptive System With Conscious-Like Function for a Humanoid Robot.
2018
In developing a humanoid robot, there are two major objectives. One is developing a physical robot having body, hands, and feet resembling those of human beings and being able to similarly control them. The other is to develop a control system that works similarly to our brain, to feel, think, act, and learn like ours. In this article, an architecture of a control system with a brain-oriented logical structure for the second objective is proposed. The proposed system autonomously adapts to the environment and implements a clearly defined “consciousness” function, through which both habitual behavior and goal-directed behavior are realized. Consciousness is regarded as a function for effecti…
Supplementary medication in multiple sclerosis: Real-world experience and potential interference with neurofilament light chain measurement
2020
Background As vitamins and dietary supplements are obtainable without prescription, treating physicians often ignore their intake by patients with multiple sclerosis (MS) and may therefore miss potential adverse effects and interactions. Objective We aimed to assess the spectrum and intake frequency of supplementary medication in a cohort of MS patients and to analyse the effect of biotin intake on measurement of serum neurofilament light chain (sNfL), an emerging marker of disease activity. Methods MS patients visiting our neurology outpatient clinic completed a questionnaire on their past or present use of vitamins or dietary supplements. In addition, the impact of two different doses of …
Vibrational and Molecular Properties of Mg2+ Binding and Ion Selectivity in the Magnesium Channel MgtE
2018
Magnesium ions (Mg2+) are crucial for various biological processes. A bacterial Mg2+ channel, MgtE, tightly regulates the intracellular Mg2+ concentration. Previous X-ray crystal structures showed that MgtE forms a dimeric structure composed of a total of 10 transmembrane α helices forming a central pore, and intracellular soluble domains constituting a Mg2+ sensor. The ion selectivity for Mg2+ over Ca2+ resides at a central cavity in the transmembrane pore of MgtE, involving a conserved aspartate residue (Asp432) from each monomer. Here, we applied ion-exchange-induced difference FTIR spectroscopy to analyze the interactions between MgtE and divalent cations, Mg2+ and Ca2+. Using site-dire…
Neuroprotection and antioxidative effects of Sijunzi Tang Decoction in the nematode Caenorhabditis elegans
2016
Abstract Introduction Knowledge about the pharmacological properties of traditional TCM formulas is scarce as is their impact on aging. This study evaluated the potential effects of Sijunzi Tang Decoction (SJZTD), Si-Wu-Tang Decoction (SWTD), and Liuwei Dihuang Decoction (LWDHD) against oxidative stress and glucotoxic stress-induced neuronal dysfunction and lifespan reduction. Methods Nematodes ( C. elegans ) were cultivated under 10 mmol/L paraquat or 400 mmol/L glucose to assess the protective effects of a systemic Traditional Chinese Medicine (TCM) treatment. Lifespan was determined by calculation of Kaplan-Meier survival curves, formation of reactive oxygen species was quantified by hyd…
Dimethyl fumarate alters intracellular Ca2+ handling in immune cells by redox-mediated pleiotropic effects
2019
Dimethyl fumarate (DMF) is widely used to treat the human autoimmune diseases multiple sclerosis (MS) and psoriasis. DMF causes short-term oxidative stress and activates the antioxidant response via the transcription factor Nrf2 but its immunosuppressive effect is not well understood. Immune cell activation depends on calcium signaling which itself is influenced by the cellular redox state. We therefore measured calcium, reactive oxygen species levels and glutathione content in lymphocytes from immunized mice before onset of experimental autoimmune encephalomyelitis, in peripheral blood mononuclear cells from MS patients treated with DMF, and in mouse splenocytes treated ex vivo with DMF. T…
Transcriptional response of Erwinia amylovora to copper shock: in vivo role of the copA gene
2017
Fire blight is a devastating plant disease caused by the bacterium Erwinia amylovora, and its control is frequently based on the use of copper-based compounds whose mechanisms of action are not well known. Consequently, in this article, we investigate the response of E. amylovora to copper shock by a whole-genome microarray approach. Transcriptional analyses showed that, in the presence of copper, 23 genes were increased in expression; these genes were classified mainly into the transport and stress functional categories. Among them, the copA gene was strongly induced and regulated in a finely tuned manner by copper. Mutation of copA, soxS, arcB, yjcE, ygcF, yhhQ, galF and EAM_3469 genes re…
Modulation of mitochondriotropic properties of cyanine dyes by in organello copper-free click reaction
2017
Cyanine (Cy) dyes show a general propensity to localize in polarized mitochondria. This mitochondriotropism was used to perform a copper-free click reaction in the mitochondria of living cells. The in organello reaction of dyes Cy3 and Cy5 led to a product that was easily traceable by Forster resonance energy transfer (FRET). As determined by confocal laser scanning microscopy, the Cy3-Cy5 conjugate showed enhanced retention in mitochondria, relative to that of the starting compounds. This enhancement of a favorable property can be achieved by synthesis in organello, but not outside mitochondria.
Dynamic compartmentalization of calcium channel signalling in neurons.
2020
Calcium fluxes through the neuronal membrane are strictly limited in time due to biophysical properties of voltage-gated and ligand-activated ion channels and receptors. Being embedded into the crowded dynamic environment of biological membranes, Ca2+-permeable receptors and channels undergo perpetual spatial rearrangement, which enables their temporary association and formation of transient signalling complexes. Thus, efficient calcium-mediated signal transduction requires mechanisms to support very precise spatiotemporal alignment of the calcium source and Ca2+-binding lipids and proteins in a highly dynamic environment. The mobility of calcium channels and calcium-sensing proteins themse…